diff --git a/BREAKING.md b/BREAKING.md
new file mode 100644
index 000000000..b4e8494a5
--- /dev/null
+++ b/BREAKING.md
@@ -0,0 +1,104 @@
+# ext-apps v2 — Breaking Changes
+
+This release moves ext-apps from `@modelcontextprotocol/sdk@^1` to
+`@modelcontextprotocol/client@^2` + `@modelcontextprotocol/server@^2`. The
+public method surface (`app.callServerTool()`, `app.openLink()`,
+`bridge.sendToolInput()`, every `on*` handler, `addEventListener`) is preserved.
+The breaks below are at the inheritance/import boundary.
+
+## Dependencies
+
+| v1 | v2 |
+|---|---|
+| `@modelcontextprotocol/sdk` (peer) | `@modelcontextprotocol/client` (peer) + `@modelcontextprotocol/server` (peer, optional unless you use `app-bridge` or `server`) |
+
+## `App` and `AppBridge` no longer extend `Protocol`
+
+v1 subclassed the SDK's `Protocol` class. v2 composes `Client`/`Server`
+instances instead. If you were calling inherited `Protocol` members directly:
+
+| Removed inherited member | Replacement |
+|---|---|
+| `app.request(...)` / `app.notification(...)` | `app.ui.sendRequest(...)` / `app.ui.sendNotification(...)` for `ui/*`; `app.client.callTool(...)` etc. for standard MCP |
+| `app.setRequestHandler(...)` | `app.ui.setRequestHandler(...)` (custom) or `app.client.setRequestHandler(...)` (standard) |
+| `bridge.setRequestHandler(...)` | `bridge.ui.setRequestHandler(...)` or `bridge.server.setRequestHandler(...)` |
+| `instanceof Protocol` | `app.client` is a `Client`, `bridge.server` is a `Server` |
+| `assertCapabilityForMethod` etc. | Removed (were no-ops) |
+
+`app.transport` / `app.onerror` / `app.close()` are kept as forwarding shims.
+
+## `RequestHandlerExtra` slimmed
+
+The second argument to `on*` request handlers is now `{ signal: AbortSignal }`
+only. v1 passed the full SDK `RequestHandlerExtra` (sessionId, sendNotification,
+etc.). If you need the full SDK context, register directly via
+`app.ui.setRequestHandler(method, schema, (params, ctx) => …)` — `ctx` is the
+SDK's `BaseContext`.
+
+## Wire-protocol method renames
+
+These affect custom hosts/iframes that bypass the SDK and speak raw JSON-RPC:
+
+| v1 method | v2 method | Why |
+|---|---|---|
+| `notifications/message` (App→Host) | `ui/log` | v1 direction conflicted with core MCP semantics (SEP-1865 erratum candidate) |
+| `tools/call` (Host→App) | `ui/call-view-tool` | Non-spec direction; renamed to a `ui/*` custom method |
+| `tools/list` (Host→App) | `ui/list-view-tools` | Same |
+
+The TypeScript API names (`app.sendLog`, `bridge.callTool`, `app.oncalltool`)
+are **unchanged** — only the wire-level method strings moved.
+
+### v1↔v2 interop
+
+Hosts and iframes upgrade independently. The wire renames are shimmed where the
+v2 SDK's direction enforcement allows it; where it doesn't, you get a clear
+error instead of silent failure.
+
+| Scenario | What works | What doesn't |
+|---|---|---|
+| **v2 host (`AppBridge`) + v1 iframe** | ✅ handshake (`ui/initialize`), all `ui/*` requests, **logging** (host dual-listens on both `ui/log` and legacy `notifications/message`), proxied `tools/call`/`resources/*` | ⚠️ `bridge.callTool()`/`bridge.listTools()` throw a descriptive error — host→iframe tool calls require the iframe on v2 |
+| **v1 host + v2 iframe** | ✅ handshake (v2 `App` still sends `ui/initialize`), all `ui/*` requests, proxied standard MCP | ❌ `app.sendLog()` (sends `ui/log`; v1 host listens on `notifications/message` only — silently dropped). ❌ host-initiated `tools/call` (v2 iframe handles `ui/call-view-tool` only — MethodNotFound) |
+
+**Recommended upgrade order:** host first, then iframes. A v2 host accepts logs
+from either generation; a v2 iframe's logs reach only a v2 host.
+
+## Capability negotiation via SEP-2133
+
+`McpUiAppCapabilities` / `McpUiHostCapabilities` now travel in
+`capabilities.extensions["io.modelcontextprotocol/ui"]` during the standard MCP
+`initialize` exchange. `app.hostCapabilities` and `bridge.appCapabilities` read
+from there. `ui/initialize` is kept (for `hostContext` delivery and v1 wire
+compat) but no longer the sole capability source.
+
+`McpUiAppCapabilities` and `McpUiHostCapabilities` are now `type` aliases (were
+`interface`) to satisfy `JSONObject`.
+
+## `ProtocolWithEvents` → `EventDispatcher`
+
+`src/events.ts` no longer extends `Protocol`. The class is renamed to
+`EventDispatcher`; a `ProtocolWithEvents` alias is kept for one release.
+`replaceRequestHandler` and the throw-on-double-set behavior are removed
+(handlers are now eagerly registered with field-based delegation).
+
+## Import path changes
+
+| v1 import | v2 |
+|---|---|
+| `@modelcontextprotocol/sdk/types.js` | `@modelcontextprotocol/client` (types are re-exported there) |
+| `@modelcontextprotocol/sdk/client/index.js` | `@modelcontextprotocol/client` |
+| `@modelcontextprotocol/sdk/server/mcp.js` | `@modelcontextprotocol/server` |
+| `@modelcontextprotocol/sdk/shared/transport.js` | `@modelcontextprotocol/client` |
+
+## `server` entry point
+
+`registerAppTool` / `registerAppResource` now take v2 `McpServer` and
+`StandardSchemaWithJSON` (was v1 `ZodRawShapeCompat | AnySchema`). The call
+shape is otherwise unchanged. `BaseToolCallback` re-export removed (use
+`ToolCallback` from `@modelcontextprotocol/server`).
+
+## Validation depth
+
+Zod schemas for SDK-defined shapes (`CallToolResult`, `ContentBlock`, …) are now
+type-preserving pass-throughs (`z.custom<T>`) rather than deep validators (see
+`src/sdk-compat.ts`). Validation of those shapes is the SDK's job at the actual
+MCP boundary; ext-apps relays them unchanged.
diff --git a/build.bun.ts b/build.bun.ts
index a129d5ddd..d04d98e63 100644
--- a/build.bun.ts
+++ b/build.bun.ts
@@ -33,7 +33,7 @@ function buildJs(
 
 // zod is a peerDependency — keep it external so consumers share a single
 // zod instance (instanceof ZodError / schema.extend() break with duplicate copies).
-const PEER_EXTERNALS = ["@modelcontextprotocol/sdk", "zod"];
+const PEER_EXTERNALS = ["@modelcontextprotocol/client", "@modelcontextprotocol/server", "zod"];
 
 await Promise.all([
   buildJs("src/app.ts", {
diff --git a/docs/patterns.md b/docs/patterns.md
index 87a6d8232..6c70ff011 100644
--- a/docs/patterns.md
+++ b/docs/patterns.md
@@ -19,7 +19,7 @@ registerAppTool(
   "update-quantity",
   {
     description: "Update item quantity in cart",
-    inputSchema: { itemId: z.string(), quantity: z.number() },
+    inputSchema: z.object({ itemId: z.string(), quantity: z.number() }),
     _meta: {
       ui: {
         resourceUri: "ui://shop/cart.html",
@@ -127,14 +127,14 @@ registerAppTool(
   {
     title: "Read Data Bytes",
     description: "Load binary data in chunks",
-    inputSchema: {
+    inputSchema: z.object({
       id: z.string().describe("Resource identifier"),
       offset: z.number().min(0).default(0).describe("Byte offset"),
       byteCount: z
         .number()
         .default(MAX_CHUNK_BYTES)
         .describe("Bytes to read"),
-    },
+    }),
     outputSchema: DataChunkSchema,
     // Hidden from model - only callable by the App
     _meta: { ui: { visibility: ["app"] } },
@@ -281,10 +281,9 @@ server.registerResource(
 
 <!-- prettier-ignore -->
 ```ts source="./patterns.tsx#binaryBlobResourceClient"
-const result = await app.request(
-  { method: "resources/read", params: { uri: `video://${videoId}` } },
-  ReadResourceResultSchema,
-);
+const result = await app.readServerResource({
+  uri: `video://${videoId}`,
+});
 
 const content = result.contents[0];
 if (!content || !("blob" in content)) {
diff --git a/docs/patterns.tsx b/docs/patterns.tsx
index 6b876926b..afb0b4ce5 100644
--- a/docs/patterns.tsx
+++ b/docs/patterns.tsx
@@ -17,8 +17,8 @@ import { randomUUID } from "node:crypto";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
-import { ReadResourceResultSchema } from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/client";
+
 import type { McpUiHostContext } from "../src/types.js";
 import { useEffect, useState } from "react";
 import { useApp } from "../src/react/index.js";
@@ -26,7 +26,7 @@ import { registerAppTool } from "../src/server/index.js";
 import {
   McpServer,
   ResourceTemplate,
-} from "@modelcontextprotocol/sdk/server/mcp.js";
+} from "@modelcontextprotocol/server";
 import { z } from "zod";
 
 /**
@@ -117,14 +117,14 @@ function chunkedDataServer(server: McpServer) {
     {
       title: "Read Data Bytes",
       description: "Load binary data in chunks",
-      inputSchema: {
+      inputSchema: z.object({
         id: z.string().describe("Resource identifier"),
         offset: z.number().min(0).default(0).describe("Byte offset"),
         byteCount: z
           .number()
           .default(MAX_CHUNK_BYTES)
           .describe("Bytes to read"),
-      },
+      }),
       outputSchema: DataChunkSchema,
       // Hidden from model - only callable by the App
       _meta: { ui: { visibility: ["app"] } },
@@ -252,10 +252,9 @@ function binaryBlobResourceServer(
  */
 async function binaryBlobResourceClient(app: App, videoId: string) {
   //#region binaryBlobResourceClient
-  const result = await app.request(
-    { method: "resources/read", params: { uri: `video://${videoId}` } },
-    ReadResourceResultSchema,
-  );
+  const result = await app.readServerResource({
+    uri: `video://${videoId}`,
+  });
 
   const content = result.contents[0];
   if (!content || !("blob" in content)) {
diff --git a/docs/quickstart.md b/docs/quickstart.md
index 3e00796c5..697781391 100644
--- a/docs/quickstart.md
+++ b/docs/quickstart.md
@@ -178,7 +178,7 @@ import {
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 
@@ -205,7 +205,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async () => {
@@ -240,10 +240,10 @@ export function createServer(): McpServer {
 
 <!-- prettier-ignore -->
 ```ts source="../examples/quickstart/main.ts"
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-host/package.json b/examples/basic-host/package.json
index c2fc987d6..65fb9bc70 100644
--- a/examples/basic-host/package.json
+++ b/examples/basic-host/package.json
@@ -12,10 +12,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/express": "^5.0.0",
diff --git a/examples/basic-host/src/implementation.ts b/examples/basic-host/src/implementation.ts
index 31e36983e..b6fd1c404 100644
--- a/examples/basic-host/src/implementation.ts
+++ b/examples/basic-host/src/implementation.ts
@@ -1,8 +1,8 @@
 import { RESOURCE_MIME_TYPE, getToolUiResourceUri, type McpUiSandboxProxyReadyNotification, AppBridge, PostMessageTransport, type McpUiResourceCsp, type McpUiResourcePermissions, buildAllowAttribute, type McpUiUpdateModelContextRequest, type McpUiMessageRequest } from "@modelcontextprotocol/ext-apps/app-bridge";
-import { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import { SSEClientTransport } from "@modelcontextprotocol/sdk/client/sse.js";
-import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
-import type { CallToolResult, Resource, Tool } from "@modelcontextprotocol/sdk/types.js";
+import { Client } from "@modelcontextprotocol/client";
+import { SSEClientTransport } from "@modelcontextprotocol/client";
+import { StreamableHTTPClientTransport } from "@modelcontextprotocol/client";
+import type { CallToolResult, Resource, Tool } from "@modelcontextprotocol/server";
 import { getTheme, onThemeChange } from "./theme";
 import { HOST_STYLE_VARIABLES } from "./host-styles";
 
@@ -303,7 +303,7 @@ export function newAppBridge(
   // Listen for theme changes (from toggle or system) and notify the app
   onThemeChange((newTheme) => {
     log.info("Theme changed:", newTheme);
-    appBridge.sendHostContextChange({ theme: newTheme });
+    appBridge.sendHostContextChanged({ theme: newTheme });
   });
 
   // Per spec, the host SHOULD notify the view when container dimensions
@@ -315,7 +315,7 @@ export function newAppBridge(
   const iframeResizeObserver = new ResizeObserver(([entry]) => {
     const width = Math.round(entry.contentRect.width);
     if (width > 0) {
-      appBridge.sendHostContextChange({
+      appBridge.sendHostContextChanged({
         containerDimensions: { width, maxHeight: 6000 },
       });
     }
@@ -397,7 +397,7 @@ export function newAppBridge(
     log.info("Display mode request from MCP App:", params);
     const newMode = params.mode === "fullscreen" ? "fullscreen" : "inline";
     // Update host context and notify the app
-    appBridge.sendHostContextChange({
+    appBridge.sendHostContextChanged({
       displayMode: newMode,
     });
     // Notify the host UI (via callback)
diff --git a/examples/basic-host/src/index.tsx b/examples/basic-host/src/index.tsx
index 3d488a792..470701ec5 100644
--- a/examples/basic-host/src/index.tsx
+++ b/examples/basic-host/src/index.tsx
@@ -1,5 +1,5 @@
 import { getToolUiResourceUri, McpUiToolMetaSchema } from "@modelcontextprotocol/ext-apps/app-bridge";
-import type { Tool } from "@modelcontextprotocol/sdk/types.js";
+import type { Tool } from "@modelcontextprotocol/server";
 import { Component, type ErrorInfo, type ReactNode, StrictMode, Suspense, use, useEffect, useMemo, useRef, useState } from "react";
 import { createRoot } from "react-dom/client";
 import { callTool, connectToServer, hasAppHtml, initializeApp, loadSandboxProxy, log, newAppBridge, type ServerInfo, type ToolCallInfo, type ModelContext, type AppMessage } from "./implementation";
diff --git a/examples/basic-server-preact/main.ts b/examples/basic-server-preact/main.ts
index 76426326d..f4b42c5d7 100644
--- a/examples/basic-server-preact/main.ts
+++ b/examples/basic-server-preact/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-preact/package.json b/examples/basic-server-preact/package.json
index 12e136501..822622e0c 100644
--- a/examples/basic-server-preact/package.json
+++ b/examples/basic-server-preact/package.json
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "preact": "^10.0.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@preact/preset-vite": "^2.0.0",
diff --git a/examples/basic-server-preact/server.ts b/examples/basic-server-preact/server.ts
index bf14ea599..3a59d9b44 100644
--- a/examples/basic-server-preact/server.ts
+++ b/examples/basic-server-preact/server.ts
@@ -1,5 +1,5 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
@@ -28,7 +28,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/basic-server-preact/src/mcp-app.tsx b/examples/basic-server-preact/src/mcp-app.tsx
index a8bdc68b8..76727b374 100644
--- a/examples/basic-server-preact/src/mcp-app.tsx
+++ b/examples/basic-server-preact/src/mcp-app.tsx
@@ -8,7 +8,7 @@ import {
   applyHostStyleVariables,
   type McpUiHostContext,
 } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import { useCallback, useEffect, useState } from "preact/hooks";
 import { render } from "preact";
 import styles from "./mcp-app.module.css";
diff --git a/examples/basic-server-react/main.ts b/examples/basic-server-react/main.ts
index ec187b68a..01d4a0cdc 100644
--- a/examples/basic-server-react/main.ts
+++ b/examples/basic-server-react/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-react/package.json b/examples/basic-server-react/package.json
index a7153e170..5ec38cc00 100644
--- a/examples/basic-server-react/package.json
+++ b/examples/basic-server-react/package.json
@@ -35,12 +35,14 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/basic-server-react/server.ts b/examples/basic-server-react/server.ts
index 23f6dda5a..b09e746a7 100644
--- a/examples/basic-server-react/server.ts
+++ b/examples/basic-server-react/server.ts
@@ -1,6 +1,6 @@
 import { registerAppResource, registerAppTool, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 
@@ -29,7 +29,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/basic-server-react/src/mcp-app.tsx b/examples/basic-server-react/src/mcp-app.tsx
index 6bb554025..8c55064a5 100644
--- a/examples/basic-server-react/src/mcp-app.tsx
+++ b/examples/basic-server-react/src/mcp-app.tsx
@@ -3,7 +3,7 @@
  */
 import type { App, McpUiHostContext } from "@modelcontextprotocol/ext-apps";
 import { useApp } from "@modelcontextprotocol/ext-apps/react";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import { StrictMode, useCallback, useEffect, useState } from "react";
 import { createRoot } from "react-dom/client";
 import styles from "./mcp-app.module.css";
diff --git a/examples/basic-server-solid/main.ts b/examples/basic-server-solid/main.ts
index c8d9de225..1e087eee2 100644
--- a/examples/basic-server-solid/main.ts
+++ b/examples/basic-server-solid/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-solid/package.json b/examples/basic-server-solid/package.json
index 0606408c8..bb5eb6e94 100644
--- a/examples/basic-server-solid/package.json
+++ b/examples/basic-server-solid/package.json
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "solid-js": "1.9.10",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/basic-server-solid/server.ts b/examples/basic-server-solid/server.ts
index 2ed2d9356..0ebd05d9d 100644
--- a/examples/basic-server-solid/server.ts
+++ b/examples/basic-server-solid/server.ts
@@ -1,5 +1,5 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
@@ -28,7 +28,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/basic-server-solid/src/mcp-app.tsx b/examples/basic-server-solid/src/mcp-app.tsx
index 66d47f3f6..c8de38670 100644
--- a/examples/basic-server-solid/src/mcp-app.tsx
+++ b/examples/basic-server-solid/src/mcp-app.tsx
@@ -8,7 +8,7 @@ import {
   applyHostStyleVariables,
   type McpUiHostContext,
 } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import { createEffect, createSignal, onMount, Show } from "solid-js";
 import { render } from "solid-js/web";
 import styles from "./mcp-app.module.css";
diff --git a/examples/basic-server-svelte/main.ts b/examples/basic-server-svelte/main.ts
index 6c50a254f..5fe4e3cfb 100644
--- a/examples/basic-server-svelte/main.ts
+++ b/examples/basic-server-svelte/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-svelte/package.json b/examples/basic-server-svelte/package.json
index 3b5430910..38a1ccbd9 100644
--- a/examples/basic-server-svelte/package.json
+++ b/examples/basic-server-svelte/package.json
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "svelte": "^5.0.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@sveltejs/vite-plugin-svelte": "^5.0.0",
diff --git a/examples/basic-server-svelte/server.ts b/examples/basic-server-svelte/server.ts
index da603ca8d..4c2cee488 100644
--- a/examples/basic-server-svelte/server.ts
+++ b/examples/basic-server-svelte/server.ts
@@ -1,5 +1,5 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
@@ -28,7 +28,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/basic-server-vanillajs/main.ts b/examples/basic-server-vanillajs/main.ts
index 286fa34f0..56225af67 100644
--- a/examples/basic-server-vanillajs/main.ts
+++ b/examples/basic-server-vanillajs/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-vanillajs/package.json b/examples/basic-server-vanillajs/package.json
index dc7c333e0..ac75a4582 100644
--- a/examples/basic-server-vanillajs/package.json
+++ b/examples/basic-server-vanillajs/package.json
@@ -25,10 +25,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/basic-server-vanillajs/server.ts b/examples/basic-server-vanillajs/server.ts
index 5b2daf704..8d1c36280 100644
--- a/examples/basic-server-vanillajs/server.ts
+++ b/examples/basic-server-vanillajs/server.ts
@@ -1,6 +1,6 @@
 import { registerAppResource, registerAppTool, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -29,7 +29,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       outputSchema: z.object({
         time: z.string(),
       }),
diff --git a/examples/basic-server-vanillajs/src/mcp-app.ts b/examples/basic-server-vanillajs/src/mcp-app.ts
index c3168c214..1ffe0aace 100644
--- a/examples/basic-server-vanillajs/src/mcp-app.ts
+++ b/examples/basic-server-vanillajs/src/mcp-app.ts
@@ -8,7 +8,7 @@ import {
   applyHostStyleVariables,
   type McpUiHostContext,
 } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import "./global.css";
 import "./mcp-app.css";
 
diff --git a/examples/basic-server-vue/main.ts b/examples/basic-server-vue/main.ts
index 669a07189..9db8b7b9e 100644
--- a/examples/basic-server-vue/main.ts
+++ b/examples/basic-server-vue/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/basic-server-vue/package.json b/examples/basic-server-vue/package.json
index c479adf2e..141d67178 100644
--- a/examples/basic-server-vue/package.json
+++ b/examples/basic-server-vue/package.json
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "vue": "^3.5.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/basic-server-vue/server.ts b/examples/basic-server-vue/server.ts
index 5aa72de03..e7ff1934a 100644
--- a/examples/basic-server-vue/server.ts
+++ b/examples/basic-server-vue/server.ts
@@ -1,5 +1,5 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { CallToolResult, ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { registerAppTool, registerAppResource, RESOURCE_MIME_TYPE } from "@modelcontextprotocol/ext-apps/server";
@@ -28,7 +28,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time as an ISO 8601 string.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/budget-allocator-server/main.ts b/examples/budget-allocator-server/main.ts
index cc488f0b1..d0ce29a7a 100644
--- a/examples/budget-allocator-server/main.ts
+++ b/examples/budget-allocator-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/budget-allocator-server/package.json b/examples/budget-allocator-server/package.json
index bd8865f16..71120eb03 100644
--- a/examples/budget-allocator-server/package.json
+++ b/examples/budget-allocator-server/package.json
@@ -27,11 +27,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "chart.js": "^4.4.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/budget-allocator-server/server.ts b/examples/budget-allocator-server/server.ts
index e52291825..e2396f871 100755
--- a/examples/budget-allocator-server/server.ts
+++ b/examples/budget-allocator-server/server.ts
@@ -4,11 +4,11 @@
  * Provides budget configuration, 24 months of historical allocation data,
  * and industry benchmarks by company stage.
  */
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -270,7 +270,7 @@ export function createServer(): McpServer {
       title: "Get Budget Data",
       description:
         "Returns budget configuration with 24 months of historical allocations and industry benchmarks by company stage",
-      inputSchema: {},
+      
       outputSchema: BudgetDataResponseSchema,
       _meta: { ui: { resourceUri } },
     },
diff --git a/examples/cohort-heatmap-server/main.ts b/examples/cohort-heatmap-server/main.ts
index d59903b34..71d2bdca8 100644
--- a/examples/cohort-heatmap-server/main.ts
+++ b/examples/cohort-heatmap-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/cohort-heatmap-server/package.json b/examples/cohort-heatmap-server/package.json
index c92105a39..a5dd81fe4 100644
--- a/examples/cohort-heatmap-server/package.json
+++ b/examples/cohort-heatmap-server/package.json
@@ -27,12 +27,14 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/cohort-heatmap-server/server.ts b/examples/cohort-heatmap-server/server.ts
index 6d07144a2..fbe7f8bc0 100644
--- a/examples/cohort-heatmap-server/server.ts
+++ b/examples/cohort-heatmap-server/server.ts
@@ -1,5 +1,5 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -178,8 +178,8 @@ export function createServer(): McpServer {
       title: "Get Cohort Retention Data",
       description:
         "Returns cohort retention heatmap data showing customer retention over time by signup month",
-      inputSchema: GetCohortDataInputSchema.shape,
-      outputSchema: CohortDataSchema.shape,
+      inputSchema: GetCohortDataInputSchema,
+      outputSchema: CohortDataSchema,
       _meta: { ui: { resourceUri } },
     },
     async ({ metric, periodType, cohortCount, maxPeriods }) => {
diff --git a/examples/customer-segmentation-server/main.ts b/examples/customer-segmentation-server/main.ts
index 130076c58..1799612b5 100644
--- a/examples/customer-segmentation-server/main.ts
+++ b/examples/customer-segmentation-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/customer-segmentation-server/package.json b/examples/customer-segmentation-server/package.json
index b7532508f..2ed4a9b41 100644
--- a/examples/customer-segmentation-server/package.json
+++ b/examples/customer-segmentation-server/package.json
@@ -27,11 +27,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "chart.js": "^4.4.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/customer-segmentation-server/server.ts b/examples/customer-segmentation-server/server.ts
index 244415d1f..bd8dbe2b6 100644
--- a/examples/customer-segmentation-server/server.ts
+++ b/examples/customer-segmentation-server/server.ts
@@ -1,8 +1,8 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -100,8 +100,8 @@ export function createServer(): McpServer {
         title: "Get Customer Data",
         description:
           "Returns customer data with segment information for visualization. Optionally filter by segment.",
-        inputSchema: GetCustomerDataInputSchema.shape,
-        outputSchema: GetCustomerDataOutputSchema.shape,
+        inputSchema: GetCustomerDataInputSchema,
+        outputSchema: GetCustomerDataOutputSchema,
         _meta: { ui: { resourceUri } },
       },
       async ({ segment }): Promise<CallToolResult> => {
diff --git a/examples/debug-server/main.ts b/examples/debug-server/main.ts
index 3c89a975b..b9b3f3219 100644
--- a/examples/debug-server/main.ts
+++ b/examples/debug-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/debug-server/package.json b/examples/debug-server/package.json
index 9f2ba836c..f8206490f 100644
--- a/examples/debug-server/package.json
+++ b/examples/debug-server/package.json
@@ -35,8 +35,10 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/debug-server/server.ts b/examples/debug-server/server.ts
index fd3452a19..716403cef 100644
--- a/examples/debug-server/server.ts
+++ b/examples/debug-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import { appendFileSync } from "node:fs";
 import path from "node:path";
diff --git a/examples/debug-server/src/mcp-app.ts b/examples/debug-server/src/mcp-app.ts
index b1c862d36..53e7a0373 100644
--- a/examples/debug-server/src/mcp-app.ts
+++ b/examples/debug-server/src/mcp-app.ts
@@ -549,15 +549,9 @@ openLinkBtn.addEventListener("click", async () => {
 
 autoResizeToggleEl.addEventListener("change", () => {
   if (autoResizeToggleEl.checked) {
-    if (!state.autoResizeCleanup) {
-      state.autoResizeCleanup = app.setupSizeChangedNotifications();
-    }
-  } else {
-    if (state.autoResizeCleanup) {
-      state.autoResizeCleanup();
-      state.autoResizeCleanup = null;
-    }
+    app.setupSizeChangedNotifications();
   }
+  // Note: v2 setupSizeChangedNotifications() has no cleanup return; toggle-off is a no-op.
   logEvent("auto-resize-toggle", { enabled: autoResizeToggleEl.checked });
 });
 
@@ -635,7 +629,7 @@ app
 
     // Auto-resize is enabled by default in App, capture cleanup if we want to toggle
     // We'll set it up ourselves since we want toggle control
-    state.autoResizeCleanup = app.setupSizeChangedNotifications();
+    app.setupSizeChangedNotifications();
   })
   .catch((e) => {
     logEvent("error", e);
diff --git a/examples/integration-server/main.ts b/examples/integration-server/main.ts
index c45787e2b..c536b6787 100644
--- a/examples/integration-server/main.ts
+++ b/examples/integration-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/integration-server/package.json b/examples/integration-server/package.json
index 807ce2d22..7427ae401 100644
--- a/examples/integration-server/package.json
+++ b/examples/integration-server/package.json
@@ -16,12 +16,14 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/integration-server/server.ts b/examples/integration-server/server.ts
index e44689d24..945c7c5b6 100644
--- a/examples/integration-server/server.ts
+++ b/examples/integration-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -33,7 +33,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time.",
-      inputSchema: {},
+      
       outputSchema: z.object({
         time: z.string(),
       }),
@@ -72,7 +72,7 @@ export function createServer(): McpServer {
   );
 
   // Sample downloadable resource — used to demo ResourceLink in ui/download-file
-  server.resource(
+  server.registerResource(
     SAMPLE_DOWNLOAD_URI,
     SAMPLE_DOWNLOAD_URI,
     {
diff --git a/examples/integration-server/src/mcp-app.tsx b/examples/integration-server/src/mcp-app.tsx
index 7f0b18c27..b8ae5a8f2 100644
--- a/examples/integration-server/src/mcp-app.tsx
+++ b/examples/integration-server/src/mcp-app.tsx
@@ -3,7 +3,7 @@
  */
 import type { App, McpUiHostContext } from "@modelcontextprotocol/ext-apps";
 import { useApp } from "@modelcontextprotocol/ext-apps/react";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import { StrictMode, useCallback, useEffect, useState } from "react";
 import { createRoot } from "react-dom/client";
 import styles from "./mcp-app.module.css";
diff --git a/examples/map-server/main.ts b/examples/map-server/main.ts
index f91f57b6e..92025b839 100644
--- a/examples/map-server/main.ts
+++ b/examples/map-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/map-server/package.json b/examples/map-server/package.json
index 52c6d8015..3cac9a304 100644
--- a/examples/map-server/package.json
+++ b/examples/map-server/package.json
@@ -27,10 +27,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/map-server/server.ts b/examples/map-server/server.ts
index 540d35c4d..b8d44afc6 100644
--- a/examples/map-server/server.ts
+++ b/examples/map-server/server.ts
@@ -5,11 +5,11 @@
  * - geocode: Search for places using OpenStreetMap Nominatim
  * - show-map: Display an interactive 3D globe at a given location
  */
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -148,7 +148,7 @@ export function createServer(): McpServer {
       title: "Show Map",
       description:
         "Display an interactive world map zoomed to a specific bounding box. Use the GeoCode tool to find the bounding box of a location.",
-      inputSchema: {
+      inputSchema: z.object({
         west: z
           .number()
           .optional()
@@ -173,7 +173,7 @@ export function createServer(): McpServer {
           .string()
           .optional()
           .describe("Optional label to display on the map"),
-      },
+      }),
       _meta: { ui: { resourceUri } },
     },
     async ({ west, south, east, north, label }): Promise<CallToolResult> => ({
@@ -196,13 +196,13 @@ export function createServer(): McpServer {
       title: "Geocode",
       description:
         "Search for places using OpenStreetMap. Returns coordinates and bounding boxes for up to 5 matches.",
-      inputSchema: {
+      inputSchema: z.object({
         query: z
           .string()
           .describe(
             "Place name or address to search for (e.g., 'Paris', 'Golden Gate Bridge', '1600 Pennsylvania Ave')",
           ),
-      },
+      }),
     },
     async ({ query }): Promise<CallToolResult> => {
       try {
diff --git a/examples/pdf-server/main.ts b/examples/pdf-server/main.ts
index 1ff848a3e..b9f228069 100644
--- a/examples/pdf-server/main.ts
+++ b/examples/pdf-server/main.ts
@@ -6,10 +6,10 @@
 
 import fs from "node:fs";
 import path from "node:path";
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import {
diff --git a/examples/pdf-server/package.json b/examples/pdf-server/package.json
index fc08d5e40..801a6b84d 100644
--- a/examples/pdf-server/package.json
+++ b/examples/pdf-server/package.json
@@ -26,12 +26,14 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "pdf-lib": "^1.17.1",
     "pdfjs-dist": "^5.0.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/pdf-server/server.test.ts b/examples/pdf-server/server.test.ts
index a2f64ee49..afb0dbed4 100644
--- a/examples/pdf-server/server.test.ts
+++ b/examples/pdf-server/server.test.ts
@@ -2,8 +2,8 @@ import { describe, it, expect, beforeEach, afterEach, spyOn } from "bun:test";
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
-import { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
+import { Client } from "@modelcontextprotocol/client";
+import { InMemoryTransport } from "@modelcontextprotocol/server";
 import {
   createPdfCache,
   createServer,
diff --git a/examples/pdf-server/server.ts b/examples/pdf-server/server.ts
index d2a0b7d8b..bdfd0f0c6 100644
--- a/examples/pdf-server/server.ts
+++ b/examples/pdf-server/server.ts
@@ -13,18 +13,16 @@
 import { randomUUID } from "crypto";
 import fs from "node:fs";
 import path from "node:path";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { Server } from "@modelcontextprotocol/sdk/server/index.js";
+import { McpServer, type Server } from "@modelcontextprotocol/server";
 import {
   registerAppResource,
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
 import {
-  RootsListChangedNotificationSchema,
   type CallToolResult,
   type ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 // Stub DOMMatrix/ImageData/Path2D before pdfjs-dist loads — its legacy
 // build instantiates DOMMatrix at module scope and the @napi-rs/canvas
 // polyfill is unreliable under npx. See ./pdfjs-polyfill.ts for details.
@@ -63,7 +61,7 @@ class FetchStandardFontDataFactory {
 import type {
   PrimitiveSchemaDefinition,
   ElicitResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import { z } from "zod";
 
 // =============================================================================
@@ -1190,7 +1188,7 @@ export function createServer(options: CreateServerOptions = {}): McpServer {
       refreshRoots(server.server);
     };
     server.server.setNotificationHandler(
-      RootsListChangedNotificationSchema,
+      "notifications/roots/list_changed",
       async () => {
         await refreshRoots(server.server);
       },
@@ -1201,10 +1199,9 @@ export function createServer(options: CreateServerOptions = {}): McpServer {
   const { readPdfRange } = createPdfCache();
 
   // Tool: list_pdfs - List available PDFs
-  server.tool(
+  server.registerTool(
     "list_pdfs",
-    "List available PDFs that can be displayed",
-    {},
+    { description: "List available PDFs that can be displayed" },
     async (): Promise<CallToolResult> => {
       const seen = new Set<string>();
       const localFiles: string[] = [];
@@ -1286,7 +1283,7 @@ export function createServer(options: CreateServerOptions = {}): McpServer {
       title: "Read PDF Bytes",
       description:
         "Read a range of bytes from a PDF (max 512KB per request). The model should NOT call this tool directly.",
-      inputSchema: {
+      inputSchema: z.object({
         url: z.string().describe("PDF URL or local file path"),
         offset: z.number().min(0).default(0).describe("Byte offset"),
         byteCount: z
@@ -1295,7 +1292,7 @@ export function createServer(options: CreateServerOptions = {}): McpServer {
           .max(MAX_CHUNK_BYTES)
           .default(MAX_CHUNK_BYTES)
           .describe("Bytes to read"),
-      },
+      }),
       outputSchema: z.object({
         url: z.string(),
         bytes: z.string().describe("Base64 encoded bytes"),
@@ -1382,7 +1379,7 @@ Returns a viewUUID in structuredContent. Pass it to \`interact\`:
 
 Accepts local files (use list_pdfs), client MCP root directories, or any HTTPS URL.
 Set \`elicit_form_inputs\` to true to prompt the user to fill form fields before display.`,
-      inputSchema: {
+      inputSchema: z.object({
         url: z
           .string()
           .default(DEFAULT_PDF)
@@ -1398,7 +1395,7 @@ Set \`elicit_form_inputs\` to true to prompt the user to fill form fields before
                   "If true and the PDF has form fields, prompt the user to fill them before displaying",
                 ),
             }),
-      },
+      }),
       outputSchema: z.object({
         viewUUID: z
           .string()
@@ -2349,7 +2346,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
 **FORMS** — fill_form: fill fields with \`fields\` array of {name, value}.
 
 **SAVE** — save_as: write the annotated PDF (annotations + form values) to a file. Pass \`path\` (absolute path or file://) for a new location, or omit \`path\` to overwrite the original. Set \`overwrite: true\` to replace an existing file (always required when omitting \`path\`).`,
-        inputSchema: {
+        inputSchema: z.object({
           viewUUID: z
             .string()
             .describe(
@@ -2446,7 +2443,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
             .describe(
               "Array of commands to execute sequentially. More efficient than separate calls. Tip: end with get_pages+getScreenshots to verify changes.",
             ),
-        },
+        }),
       },
       async (
         {
@@ -2523,7 +2520,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
           const result = await processInteractCommand(
             uuid,
             commandList[i],
-            extra.signal,
+            extra.mcpReq.signal,
           );
           if (result.isError) {
             const errText = result.content
@@ -2580,7 +2577,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
         title: "Submit Page Data",
         description:
           "Submit rendered page data for a get_pages request (used by viewer). The model should NOT call this tool directly.",
-        inputSchema: {
+        inputSchema: z.object({
           requestId: z
             .string()
             .describe("The request ID from the get_pages command"),
@@ -2593,7 +2590,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
               }),
             )
             .describe("Page data entries"),
-        },
+        }),
         _meta: { ui: { visibility: ["app"] } },
       },
       async ({ requestId, pages }): Promise<CallToolResult> => {
@@ -2623,7 +2620,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
         title: "Submit Save Data",
         description:
           "Submit annotated PDF bytes for a save_as request (used by viewer). The model should NOT call this tool directly.",
-        inputSchema: {
+        inputSchema: z.object({
           requestId: z
             .string()
             .describe("The request ID from the save_as command"),
@@ -2632,7 +2629,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
             .string()
             .optional()
             .describe("Error message if the viewer failed to build bytes"),
-        },
+        }),
         _meta: { ui: { visibility: ["app"] } },
       },
       async ({ requestId, data, error }): Promise<CallToolResult> => {
@@ -2662,7 +2659,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
         title: "Submit Viewer State",
         description:
           "Submit a viewer-state snapshot for a get_viewer_state request (used by viewer). The model should NOT call this tool directly.",
-        inputSchema: {
+        inputSchema: z.object({
           requestId: z
             .string()
             .describe("The request ID from the get_viewer_state command"),
@@ -2674,7 +2671,7 @@ Example — add a signature image and a stamp, then screenshot to verify:
             .string()
             .optional()
             .describe("Error message if the viewer failed to read state"),
-        },
+        }),
         _meta: { ui: { visibility: ["app"] } },
       },
       async ({ requestId, state, error }): Promise<CallToolResult> => {
@@ -2704,9 +2701,9 @@ Example — add a signature image and a stamp, then screenshot to verify:
         title: "Poll PDF Commands",
         description:
           "Poll for pending commands for a PDF viewer. The model should NOT call this tool directly.",
-        inputSchema: {
+        inputSchema: z.object({
           viewUUID: z.string().describe("The viewUUID of the PDF viewer"),
-        },
+        }),
         _meta: { ui: { visibility: ["app"] } },
       },
       async ({ viewUUID: uuid }): Promise<CallToolResult> => {
@@ -2751,10 +2748,10 @@ Example — add a signature image and a stamp, then screenshot to verify:
       title: "Save PDF",
       description:
         "Save annotated PDF bytes back to a local file. The model should NOT call this tool directly — use interact with action: save_as instead.",
-      inputSchema: {
+      inputSchema: z.object({
         url: z.string().describe("Original PDF URL or local file path"),
         data: z.string().describe("Base64-encoded PDF bytes"),
-      },
+      }),
       outputSchema: z.object({
         filePath: z.string(),
         mtimeMs: z.number(),
diff --git a/examples/pdf-server/src/mcp-app.ts b/examples/pdf-server/src/mcp-app.ts
index f4a17901d..f28d0c100 100644
--- a/examples/pdf-server/src/mcp-app.ts
+++ b/examples/pdf-server/src/mcp-app.ts
@@ -12,8 +12,7 @@ import {
   applyDocumentTheme,
   applyHostStyleVariables,
 } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
-import type { ContentBlock } from "@modelcontextprotocol/sdk/spec.types.js";
+import type { CallToolResult, ContentBlock } from "@modelcontextprotocol/client";
 import * as pdfjsLib from "pdfjs-dist";
 import { AnnotationLayer, AnnotationMode, TextLayer } from "pdfjs-dist";
 import "pdfjs-dist/web/pdf_viewer.css";
diff --git a/examples/qr-server/package.json b/examples/qr-server/package.json
index a7813e3c5..647a21531 100644
--- a/examples/qr-server/package.json
+++ b/examples/qr-server/package.json
@@ -9,6 +9,8 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0"
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   }
 }
diff --git a/examples/quickstart/main.ts b/examples/quickstart/main.ts
index 06895a49a..f954d0b0c 100644
--- a/examples/quickstart/main.ts
+++ b/examples/quickstart/main.ts
@@ -1,7 +1,7 @@
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/quickstart/package.json b/examples/quickstart/package.json
index 8451e20eb..a84725e1a 100644
--- a/examples/quickstart/package.json
+++ b/examples/quickstart/package.json
@@ -16,9 +16,11 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
-    "express": "^5.1.0"
+    "express": "^5.1.0",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/quickstart/server.ts b/examples/quickstart/server.ts
index eb3c3b1ab..78e5cac00 100644
--- a/examples/quickstart/server.ts
+++ b/examples/quickstart/server.ts
@@ -3,7 +3,7 @@ import {
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 
@@ -30,7 +30,7 @@ export function createServer(): McpServer {
     {
       title: "Get Time",
       description: "Returns the current server time.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } }, // Links this tool to its UI resource
     },
     async () => {
diff --git a/examples/say-server/package.json b/examples/say-server/package.json
index 2e90491e7..6d20328fa 100644
--- a/examples/say-server/package.json
+++ b/examples/say-server/package.json
@@ -16,6 +16,8 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0"
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   }
 }
diff --git a/examples/scenario-modeler-server/main.ts b/examples/scenario-modeler-server/main.ts
index dbd3ab6ae..01bf52cdf 100644
--- a/examples/scenario-modeler-server/main.ts
+++ b/examples/scenario-modeler-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/scenario-modeler-server/package.json b/examples/scenario-modeler-server/package.json
index e00afc09c..94695447d 100644
--- a/examples/scenario-modeler-server/package.json
+++ b/examples/scenario-modeler-server/package.json
@@ -27,13 +27,15 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "chart.js": "^4.4.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/scenario-modeler-server/server.ts b/examples/scenario-modeler-server/server.ts
index b59851c40..8a9b9990e 100644
--- a/examples/scenario-modeler-server/server.ts
+++ b/examples/scenario-modeler-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppResource,
   registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -305,8 +305,8 @@ export function createServer(): McpServer {
         title: "Get Scenario Data",
         description:
           "Returns SaaS scenario templates and optionally computes custom projections for given inputs",
-        inputSchema: GetScenarioDataInputSchema.shape,
-        outputSchema: GetScenarioDataOutputSchema.shape,
+        inputSchema: GetScenarioDataInputSchema,
+        outputSchema: GetScenarioDataOutputSchema,
         _meta: { ui: { resourceUri } },
       },
       async (args: {
diff --git a/examples/shadertoy-server/main.ts b/examples/shadertoy-server/main.ts
index ac8f6ad8e..4c7db699f 100644
--- a/examples/shadertoy-server/main.ts
+++ b/examples/shadertoy-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/shadertoy-server/package.json b/examples/shadertoy-server/package.json
index 03bcb96c5..7287ab97f 100644
--- a/examples/shadertoy-server/package.json
+++ b/examples/shadertoy-server/package.json
@@ -25,10 +25,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/shadertoy-server/server.ts b/examples/shadertoy-server/server.ts
index a4bfe9e00..9422b82a5 100644
--- a/examples/shadertoy-server/server.ts
+++ b/examples/shadertoy-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppTool,
   RESOURCE_MIME_TYPE,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
diff --git a/examples/sheet-music-server/main.ts b/examples/sheet-music-server/main.ts
index 8b143a7ae..71f3f0d16 100644
--- a/examples/sheet-music-server/main.ts
+++ b/examples/sheet-music-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/sheet-music-server/package.json b/examples/sheet-music-server/package.json
index 3706c25a4..2b4f16a01 100644
--- a/examples/sheet-music-server/package.json
+++ b/examples/sheet-music-server/package.json
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "abcjs": "^6.4.4",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/sheet-music-server/server.ts b/examples/sheet-music-server/server.ts
index cfd319b51..b831ae25c 100644
--- a/examples/sheet-music-server/server.ts
+++ b/examples/sheet-music-server/server.ts
@@ -1,8 +1,8 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
diff --git a/examples/system-monitor-server/main.ts b/examples/system-monitor-server/main.ts
index 365a56046..7e6a25392 100644
--- a/examples/system-monitor-server/main.ts
+++ b/examples/system-monitor-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/system-monitor-server/package.json b/examples/system-monitor-server/package.json
index c80b9ad7c..8d29dc58f 100644
--- a/examples/system-monitor-server/package.json
+++ b/examples/system-monitor-server/package.json
@@ -27,12 +27,14 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "chart.js": "^4.4.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "systeminformation": "^5.31.5",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/system-monitor-server/server.ts b/examples/system-monitor-server/server.ts
index 8fac5f2f9..31f430944 100644
--- a/examples/system-monitor-server/server.ts
+++ b/examples/system-monitor-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppResource,
   registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
@@ -135,8 +135,8 @@ export function createServer(): McpServer {
       title: "Get System Info",
       description:
         "Returns system information, including hostname, platform, CPU info, and memory.",
-      inputSchema: {},
-      outputSchema: SystemInfoSchema.shape,
+      
+      outputSchema: SystemInfoSchema,
       _meta: { ui: { resourceUri } },
     },
     (): CallToolResult => {
@@ -156,8 +156,8 @@ export function createServer(): McpServer {
       title: "Poll System Stats",
       description:
         "Returns dynamic system metrics for polling: per-core CPU timing, memory usage, and uptime. App-only.",
-      inputSchema: {},
-      outputSchema: PollStatsSchema.shape,
+      
+      outputSchema: PollStatsSchema,
       _meta: { ui: { visibility: ["app"] } },
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/threejs-server/main.ts b/examples/threejs-server/main.ts
index 13a2084a8..7d1f6bf88 100644
--- a/examples/threejs-server/main.ts
+++ b/examples/threejs-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/threejs-server/package.json b/examples/threejs-server/package.json
index d4b8192f7..79a1c20fc 100644
--- a/examples/threejs-server/package.json
+++ b/examples/threejs-server/package.json
@@ -27,13 +27,15 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
     "three": "^0.181.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/threejs-server/server.ts b/examples/threejs-server/server.ts
index ae320df80..698758a1f 100644
--- a/examples/threejs-server/server.ts
+++ b/examples/threejs-server/server.ts
@@ -8,8 +8,8 @@ import {
   registerAppResource,
   registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import type { ReadResourceResult } from "@modelcontextprotocol/sdk/types.js";
+import { McpServer } from "@modelcontextprotocol/server";
+import type { ReadResourceResult } from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -161,7 +161,7 @@ export function createServer(): McpServer {
       title: "Show Three.js Scene",
       description:
         "Render an interactive 3D scene with custom Three.js code. Supports transparent backgrounds (alpha: true) for seamless host UI integration. Available globals: THREE, OrbitControls, EffectComposer, RenderPass, UnrealBloomPass, canvas, width, height.",
-      inputSchema: {
+      inputSchema: z.object({
         code: z
           .string()
           .default(DEFAULT_THREEJS_CODE)
@@ -172,7 +172,7 @@ export function createServer(): McpServer {
           .positive()
           .default(400)
           .describe("Height in pixels"),
-      },
+      }),
       outputSchema: z.object({
         success: z.boolean(),
       }),
@@ -192,7 +192,7 @@ export function createServer(): McpServer {
     {
       title: "Learn Three.js",
       description: "Get documentation and examples for using the Three.js View",
-      inputSchema: {},
+      
     },
     async () => {
       return {
diff --git a/examples/threejs-server/src/mcp-app-wrapper.tsx b/examples/threejs-server/src/mcp-app-wrapper.tsx
index 9ef24d263..a5a98edbb 100644
--- a/examples/threejs-server/src/mcp-app-wrapper.tsx
+++ b/examples/threejs-server/src/mcp-app-wrapper.tsx
@@ -6,7 +6,7 @@
  */
 import type { App, McpUiHostContext } from "@modelcontextprotocol/ext-apps";
 import { useApp } from "@modelcontextprotocol/ext-apps/react";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import { StrictMode, useState, useEffect } from "react";
 import { createRoot } from "react-dom/client";
 import ThreeJSApp from "./threejs-app.tsx";
diff --git a/examples/transcript-server/main.ts b/examples/transcript-server/main.ts
index 68db8dc7d..c79cbf655 100644
--- a/examples/transcript-server/main.ts
+++ b/examples/transcript-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/transcript-server/package.json b/examples/transcript-server/package.json
index 341780127..5c0d9b74e 100644
--- a/examples/transcript-server/package.json
+++ b/examples/transcript-server/package.json
@@ -25,10 +25,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/transcript-server/server.ts b/examples/transcript-server/server.ts
index 56bf88d99..f2ac58938 100644
--- a/examples/transcript-server/server.ts
+++ b/examples/transcript-server/server.ts
@@ -1,8 +1,8 @@
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import {
@@ -33,7 +33,7 @@ export function createServer(): McpServer {
       title: "Transcribe Speech",
       description:
         "Opens a live speech transcription interface using the Web Speech API.",
-      inputSchema: {},
+      
       _meta: { ui: { resourceUri } },
     },
     async (): Promise<CallToolResult> => {
diff --git a/examples/video-resource-server/main.ts b/examples/video-resource-server/main.ts
index 082fa5abc..c1469f053 100644
--- a/examples/video-resource-server/main.ts
+++ b/examples/video-resource-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/video-resource-server/package.json b/examples/video-resource-server/package.json
index fb01e3136..e194096ba 100644
--- a/examples/video-resource-server/package.json
+++ b/examples/video-resource-server/package.json
@@ -25,10 +25,12 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/video-resource-server/server.ts b/examples/video-resource-server/server.ts
index 2cb317e41..3718e7d94 100644
--- a/examples/video-resource-server/server.ts
+++ b/examples/video-resource-server/server.ts
@@ -12,11 +12,11 @@ import {
 import {
   McpServer,
   ResourceTemplate,
-} from "@modelcontextprotocol/sdk/server/mcp.js";
+} from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { z } from "zod";
@@ -135,14 +135,14 @@ Available videos:
 ${Object.entries(VIDEO_LIBRARY)
   .map(([id, v]) => `- ${id}: ${v.description}`)
   .join("\n")}`,
-      inputSchema: {
+      inputSchema: z.object({
         videoId: z
           .enum(Object.keys(VIDEO_LIBRARY) as [string, ...string[]])
           .default("bunny-1mb")
           .describe(
             `Video ID to play. Available: ${Object.keys(VIDEO_LIBRARY).join(", ")}`,
           ),
-      },
+      }),
       outputSchema: z.object({
         videoUri: z.string(),
         description: z.string(),
diff --git a/examples/video-resource-server/src/mcp-app.ts b/examples/video-resource-server/src/mcp-app.ts
index 88ed913ee..31fe7b045 100644
--- a/examples/video-resource-server/src/mcp-app.ts
+++ b/examples/video-resource-server/src/mcp-app.ts
@@ -5,7 +5,7 @@
  * The video is served as a base64 blob and converted to a data URI for playback.
  */
 import { App, type McpUiHostContext } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import "./global.css";
 import "./mcp-app.css";
 
diff --git a/examples/wiki-explorer-server/main.ts b/examples/wiki-explorer-server/main.ts
index cc7b3a221..3b6be02e4 100644
--- a/examples/wiki-explorer-server/main.ts
+++ b/examples/wiki-explorer-server/main.ts
@@ -4,10 +4,10 @@
  * Or: node dist/index.js [--stdio]
  */
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/server/stdio";
+import { createMcpExpressApp } from "@modelcontextprotocol/express";
+import type { McpServer } from "@modelcontextprotocol/server";
+import { NodeStreamableHTTPServerTransport as StreamableHTTPServerTransport } from "@modelcontextprotocol/node";
 import cors from "cors";
 import type { Request, Response } from "express";
 import { createServer } from "./server.js";
diff --git a/examples/wiki-explorer-server/package.json b/examples/wiki-explorer-server/package.json
index 605c39ae3..aef7f8c2c 100644
--- a/examples/wiki-explorer-server/package.json
+++ b/examples/wiki-explorer-server/package.json
@@ -27,11 +27,13 @@
   },
   "dependencies": {
     "@modelcontextprotocol/ext-apps": "^1.0.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
     "cheerio": "^1.0.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^4.1.13"
+    "zod": "^4.1.13",
+    "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz"
   },
   "devDependencies": {
     "@types/cors": "^2.8.19",
diff --git a/examples/wiki-explorer-server/server.ts b/examples/wiki-explorer-server/server.ts
index fe2e89b53..395e9bd32 100644
--- a/examples/wiki-explorer-server/server.ts
+++ b/examples/wiki-explorer-server/server.ts
@@ -3,11 +3,11 @@ import {
   registerAppResource,
   registerAppTool,
 } from "@modelcontextprotocol/ext-apps/server";
-import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { McpServer } from "@modelcontextprotocol/server";
 import type {
   CallToolResult,
   ReadResourceResult,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/server";
 import * as cheerio from "cheerio";
 import fs from "node:fs/promises";
 import path from "node:path";
diff --git a/examples/wiki-explorer-server/src/mcp-app.ts b/examples/wiki-explorer-server/src/mcp-app.ts
index 69bec05d4..11aeb158d 100644
--- a/examples/wiki-explorer-server/src/mcp-app.ts
+++ b/examples/wiki-explorer-server/src/mcp-app.ts
@@ -2,7 +2,7 @@
  * Wiki Explorer - Force-directed graph visualization of Wikipedia link networks
  */
 import { App, type McpUiHostContext } from "@modelcontextprotocol/ext-apps";
-import type { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
+import type { CallToolResult } from "@modelcontextprotocol/server";
 import {
   forceCenter,
   forceCollide,
diff --git a/package-lock.json b/package-lock.json
index b63a8e550..7c217feae 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,10 @@
       ],
       "devDependencies": {
         "@boneskull/typedoc-plugin-mermaid": "^0.2.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/client": "file:../../../../../tmp/modelcontextprotocol-client-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/express": "file:../../../../../tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/node": "file:../../../../../tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:../../../../../tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "@playwright/test": "1.57.0",
         "@types/bun": "^1.3.2",
         "@types/node": "20.19.27",
@@ -47,12 +50,16 @@
         "node": ">=20"
       },
       "peerDependencies": {
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/client": "file:../../../../../tmp/modelcontextprotocol-client-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:../../../../../tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "react": "^17.0.0 || ^18.0.0 || ^19.0.0",
         "react-dom": "^17.0.0 || ^18.0.0 || ^19.0.0",
         "zod": "^3.25.0 || ^4.0.0"
       },
       "peerDependenciesMeta": {
+        "@modelcontextprotocol/server": {
+          "optional": true
+        },
         "react": {
           "optional": true
         },
@@ -65,8 +72,10 @@
       "name": "@modelcontextprotocol/ext-apps-basic-host",
       "version": "1.5.0",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "react": "^19.2.0",
         "react-dom": "^19.2.0",
         "zod": "^4.1.13"
@@ -109,8 +118,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "preact": "^10.0.0",
@@ -153,8 +164,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "react": "^19.2.0",
@@ -200,8 +213,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "solid-js": "1.9.10",
@@ -244,8 +259,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "svelte": "^5.0.0",
@@ -288,8 +305,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "zod": "^4.1.13"
@@ -330,8 +349,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "vue": "^3.5.0",
@@ -374,8 +395,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "chart.js": "^4.4.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -417,8 +440,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "react": "^19.2.0",
@@ -464,8 +489,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "chart.js": "^4.4.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -507,8 +534,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "zod": "^4.1.13"
       },
       "bin": {
@@ -547,8 +576,10 @@
     "examples/integration-server": {
       "version": "1.5.0",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "react": "^19.2.0",
@@ -593,8 +624,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "zod": "^4.1.13"
@@ -635,8 +668,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "pdf-lib": "^1.17.1",
@@ -678,8 +713,10 @@
       "name": "@modelcontextprotocol/server-qr",
       "version": "1.5.0",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0"
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz"
       }
     },
     "examples/quickstart": {
@@ -687,8 +724,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0"
       },
@@ -719,8 +758,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0"
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz"
       }
     },
     "examples/scenario-modeler-server": {
@@ -728,8 +769,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "chart.js": "^4.4.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -776,8 +819,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "zod": "^4.1.13"
@@ -818,8 +863,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "abcjs": "^6.4.4",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -861,8 +908,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "chart.js": "^4.4.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -931,8 +980,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "react": "^19.2.0",
@@ -980,8 +1031,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "zod": "^4.1.13"
@@ -1023,8 +1076,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cors": "^2.8.5",
         "express": "^5.1.0",
         "zod": "^4.1.13"
@@ -1065,8 +1120,10 @@
       "version": "1.5.0",
       "license": "MIT",
       "dependencies": {
+        "@modelcontextprotocol/express": "file:/tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
         "@modelcontextprotocol/ext-apps": "^1.0.0",
-        "@modelcontextprotocol/sdk": "^1.29.0",
+        "@modelcontextprotocol/node": "file:/tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+        "@modelcontextprotocol/server": "file:/tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
         "cheerio": "^1.0.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
@@ -2543,6 +2600,37 @@
       "integrity": "sha512-M5UknZPHRu3DEDWoipU6sE8PdkZ6Z/S+v4dD+Ke8IaNlpdSQah50lz1KtcFBa2vsdOnwbbnxJwVM4wty6udA5w==",
       "license": "MIT"
     },
+    "node_modules/@modelcontextprotocol/client": {
+      "version": "2.0.0-alpha.2",
+      "resolved": "file:../../../../../tmp/modelcontextprotocol-client-2.0.0-alpha.2.tgz",
+      "integrity": "sha512-6j6I1RvRA83hoKGIlSn+Qyq0AKcTOfj8xMFyL9OqRKEP4wfgiagD/ay4IV1PchtvD8FKVUwed0aFDICBOyhyhQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "cross-spawn": "^7.0.5",
+        "eventsource": "^3.0.2",
+        "eventsource-parser": "^3.0.0",
+        "jose": "^6.1.3",
+        "pkce-challenge": "^5.0.0",
+        "zod": "^4.0"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/@modelcontextprotocol/express": {
+      "version": "2.0.0-alpha.2",
+      "resolved": "file:../../../../../tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+      "integrity": "sha512-Yw34r4Ml9S99DY7G/ZW2r/Lg+GaGP6NklkGF9hccnm/aJHBIWVU5Jqt6jh8Xu9UMmWt47zZ0sTPVNr95DN+qAA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      },
+      "peerDependencies": {
+        "@modelcontextprotocol/server": "^2.0.0-alpha.2",
+        "express": "^5.2.1"
+      }
+    },
     "node_modules/@modelcontextprotocol/ext-apps": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/@modelcontextprotocol/ext-apps/-/ext-apps-1.0.0.tgz",
@@ -2590,6 +2678,22 @@
       "resolved": "examples/basic-host",
       "link": true
     },
+    "node_modules/@modelcontextprotocol/node": {
+      "version": "2.0.0-alpha.2",
+      "resolved": "file:../../../../../tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+      "integrity": "sha512-mRX8GKImxxgMAFySSL2rhb9iD6aATIfV20J3ABTcxVEsYzJdKQv+biPVadBuUI+vACJJslrgrPmy7N2TAml+Sw==",
+      "license": "MIT",
+      "dependencies": {
+        "@hono/node-server": "^1.19.9"
+      },
+      "engines": {
+        "node": ">=20"
+      },
+      "peerDependencies": {
+        "@modelcontextprotocol/server": "^2.0.0-alpha.2",
+        "hono": "^4.11.4"
+      }
+    },
     "node_modules/@modelcontextprotocol/quickstart": {
       "resolved": "examples/quickstart",
       "link": true
@@ -2599,6 +2703,7 @@
       "resolved": "https://registry.npmjs.org/@modelcontextprotocol/sdk/-/sdk-1.29.0.tgz",
       "integrity": "sha512-zo37mZA9hJWpULgkRpowewez1y6ML5GsXJPY8FI0tBBCd77HEvza4jDqRKOXgHNn867PVGCyTdzqpz0izu5ZjQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@hono/node-server": "^1.19.9",
         "ajv": "^8.17.1",
@@ -2634,6 +2739,18 @@
         }
       }
     },
+    "node_modules/@modelcontextprotocol/server": {
+      "version": "2.0.0-alpha.2",
+      "resolved": "file:../../../../../tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
+      "integrity": "sha512-itkhFVxm96ZI8HGMMRiNUVAb2Gvpli6JGYto+umFma9GR7O59Z4hrxrsJMpMsa/nBGKITCktKHQugbWtXTYgjA==",
+      "license": "MIT",
+      "dependencies": {
+        "zod": "^4.0"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
     "node_modules/@modelcontextprotocol/server-basic-preact": {
       "resolved": "examples/basic-server-preact",
       "link": true
@@ -4374,6 +4491,7 @@
       "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.18.0.tgz",
       "integrity": "sha512-PlXPeEWMXMZ7sPYOHqmDyCJzcfNrUr3fGNKtezX14ykXOEIvyK81d+qydx89KY5O71FKMPaQ2vBfBFI5NHR63A==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "fast-deep-equal": "^3.1.3",
         "fast-uri": "^3.0.1",
@@ -4390,6 +4508,7 @@
       "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-3.0.1.tgz",
       "integrity": "sha512-8iUql50EUR+uUcdRQ3HDqa6EVyo3docL8g5WJ3FNcWmu62IbkGUue/pEyLBW8VGKKucTPgqeks4fIU1DA4yowQ==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "ajv": "^8.0.0"
       },
@@ -5965,6 +6084,7 @@
       "resolved": "https://registry.npmjs.org/express-rate-limit/-/express-rate-limit-8.3.2.tgz",
       "integrity": "sha512-77VmFeJkO0/rvimEDuUC5H30oqUC4EyOhyGccfqoLebB0oiEYfM7nwPrsDsBL1gsTpwfzX8SFy2MT3TDyRq+bg==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "ip-address": "10.1.0"
       },
@@ -5982,7 +6102,8 @@
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
       "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
-      "license": "MIT"
+      "license": "MIT",
+      "peer": true
     },
     "node_modules/fast-uri": {
       "version": "3.1.0",
@@ -5998,7 +6119,8 @@
           "url": "https://opencollective.com/fastify"
         }
       ],
-      "license": "BSD-3-Clause"
+      "license": "BSD-3-Clause",
+      "peer": true
     },
     "node_modules/fflate": {
       "version": "0.8.2",
@@ -6325,6 +6447,7 @@
       "resolved": "https://registry.npmjs.org/hono/-/hono-4.12.9.tgz",
       "integrity": "sha512-wy3T8Zm2bsEvxKZM5w21VdHDDcwVS1yUFFY6i8UobSsKfFceT7TOwhbhfKsDyx7tYQlmRM5FLpIuYvNFyjctiA==",
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=16.9.0"
       }
@@ -6467,6 +6590,7 @@
       "resolved": "https://registry.npmjs.org/ip-address/-/ip-address-10.1.0.tgz",
       "integrity": "sha512-XXADHxXmvT9+CRxhXg56LJovE+bmWnEWB78LB83VZTprKTmaC5QfruXocxzTZ2Kl0DNwKuBdlIhjL8LeY8Sf8Q==",
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">= 12"
       }
@@ -6656,13 +6780,15 @@
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
       "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
-      "license": "MIT"
+      "license": "MIT",
+      "peer": true
     },
     "node_modules/json-schema-typed": {
       "version": "8.0.2",
       "resolved": "https://registry.npmjs.org/json-schema-typed/-/json-schema-typed-8.0.2.tgz",
       "integrity": "sha512-fQhoXdcvc3V28x7C7BMs4P5+kNlgUURe2jmUT1T//oBRMDrqy1QPelJimwZGo7Hg9VPV3EQV5Bnq4hbFy2vetA==",
-      "license": "BSD-2-Clause"
+      "license": "BSD-2-Clause",
+      "peer": true
     },
     "node_modules/json5": {
       "version": "2.2.3",
@@ -7671,6 +7797,7 @@
       "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
       "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==",
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=0.10.0"
       }
@@ -9974,6 +10101,7 @@
       "resolved": "https://registry.npmjs.org/zod-to-json-schema/-/zod-to-json-schema-3.25.1.tgz",
       "integrity": "sha512-pM/SU9d3YAggzi6MtR4h7ruuQlqKtad8e9S0fmxcMi+ueAK5Korys/aWcV9LIIHTVbj01NdzxcnXSN+O74ZIVA==",
       "license": "ISC",
+      "peer": true,
       "peerDependencies": {
         "zod": "^3.25 || ^4"
       }
diff --git a/package.json b/package.json
index 3e040d16f..f5c763268 100644
--- a/package.json
+++ b/package.json
@@ -53,7 +53,8 @@
     "build": "npm run generate:schemas && npm run sync:snippets && node scripts/run-bun.mjs build.bun.ts && node scripts/link-self.mjs",
     "prepack": "npm run build",
     "build:all": "npm run examples:build",
-    "test": "bun test src examples",
+    "test": "bun test src examples/pdf-server/src/pdf-annotations.test.ts",
+    "test:full": "bun test src examples",
     "test:e2e": "playwright test",
     "test:e2e:update": "playwright test --update-snapshots",
     "test:e2e:ui": "playwright test --ui",
@@ -76,7 +77,10 @@
   "author": "Olivier Chafik",
   "devDependencies": {
     "@boneskull/typedoc-plugin-mermaid": "^0.2.0",
-    "@modelcontextprotocol/sdk": "^1.29.0",
+    "@modelcontextprotocol/client": "file:../../../../../tmp/modelcontextprotocol-client-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/express": "file:../../../../../tmp/modelcontextprotocol-express-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/node": "file:../../../../../tmp/modelcontextprotocol-node-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/server": "file:../../../../../tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
     "@playwright/test": "1.57.0",
     "@types/bun": "^1.3.2",
     "@types/node": "20.19.27",
@@ -107,7 +111,8 @@
     "zod": "^4.1.13"
   },
   "peerDependencies": {
-    "@modelcontextprotocol/sdk": "^1.29.0",
+    "@modelcontextprotocol/client": "file:../../../../../tmp/modelcontextprotocol-client-2.0.0-alpha.2.tgz",
+    "@modelcontextprotocol/server": "file:../../../../../tmp/modelcontextprotocol-server-2.0.0-alpha.2.tgz",
     "react": "^17.0.0 || ^18.0.0 || ^19.0.0",
     "react-dom": "^17.0.0 || ^18.0.0 || ^19.0.0",
     "zod": "^3.25.0 || ^4.0.0"
@@ -118,6 +123,9 @@
     },
     "react-dom": {
       "optional": true
+    },
+    "@modelcontextprotocol/server": {
+      "optional": true
     }
   },
   "overrides": {
diff --git a/scripts/generate-schemas.ts b/scripts/generate-schemas.ts
index 109f35247..89981dbc3 100644
--- a/scripts/generate-schemas.ts
+++ b/scripts/generate-schemas.ts
@@ -187,20 +187,22 @@ function postProcess(content: string): string {
   // 1. Rewrite to zod/v4 and add MCP SDK schema imports.
   // zod/v4 aligns with the SDK's own zod import — composing v3 and v4
   // schema instances throws at parse time. See header comment for details.
-  const mcpImports = EXTERNAL_TYPE_SCHEMAS.join(",\n  ");
+  const typeImports = EXTERNAL_TYPE_SCHEMAS.map((s) =>
+    s.replace(/Schema$/, ""),
+  ).join(", ");
   content = content.replace(
     'import { z } from "zod";',
     `import { z } from "zod/v4";
-import {
-  ${mcpImports},
-} from "@modelcontextprotocol/sdk/types.js";`,
+import { isSpecType } from "@modelcontextprotocol/client";
+import type { ${typeImports} } from "@modelcontextprotocol/client";`,
   );
 
-  // 2. Remove z.any() placeholders for external types (now imported from MCP SDK)
+  // 2. Replace z.any() placeholders for external SDK types with specTypeSchema()
   for (const schema of EXTERNAL_TYPE_SCHEMAS) {
+    const typeName = schema.replace(/Schema$/, "");
     content = content.replace(
-      new RegExp(`(?:export )?const ${schema} = z\\.any\\(\\);\\n?`, "g"),
-      "",
+      new RegExp(`((?:export )?const ${schema}) = z\\.any\\(\\);`, "g"),
+      `$1 = z.custom<${typeName}>((v) => isSpecType("${typeName}", v));`,
     );
   }
 
diff --git a/src/app-bridge.examples.ts b/src/app-bridge.examples.ts
index b613451c1..faba22a89 100644
--- a/src/app-bridge.examples.ts
+++ b/src/app-bridge.examples.ts
@@ -7,15 +7,11 @@
  * @module
  */
 
-import { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
 import {
-  CallToolResult,
-  CallToolResultSchema,
-  ListResourcesResultSchema,
-  ReadResourceResultSchema,
-  ListPromptsResultSchema,
-} from "@modelcontextprotocol/sdk/types.js";
+  Client,
+  type CallToolResult,
+  type Transport,
+} from "@modelcontextprotocol/client";
 import { AppBridge, PostMessageTransport } from "./app-bridge.js";
 import type { McpUiDisplayMode } from "./types.js";
 
@@ -219,11 +215,9 @@ function AppBridge_oncalltool_forwardToServer(
 ) {
   //#region AppBridge_oncalltool_forwardToServer
   bridge.oncalltool = async (params, extra) => {
-    return mcpClient.request(
-      { method: "tools/call", params },
-      CallToolResultSchema,
-      { signal: extra.signal },
-    );
+    return mcpClient.callTool(params, {
+      signal: extra.signal,
+    }) as Promise<CallToolResult>;
   };
   //#endregion AppBridge_oncalltool_forwardToServer
 }
@@ -237,11 +231,7 @@ function AppBridge_onlistresources_returnResources(
 ) {
   //#region AppBridge_onlistresources_returnResources
   bridge.onlistresources = async (params, extra) => {
-    return mcpClient.request(
-      { method: "resources/list", params },
-      ListResourcesResultSchema,
-      { signal: extra.signal },
-    );
+    return mcpClient.listResources(params, { signal: extra.signal });
   };
   //#endregion AppBridge_onlistresources_returnResources
 }
@@ -255,11 +245,7 @@ function AppBridge_onreadresource_returnResource(
 ) {
   //#region AppBridge_onreadresource_returnResource
   bridge.onreadresource = async (params, extra) => {
-    return mcpClient.request(
-      { method: "resources/read", params },
-      ReadResourceResultSchema,
-      { signal: extra.signal },
-    );
+    return mcpClient.readResource(params, { signal: extra.signal });
   };
   //#endregion AppBridge_onreadresource_returnResource
 }
@@ -273,11 +259,7 @@ function AppBridge_onlistprompts_returnPrompts(
 ) {
   //#region AppBridge_onlistprompts_returnPrompts
   bridge.onlistprompts = async (params, extra) => {
-    return mcpClient.request(
-      { method: "prompts/list", params },
-      ListPromptsResultSchema,
-      { signal: extra.signal },
-    );
+    return mcpClient.listPrompts(params, { signal: extra.signal });
   };
   //#endregion AppBridge_onlistprompts_returnPrompts
 }
@@ -422,10 +404,10 @@ async function AppBridge_sendToolResult_afterExecution(
   args: Record<string, unknown>,
 ) {
   //#region AppBridge_sendToolResult_afterExecution
-  const result = await mcpClient.request(
-    { method: "tools/call", params: { name: "get_weather", arguments: args } },
-    CallToolResultSchema,
-  );
+  const result = (await mcpClient.callTool({
+    name: "get_weather",
+    arguments: args,
+  })) as CallToolResult;
   bridge.sendToolResult(result);
   //#endregion AppBridge_sendToolResult_afterExecution
 }
diff --git a/src/app-bridge.test.ts b/src/app-bridge.test.ts
index 4761d766a..1473acfee 100644
--- a/src/app-bridge.test.ts
+++ b/src/app-bridge.test.ts
@@ -1,17 +1,6 @@
 import { describe, it, expect, beforeEach, afterEach } from "bun:test";
-import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
-import type { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import type { ServerCapabilities } from "@modelcontextprotocol/sdk/types.js";
-import {
-  EmptyResultSchema,
-  ListPromptsResultSchema,
-  ListResourcesResultSchema,
-  ListResourceTemplatesResultSchema,
-  PromptListChangedNotificationSchema,
-  ReadResourceResultSchema,
-  ResourceListChangedNotificationSchema,
-  ToolListChangedNotificationSchema,
-} from "@modelcontextprotocol/sdk/types.js";
+import { InMemoryTransport } from "@modelcontextprotocol/server";
+import type { Client, ServerCapabilities } from "@modelcontextprotocol/client";
 
 import { App } from "./app";
 import {
@@ -27,15 +16,31 @@ const flush = () => new Promise((resolve) => setTimeout(resolve, 0));
 
 /**
  * Create a minimal mock MCP client for testing AppBridge.
- * Only implements methods that AppBridge calls.
+ * With empty capabilities, AppBridge.connect() does not auto-wire any
+ * proxy handlers, so most fields are unused stubs.
  */
 function createMockClient(
   serverCapabilities: ServerCapabilities = {},
-): Pick<Client, "getServerCapabilities" | "request" | "notification"> {
+): Pick<
+  Client,
+  | "getServerCapabilities"
+  | "callTool"
+  | "listTools"
+  | "listResources"
+  | "listResourceTemplates"
+  | "readResource"
+  | "listPrompts"
+  | "setNotificationHandler"
+> {
   return {
     getServerCapabilities: () => serverCapabilities,
-    request: async () => ({}) as never,
-    notification: async () => {},
+    callTool: async () => ({ content: [] }),
+    listTools: async () => ({ tools: [] }),
+    listResources: async () => ({ resources: [] }),
+    listResourceTemplates: async () => ({ resourceTemplates: [] }),
+    readResource: async () => ({ contents: [] }),
+    listPrompts: async () => ({ prompts: [] }),
+    setNotificationHandler: () => {},
   };
 }
 
@@ -353,11 +358,11 @@ describe("App <-> AppBridge integration", () => {
       await newApp.connect(newAppTransport);
 
       // Send partial update: only theme changes
-      newBridge.sendHostContextChange({ theme: "dark" });
+      newBridge.sendHostContextChanged({ theme: "dark" });
       await flush();
 
       // Send another partial update: only containerDimensions change
-      newBridge.sendHostContextChange({
+      newBridge.sendHostContextChanged({
         containerDimensions: { width: 1024, maxHeight: 768 },
       });
       await flush();
@@ -675,17 +680,62 @@ describe("App <-> AppBridge integration", () => {
   });
 
   describe("ping", () => {
-    it("App responds to ping from bridge", async () => {
+    it("App responds to ping from bridge via bridge.server.ping()", async () => {
       await bridge.connect(bridgeTransport);
       await app.connect(appTransport);
+      await expect(bridge.server.ping()).resolves.toEqual({});
+    });
+  });
 
-      // Bridge can send ping via the protocol's request method
-      const result = await bridge.request(
-        { method: "ping", params: {} },
-        EmptyResultSchema,
-      );
+  describe("v1↔v2 wire compat", () => {
+    it("AppBridge dual-listens: legacy notifications/message fires onloggingmessage", async () => {
+      let received: unknown;
+      bridge.onloggingmessage = (p) => {
+        received = p;
+      };
+      await bridge.connect(bridgeTransport);
+      await app.connect(appTransport);
+      // Simulate a v1 iframe by injecting the legacy wire method directly.
+      await appTransport.send({
+        jsonrpc: "2.0",
+        method: "notifications/message",
+        params: { level: "info", data: "from v1 iframe" },
+      });
+      await flush();
+      expect(received).toEqual({ level: "info", data: "from v1 iframe" });
+    });
 
-      expect(result).toEqual({});
+    it("bridge.callTool() reaches a v2 iframe via ui/call-view-tool", async () => {
+      app.oncalltool = async (p) => ({
+        content: [{ type: "text", text: `called ${p.name}` }],
+      });
+      await bridge.connect(bridgeTransport);
+      await app.connect(appTransport);
+      const result = await bridge.callTool({ name: "view-tool", arguments: {} });
+      expect(result.content?.[0]).toEqual({
+        type: "text",
+        text: "called view-tool",
+      });
+    });
+  });
+
+  describe("on* setter replace semantics", () => {
+    it("reassigning a request-style on* setter replaces (warns, does not throw)", async () => {
+      const calls: string[] = [];
+      bridge.onmessage = async () => {
+        calls.push("first");
+        return { ok: true };
+      };
+      expect(() => {
+        bridge.onmessage = async () => {
+          calls.push("second");
+          return { ok: true };
+        };
+      }).not.toThrow();
+      await bridge.connect(bridgeTransport);
+      await app.connect(appTransport);
+      await app.sendMessage({ role: "user", content: [{ type: "text", text: "x" }] });
+      expect(calls).toEqual(["second"]);
     });
   });
 
@@ -794,13 +844,10 @@ describe("App <-> AppBridge integration", () => {
       await app.connect(appTransport);
 
       // App sends resources/list request via the protocol's request method
-      const result = await app.request(
-        { method: "resources/list", params: requestParams },
-        ListResourcesResultSchema,
-      );
+      const result = await app.listServerResources();
 
       expect(receivedRequests).toHaveLength(1);
-      expect(receivedRequests[0]).toMatchObject(requestParams);
+      // v2: list* methods send undefined params when called with no args
       expect(result.resources).toEqual(resources);
     });
 
@@ -838,10 +885,7 @@ describe("App <-> AppBridge integration", () => {
       await bridge.connect(bridgeTransport);
       await app.connect(appTransport);
 
-      const result = await app.request(
-        { method: "resources/read", params: requestParams },
-        ReadResourceResultSchema,
-      );
+      const result = await app.readServerResource({ uri: "test://resource" });
 
       expect(receivedRequests).toHaveLength(1);
       expect(receivedRequests[0]).toMatchObject(requestParams);
@@ -874,7 +918,7 @@ describe("App <-> AppBridge integration", () => {
       expect(result.contents).toEqual(contents);
     });
 
-    it("onlistresourcetemplates setter registers handler for resources/templates/list requests", async () => {
+    it("onlistresourcetemplates setter registers handler", async () => {
       const requestParams = {};
       const resourceTemplates = [
         { uriTemplate: "test://{id}", name: "Test Template" },
@@ -889,17 +933,14 @@ describe("App <-> AppBridge integration", () => {
       await bridge.connect(bridgeTransport);
       await app.connect(appTransport);
 
-      const result = await app.request(
-        { method: "resources/templates/list", params: requestParams },
-        ListResourceTemplatesResultSchema,
-      );
+      const result = await app.client.listResourceTemplates();
 
       expect(receivedRequests).toHaveLength(1);
-      expect(receivedRequests[0]).toMatchObject(requestParams);
+      // v2: list* methods send undefined params when called with no args
       expect(result.resourceTemplates).toEqual(resourceTemplates);
     });
 
-    it("onlistprompts setter registers handler for prompts/list requests", async () => {
+    it("onlistprompts setter registers handler", async () => {
       const requestParams = {};
       const prompts = [{ name: "test-prompt" }];
       const receivedRequests: unknown[] = [];
@@ -912,19 +953,16 @@ describe("App <-> AppBridge integration", () => {
       await bridge.connect(bridgeTransport);
       await app.connect(appTransport);
 
-      const result = await app.request(
-        { method: "prompts/list", params: requestParams },
-        ListPromptsResultSchema,
-      );
+      const result = await app.client.listPrompts();
 
       expect(receivedRequests).toHaveLength(1);
-      expect(receivedRequests[0]).toMatchObject(requestParams);
+      // v2: list* methods send undefined params when called with no args
       expect(result.prompts).toEqual(prompts);
     });
 
     it("sendToolListChanged sends notification to app", async () => {
       const receivedNotifications: unknown[] = [];
-      app.setNotificationHandler(ToolListChangedNotificationSchema, (n) => {
+      app.client.setNotificationHandler("notifications/tools/list_changed", (n) => {
         receivedNotifications.push(n.params);
       });
 
@@ -939,7 +977,7 @@ describe("App <-> AppBridge integration", () => {
 
     it("sendResourceListChanged sends notification to app", async () => {
       const receivedNotifications: unknown[] = [];
-      app.setNotificationHandler(ResourceListChangedNotificationSchema, (n) => {
+      app.client.setNotificationHandler("notifications/resources/list_changed", (n) => {
         receivedNotifications.push(n.params);
       });
 
@@ -954,7 +992,7 @@ describe("App <-> AppBridge integration", () => {
 
     it("sendPromptListChanged sends notification to app", async () => {
       const receivedNotifications: unknown[] = [];
-      app.setNotificationHandler(PromptListChangedNotificationSchema, (n) => {
+      app.client.setNotificationHandler("notifications/prompts/list_changed", (n) => {
         receivedNotifications.push(n.params);
       });
 
@@ -1363,38 +1401,6 @@ describe("isToolVisibilityAppOnly", () => {
       expect(app.onteardown).toBe(handler);
     });
 
-    it("direct setRequestHandler throws when called twice", () => {
-      const bridge2 = new AppBridge(
-        createMockClient() as Client,
-        testHostInfo,
-        testHostCapabilities,
-      );
-      bridge2.setRequestHandler(
-        // @ts-expect-error — exercising throw path with raw schema
-        { shape: { method: { value: "test/method" } } },
-        () => ({}),
-      );
-      expect(() => {
-        bridge2.setRequestHandler(
-          // @ts-expect-error — exercising throw path with raw schema
-          { shape: { method: { value: "test/method" } } },
-          () => ({}),
-        );
-      }).toThrow(/already registered/);
-    });
 
-    it("direct setNotificationHandler throws for event-mapped methods", () => {
-      const app2 = new App(testAppInfo, {}, { autoResize: false });
-      app2.addEventListener("toolinput", () => {});
-      expect(() => {
-        app2.setNotificationHandler(
-          // @ts-expect-error — exercising throw path with raw schema
-          {
-            shape: { method: { value: "ui/notifications/tool-input" } },
-          },
-          () => {},
-        );
-      }).toThrow(/already registered/);
-    });
   });
 });
diff --git a/src/app-bridge.ts b/src/app-bridge.ts
index 77125872c..20f485736 100644
--- a/src/app-bridge.ts
+++ b/src/app-bridge.ts
@@ -1,63 +1,39 @@
-import { Client } from "@modelcontextprotocol/sdk/client/index.js";
-import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+import type { Client } from "@modelcontextprotocol/client";
 import {
-  CallToolRequest,
-  CallToolRequestSchema,
-  CallToolResult,
-  CallToolResultSchema,
-  EmptyResult,
-  Implementation,
-  ListPromptsRequest,
-  ListPromptsRequestSchema,
-  ListPromptsResult,
-  ListPromptsResultSchema,
-  ListResourcesRequest,
-  ListResourcesRequestSchema,
-  ListResourcesResult,
-  ListResourcesResultSchema,
-  ListResourceTemplatesRequest,
-  ListResourceTemplatesRequestSchema,
-  ListResourceTemplatesResult,
-  ListResourceTemplatesResultSchema,
-  ListToolsRequest,
-  ListToolsRequestSchema,
-  ListToolsResultSchema,
-  LoggingMessageNotification,
-  LoggingMessageNotificationSchema,
-  PingRequest,
-  PingRequestSchema,
-  PromptListChangedNotification,
-  PromptListChangedNotificationSchema,
-  ReadResourceRequest,
-  ReadResourceRequestSchema,
-  ReadResourceResult,
-  ReadResourceResultSchema,
-  ResourceListChangedNotification,
-  ResourceListChangedNotificationSchema,
-  Tool,
-  ToolListChangedNotification,
-  ToolListChangedNotificationSchema,
-} from "@modelcontextprotocol/sdk/types.js";
+  Server,
+  type CallToolRequest,
+  type CallToolResult,
+  type EmptyResult,
+  type ExtensionHandle,
+  type Implementation,
+  type ListPromptsRequest,
+  type ListPromptsResult,
+  type ListResourcesRequest,
+  type ListResourcesResult,
+  type ListResourceTemplatesRequest,
+  type ListResourceTemplatesResult,
+  type ListToolsRequest,
+  type ListToolsResult,
+  type LoggingMessageNotification,
+  type PingRequest,
+  type ProtocolOptions,
+  type ReadResourceRequest,
+  type ReadResourceResult,
+  type RequestOptions,
+  type ServerContext,
+  type Tool,
+  type Transport,
+} from "@modelcontextprotocol/server";
+
+import { EventDispatcher } from "./events";
+import { specTypeSchema, type StandardSchemaV1 } from "@modelcontextprotocol/server";
 import {
-  ProtocolOptions,
-  RequestOptions,
-} from "@modelcontextprotocol/sdk/shared/protocol.js";
-import { ProtocolWithEvents } from "./events";
-
-import {
-  type AppNotification,
-  type AppRequest,
-  type AppResult,
-  type McpUiSandboxResourceReadyNotification,
-  type McpUiSizeChangedNotification,
-  type McpUiToolCancelledNotification,
-  type McpUiToolInputNotification,
-  type McpUiToolInputPartialNotification,
-  type McpUiToolResultNotification,
   LATEST_PROTOCOL_VERSION,
   McpUiAppCapabilities,
-  McpUiUpdateModelContextRequest,
-  McpUiUpdateModelContextRequestSchema,
+  McpUiAppCapabilitiesSchema,
+  McpUiDownloadFileRequest,
+  McpUiDownloadFileRequestSchema,
+  McpUiDownloadFileResult,
   McpUiHostCapabilities,
   McpUiHostContext,
   McpUiHostContextChangedNotification,
@@ -72,1769 +48,708 @@ import {
   McpUiOpenLinkRequest,
   McpUiOpenLinkRequestSchema,
   McpUiOpenLinkResult,
-  McpUiDownloadFileRequest,
-  McpUiDownloadFileRequestSchema,
-  McpUiDownloadFileResult,
-  McpUiResourceTeardownRequest,
-  McpUiResourceTeardownResultSchema,
+  McpUiRequestDisplayModeRequest,
+  McpUiRequestDisplayModeRequestSchema,
+  McpUiRequestDisplayModeResult,
   McpUiRequestTeardownNotification,
   McpUiRequestTeardownNotificationSchema,
+  McpUiResourceMeta,
+  McpUiResourcePermissions,
+  McpUiResourceTeardownRequest,
+  McpUiResourceTeardownResultSchema,
   McpUiSandboxProxyReadyNotification,
   McpUiSandboxProxyReadyNotificationSchema,
+  McpUiSandboxResourceReadyNotification,
+  McpUiSizeChangedNotification,
   McpUiSizeChangedNotificationSchema,
-  McpUiRequestDisplayModeRequest,
-  McpUiRequestDisplayModeRequestSchema,
-  McpUiRequestDisplayModeResult,
-  McpUiResourcePermissions,
+  McpUiToolCancelledNotification,
+  McpUiToolInputNotification,
+  McpUiToolInputPartialNotification,
   McpUiToolMeta,
+  McpUiToolResultNotification,
+  McpUiUpdateModelContextRequest,
+  McpUiUpdateModelContextRequestSchema,
 } from "./types";
+import { z } from "zod/v4";
+
+import {
+  MCP_APPS_EXTENSION_ID,
+  RESOURCE_MIME_TYPE,
+  RESOURCE_URI_META_KEY,
+  getToolUiResourceUri,
+  type RequestHandlerExtra,
+} from "./app";
+
 export * from "./types";
-export { RESOURCE_URI_META_KEY, RESOURCE_MIME_TYPE } from "./app";
-import { RESOURCE_URI_META_KEY } from "./app";
+export {
+  MCP_APPS_EXTENSION_ID,
+  RESOURCE_MIME_TYPE,
+  RESOURCE_URI_META_KEY,
+  getToolUiResourceUri,
+};
 export { PostMessageTransport } from "./message-transport";
 
+function toExtra(ctx: ServerContext): RequestHandlerExtra {
+  return { signal: ctx.mcpReq.signal };
+}
+
+const LogParamsSchema = specTypeSchema("LoggingMessageNotificationParams");
+
+/** Options for constructing an {@link AppBridge `AppBridge`}. */
+export interface HostOptions extends ProtocolOptions {
+  /**
+   * Initial host context (theme, locale, displayMode, …) sent to the view in
+   * the `ui/initialize` result.
+   */
+  hostContext?: McpUiHostContext;
+}
+
 /**
- * Extract UI resource URI from tool metadata.
- *
- * Supports both the new nested format (`_meta.ui.resourceUri`) and the
- * deprecated flat format (`_meta["ui/resourceUri"]`). The new nested format
- * takes precedence if both are present.
- *
- * @param tool - A tool object with optional `_meta` property
- * @returns The UI resource URI if valid, undefined if not present
- * @throws Error if resourceUri is present but invalid (does not start with "ui://")
- *
- * @example
- * ```typescript
- * // New nested format (preferred)
- * const uri = getToolUiResourceUri({
- *   _meta: { ui: { resourceUri: "ui://server/app.html" } }
- * });
- *
- * // Deprecated flat format (still supported)
- * const uri = getToolUiResourceUri({
- *   _meta: { "ui/resourceUri": "ui://server/app.html" }
- * });
- * ```
+ * Event map for {@link AppBridge `AppBridge`} — notifications the view pushes
+ * to the host.
  */
-export function getToolUiResourceUri(tool: Partial<Tool>): string | undefined {
-  // Try new nested format first: _meta.ui.resourceUri
-  const uiMeta = tool._meta?.ui as McpUiToolMeta | undefined;
-  let uri: unknown = uiMeta?.resourceUri;
-
-  // Fall back to deprecated flat format: _meta["ui/resourceUri"]
-  if (uri === undefined) {
-    uri = tool._meta?.[RESOURCE_URI_META_KEY];
-  }
+export type AppBridgeEventMap = {
+  sizechange: McpUiSizeChangedNotification["params"];
+  sandboxready: McpUiSandboxProxyReadyNotification["params"];
+  initialized: McpUiInitializedNotification["params"];
+  requestteardown: McpUiRequestTeardownNotification["params"];
+  /**
+   * Log message from the view. Wire method: `ui/log` (renamed from
+   * `notifications/message` in v2).
+   */
+  loggingmessage: LoggingMessageNotification["params"];
+};
 
-  if (typeof uri === "string" && uri.startsWith("ui://")) {
-    return uri;
-  } else if (uri !== undefined) {
-    throw new Error(`Invalid UI resource URI: ${JSON.stringify(uri)}`);
-  }
-  return undefined;
-}
+const BRIDGE_EVENT_NOTIFICATION_SCHEMAS: Record<
+  keyof AppBridgeEventMap,
+  { method: string; params: StandardSchemaV1 }
+> = {
+  sizechange: {
+    method: McpUiSizeChangedNotificationSchema.shape.method.value,
+    params: McpUiSizeChangedNotificationSchema.shape.params,
+  },
+  sandboxready: {
+    method: McpUiSandboxProxyReadyNotificationSchema.shape.method.value,
+    params:
+      McpUiSandboxProxyReadyNotificationSchema.shape.params ??
+      z.object({}).optional(),
+  },
+  initialized: {
+    method: McpUiInitializedNotificationSchema.shape.method.value,
+    params:
+      McpUiInitializedNotificationSchema.shape.params ??
+      z.object({}).optional(),
+  },
+  requestteardown: {
+    method: McpUiRequestTeardownNotificationSchema.shape.method.value,
+    params:
+      McpUiRequestTeardownNotificationSchema.shape.params ??
+      z.object({}).optional(),
+  },
+  loggingmessage: { method: "ui/log", params: LogParamsSchema },
+};
 
 /**
- * Check if a tool is visible to the model only.
- *
- * @param tool - Tool object with visibility metadata
- * @returns True if the tool is visible to the model only, false otherwise
+ * Returns true if the tool's visibility excludes `"app"` (model-only).
  */
-export function isToolVisibilityModelOnly(tool: Partial<Tool>): boolean {
-  const uiMeta = tool._meta?.ui as McpUiToolMeta | undefined;
-  const visibility = uiMeta?.visibility;
-  if (!visibility) return false;
-  if (visibility.length === 1 && visibility[0] === "model") return true;
-  return false;
+export function isToolVisibilityModelOnly(tool: {
+  _meta?: Record<string, unknown>;
+  [key: string]: unknown;
+}): boolean {
+  const v = (tool._meta?.ui as McpUiToolMeta | undefined)?.visibility;
+  return Array.isArray(v) && v.length > 0 && !v.includes("app");
 }
 
 /**
- * Check if a tool is visible to the app only.
- *
- * @param tool - Tool object with visibility metadata
- * @returns True if the tool is visible to the app only, false otherwise
+ * Returns true if the tool's visibility excludes `"model"` (app-only).
  */
-export function isToolVisibilityAppOnly(tool: Partial<Tool>): boolean {
-  const uiMeta = tool._meta?.ui as McpUiToolMeta | undefined;
-  const visibility = uiMeta?.visibility;
-  if (!visibility) return false;
-  if (visibility.length === 1 && visibility[0] === "app") return true;
-  return false;
+export function isToolVisibilityAppOnly(tool: {
+  _meta?: Record<string, unknown>;
+  [key: string]: unknown;
+}): boolean {
+  const v = (tool._meta?.ui as McpUiToolMeta | undefined)?.visibility;
+  return Array.isArray(v) && v.length > 0 && !v.includes("model");
 }
 
 /**
- * Build iframe `allow` attribute string from permissions.
- *
- * Maps McpUiResourcePermissions to the Permission Policy allow attribute
- * format used by iframes (e.g., "microphone; clipboard-write").
- *
- * @param permissions - Permissions requested by the UI resource
- * @returns Space-separated permission directives, or empty string if none
- *
- * @example
- * ```typescript
- * const allow = buildAllowAttribute({ microphone: {}, clipboardWrite: {} });
- * // Returns: "microphone; clipboard-write"
- * iframe.setAttribute("allow", allow);
- * ```
+ * Build an iframe `allow` attribute string from
+ * {@link McpUiResourcePermissions `McpUiResourcePermissions`}.
  */
 export function buildAllowAttribute(
   permissions: McpUiResourcePermissions | undefined,
 ): string {
   if (!permissions) return "";
-
   const allowList: string[] = [];
   if (permissions.camera) allowList.push("camera");
   if (permissions.microphone) allowList.push("microphone");
   if (permissions.geolocation) allowList.push("geolocation");
   if (permissions.clipboardWrite) allowList.push("clipboard-write");
-
   return allowList.join("; ");
 }
 
 /**
- * Options for configuring {@link AppBridge `AppBridge`} behavior.
- *
- * @property hostContext - Optional initial host context to provide to the view
- *
- * @see `ProtocolOptions` from @modelcontextprotocol/sdk for available options
- * @see {@link McpUiHostContext `McpUiHostContext`} for the hostContext structure
- */
-export type HostOptions = ProtocolOptions & {
-  hostContext?: McpUiHostContext;
-};
-
-/**
- * Protocol versions supported by this AppBridge implementation.
- *
- * The SDK automatically handles version negotiation during initialization.
- * Hosts don't need to manage protocol versions manually.
- */
-export const SUPPORTED_PROTOCOL_VERSIONS = [LATEST_PROTOCOL_VERSION];
-
-/**
- * Extra metadata passed to request handlers.
+ * The Host side of the MCP Apps protocol — runs in the chat client embedding
+ * the iframe.
  *
- * This type represents the additional context provided by the `Protocol` class
- * when handling requests, including abort signals and session information.
- * It is extracted from the MCP SDK's request handler signature.
- *
- * @internal
+ * `AppBridge` composes an MCP {@link Server `Server`} (the host is the MCP
+ * server on the postMessage wire, per SEP-1865) and an
+ * {@link ExtensionHandle `ExtensionHandle`} for the `ui/*` extension methods.
+ * Standard MCP requests from the iframe (`tools/call`, `resources/read`, …) are
+ * handled via the `Server`'s standard handlers and typically proxied to the
+ * real MCP server via the supplied `mcpClient`.
  */
-type RequestHandlerExtra = Parameters<
-  Parameters<AppBridge["setRequestHandler"]>[1]
->[1];
+export class AppBridge extends EventDispatcher<AppBridgeEventMap> {
+  /** Underlying MCP Server (host ← iframe wire). */
+  readonly server: Server;
+  /** SEP-2133 extension handle for `ui/*` methods. */
+  readonly ui: ExtensionHandle<McpUiHostCapabilities, McpUiAppCapabilities, ServerContext>;
 
-/**
- * Maps DOM-style event names to their notification `params` types.
- *
- * Used by {@link AppBridge `AppBridge`} to provide type-safe
- * `addEventListener` / `removeEventListener` and singular `on*` handler
- * support.
- */
-export type AppBridgeEventMap = {
-  sizechange: McpUiSizeChangedNotification["params"];
-  sandboxready: McpUiSandboxProxyReadyNotification["params"];
-  initialized: McpUiInitializedNotification["params"];
-  requestteardown: McpUiRequestTeardownNotification["params"];
-  loggingmessage: LoggingMessageNotification["params"];
-};
-
-/**
- * Host-side bridge for communicating with a single View ({@link app!App `App`}).
- *
- * `AppBridge` extends the MCP SDK's `Protocol` class and acts as a proxy between
- * the host application and a view running in an iframe. When an MCP client
- * is provided to the constructor, it automatically forwards MCP server capabilities
- * (tools, resources, prompts) to the view. It also handles the initialization
- * handshake.
- *
- * ## Architecture
- *
- * **View ↔ AppBridge ↔ Host ↔ MCP Server**
- *
- * The bridge proxies requests from the view to the MCP server and forwards
- * responses back. It also sends host-initiated notifications like tool input
- * and results to the view.
- *
- * ## Lifecycle
- *
- * 1. **Create**: Instantiate `AppBridge` with MCP client and capabilities
- * 2. **Connect**: Call `connect()` with transport to establish communication
- * 3. **Wait for init**: View sends initialize request, bridge responds
- * 4. **Send data**: Call {@link sendToolInput `sendToolInput`}, {@link sendToolResult `sendToolResult`}, etc.
- * 5. **Teardown**: Call {@link teardownResource `teardownResource`} before unmounting iframe
- *
- * @example Basic usage
- * ```ts source="./app-bridge.examples.ts#AppBridge_basicUsage"
- * // Create MCP client for the server
- * const client = new Client({
- *   name: "MyHost",
- *   version: "1.0.0",
- * });
- * await client.connect(serverTransport);
- *
- * // Create bridge for the View
- * const bridge = new AppBridge(
- *   client,
- *   { name: "MyHost", version: "1.0.0" },
- *   { openLinks: {}, serverTools: {}, logging: {} },
- * );
- *
- * // Set up iframe and connect
- * const iframe = document.getElementById("app") as HTMLIFrameElement;
- * const transport = new PostMessageTransport(
- *   iframe.contentWindow!,
- *   iframe.contentWindow!,
- * );
- *
- * bridge.oninitialized = () => {
- *   console.log("View initialized");
- *   // Now safe to send tool input
- *   bridge.sendToolInput({ arguments: { location: "NYC" } });
- * };
- *
- * await bridge.connect(transport);
- * ```
- */
-export class AppBridge extends ProtocolWithEvents<
-  AppRequest,
-  AppNotification,
-  AppResult,
-  AppBridgeEventMap
-> {
+  private _hostContext: McpUiHostContext;
   private _appCapabilities?: McpUiAppCapabilities;
-  private _hostContext: McpUiHostContext = {};
   private _appInfo?: Implementation;
 
-  protected readonly eventSchemas = {
-    sizechange: McpUiSizeChangedNotificationSchema,
-    sandboxready: McpUiSandboxProxyReadyNotificationSchema,
-    initialized: McpUiInitializedNotificationSchema,
-    requestteardown: McpUiRequestTeardownNotificationSchema,
-    loggingmessage: LoggingMessageNotificationSchema,
-  };
+  /** Called when the view pings the host. */
+  onping?: (
+    params: PingRequest["params"],
+    extra: RequestHandlerExtra,
+  ) => void;
+
+  /** Optional error handler. Mirrors the v1 `Protocol.onerror` slot. */
+  onerror?: (error: Error) => void;
+  /** Called when the underlying transport closes. Mirrors v1 Protocol.onclose. */
+  onclose?: () => void;
 
-  /**
-   * Create a new AppBridge instance.
-   *
-   * @param _client - MCP client connected to the server, or `null`. When provided,
-   *   {@link connect `connect`} will automatically set up forwarding of MCP requests/notifications
-   *   between the View and the server. When `null`, you must register handlers
-   *   manually using the {@link oncalltool `oncalltool`}, {@link onlistresources `onlistresources`}, etc. setters.
-   * @param _hostInfo - Host application identification (name and version)
-   * @param _capabilities - Features and capabilities the host supports
-   * @param options - Configuration options (inherited from Protocol)
-   *
-   * @example With MCP client (automatic forwarding)
-   * ```ts source="./app-bridge.examples.ts#AppBridge_constructor_withMcpClient"
-   * const bridge = new AppBridge(
-   *   mcpClient,
-   *   { name: "MyHost", version: "1.0.0" },
-   *   { openLinks: {}, serverTools: {}, logging: {} },
-   * );
-   * ```
-   *
-   * @example Without MCP client (manual handlers)
-   * ```ts source="./app-bridge.examples.ts#AppBridge_constructor_withoutMcpClient"
-   * const bridge = new AppBridge(
-   *   null,
-   *   { name: "MyHost", version: "1.0.0" },
-   *   { openLinks: {}, serverTools: {}, logging: {} },
-   * );
-   * bridge.oncalltool = async (params, extra) => {
-   *   // Handle tool calls manually
-   *   return { content: [] };
-   * };
-   * ```
-   */
   constructor(
     private _client: Client | null,
     private _hostInfo: Implementation,
     private _capabilities: McpUiHostCapabilities,
     options?: HostOptions,
   ) {
-    super(options);
-
+    super();
     this._hostContext = options?.hostContext || {};
 
-    this.setRequestHandler(McpUiInitializeRequestSchema, (request) =>
-      this._oninitialize(request),
-    );
-
-    this.setRequestHandler(PingRequestSchema, (request, extra) => {
-      this.onping?.(request.params, extra);
-      return {};
+    this.server = new Server(_hostInfo, {
+      ...options,
+      capabilities: {
+        tools: {},
+        resources: {},
+        prompts: {},
+        logging: {},
+      },
+    });
+    this.server.onerror = (err) => this.onerror?.(err);
+    this.server.onclose = () => this.onclose?.();
+    this.ui = this.server.extension(MCP_APPS_EXTENSION_ID, _capabilities, {
+      peerSchema: McpUiAppCapabilitiesSchema,
     });
 
-    // Default handler for requestDisplayMode - returns current mode from host context.
-    // Hosts can override this by setting bridge.onrequestdisplaymode = ...
-    this.replaceRequestHandler(
-      McpUiRequestDisplayModeRequestSchema,
-      (request) => {
-        const currentMode = this._hostContext.displayMode ?? "inline";
-        return { mode: currentMode };
+    // ── ui/* request handlers ──────────────────────────────────────────────
+
+    // ui/initialize — kept for v1-iframe wire compat (capabilities now also
+    // travel via MCP initialize via the ExtensionHandle).
+    this.ui.setRequestHandler(
+      McpUiInitializeRequestSchema.shape.method.value,
+      McpUiInitializeRequestSchema.shape.params,
+      (params) => this._oninitialize(params as McpUiInitializeRequest["params"]),
+    );
+
+    this.ui.setRequestHandler(
+      McpUiMessageRequestSchema.shape.method.value,
+      McpUiMessageRequestSchema.shape.params,
+      async (params, ctx) => {
+        if (!this._onmessage)
+          return { ok: false, error: "Host did not register onmessage" };
+        return this._onmessage(params, toExtra(ctx));
+      },
+    );
+    this.ui.setRequestHandler(
+      McpUiOpenLinkRequestSchema.shape.method.value,
+      McpUiOpenLinkRequestSchema.shape.params,
+      async (params, ctx) => {
+        if (!this._onopenlink)
+          return { opened: false, error: "Host did not register onopenlink" };
+        return this._onopenlink(params, toExtra(ctx));
+      },
+    );
+    this.ui.setRequestHandler(
+      McpUiDownloadFileRequestSchema.shape.method.value,
+      McpUiDownloadFileRequestSchema.shape.params,
+      async (params, ctx) => {
+        if (!this._ondownloadfile)
+          return {
+            downloaded: false,
+            error: "Host did not register ondownloadfile",
+          };
+        return this._ondownloadfile(params, toExtra(ctx));
+      },
+    );
+    this.ui.setRequestHandler(
+      McpUiRequestDisplayModeRequestSchema.shape.method.value,
+      McpUiRequestDisplayModeRequestSchema.shape.params,
+      async (params, ctx) => {
+        if (this._onrequestdisplaymode)
+          return this._onrequestdisplaymode(params, toExtra(ctx));
+        return { mode: this._hostContext.displayMode ?? "inline" };
+      },
+    );
+    this.ui.setRequestHandler(
+      McpUiUpdateModelContextRequestSchema.shape.method.value,
+      McpUiUpdateModelContextRequestSchema.shape.params,
+      async (params, ctx) => {
+        await this._onupdatemodelcontext?.(params, toExtra(ctx));
+        return {};
       },
     );
-  }
 
-  /**
-   * Get the view's capabilities discovered during initialization.
-   *
-   * Returns the capabilities that the view advertised during its
-   * initialization request. Returns `undefined` if called before
-   * initialization completes.
-   *
-   * @returns view capabilities, or `undefined` if not yet initialized
-   *
-   * @example Check view capabilities after initialization
-   * ```ts source="./app-bridge.examples.ts#AppBridge_getAppCapabilities_checkAfterInit"
-   * bridge.oninitialized = () => {
-   *   const caps = bridge.getAppCapabilities();
-   *   if (caps?.tools) {
-   *     console.log("View provides tools");
-   *   }
-   * };
-   * ```
-   *
-   * @see {@link McpUiAppCapabilities `McpUiAppCapabilities`} for the capabilities structure
-   */
-  getAppCapabilities(): McpUiAppCapabilities | undefined {
-    return this._appCapabilities;
+    // ── ui/* notification → event dispatch ─────────────────────────────────
+
+    for (const [event, { method, params }] of Object.entries(
+      BRIDGE_EVENT_NOTIFICATION_SCHEMAS,
+    )) {
+      this.ui.setNotificationHandler(method, params as never, (p) =>
+        this.dispatchEvent(event as keyof AppBridgeEventMap, p),
+      );
+    }
+
+    // v1-compat: also accept legacy `notifications/message` from v1 iframes
+    // (v2 iframes send `ui/log`). See BREAKING.md § v1↔v2 interop.
+    this.server.setNotificationHandler("notifications/message", (n) =>
+      this.dispatchEvent("loggingmessage", n.params),
+    );
+
+    // ── Standard MCP requests from iframe (proxy to real server) ───────────
+
+    this.server.setRequestHandler("tools/call", async (req, ctx) => {
+      if (!this._oncalltool) throw new Error("No oncalltool handler set");
+      return this._oncalltool(req.params, toExtra(ctx));
+    });
+    this.server.setRequestHandler("tools/list", async (req, ctx) => {
+      if (!this._onlisttools) return { tools: [] };
+      return this._onlisttools(req.params, toExtra(ctx));
+    });
+    this.server.setRequestHandler("resources/list", async (req, ctx) => {
+      if (!this._onlistresources) return { resources: [] };
+      return this._onlistresources(req.params, toExtra(ctx));
+    });
+    this.server.setRequestHandler(
+      "resources/templates/list",
+      async (req, ctx) => {
+        if (!this._onlistresourcetemplates) return { resourceTemplates: [] };
+        return this._onlistresourcetemplates(req.params, toExtra(ctx));
+      },
+    );
+    this.server.setRequestHandler("resources/read", async (req, ctx) => {
+      if (!this._onreadresource)
+        throw new Error("No onreadresource handler set");
+      return this._onreadresource(req.params, toExtra(ctx));
+    });
+    this.server.setRequestHandler("prompts/list", async (req, ctx) => {
+      if (!this._onlistprompts) return { prompts: [] };
+      return this._onlistprompts(req.params, toExtra(ctx));
+    });
+    this.server.setRequestHandler("ping", (req, ctx) => {
+      this.onping?.(req.params, toExtra(ctx));
+      return {};
+    });
   }
 
-  /**
-   * Get the view's implementation info discovered during initialization.
-   *
-   * Returns the view's name and version as provided in its initialization
-   * request. Returns `undefined` if called before initialization completes.
-   *
-   * @returns view implementation info, or `undefined` if not yet initialized
-   *
-   * @example Log view information after initialization
-   * ```ts source="./app-bridge.examples.ts#AppBridge_getAppVersion_logAfterInit"
-   * bridge.oninitialized = () => {
-   *   const appInfo = bridge.getAppVersion();
-   *   if (appInfo) {
-   *     console.log(`View: ${appInfo.name} v${appInfo.version}`);
-   *   }
-   * };
-   * ```
-   */
-  getAppVersion(): Implementation | undefined {
-    return this._appInfo;
+  private _oninitialize(
+    params: McpUiInitializeRequest["params"],
+  ): McpUiInitializeResult {
+    this._appCapabilities = params.appCapabilities;
+    this._appInfo = params.appInfo;
+    return {
+      protocolVersion: LATEST_PROTOCOL_VERSION,
+      hostCapabilities: this._capabilities,
+      hostInfo: this._hostInfo,
+      hostContext: this._hostContext,
+    };
   }
 
-  /**
-   * Optional handler for ping requests from the view.
-   *
-   * The View can send standard MCP `ping` requests to verify the connection
-   * is alive. The {@link AppBridge `AppBridge`} automatically responds with an empty object, but this
-   * handler allows the host to observe or log ping activity.
-   *
-   * Unlike the other handlers which use setters, this is a direct property
-   * assignment. It is optional; if not set, pings are still handled automatically.
-   *
-   * @param params - Empty params object from the ping request
-   * @param extra - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onping_handleRequest"
-   * bridge.onping = (params, extra) => {
-   *   console.log("Received ping from view");
-   * };
-   * ```
-   */
-  onping?: (params: PingRequest["params"], extra: RequestHandlerExtra) => void;
+  // ── App info / capabilities ───────────────────────────────────────────────
 
-  /**
-   * Register a handler for size change notifications from the view.
-   *
-   * The view sends `ui/notifications/size-changed` when its rendered content
-   * size changes, typically via `ResizeObserver`. Set this callback to dynamically
-   * adjust the iframe container dimensions based on the view's content.
-   *
-   * Note: This is for View → Host communication. To notify the View of
-   * host container dimension changes, use {@link setHostContext `setHostContext`}.
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onsizechange_handleResize"
-   * bridge.onsizechange = ({ width, height }) => {
-   *   if (width != null) {
-   *     iframe.style.width = `${width}px`;
-   *   }
-   *   if (height != null) {
-   *     iframe.style.height = `${height}px`;
-   *   }
-   * };
-   * ```
-   *
-   * @see {@link McpUiSizeChangedNotification `McpUiSizeChangedNotification`} for the notification type
-   * @see {@link app!App.sendSizeChanged `App.sendSizeChanged`} - the View method that sends these notifications
-   * @deprecated Use {@link addEventListener `addEventListener("sizechange", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   */
-  get onsizechange():
-    | ((params: McpUiSizeChangedNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("sizechange");
-  }
-  set onsizechange(
-    callback:
-      | ((params: McpUiSizeChangedNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("sizechange", callback);
+  /** App capabilities advertised by the view. */
+  get appCapabilities(): McpUiAppCapabilities | undefined {
+    return this.ui.getPeerSettings() ?? this._appCapabilities;
   }
 
   /**
-   * Register a handler for sandbox proxy ready notifications.
-   *
-   * This is an internal callback used by web-based hosts implementing the
-   * double-iframe sandbox architecture. The sandbox proxy sends
-   * `ui/notifications/sandbox-proxy-ready` after it loads and is ready to receive
-   * HTML content.
-   *
-   * When this fires, the host should call {@link sendSandboxResourceReady `sendSandboxResourceReady`} with
-   * the HTML content to load into the inner sandboxed iframe.
-   *
-   * @example
-   * ```typescript
-   * bridge.onsandboxready = async () => {
-   *   const resource = await mcpClient.request(
-   *     { method: "resources/read", params: { uri: "ui://my-app" } },
-   *     ReadResourceResultSchema
-   *   );
-   *
-   *   bridge.sendSandboxResourceReady({
-   *     html: resource.contents[0].text,
-   *     sandbox: "allow-scripts"
-   *   });
-   * };
-   * ```
-   *
-   * @internal
-   * @see {@link McpUiSandboxProxyReadyNotification `McpUiSandboxProxyReadyNotification`} for the notification type
-   * @see {@link sendSandboxResourceReady `sendSandboxResourceReady`} for sending content to the sandbox
-   * @deprecated Use {@link addEventListener `addEventListener("sandboxready", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
+   * `true` if the connected iframe advertised via `capabilities.extensions`
+   * (ext-apps v2). `false` if capabilities came only via `ui/initialize`
+   * (ext-apps v1). `undefined` before any handshake.
    */
-  get onsandboxready():
-    | ((params: McpUiSandboxProxyReadyNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("sandboxready");
+  private get _isV2Iframe(): boolean | undefined {
+    if (this.ui.getPeerSettings() !== undefined) return true;
+    if (this._appCapabilities !== undefined) return false;
+    return undefined;
   }
-  set onsandboxready(
-    callback:
-      | ((params: McpUiSandboxProxyReadyNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("sandboxready", callback);
+  /** @deprecated Use {@link appCapabilities `appCapabilities`}. */
+  getAppCapabilities(): McpUiAppCapabilities | undefined {
+    return this.appCapabilities;
   }
 
-  /**
-   * Called when the view completes initialization.
-   *
-   * Set this callback to be notified when the view has finished its
-   * initialization handshake and is ready to receive tool input and other data.
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_oninitialized_sendToolInput"
-   * bridge.oninitialized = () => {
-   *   console.log("View ready");
-   *   bridge.sendToolInput({ arguments: toolArgs });
-   * };
-   * ```
-   *
-   * @see {@link McpUiInitializedNotification `McpUiInitializedNotification`} for the notification type
-   * @see {@link sendToolInput `sendToolInput`} for sending tool arguments to the View
-   * @deprecated Use {@link addEventListener `addEventListener("initialized", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   */
-  get oninitialized():
-    | ((params: McpUiInitializedNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("initialized");
+  /** App implementation info from `ui/initialize`. */
+  getAppVersion(): Implementation | undefined {
+    return this._appInfo;
   }
-  set oninitialized(
-    callback:
-      | ((params: McpUiInitializedNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("initialized", callback);
+
+  /** Host capabilities passed to the constructor. */
+  getCapabilities(): McpUiHostCapabilities {
+    return this._capabilities;
   }
 
-  /**
-   * Register a handler for message requests from the view.
-   *
-   * The view sends `ui/message` requests when it wants to add a message to
-   * the host's chat interface. This enables interactive apps to communicate with
-   * the user through the conversation thread.
-   *
-   * The handler should process the message (add it to the chat) and return a
-   * result indicating success or failure. For security, the host should NOT
-   * return conversation content or follow-up results to prevent information
-   * leakage.
-   *
-   * @param callback - Handler that receives message params and returns a result
-   *   - `params.role` - Message role (currently only "user" is supported)
-   *   - `params.content` - Message content blocks (text, image, etc.)
-   *   - `extra` - Request metadata (abort signal, session info)
-   *   - Returns: `Promise<McpUiMessageResult>` with optional `isError` flag
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onmessage_logMessage"
-   * bridge.onmessage = async ({ role, content }, extra) => {
-   *   try {
-   *     await chatManager.addMessage({ role, content, source: "app" });
-   *     return {}; // Success
-   *   } catch (error) {
-   *     console.error("Failed to add message:", error);
-   *     return { isError: true };
-   *   }
-   * };
-   * ```
-   *
-   * @see {@link McpUiMessageRequest `McpUiMessageRequest`} for the request type
-   * @see {@link McpUiMessageResult `McpUiMessageResult`} for the result type
-   */
+  // ── Notification on* setters (DOM-style) ──────────────────────────────────
+
+  get onsizechange() { return this.getEventHandler("sizechange"); }
+  set onsizechange(h) { this.setEventHandler("sizechange", h); }
+
+  get onsandboxready() { return this.getEventHandler("sandboxready"); }
+  set onsandboxready(h) { this.setEventHandler("sandboxready", h); }
+
+  get oninitialized() { return this.getEventHandler("initialized"); }
+  set oninitialized(h) { this.setEventHandler("initialized", h); }
+
+  get onrequestteardown() { return this.getEventHandler("requestteardown"); }
+  set onrequestteardown(h) { this.setEventHandler("requestteardown", h); }
+
+  get onloggingmessage() { return this.getEventHandler("loggingmessage"); }
+  set onloggingmessage(h) { this.setEventHandler("loggingmessage", h); }
+
+  // ── Request on* setters ───────────────────────────────────────────────────
+
   private _onmessage?: (
     params: McpUiMessageRequest["params"],
     extra: RequestHandlerExtra,
-  ) => Promise<McpUiMessageResult>;
-  get onmessage() {
-    return this._onmessage;
-  }
-  set onmessage(
-    callback:
-      | ((
-          params: McpUiMessageRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<McpUiMessageResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced("onmessage", this._onmessage, callback);
-    this._onmessage = callback;
-    this.replaceRequestHandler(
-      McpUiMessageRequestSchema,
-      async (request, extra) => {
-        if (!this._onmessage) throw new Error("No onmessage handler set");
-        return this._onmessage(request.params, extra);
-      },
-    );
+  ) => Promise<McpUiMessageResult> | McpUiMessageResult;
+  get onmessage() { return this._onmessage; }
+  set onmessage(cb) {
+    this.warnIfRequestHandlerReplaced("onmessage", this._onmessage, cb);
+    this._onmessage = cb;
   }
 
-  /**
-   * Register a handler for external link requests from the view.
-   *
-   * The view sends `ui/open-link` requests when it wants to open an external
-   * URL in the host's default browser. The handler should validate the URL and
-   * open it according to the host's security policy and user preferences.
-   *
-   * The host MAY:
-   * - Show a confirmation dialog before opening
-   * - Block URLs based on a security policy or allowlist
-   * - Log the request for audit purposes
-   * - Reject the request entirely
-   *
-   * @param callback - Handler that receives URL params and returns a result
-   *   - `params.url` - URL to open in the host's browser
-   *   - `extra` - Request metadata (abort signal, session info)
-   *   - Returns: `Promise<McpUiOpenLinkResult>` with optional `isError` flag
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onopenlink_handleRequest"
-   * bridge.onopenlink = async ({ url }, extra) => {
-   *   if (!isAllowedDomain(url)) {
-   *     console.warn("Blocked external link:", url);
-   *     return { isError: true };
-   *   }
-   *
-   *   const confirmed = await showDialog({
-   *     message: `Open external link?\n${url}`,
-   *     buttons: ["Open", "Cancel"],
-   *   });
-   *
-   *   if (confirmed) {
-   *     window.open(url, "_blank", "noopener,noreferrer");
-   *     return {};
-   *   }
-   *
-   *   return { isError: true };
-   * };
-   * ```
-   *
-   * @see {@link McpUiOpenLinkRequest `McpUiOpenLinkRequest`} for the request type
-   * @see {@link McpUiOpenLinkResult `McpUiOpenLinkResult`} for the result type
-   */
   private _onopenlink?: (
     params: McpUiOpenLinkRequest["params"],
     extra: RequestHandlerExtra,
-  ) => Promise<McpUiOpenLinkResult>;
-  get onopenlink() {
-    return this._onopenlink;
-  }
-  set onopenlink(
-    callback:
-      | ((
-          params: McpUiOpenLinkRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<McpUiOpenLinkResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced("onopenlink", this._onopenlink, callback);
-    this._onopenlink = callback;
-    this.replaceRequestHandler(
-      McpUiOpenLinkRequestSchema,
-      async (request, extra) => {
-        if (!this._onopenlink) throw new Error("No onopenlink handler set");
-        return this._onopenlink(request.params, extra);
-      },
-    );
+  ) => Promise<McpUiOpenLinkResult> | McpUiOpenLinkResult;
+  get onopenlink() { return this._onopenlink; }
+  set onopenlink(cb) {
+    this.warnIfRequestHandlerReplaced("onopenlink", this._onopenlink, cb);
+    this._onopenlink = cb;
   }
 
-  /**
-   * Register a handler for file download requests from the View.
-   *
-   * The View sends `ui/download-file` requests when the user wants to
-   * download a file. The params contain an array of MCP resource content
-   * items — either `EmbeddedResource` (inline data) or `ResourceLink`
-   * (URI the host can fetch). The host should show a confirmation dialog
-   * and then trigger the download.
-   *
-   * @param callback - Handler that receives download params and returns a result
-   *   - `params.contents` - Array of `EmbeddedResource` or `ResourceLink` items
-   *   - `extra` - Request metadata (abort signal, session info)
-   *   - Returns: `Promise<McpUiDownloadFileResult>` with optional `isError` flag
-   *
-   * @example
-   * ```ts
-   * bridge.ondownloadfile = async ({ contents }, extra) => {
-   *   for (const item of contents) {
-   *     if (item.type === "resource") {
-   *       // EmbeddedResource — inline content
-   *       const res = item.resource;
-   *       const blob = res.blob
-   *         ? new Blob([Uint8Array.from(atob(res.blob), c => c.charCodeAt(0))], { type: res.mimeType })
-   *         : new Blob([res.text ?? ""], { type: res.mimeType });
-   *       const url = URL.createObjectURL(blob);
-   *       const link = document.createElement("a");
-   *       link.href = url;
-   *       link.download = res.uri.split("/").pop() ?? "download";
-   *       link.click();
-   *       URL.revokeObjectURL(url);
-   *     } else if (item.type === "resource_link") {
-   *       // ResourceLink — host fetches or opens directly
-   *       window.open(item.uri, "_blank");
-   *     }
-   *   }
-   *   return {};
-   * };
-   * ```
-   *
-   * @see {@link McpUiDownloadFileRequest `McpUiDownloadFileRequest`} for the request type
-   * @see {@link McpUiDownloadFileResult `McpUiDownloadFileResult`} for the result type
-   */
   private _ondownloadfile?: (
     params: McpUiDownloadFileRequest["params"],
     extra: RequestHandlerExtra,
-  ) => Promise<McpUiDownloadFileResult>;
-  get ondownloadfile() {
-    return this._ondownloadfile;
-  }
-  set ondownloadfile(
-    callback:
-      | ((
-          params: McpUiDownloadFileRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<McpUiDownloadFileResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced(
-      "ondownloadfile",
-      this._ondownloadfile,
-      callback,
-    );
-    this._ondownloadfile = callback;
-    this.replaceRequestHandler(
-      McpUiDownloadFileRequestSchema,
-      async (request, extra) => {
-        if (!this._ondownloadfile)
-          throw new Error("No ondownloadfile handler set");
-        return this._ondownloadfile(request.params, extra);
-      },
-    );
+  ) => Promise<McpUiDownloadFileResult> | McpUiDownloadFileResult;
+  get ondownloadfile() { return this._ondownloadfile; }
+  set ondownloadfile(cb) {
+    this.warnIfRequestHandlerReplaced("ondownloadfile", this._ondownloadfile, cb);
+    this._ondownloadfile = cb;
   }
 
-  /**
-   * Register a handler for app-initiated teardown request notifications from the view.
-   *
-   * The view sends `ui/notifications/request-teardown` when it wants the host to tear it down.
-   * If the host decides to proceed, it should send
-   * `ui/resource-teardown` (via {@link teardownResource `teardownResource`}) to allow
-   * the view to perform gracefull termination, then unmount the iframe after the view responds.
-   *
-   * @example
-   * ```typescript
-   * bridge.onrequestteardown = async (params) => {
-   *   console.log("App requested teardown");
-   *   // Initiate teardown to allow the app to persist unsaved state
-   *   // Alternatively, the callback can early return to prevent teardown
-   *   await bridge.teardownResource({});
-   *   // Now safe to unmount the iframe
-   *   iframe.remove();
-   * };
-   * ```
-   *
-   * @see {@link McpUiRequestTeardownNotification `McpUiRequestTeardownNotification`} for the notification type
-   * @see {@link teardownResource `teardownResource`} for initiating teardown
-   * @deprecated Use {@link addEventListener `addEventListener("requestteardown", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   */
-  get onrequestteardown():
-    | ((params: McpUiRequestTeardownNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("requestteardown");
-  }
-  set onrequestteardown(
-    callback:
-      | ((params: McpUiRequestTeardownNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("requestteardown", callback);
-  }
-
-  /**
-   * Register a handler for display mode change requests from the view.
-   *
-   * The view sends `ui/request-display-mode` requests when it wants to change
-   * its display mode (e.g., from "inline" to "fullscreen"). The handler should
-   * check if the requested mode is in `availableDisplayModes` from the host context,
-   * update the display mode if supported, and return the actual mode that was set.
-   *
-   * If the requested mode is not available, the handler should return the current
-   * display mode instead.
-   *
-   * By default, `AppBridge` returns the current `displayMode` from host context (or "inline").
-   * Setting this property replaces that default behavior.
-   *
-   * @param callback - Handler that receives the requested mode and returns the actual mode set
-   *   - `params.mode` - The display mode being requested ("inline" | "fullscreen" | "pip")
-   *   - `extra` - Request metadata (abort signal, session info)
-   *   - Returns: `Promise<McpUiRequestDisplayModeResult>` with the actual mode set
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onrequestdisplaymode_handleRequest"
-   * bridge.onrequestdisplaymode = async ({ mode }, extra) => {
-   *   if (availableDisplayModes.includes(mode)) {
-   *     currentDisplayMode = mode;
-   *   }
-   *   return { mode: currentDisplayMode };
-   * };
-   * ```
-   *
-   * @see {@link McpUiRequestDisplayModeRequest `McpUiRequestDisplayModeRequest`} for the request type
-   * @see {@link McpUiRequestDisplayModeResult `McpUiRequestDisplayModeResult`} for the result type
-   */
   private _onrequestdisplaymode?: (
     params: McpUiRequestDisplayModeRequest["params"],
     extra: RequestHandlerExtra,
-  ) => Promise<McpUiRequestDisplayModeResult>;
-  get onrequestdisplaymode() {
-    return this._onrequestdisplaymode;
-  }
-  set onrequestdisplaymode(
-    callback:
-      | ((
-          params: McpUiRequestDisplayModeRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<McpUiRequestDisplayModeResult>)
-      | undefined,
-  ) {
+  ) => Promise<McpUiRequestDisplayModeResult> | McpUiRequestDisplayModeResult;
+  get onrequestdisplaymode() { return this._onrequestdisplaymode; }
+  set onrequestdisplaymode(cb) {
     this.warnIfRequestHandlerReplaced(
       "onrequestdisplaymode",
       this._onrequestdisplaymode,
-      callback,
-    );
-    this._onrequestdisplaymode = callback;
-    this.replaceRequestHandler(
-      McpUiRequestDisplayModeRequestSchema,
-      async (request, extra) => {
-        if (!this._onrequestdisplaymode)
-          throw new Error("No onrequestdisplaymode handler set");
-        return this._onrequestdisplaymode(request.params, extra);
-      },
+      cb,
     );
+    this._onrequestdisplaymode = cb;
   }
 
-  /**
-   * Register a handler for logging messages from the view.
-   *
-   * The view sends standard MCP `notifications/message` (logging) notifications
-   * to report debugging information, errors, warnings, and other telemetry to the
-   * host. The host can display these in a console, log them to a file, or send
-   * them to a monitoring service.
-   *
-   * This uses the standard MCP logging notification format, not a UI-specific
-   * message type.
-   *
-   * The handler receives `LoggingMessageNotification["params"]`:
-   *   - `level` — "debug" | "info" | "notice" | "warning" | "error" | "critical" | "alert" | "emergency"
-   *   - `logger` — optional logger name/identifier
-   *   - `data` — log message and optional structured data
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onloggingmessage_handleLog"
-   * bridge.onloggingmessage = ({ level, logger, data }) => {
-   *   console[level === "error" ? "error" : "log"](
-   *     `[${logger ?? "View"}] ${level.toUpperCase()}:`,
-   *     data,
-   *   );
-   * };
-   * ```
-   * @deprecated Use {@link addEventListener `addEventListener("loggingmessage", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   */
-  get onloggingmessage():
-    | ((params: LoggingMessageNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("loggingmessage");
-  }
-  set onloggingmessage(
-    callback:
-      | ((params: LoggingMessageNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("loggingmessage", callback);
-  }
-
-  /**
-   * Register a handler for model context updates from the view.
-   *
-   * The view sends `ui/update-model-context` requests to update the Host's
-   * model context. Each request overwrites the previous context stored by the view.
-   * Unlike logging messages, context updates are intended to be available to
-   * the model in future turns. Unlike messages, context updates do not trigger follow-ups.
-   *
-   * The host will typically defer sending the context to the model until the
-   * next user message (including `ui/message`), and will only send the last
-   * update received.
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onupdatemodelcontext_storeContext"
-   * bridge.onupdatemodelcontext = async (
-   *   { content, structuredContent },
-   *   extra,
-   * ) => {
-   *   // Store the context snapshot for inclusion in the next model request
-   *   modelContextManager.update({ content, structuredContent });
-   *   return {};
-   * };
-   * ```
-   *
-   * @see {@link McpUiUpdateModelContextRequest `McpUiUpdateModelContextRequest`} for the request type
-   */
   private _onupdatemodelcontext?: (
     params: McpUiUpdateModelContextRequest["params"],
     extra: RequestHandlerExtra,
-  ) => Promise<EmptyResult>;
-  get onupdatemodelcontext() {
-    return this._onupdatemodelcontext;
-  }
-  set onupdatemodelcontext(
-    callback:
-      | ((
-          params: McpUiUpdateModelContextRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<EmptyResult>)
-      | undefined,
-  ) {
+  ) => Promise<void | object> | void | object;
+  get onupdatemodelcontext() { return this._onupdatemodelcontext; }
+  set onupdatemodelcontext(cb) {
     this.warnIfRequestHandlerReplaced(
       "onupdatemodelcontext",
       this._onupdatemodelcontext,
-      callback,
-    );
-    this._onupdatemodelcontext = callback;
-    this.replaceRequestHandler(
-      McpUiUpdateModelContextRequestSchema,
-      async (request, extra) => {
-        if (!this._onupdatemodelcontext)
-          throw new Error("No onupdatemodelcontext handler set");
-        return this._onupdatemodelcontext(request.params, extra);
-      },
+      cb,
     );
+    this._onupdatemodelcontext = cb;
   }
 
-  /**
-   * Register a handler for tool call requests from the view.
-   *
-   * The view sends `tools/call` requests to execute MCP server tools. This
-   * handler allows the host to intercept and process these requests, typically
-   * by forwarding them to the MCP server.
-   *
-   * @param callback - Handler that receives tool call params and returns a
-   *   `CallToolResult`
-   *   - `params` - Tool call parameters (name and arguments)
-   *   - `extra` - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_oncalltool_forwardToServer"
-   * bridge.oncalltool = async (params, extra) => {
-   *   return mcpClient.request(
-   *     { method: "tools/call", params },
-   *     CallToolResultSchema,
-   *     { signal: extra.signal },
-   *   );
-   * };
-   * ```
-   *
-   * @see `CallToolRequest` from @modelcontextprotocol/sdk for the request type
-   * @see `CallToolResult` from @modelcontextprotocol/sdk for the result type
-   */
   private _oncalltool?: (
     params: CallToolRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<CallToolResult>;
-  get oncalltool() {
-    return this._oncalltool;
-  }
-  set oncalltool(
-    callback:
-      | ((
-          params: CallToolRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<CallToolResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced("oncalltool", this._oncalltool, callback);
-    this._oncalltool = callback;
-    this.replaceRequestHandler(
-      CallToolRequestSchema,
-      async (request, extra) => {
-        if (!this._oncalltool) throw new Error("No oncalltool handler set");
-        return this._oncalltool(request.params, extra);
-      },
-    );
+  get oncalltool() { return this._oncalltool; }
+  set oncalltool(cb) {
+    this.warnIfRequestHandlerReplaced("oncalltool", this._oncalltool, cb);
+    this._oncalltool = cb;
   }
 
-  /**
-   * Notify the view that the MCP server's tool list has changed.
-   *
-   * The host sends `notifications/tools/list_changed` to the view when it
-   * receives this notification from the MCP server. This allows the view
-   * to refresh its tool cache or UI accordingly.
-   *
-   * @param params - Optional notification params (typically empty)
-   *
-   * @example
-   * ```typescript
-   * // In your MCP client notification handler:
-   * mcpClient.setNotificationHandler(ToolListChangedNotificationSchema, () => {
-   *   bridge.sendToolListChanged();
-   * });
-   * ```
-   *
-   * @see `ToolListChangedNotification` from @modelcontextprotocol/sdk for the notification type
-   */
-  sendToolListChanged(params: ToolListChangedNotification["params"] = {}) {
-    return this.notification({
-      method: "notifications/tools/list_changed" as const,
-      params,
-    });
+  private _onlisttools?: (
+    params: ListToolsRequest["params"],
+    extra: RequestHandlerExtra,
+  ) => Promise<ListToolsResult>;
+  get onlisttools() { return this._onlisttools; }
+  set onlisttools(cb) {
+    this.warnIfRequestHandlerReplaced("onlisttools", this._onlisttools, cb);
+    this._onlisttools = cb;
   }
 
-  /**
-   * Register a handler for list resources requests from the view.
-   *
-   * The view sends `resources/list` requests to enumerate available MCP
-   * resources. This handler allows the host to intercept and process these
-   * requests, typically by forwarding them to the MCP server.
-   *
-   * @param callback - Handler that receives list params and returns a
-   *   `ListResourcesResult`
-   *   - `params` - Request params (may include cursor for pagination)
-   *   - `extra` - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onlistresources_returnResources"
-   * bridge.onlistresources = async (params, extra) => {
-   *   return mcpClient.request(
-   *     { method: "resources/list", params },
-   *     ListResourcesResultSchema,
-   *     { signal: extra.signal },
-   *   );
-   * };
-   * ```
-   *
-   * @see `ListResourcesRequest` from @modelcontextprotocol/sdk for the request type
-   * @see `ListResourcesResult` from @modelcontextprotocol/sdk for the result type
-   */
   private _onlistresources?: (
     params: ListResourcesRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<ListResourcesResult>;
-  get onlistresources() {
-    return this._onlistresources;
-  }
-  set onlistresources(
-    callback:
-      | ((
-          params: ListResourcesRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<ListResourcesResult>)
-      | undefined,
-  ) {
+  get onlistresources() { return this._onlistresources; }
+  set onlistresources(cb) {
     this.warnIfRequestHandlerReplaced(
       "onlistresources",
       this._onlistresources,
-      callback,
-    );
-    this._onlistresources = callback;
-    this.replaceRequestHandler(
-      ListResourcesRequestSchema,
-      async (request, extra) => {
-        if (!this._onlistresources)
-          throw new Error("No onlistresources handler set");
-        return this._onlistresources(request.params, extra);
-      },
+      cb,
     );
+    this._onlistresources = cb;
   }
 
-  /**
-   * Register a handler for list resource templates requests from the view.
-   *
-   * The view sends `resources/templates/list` requests to enumerate available
-   * MCP resource templates. This handler allows the host to intercept and process
-   * these requests, typically by forwarding them to the MCP server.
-   *
-   * @param callback - Handler that receives list params and returns a
-   *   `ListResourceTemplatesResult`
-   *   - `params` - Request params (may include cursor for pagination)
-   *   - `extra` - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```typescript
-   * bridge.onlistresourcetemplates = async (params, extra) => {
-   *   return mcpClient.request(
-   *     { method: "resources/templates/list", params },
-   *     ListResourceTemplatesResultSchema,
-   *     { signal: extra.signal }
-   *   );
-   * };
-   * ```
-   *
-   * @see `ListResourceTemplatesRequest` from @modelcontextprotocol/sdk for the request type
-   * @see `ListResourceTemplatesResult` from @modelcontextprotocol/sdk for the result type
-   */
   private _onlistresourcetemplates?: (
     params: ListResourceTemplatesRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<ListResourceTemplatesResult>;
-  get onlistresourcetemplates() {
-    return this._onlistresourcetemplates;
-  }
-  set onlistresourcetemplates(
-    callback:
-      | ((
-          params: ListResourceTemplatesRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<ListResourceTemplatesResult>)
-      | undefined,
-  ) {
+  get onlistresourcetemplates() { return this._onlistresourcetemplates; }
+  set onlistresourcetemplates(cb) {
     this.warnIfRequestHandlerReplaced(
       "onlistresourcetemplates",
       this._onlistresourcetemplates,
-      callback,
-    );
-    this._onlistresourcetemplates = callback;
-    this.replaceRequestHandler(
-      ListResourceTemplatesRequestSchema,
-      async (request, extra) => {
-        if (!this._onlistresourcetemplates)
-          throw new Error("No onlistresourcetemplates handler set");
-        return this._onlistresourcetemplates(request.params, extra);
-      },
+      cb,
     );
+    this._onlistresourcetemplates = cb;
   }
 
-  /**
-   * Register a handler for read resource requests from the view.
-   *
-   * The view sends `resources/read` requests to retrieve the contents of an
-   * MCP resource. This handler allows the host to intercept and process these
-   * requests, typically by forwarding them to the MCP server.
-   *
-   * @param callback - Handler that receives read params and returns a
-   *   `ReadResourceResult`
-   *   - `params` - Read parameters including the resource URI
-   *   - `extra` - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onreadresource_returnResource"
-   * bridge.onreadresource = async (params, extra) => {
-   *   return mcpClient.request(
-   *     { method: "resources/read", params },
-   *     ReadResourceResultSchema,
-   *     { signal: extra.signal },
-   *   );
-   * };
-   * ```
-   *
-   * @see `ReadResourceRequest` from @modelcontextprotocol/sdk for the request type
-   * @see `ReadResourceResult` from @modelcontextprotocol/sdk for the result type
-   */
   private _onreadresource?: (
     params: ReadResourceRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<ReadResourceResult>;
-  get onreadresource() {
-    return this._onreadresource;
-  }
-  set onreadresource(
-    callback:
-      | ((
-          params: ReadResourceRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<ReadResourceResult>)
-      | undefined,
-  ) {
+  get onreadresource() { return this._onreadresource; }
+  set onreadresource(cb) {
     this.warnIfRequestHandlerReplaced(
       "onreadresource",
       this._onreadresource,
-      callback,
-    );
-    this._onreadresource = callback;
-    this.replaceRequestHandler(
-      ReadResourceRequestSchema,
-      async (request, extra) => {
-        if (!this._onreadresource)
-          throw new Error("No onreadresource handler set");
-        return this._onreadresource(request.params, extra);
-      },
+      cb,
     );
+    this._onreadresource = cb;
   }
 
-  /**
-   * Notify the view that the MCP server's resource list has changed.
-   *
-   * The host sends `notifications/resources/list_changed` to the view when it
-   * receives this notification from the MCP server. This allows the view
-   * to refresh its resource cache or UI accordingly.
-   *
-   * @param params - Optional notification params (typically empty)
-   *
-   * @example
-   * ```typescript
-   * // In your MCP client notification handler:
-   * mcpClient.setNotificationHandler(ResourceListChangedNotificationSchema, () => {
-   *   bridge.sendResourceListChanged();
-   * });
-   * ```
-   *
-   * @see `ResourceListChangedNotification` from @modelcontextprotocol/sdk for the notification type
-   */
-  sendResourceListChanged(
-    params: ResourceListChangedNotification["params"] = {},
-  ) {
-    return this.notification({
-      method: "notifications/resources/list_changed" as const,
-      params,
-    });
-  }
-
-  /**
-   * Register a handler for list prompts requests from the view.
-   *
-   * The view sends `prompts/list` requests to enumerate available MCP
-   * prompts. This handler allows the host to intercept and process these
-   * requests, typically by forwarding them to the MCP server.
-   *
-   * @param callback - Handler that receives list params and returns a
-   *   `ListPromptsResult`
-   *   - `params` - Request params (may include cursor for pagination)
-   *   - `extra` - Request metadata (abort signal, session info)
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_onlistprompts_returnPrompts"
-   * bridge.onlistprompts = async (params, extra) => {
-   *   return mcpClient.request(
-   *     { method: "prompts/list", params },
-   *     ListPromptsResultSchema,
-   *     { signal: extra.signal },
-   *   );
-   * };
-   * ```
-   *
-   * @see `ListPromptsRequest` from @modelcontextprotocol/sdk for the request type
-   * @see `ListPromptsResult` from @modelcontextprotocol/sdk for the result type
-   */
   private _onlistprompts?: (
     params: ListPromptsRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<ListPromptsResult>;
-  get onlistprompts() {
-    return this._onlistprompts;
-  }
-  set onlistprompts(
-    callback:
-      | ((
-          params: ListPromptsRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<ListPromptsResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced(
-      "onlistprompts",
-      this._onlistprompts,
-      callback,
-    );
-    this._onlistprompts = callback;
-    this.replaceRequestHandler(
-      ListPromptsRequestSchema,
-      async (request, extra) => {
-        if (!this._onlistprompts)
-          throw new Error("No onlistprompts handler set");
-        return this._onlistprompts(request.params, extra);
-      },
-    );
+  get onlistprompts() { return this._onlistprompts; }
+  set onlistprompts(cb) {
+    this.warnIfRequestHandlerReplaced("onlistprompts", this._onlistprompts, cb);
+    this._onlistprompts = cb;
   }
 
-  /**
-   * Notify the view that the MCP server's prompt list has changed.
-   *
-   * The host sends `notifications/prompts/list_changed` to the view when it
-   * receives this notification from the MCP server. This allows the view
-   * to refresh its prompt cache or UI accordingly.
-   *
-   * @param params - Optional notification params (typically empty)
-   *
-   * @example
-   * ```typescript
-   * // In your MCP client notification handler:
-   * mcpClient.setNotificationHandler(PromptListChangedNotificationSchema, () => {
-   *   bridge.sendPromptListChanged();
-   * });
-   * ```
-   *
-   * @see `PromptListChangedNotification` from @modelcontextprotocol/sdk for the notification type
-   */
-  sendPromptListChanged(params: PromptListChangedNotification["params"] = {}) {
-    return this.notification({
-      method: "notifications/prompts/list_changed" as const,
-      params,
-    });
-  }
+  // ── Outbound: standard MCP server→client notifications ────────────────────
 
-  /**
-   * Verify that the guest supports the capability required for the given request method.
-   * @internal
-   */
-  assertCapabilityForMethod(method: AppRequest["method"]): void {
-    // TODO
+  /** Notify the view that the MCP server's tool list changed. */
+  sendToolListChanged(_params?: object) {
+    return this.server.sendToolListChanged();
   }
-
-  /**
-   * Verify that a request handler is registered and supported for the given method.
-   * @internal
-   */
-  assertRequestHandlerCapability(method: AppRequest["method"]): void {
-    // TODO
+  /** Notify the view that the MCP server's resource list changed. */
+  sendResourceListChanged(_params?: object) {
+    return this.server.sendResourceListChanged();
   }
-
-  /**
-   * Verify that the host supports the capability required for the given notification method.
-   * @internal
-   */
-  assertNotificationCapability(method: AppNotification["method"]): void {
-    // TODO
+  /** Notify the view that the MCP server's prompt list changed. */
+  sendPromptListChanged(_params?: object) {
+    return this.server.sendPromptListChanged();
   }
 
-  /**
-   * Verify that task creation is supported for the given request method.
-   * @internal
-   */
-  protected assertTaskCapability(_method: string): void {
-    throw new Error("Tasks are not supported in MCP Apps");
-  }
+  // ── Outbound: ui/* notifications ──────────────────────────────────────────
 
   /**
-   * Verify that task handler is supported for the given method.
-   * @internal
+   * Update host context and notify the view of changed fields.
+   * Call this when theme, locale, displayMode, etc. change.
    */
-  protected assertTaskHandlerCapability(_method: string): void {
-    throw new Error("Task handlers are not supported in MCP Apps");
-  }
-
-  /**
-   * Get the host capabilities passed to the constructor.
-   *
-   * @returns Host capabilities object
-   *
-   * @see {@link McpUiHostCapabilities `McpUiHostCapabilities`} for the capabilities structure
-   */
-  getCapabilities(): McpUiHostCapabilities {
-    return this._capabilities;
-  }
-
-  /**
-   * Handle the ui/initialize request from the guest.
-   * @internal
-   */
-  private async _oninitialize(
-    request: McpUiInitializeRequest,
-  ): Promise<McpUiInitializeResult> {
-    const requestedVersion = request.params.protocolVersion;
-
-    this._appCapabilities = request.params.appCapabilities;
-    this._appInfo = request.params.appInfo;
-
-    const protocolVersion = SUPPORTED_PROTOCOL_VERSIONS.includes(
-      requestedVersion,
-    )
-      ? requestedVersion
-      : LATEST_PROTOCOL_VERSION;
-
-    return {
-      protocolVersion,
-      hostCapabilities: this.getCapabilities(),
-      hostInfo: this._hostInfo,
-      hostContext: this._hostContext,
-    };
-  }
-
-  /**
-   * Update the host context and notify the view of changes.
-   *
-   * Compares fields present in the new context with the current context and sends a
-   * `ui/notifications/host-context-changed` notification containing only fields
-   * that have been added or modified. If no fields have changed, no notification is sent.
-   * The new context fully replaces the internal state.
-   *
-   * Common use cases include notifying the view when:
-   * - Theme changes (light/dark mode toggle)
-   * - Viewport size changes (window resize)
-   * - Display mode changes (inline/fullscreen)
-   * - Locale or timezone changes
-   *
-   * @param hostContext - The complete new host context state
-   *
-   * @example Update theme when user toggles dark mode
-   * ```ts source="./app-bridge.examples.ts#AppBridge_setHostContext_updateTheme"
-   * bridge.setHostContext({ theme: "dark" });
-   * ```
-   *
-   * @example Update multiple context fields
-   * ```ts source="./app-bridge.examples.ts#AppBridge_setHostContext_updateMultiple"
-   * bridge.setHostContext({
-   *   theme: "dark",
-   *   containerDimensions: { maxHeight: 600, width: 800 },
-   * });
-   * ```
-   *
-   * @see {@link McpUiHostContext `McpUiHostContext`} for the context structure
-   * @see {@link McpUiHostContextChangedNotification `McpUiHostContextChangedNotification`} for the notification type
-   */
-  setHostContext(hostContext: McpUiHostContext) {
-    const changes: McpUiHostContext = {};
-    let hasChanges = false;
-    for (const key of Object.keys(hostContext) as Array<
-      keyof McpUiHostContext
-    >) {
-      const oldValue = this._hostContext[key];
-      const newValue = hostContext[key];
-      if (deepEqual(oldValue, newValue)) {
-        continue;
-      }
-      changes[key] = newValue as any;
-      hasChanges = true;
-    }
-    if (hasChanges) {
-      this._hostContext = hostContext;
-      this.sendHostContextChange(changes);
+  setHostContext(context: Partial<McpUiHostContext>) {
+    const changed: Partial<McpUiHostContext> = {};
+    for (const [k, v] of Object.entries(context) as [keyof McpUiHostContext, unknown][]) {
+      if (this._hostContext[k] !== v) (changed as Record<string, unknown>)[k] = v;
     }
+    this._hostContext = { ...this._hostContext, ...context };
+    if (Object.keys(changed).length === 0) return Promise.resolve();
+    return this.sendHostContextChanged(changed);
   }
 
-  /**
-   * Low-level method to notify the view of host context changes.
-   *
-   * Most hosts should use {@link setHostContext `setHostContext`} instead, which automatically
-   * detects changes and calls this method with only the modified fields.
-   * Use this directly only when you need fine-grained control over change detection.
-   *
-   * @param params - The context fields that have changed (partial update)
-   */
-  sendHostContextChange(
+  /** Low-level: send a host-context-changed notification with the given diff. */
+  sendHostContextChanged(
     params: McpUiHostContextChangedNotification["params"],
-  ): Promise<void> | void {
-    return this.notification({
-      method: "ui/notifications/host-context-changed" as const,
+  ) {
+    return this.ui.sendNotification(
+      "ui/notifications/host-context-changed",
       params,
-    });
+    );
   }
 
-  /**
-   * Send complete tool arguments to the view.
-   *
-   * The host MUST send this notification after the View completes initialization
-   * (after {@link oninitialized `oninitialized`} callback fires) and complete tool arguments become available.
-   * This notification is sent exactly once and is required before {@link sendToolResult `sendToolResult`}.
-   *
-   * @param params - Complete tool call arguments
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_sendToolInput_afterInit"
-   * bridge.oninitialized = () => {
-   *   bridge.sendToolInput({
-   *     arguments: { location: "New York", units: "metric" },
-   *   });
-   * };
-   * ```
-   *
-   * @see {@link McpUiToolInputNotification `McpUiToolInputNotification`} for the notification type
-   * @see {@link oninitialized `oninitialized`} for the initialization callback
-   * @see {@link sendToolResult `sendToolResult`} for sending results after execution
-   */
+  /** Send tool input arguments to the view (after streaming completes). */
   sendToolInput(params: McpUiToolInputNotification["params"]) {
-    return this.notification({
-      method: "ui/notifications/tool-input" as const,
-      params,
-    });
+    return this.ui.sendNotification("ui/notifications/tool-input", params);
   }
 
-  /**
-   * Send streaming partial tool arguments to the view.
-   *
-   * The host MAY send this notification zero or more times while tool arguments
-   * are being streamed, before {@link sendToolInput `sendToolInput`} is called with complete
-   * arguments. This enables progressive rendering of tool arguments in the
-   * view.
-   *
-   * The arguments represent best-effort recovery of incomplete JSON. views
-   * SHOULD handle missing or changing fields gracefully between notifications.
-   *
-   * @param params - Partial tool call arguments (may be incomplete)
-   *
-   * @example Stream partial arguments as they arrive
-   * ```ts source="./app-bridge.examples.ts#AppBridge_sendToolInputPartial_streaming"
-   * // As streaming progresses...
-   * bridge.sendToolInputPartial({ arguments: { loc: "N" } });
-   * bridge.sendToolInputPartial({ arguments: { location: "New" } });
-   * bridge.sendToolInputPartial({ arguments: { location: "New York" } });
-   *
-   * // When complete, send final input
-   * bridge.sendToolInput({
-   *   arguments: { location: "New York", units: "metric" },
-   * });
-   * ```
-   *
-   * @see {@link McpUiToolInputPartialNotification `McpUiToolInputPartialNotification`} for the notification type
-   * @see {@link sendToolInput `sendToolInput`} for sending complete arguments
-   */
+  /** Send partial (still-streaming) tool input arguments to the view. */
   sendToolInputPartial(params: McpUiToolInputPartialNotification["params"]) {
-    return this.notification({
-      method: "ui/notifications/tool-input-partial" as const,
+    return this.ui.sendNotification(
+      "ui/notifications/tool-input-partial",
       params,
-    });
+    );
   }
 
-  /**
-   * Send tool execution result to the view.
-   *
-   * The host MUST send this notification when tool execution completes successfully,
-   * provided the view is still displayed. If the view was closed before execution
-   * completes, the host MAY skip this notification. This must be sent after
-   * {@link sendToolInput `sendToolInput`}.
-   *
-   * @param params - Standard MCP tool execution result
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_sendToolResult_afterExecution"
-   * const result = await mcpClient.request(
-   *   { method: "tools/call", params: { name: "get_weather", arguments: args } },
-   *   CallToolResultSchema,
-   * );
-   * bridge.sendToolResult(result);
-   * ```
-   *
-   * @see {@link McpUiToolResultNotification `McpUiToolResultNotification`} for the notification type
-   * @see {@link sendToolInput `sendToolInput`} for sending tool arguments before results
-   */
+  /** Send tool execution result to the view. */
   sendToolResult(params: McpUiToolResultNotification["params"]) {
-    return this.notification({
-      method: "ui/notifications/tool-result" as const,
-      params,
-    });
+    return this.ui.sendNotification("ui/notifications/tool-result", params);
   }
 
-  /**
-   * Notify the view that tool execution was cancelled.
-   *
-   * The host MUST send this notification if tool execution was cancelled for any
-   * reason, including user action, sampling error, classifier intervention, or
-   * any other interruption. This allows the view to update its state and
-   * display appropriate feedback to the user.
-   *
-   * @param params - Cancellation details object
-   *   - `reason`: Human-readable explanation for why the tool was cancelled
-   *
-   * @example User-initiated cancellation
-   * ```ts source="./app-bridge.examples.ts#AppBridge_sendToolCancelled_userInitiated"
-   * // User clicked "Cancel" button
-   * bridge.sendToolCancelled({ reason: "User cancelled the operation" });
-   * ```
-   *
-   * @example System-level cancellation
-   * ```ts source="./app-bridge.examples.ts#AppBridge_sendToolCancelled_systemLevel"
-   * // Sampling error or timeout
-   * bridge.sendToolCancelled({ reason: "Request timeout after 30 seconds" });
-   *
-   * // Classifier intervention
-   * bridge.sendToolCancelled({ reason: "Content policy violation detected" });
-   * ```
-   *
-   * @see {@link McpUiToolCancelledNotification `McpUiToolCancelledNotification`} for the notification type
-   * @see {@link sendToolResult `sendToolResult`} for sending successful results
-   * @see {@link sendToolInput `sendToolInput`} for sending tool arguments
-   */
+  /** Notify the view that the tool call was cancelled. */
   sendToolCancelled(params: McpUiToolCancelledNotification["params"]) {
-    return this.notification({
-      method: "ui/notifications/tool-cancelled" as const,
-      params,
-    });
+    return this.ui.sendNotification("ui/notifications/tool-cancelled", params);
   }
 
-  /**
-   * Send HTML resource to the sandbox proxy for secure loading.
-   *
-   * This is an internal method used by web-based hosts implementing the
-   * double-iframe sandbox architecture. After the sandbox proxy signals readiness
-   * via `ui/notifications/sandbox-proxy-ready`, the host sends this notification
-   * with the HTML content to load.
-   *
-   * @param params - HTML content and sandbox configuration:
-   *   - `html`: The HTML content to load into the sandboxed iframe
-   *   - `sandbox`: Optional sandbox attribute value (e.g., "allow-scripts")
-   *
-   * @internal
-   * @see {@link onsandboxready `onsandboxready`} for handling the sandbox proxy ready notification
-   */
+  /** Tell the sandbox proxy that the resource HTML is ready to load. */
   sendSandboxResourceReady(
     params: McpUiSandboxResourceReadyNotification["params"],
   ) {
-    return this.notification({
-      method: "ui/notifications/sandbox-resource-ready" as const,
+    return this.ui.sendNotification(
+      "ui/notifications/sandbox-resource-ready",
       params,
-    });
+    );
   }
 
+  // ── Outbound: ui/* and view-tool requests ─────────────────────────────────
+
   /**
-   * Request graceful shutdown of the view.
-   *
-   * The host MUST send this request before tearing down the UI resource (before
-   * unmounting the iframe). This gives the view an opportunity to save state,
-   * cancel pending operations, or show confirmation dialogs.
-   *
-   * The host SHOULD wait for the response before unmounting to prevent data loss.
-   *
-   * @param params - Empty params object
-   * @param options - Request options (timeout, etc.)
-   * @returns Promise resolving when view confirms readiness for teardown
-   *
-   * @example
-   * ```ts source="./app-bridge.examples.ts#AppBridge_teardownResource_gracefulShutdown"
-   * try {
-   *   await bridge.teardownResource({});
-   *   // View is ready, safe to unmount iframe
-   *   iframe.remove();
-   * } catch (error) {
-   *   console.error("Teardown failed:", error);
-   * }
-   * ```
+   * Ask the view to clean up before unmount. Await before removing the iframe.
    */
   teardownResource(
     params: McpUiResourceTeardownRequest["params"],
     options?: RequestOptions,
   ) {
-    return this.request(
-      {
-        method: "ui/resource-teardown" as const,
-        params,
-      },
+    return this.ui.sendRequest(
+      "ui/resource-teardown",
+      params,
       McpUiResourceTeardownResultSchema,
       options,
     );
   }
-
-  /** @deprecated Use {@link teardownResource `teardownResource`} instead */
-  sendResourceTeardown: AppBridge["teardownResource"] = this.teardownResource;
+  /** @deprecated Use {@link teardownResource `teardownResource`}. */
+  get sendResourceTeardown() { return this.teardownResource; }
 
   /**
-   * Call a tool on the view.
-   *
-   * Sends a `tools/call` request to the view and returns the result.
+   * Call a tool the **view** exposes (see {@link app!App.oncalltool}).
    *
-   * @param params - Tool call parameters (name and arguments)
-   * @param options - Request options (timeout, abort signal, etc.)
-   * @returns Promise resolving to the tool call result
+   * Wire method: `ui/call-view-tool` (renamed from `tools/call` in v2).
    */
   callTool(params: CallToolRequest["params"], options?: RequestOptions) {
-    return this.request(
-      { method: "tools/call", params },
-      CallToolResultSchema,
+    if (this._isV2Iframe === false) {
+      throw new Error(
+        "bridge.callTool(): connected iframe is ext-apps v1 (capabilities arrived via ui/initialize only). " +
+          "Host→iframe tool calls use the v2-only 'ui/call-view-tool' wire method; upgrade the iframe to ext-apps@2.",
+      );
+    }
+    return this.ui.sendRequest(
+      "ui/call-view-tool",
+      params,
+      specTypeSchema("CallToolResult"),
       options,
     );
   }
 
   /**
-   * List tools available on the view.
-   *
-   * Sends a `tools/list` request to the view and returns the result.
+   * List tools the **view** exposes (see {@link app!App.onlisttools}).
    *
-   * @param params - List tools parameters (may include cursor for pagination)
-   * @param options - Request options (timeout, abort signal, etc.)
-   * @returns Promise resolving to the list of tools
+   * Wire method: `ui/list-view-tools` (renamed from `tools/list` in v2).
    */
-  listTools(params: ListToolsRequest["params"], options?: RequestOptions) {
-    return this.request(
-      { method: "tools/list", params },
-      ListToolsResultSchema,
+  listTools(params?: ListToolsRequest["params"], options?: RequestOptions) {
+    if (this._isV2Iframe === false) {
+      throw new Error(
+        "bridge.listTools(): connected iframe is ext-apps v1 (capabilities arrived via ui/initialize only). " +
+          "Host→iframe tool listing uses the v2-only 'ui/list-view-tools' wire method; upgrade the iframe to ext-apps@2.",
+      );
+    }
+    return this.ui.sendRequest(
+      "ui/list-view-tools",
+      params,
+      specTypeSchema("ListToolsResult"),
       options,
     );
   }
 
+  // ── Lifecycle ─────────────────────────────────────────────────────────────
+
   /**
-   * Connect to the view via transport and optionally set up message forwarding.
-   *
-   * This method establishes the transport connection. If an MCP client was passed
-   * to the constructor, it also automatically sets up request/notification forwarding
-   * based on the MCP server's capabilities, proxying the following to the view:
-   * - Tools (tools/call, notifications/tools/list_changed)
-   * - Resources (resources/list, resources/read, resources/templates/list, notifications/resources/list_changed)
-   * - Prompts (prompts/list, notifications/prompts/list_changed)
-   *
-   * If no client was passed to the constructor, no automatic forwarding is set up
-   * and you must register handlers manually using the {@link oncalltool `oncalltool`}, {@link onlistresources `onlistresources`},
-   * etc. setters.
-   *
-   * After calling connect, wait for the {@link oninitialized `oninitialized`} callback before sending
-   * tool input and other data to the View.
-   *
-   * @param transport - Transport layer (typically {@link PostMessageTransport `PostMessageTransport`})
-   * @returns Promise resolving when connection is established
-   *
-   * @throws {Error} If a client was passed but server capabilities are not available.
-   *   This occurs when connect() is called before the MCP client has completed its
-   *   initialization with the server. Ensure `await client.connect()` completes
-   *   before calling `bridge.connect()`.
-   *
-   * @example With MCP client (automatic forwarding)
-   * ```ts source="./app-bridge.examples.ts#AppBridge_connect_withMcpClient"
-   * const bridge = new AppBridge(mcpClient, hostInfo, capabilities);
-   * const transport = new PostMessageTransport(
-   *   iframe.contentWindow!,
-   *   iframe.contentWindow!,
-   * );
+   * Connect to the iframe.
    *
-   * bridge.oninitialized = () => {
-   *   console.log("View ready");
-   *   bridge.sendToolInput({ arguments: toolArgs });
-   * };
-   *
-   * await bridge.connect(transport);
-   * ```
-   *
-   * @example Without MCP client (manual handlers)
-   * ```ts source="./app-bridge.examples.ts#AppBridge_connect_withoutMcpClient"
-   * const bridge = new AppBridge(null, hostInfo, capabilities);
-   *
-   * // Register handlers manually
-   * bridge.oncalltool = async (params, extra) => {
-   *   // Custom tool call handling
-   *   return { content: [] };
-   * };
-   *
-   * await bridge.connect(transport);
-   * ```
+   * If an `mcpClient` was passed to the constructor, automatically wires the
+   * standard-MCP proxy handlers (`oncalltool`, `onreadresource`, …) to forward
+   * to that client, and relays `list_changed` notifications.
    */
-  async connect(transport: Transport) {
-    if (this.transport) {
+  async connect(transport: Transport): Promise<void> {
+    if (this.server.transport) {
       throw new Error(
         "AppBridge is already connected. Call close() before connecting again.",
       );
     }
     if (this._client) {
-      // When a client was passed to the constructor, automatically forward
-      // MCP requests/notifications between the view and the server
-      const serverCapabilities = this._client.getServerCapabilities();
-      if (!serverCapabilities) {
-        throw new Error("Client server capabilities not available");
-      }
-
-      if (serverCapabilities.tools) {
-        this.oncalltool = async (params, extra) => {
-          return this._client!.request(
-            { method: "tools/call", params },
-            CallToolResultSchema,
-            { signal: extra.signal },
-          );
-        };
-        if (serverCapabilities.tools.listChanged) {
+      const sc = this._client.getServerCapabilities();
+      if (!sc) throw new Error("Client server capabilities not available");
+
+      if (sc.tools) {
+        this.oncalltool = async (params, extra) =>
+          this._client!.callTool(params, {
+            signal: extra.signal,
+          }) as Promise<CallToolResult>;
+        this.onlisttools = async (params, extra) =>
+          this._client!.listTools(params, { signal: extra.signal });
+        if (sc.tools.listChanged) {
           this._client.setNotificationHandler(
-            ToolListChangedNotificationSchema,
-            (n) => this.sendToolListChanged(n.params),
+            "notifications/tools/list_changed",
+            () => this.sendToolListChanged(),
           );
         }
       }
-      if (serverCapabilities.resources) {
-        this.onlistresources = async (params, extra) => {
-          return this._client!.request(
-            { method: "resources/list", params },
-            ListResourcesResultSchema,
-            { signal: extra.signal },
-          );
-        };
-        this.onlistresourcetemplates = async (params, extra) => {
-          return this._client!.request(
-            { method: "resources/templates/list", params },
-            ListResourceTemplatesResultSchema,
-            { signal: extra.signal },
-          );
-        };
-        this.onreadresource = async (params, extra) => {
-          return this._client!.request(
-            { method: "resources/read", params },
-            ReadResourceResultSchema,
-            { signal: extra.signal },
-          );
-        };
-        if (serverCapabilities.resources.listChanged) {
+      if (sc.resources) {
+        this.onlistresources = async (params, extra) =>
+          this._client!.listResources(params, { signal: extra.signal });
+        this.onlistresourcetemplates = async (params, extra) =>
+          this._client!.listResourceTemplates(params, {
+            signal: extra.signal,
+          });
+        this.onreadresource = async (params, extra) =>
+          this._client!.readResource(params, { signal: extra.signal });
+        if (sc.resources.listChanged) {
           this._client.setNotificationHandler(
-            ResourceListChangedNotificationSchema,
-            (n) => this.sendResourceListChanged(n.params),
+            "notifications/resources/list_changed",
+            () => this.sendResourceListChanged(),
           );
         }
       }
-      if (serverCapabilities.prompts) {
-        this.onlistprompts = async (params, extra) => {
-          return this._client!.request(
-            { method: "prompts/list", params },
-            ListPromptsResultSchema,
-            { signal: extra.signal },
-          );
-        };
-        if (serverCapabilities.prompts.listChanged) {
+      if (sc.prompts) {
+        this.onlistprompts = async (params, extra) =>
+          this._client!.listPrompts(params, { signal: extra.signal });
+        if (sc.prompts.listChanged) {
           this._client.setNotificationHandler(
-            PromptListChangedNotificationSchema,
-            (n) => this.sendPromptListChanged(n.params),
+            "notifications/prompts/list_changed",
+            () => this.sendPromptListChanged(),
           );
         }
       }
     }
+    return this.server.connect(transport);
+  }
 
-    // MCP-UI specific handlers are registered by the host component
-    // after the proxy is created. The standard MCP initialization
-    // (via oninitialized callback set in constructor) handles the ready signal.
-
-    return super.connect(transport);
+  /** Close the connection. */
+  async close(): Promise<void> {
+    return this.server.close();
   }
-}
 
-function deepEqual(a: any, b: any): boolean {
-  return JSON.stringify(a) === JSON.stringify(b);
+  /** Underlying transport (for diagnostics). */
+  get transport(): Transport | undefined {
+    return this.server.transport;
+  }
 }
diff --git a/src/app.examples.ts b/src/app.examples.ts
index a0a582076..939a02536 100644
--- a/src/app.examples.ts
+++ b/src/app.examples.ts
@@ -7,11 +7,11 @@
  * @module
  */
 
-import type { Tool } from "@modelcontextprotocol/sdk/types.js";
+import type { Tool } from "@modelcontextprotocol/client";
 import type {
   McpServer,
   ToolCallback,
-} from "@modelcontextprotocol/sdk/server/mcp.js";
+} from "@modelcontextprotocol/server";
 import {
   App,
   PostMessageTransport,
@@ -551,10 +551,7 @@ async function App_setupAutoResize_manual(transport: PostMessageTransport) {
   await app.connect(transport);
 
   // Later, enable auto-resize manually
-  const cleanup = app.setupSizeChangedNotifications();
-
-  // Clean up when done
-  cleanup();
+  app.setupSizeChangedNotifications();
   //#endregion App_setupAutoResize_manual
 }
 
diff --git a/src/app.ts b/src/app.ts
index f5f97b37c..e11a35cac 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -1,52 +1,48 @@
 import {
+  Client,
+  type CallToolRequest,
+  type ClientContext,
+  type CallToolResult,
+  type ExtensionHandle,
+  type Implementation,
+  type ListResourcesRequest,
+  type ListResourcesResult,
+  type ListToolsRequest,
+  type ListToolsResult,
+  type LoggingMessageNotification,
+  type ProtocolOptions,
+  type ReadResourceRequest,
+  type ReadResourceResult,
   type RequestOptions,
-  ProtocolOptions,
-} from "@modelcontextprotocol/sdk/shared/protocol.js";
+  type Transport,
+} from "@modelcontextprotocol/client";
 
-import {
-  CallToolRequest,
-  CallToolRequestSchema,
-  CallToolResult,
-  CallToolResultSchema,
-  EmptyResultSchema,
-  Implementation,
-  ListResourcesRequest,
-  ListResourcesResult,
-  ListResourcesResultSchema,
-  ListToolsRequest,
-  ListToolsRequestSchema,
-  ListToolsResult,
-  LoggingMessageNotification,
-  PingRequestSchema,
-  ReadResourceRequest,
-  ReadResourceResult,
-  ReadResourceResultSchema,
-} from "@modelcontextprotocol/sdk/types.js";
-import { AppNotification, AppRequest, AppResult } from "./types";
-import { ProtocolWithEvents } from "./events";
-export { ProtocolWithEvents };
+import { EventDispatcher } from "./events";
+export { EventDispatcher, ProtocolWithEvents } from "./events";
 import { PostMessageTransport } from "./message-transport";
+import { specTypeSchema } from "@modelcontextprotocol/client";
 import {
   LATEST_PROTOCOL_VERSION,
   McpUiAppCapabilities,
-  McpUiUpdateModelContextRequest,
+  McpUiAppCapabilitiesSchema,
+  McpUiDownloadFileRequest,
+  McpUiDownloadFileResultSchema,
   McpUiHostCapabilities,
+  McpUiHostCapabilitiesSchema,
   McpUiHostContext,
   McpUiHostContextChangedNotification,
   McpUiHostContextChangedNotificationSchema,
-  McpUiInitializedNotification,
-  McpUiInitializeRequest,
   McpUiInitializeResultSchema,
   McpUiMessageRequest,
   McpUiMessageResultSchema,
   McpUiOpenLinkRequest,
   McpUiOpenLinkResultSchema,
-  McpUiDownloadFileRequest,
-  McpUiDownloadFileResultSchema,
+  McpUiRequestDisplayModeRequest,
+  McpUiRequestDisplayModeResultSchema,
+  McpUiRequestTeardownNotification,
   McpUiResourceTeardownRequest,
   McpUiResourceTeardownRequestSchema,
   McpUiResourceTeardownResult,
-  McpUiRequestTeardownNotification,
   McpUiSizeChangedNotification,
   McpUiToolCancelledNotification,
   McpUiToolCancelledNotificationSchema,
@@ -56,117 +52,88 @@ import {
   McpUiToolInputPartialNotificationSchema,
   McpUiToolResultNotification,
   McpUiToolResultNotificationSchema,
-  McpUiRequestDisplayModeRequest,
-  McpUiRequestDisplayModeResultSchema,
+  McpUiUpdateModelContextRequest,
 } from "./types";
-import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
 
 export { PostMessageTransport } from "./message-transport";
 export * from "./types";
 export {
-  applyHostStyleVariables,
+  applyDocumentTheme,
   applyHostFonts,
+  applyHostStyleVariables,
   getDocumentTheme,
-  applyDocumentTheme,
 } from "./styles";
 
+/** SEP-2133 extension identifier for MCP Apps. */
+export const MCP_APPS_EXTENSION_ID = "io.modelcontextprotocol/ui";
+
 /**
  * Metadata key for associating a UI resource URI with a tool.
  *
  * MCP servers include this key in tool definition metadata (via `tools/list`)
  * to indicate which UI resource should be displayed when the tool is called.
- * When hosts see a tool with this metadata, they fetch and render the
- * corresponding {@link App `App`}.
- *
- * **Note**: This constant is provided for reference and backwards compatibility.
- * Server developers should use {@link server-helpers!registerAppTool `registerAppTool`}
- * with the `_meta.ui.resourceUri` format instead. Host developers must check both
- * formats for compatibility.
  *
- * @example Modern format (server-side, not in Apps)
- * ```ts source="./app.examples.ts#RESOURCE_URI_META_KEY_modernFormat"
- * // Preferred: Use registerAppTool with nested ui.resourceUri
- * registerAppTool(
- *   server,
- *   "weather",
- *   {
- *     description: "Get weather forecast",
- *     _meta: {
- *       ui: { resourceUri: "ui://weather/forecast" },
- *     },
- *   },
- *   handler,
- * );
- * ```
- *
- * @example Legacy format (deprecated, for backwards compatibility)
- * ```ts source="./app.examples.ts#RESOURCE_URI_META_KEY_legacyFormat"
- * // Deprecated: Direct use of RESOURCE_URI_META_KEY
- * server.registerTool(
- *   "weather",
- *   {
- *     description: "Get weather forecast",
- *     _meta: {
- *       [RESOURCE_URI_META_KEY]: "ui://weather/forecast",
- *     },
- *   },
- *   handler,
- * );
- * ```
- *
- * @example How hosts check for this metadata (must support both formats)
- * ```ts source="./app.examples.ts#RESOURCE_URI_META_KEY_hostSide"
- * // Hosts should check both modern and legacy formats
- * const meta = tool._meta;
- * const uiMeta = meta?.ui as McpUiToolMeta | undefined;
- * const legacyUri = meta?.[RESOURCE_URI_META_KEY] as string | undefined;
- * const uiUri = uiMeta?.resourceUri ?? legacyUri;
- * if (typeof uiUri === "string" && uiUri.startsWith("ui://")) {
- *   // Fetch the resource and display the UI
- * }
- * ```
+ * **Note**: Prefer the nested `_meta.ui.resourceUri` format via
+ * {@link server-helpers!registerAppTool `registerAppTool`}. This flat key is
+ * kept for backwards compatibility.
  */
 export const RESOURCE_URI_META_KEY = "ui/resourceUri";
 
+/** MIME type identifying an MCP App HTML resource. */
+export const RESOURCE_MIME_TYPE = "text/html;profile=mcp-app";
+
 /**
- * MIME type for MCP UI resources.
+ * Extract UI resource URI from tool metadata.
  *
- * Identifies HTML content as an MCP App UI resource.
- *
- * Used by {@link server-helpers!registerAppResource `registerAppResource`} as the default MIME type for app resources.
+ * Supports both the nested `_meta.ui.resourceUri` format and the deprecated
+ * flat `_meta["ui/resourceUri"]` format.
  */
-export const RESOURCE_MIME_TYPE = "text/html;profile=mcp-app";
+export function getToolUiResourceUri(tool: {
+  _meta?: Record<string, unknown>;
+}): string | undefined {
+  const meta = tool._meta;
+  if (!meta) return undefined;
+  const ui = meta.ui as { resourceUri?: unknown } | undefined;
+  const hasNested = ui != null && "resourceUri" in ui;
+  const candidate = hasNested ? ui.resourceUri : meta[RESOURCE_URI_META_KEY];
+  if (candidate === undefined && !hasNested) return undefined;
+  if (typeof candidate !== "string" || !candidate.startsWith("ui://")) {
+    throw new Error(
+      'Invalid UI resource URI (must be a string starting with "ui://"): ' +
+        JSON.stringify(candidate),
+    );
+  }
+  return candidate;
+}
 
 /**
- * Options for configuring {@link App `App`} behavior.
- *
- * Extends `ProtocolOptions` from the MCP SDK with `App`-specific configuration.
+ * Handler context passed to `on*` request handlers.
  *
- * @see `ProtocolOptions` from @modelcontextprotocol/sdk for inherited options
+ * In v2 this is a slimmed adapter over the SDK's `BaseContext`. Most v1
+ * consumers only used `signal`.
  */
-type AppOptions = ProtocolOptions & {
+export type RequestHandlerExtra = {
+  /** AbortSignal that fires if the request is cancelled. */
+  signal: AbortSignal;
+};
+
+function toExtra(ctx: { mcpReq: { signal: AbortSignal } }): RequestHandlerExtra {
+  return { signal: ctx.mcpReq.signal };
+}
+
+/**
+ * Options for constructing an {@link App `App`}.
+ */
+export interface AppOptions extends ProtocolOptions {
   /**
-   * Automatically report size changes to the host using `ResizeObserver`.
-   *
-   * When enabled, the {@link App `App`} monitors `document.body` and `document.documentElement`
-   * for size changes and automatically sends `ui/notifications/size-changed`
-   * notifications to the host.
-   *
-   * @default true
+   * Automatically observe document size and emit
+   * `ui/notifications/size-changed` to the host. Default: `true`.
    */
   autoResize?: boolean;
-};
-
-type RequestHandlerExtra = Parameters<
-  Parameters<App["setRequestHandler"]>[1]
->[1];
+}
 
 /**
- * Maps DOM-style event names to their notification `params` types.
- *
- * Used by {@link App `App`} (which extends {@link ProtocolWithEvents `ProtocolWithEvents`})
- * to provide type-safe `addEventListener` / `removeEventListener` and
- * singular `on*` handler support.
+ * Event map for {@link App `App`} — notifications the host pushes to the view.
  */
 export type AppEventMap = {
   toolinput: McpUiToolInputNotification["params"];
@@ -176,675 +143,218 @@ export type AppEventMap = {
   hostcontextchanged: McpUiHostContextChangedNotification["params"];
 };
 
+const APP_EVENT_NOTIFICATION_SCHEMAS = {
+  toolinput: McpUiToolInputNotificationSchema,
+  toolinputpartial: McpUiToolInputPartialNotificationSchema,
+  toolresult: McpUiToolResultNotificationSchema,
+  toolcancelled: McpUiToolCancelledNotificationSchema,
+  hostcontextchanged: McpUiHostContextChangedNotificationSchema,
+} as const;
+
 /**
- * Main class for MCP Apps to communicate with their host.
- *
- * The `App` class provides a framework-agnostic way to build interactive MCP Apps
- * that run inside host applications. It extends the MCP SDK's `Protocol` class and
- * handles the connection lifecycle, initialization handshake, and bidirectional
- * communication with the host.
- *
- * ## Architecture
- *
- * Views (Apps) act as MCP clients connecting to the host via {@link PostMessageTransport `PostMessageTransport`}.
- * The host proxies requests to the actual MCP server and forwards
- * responses back to the App.
- *
- * ## Lifecycle
- *
- * 1. **Create**: Instantiate App with info and capabilities
- * 2. **Connect**: Call `connect()` to establish transport and perform handshake
- * 3. **Interactive**: Send requests, receive notifications, call tools
- * 4. **Teardown**: Host sends teardown request before unmounting
- *
- * ## Inherited Methods
+ * The View side of the MCP Apps protocol — runs inside the iframe.
  *
- * As a subclass of {@link ProtocolWithEvents `ProtocolWithEvents`}, `App` inherits:
- * - `setRequestHandler()` - Register handlers for requests from host
- * - `setNotificationHandler()` - Register handlers for notifications from host
- * - `addEventListener()` - Append a listener for a notification event (multi-listener)
- * - `removeEventListener()` - Remove a previously added listener
- *
- * @see {@link ProtocolWithEvents `ProtocolWithEvents`} for the DOM-model event system
- *
- * ## Notification Setters (DOM-model `on*` handlers)
- *
- * For common notifications, the `App` class provides getter/setter properties
- * that follow DOM-model replace semantics (like `el.onclick`):
- * - `ontoolinput` - Complete tool arguments from host
- * - `ontoolinputpartial` - Streaming partial tool arguments
- * - `ontoolresult` - Tool execution results
- * - `ontoolcancelled` - Tool execution was cancelled by user or host
- * - `onhostcontextchanged` - Host context changes (theme, locale, etc.)
- *
- * Assigning replaces the previous handler; assigning `undefined` clears it.
- * Use `addEventListener` to attach multiple listeners without replacing.
- *
- * @example Basic usage with PostMessageTransport
- * ```ts source="./app.examples.ts#App_basicUsage"
- * const app = new App(
- *   { name: "WeatherApp", version: "1.0.0" },
- *   {}, // capabilities
- * );
- *
- * // Register handlers before connecting to ensure no notifications are missed
- * app.ontoolinput = (params) => {
- *   console.log("Tool arguments:", params.arguments);
- * };
+ * `App` composes an MCP {@link Client `Client`} (the iframe is the MCP client
+ * on the postMessage wire, per SEP-1865) and an
+ * {@link ExtensionHandle `ExtensionHandle`} for the `ui/*` extension methods.
+ * Standard MCP methods (`tools/call`, `resources/read`, …) are proxied through
+ * the host to the real MCP server via the underlying `Client`.
  *
+ * @example
+ * ```ts
+ * const app = new App({ name: "MyApp", version: "1.0.0" }, {});
+ * app.ontoolresult = (r) => render(r);
  * await app.connect();
  * ```
  */
-export class App extends ProtocolWithEvents<
-  AppRequest,
-  AppNotification,
-  AppResult,
-  AppEventMap
-> {
-  private _hostCapabilities?: McpUiHostCapabilities;
-  private _hostInfo?: Implementation;
-  private _hostContext?: McpUiHostContext;
-
-  protected readonly eventSchemas = {
-    toolinput: McpUiToolInputNotificationSchema,
-    toolinputpartial: McpUiToolInputPartialNotificationSchema,
-    toolresult: McpUiToolResultNotificationSchema,
-    toolcancelled: McpUiToolCancelledNotificationSchema,
-    hostcontextchanged: McpUiHostContextChangedNotificationSchema,
-  };
+export class App extends EventDispatcher<AppEventMap> {
+  /** Underlying MCP Client (iframe → host wire). */
+  readonly client: Client;
+  /** SEP-2133 extension handle for `ui/*` methods. */
+  readonly ui: ExtensionHandle<McpUiAppCapabilities, McpUiHostCapabilities, ClientContext>;
 
-  protected override onEventDispatch<K extends keyof AppEventMap>(
-    event: K,
-    params: AppEventMap[K],
-  ): void {
-    if (event === "hostcontextchanged") {
-      this._hostContext = { ...this._hostContext, ...params };
-    }
-  }
+  private _hostContext?: McpUiHostContext;
+  private _hostInfo?: Implementation;
+  private _resizeObserver?: ResizeObserver;
 
   /**
-   * Create a new MCP App instance.
-   *
-   * @param _appInfo - App identification (name and version)
-   * @param _capabilities - Features and capabilities this app provides
-   * @param options - Configuration options including `autoResize` behavior
-   *
-   * @example
-   * ```ts source="./app.examples.ts#App_constructor_basic"
-   * const app = new App(
-   *   { name: "MyApp", version: "1.0.0" },
-   *   { tools: { listChanged: true } }, // capabilities
-   *   { autoResize: true }, // options
-   * );
-   * ```
+   * Optional error handler. Called when the underlying transport surfaces an
+   * error. Mirrors the v1 `Protocol.onerror` slot.
    */
+  onerror?: (error: Error) => void;
+  /** Called when the underlying transport closes. Mirrors v1 Protocol.onclose. */
+  onclose?: () => void;
+
   constructor(
     private _appInfo: Implementation,
     private _capabilities: McpUiAppCapabilities = {},
-    private options: AppOptions = { autoResize: true },
+    readonly options: AppOptions = { autoResize: true },
   ) {
-    super(options);
-
-    this.setRequestHandler(PingRequestSchema, (request) => {
-      console.log("Received ping:", request.params);
-      return {};
+    super();
+    this.client = new Client(_appInfo, {
+      ...options,
+      capabilities: { roots: undefined },
+    });
+    this.client.onerror = (err) => this.onerror?.(err);
+    this.client.onclose = () => this.onclose?.();
+    this.ui = this.client.extension(MCP_APPS_EXTENSION_ID, _capabilities, {
+      peerSchema: McpUiHostCapabilitiesSchema,
     });
 
-    // Eagerly register the hostcontextchanged event slot so that
-    // onEventDispatch (which merges into _hostContext) fires even if the
-    // user never assigns onhostcontextchanged or calls addEventListener.
-    this.setEventHandler("hostcontextchanged", undefined);
+    // Wire incoming ui/* notifications to the DOM-style event system.
+    for (const [event, schema] of Object.entries(
+      APP_EVENT_NOTIFICATION_SCHEMAS,
+    )) {
+      this.ui.setNotificationHandler(
+        schema.shape.method.value as string,
+        (schema.shape.params ?? schema) as never,
+        (params) => this.dispatchEvent(event as keyof AppEventMap, params),
+      );
+    }
+
+    // ui/resource-teardown (host → app request)
+    this.ui.setRequestHandler(
+      McpUiResourceTeardownRequestSchema.shape.method.value,
+      McpUiResourceTeardownRequestSchema.shape.params,
+      async (params, ctx) => {
+        if (this._onteardown) return this._onteardown(params, toExtra(ctx));
+        return {};
+      },
+    );
+
+    // Non-spec host→iframe tool surface (renamed from tools/call & tools/list).
+    this.ui.setRequestHandler(
+      "ui/call-view-tool",
+      specTypeSchema("CallToolRequestParams"),
+      async (params, ctx) => {
+        if (!this._oncalltool) throw new Error("No oncalltool handler set");
+        return this._oncalltool(params, toExtra(ctx));
+      },
+    );
+    this.ui.setRequestHandler(
+      "ui/list-view-tools",
+      specTypeSchema("PaginatedRequestParams"),
+      async (params, ctx) => {
+        if (!this._onlisttools) throw new Error("No onlisttools handler set");
+        return this._onlisttools(params, toExtra(ctx));
+      },
+    );
   }
 
+  /** Merge `hostcontextchanged` params into cached state before listeners fire. */
+  protected override onEventDispatch<K extends keyof AppEventMap>(
+    event: K,
+    params: AppEventMap[K],
+  ): void {
+    if (event === "hostcontextchanged") {
+      this._hostContext = { ...(this._hostContext ?? {}), ...(params as McpUiHostContext) };
+    }
+  }
+
+  // ── Host info / capabilities / context ────────────────────────────────────
+
   /**
-   * Get the host's capabilities discovered during initialization.
-   *
-   * Returns the capabilities that the host advertised during the
-   * {@link connect `connect`} handshake. Returns `undefined` if called before
-   * connection is established.
-   *
-   * @returns Host capabilities, or `undefined` if not yet connected
-   *
-   * @example Check host capabilities after connection
-   * ```ts source="./app.examples.ts#App_getHostCapabilities_checkAfterConnection"
-   * await app.connect();
-   * if (app.getHostCapabilities()?.serverTools) {
-   *   console.log("Host supports server tool calls");
-   * }
-   * ```
-   *
-   * @see {@link connect `connect`} for the initialization handshake
-   * @see {@link McpUiHostCapabilities `McpUiHostCapabilities`} for the capabilities structure
+   * Host capabilities advertised via `capabilities.extensions[io.modelcontextprotocol/ui]`
+   * during the MCP `initialize` handshake.
    */
+  get hostCapabilities(): McpUiHostCapabilities | undefined {
+    return this.ui.getPeerSettings();
+  }
+  /** @deprecated Use {@link hostCapabilities `hostCapabilities`}. */
   getHostCapabilities(): McpUiHostCapabilities | undefined {
-    return this._hostCapabilities;
+    return this.hostCapabilities;
   }
 
-  /**
-   * Get the host's implementation info discovered during initialization.
-   *
-   * Returns the host's name and version as advertised during the
-   * {@link connect `connect`} handshake. Returns `undefined` if called before
-   * connection is established.
-   *
-   * @returns Host implementation info, or `undefined` if not yet connected
-   *
-   * @example Log host information after connection
-   * ```ts source="./app.examples.ts#App_getHostVersion_logAfterConnection"
-   * await app.connect(transport);
-   * const { name, version } = app.getHostVersion() ?? {};
-   * console.log(`Connected to ${name} v${version}`);
-   * ```
-   *
-   * @see {@link connect `connect`} for the initialization handshake
-   */
+  /** Host implementation info from `ui/initialize`. */
   getHostVersion(): Implementation | undefined {
     return this._hostInfo;
   }
 
   /**
-   * Get the host context discovered during initialization.
-   *
-   * Returns the host context that was provided in the initialization response,
-   * including tool info, theme, locale, and other environment details.
-   * This context is automatically updated when the host sends
-   * `ui/notifications/host-context-changed` notifications.
-   *
-   * Returns `undefined` if called before connection is established.
-   *
-   * @returns Host context, or `undefined` if not yet connected
-   *
-   * @example Access host context after connection
-   * ```ts source="./app.examples.ts#App_getHostContext_accessAfterConnection"
-   * await app.connect(transport);
-   * const context = app.getHostContext();
-   * if (context?.theme === "dark") {
-   *   document.body.classList.add("dark-theme");
-   * }
-   * if (context?.toolInfo) {
-   *   console.log("Tool:", context.toolInfo.tool.name);
-   * }
-   * ```
-   *
-   * @see {@link connect `connect`} for the initialization handshake
-   * @see {@link onhostcontextchanged `onhostcontextchanged`} for context change notifications
-   * @see {@link McpUiHostContext `McpUiHostContext`} for the context structure
+   * Current host context (theme, locale, displayMode, hostStyles, …). Updated
+   * automatically by `ui/notifications/host-context-changed`.
    */
   getHostContext(): McpUiHostContext | undefined {
     return this._hostContext;
   }
 
-  /**
-   * Convenience handler for receiving complete tool input from the host.
-   *
-   * Set this property to register a handler that will be called when the host
-   * sends a tool's complete arguments. This is sent after a tool call begins
-   * and before the tool result is available.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   * Use {@link addEventListener `addEventListener`} to attach multiple listeners
-   * without replacing.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing notifications.
-   *
-   * @example
-   * ```ts source="./app.examples.ts#App_ontoolinput_setter"
-   * // Register before connecting to ensure no notifications are missed
-   * app.ontoolinput = (params) => {
-   *   console.log("Tool:", params.arguments);
-   *   // Update your UI with the tool arguments
-   * };
-   * await app.connect();
-   * ```
-   *
-   * @deprecated Use {@link addEventListener `addEventListener("toolinput", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   * @see {@link McpUiToolInputNotification `McpUiToolInputNotification`} for the notification structure
-   */
-  get ontoolinput():
-    | ((params: McpUiToolInputNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("toolinput");
-  }
-  set ontoolinput(
-    callback:
-      | ((params: McpUiToolInputNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("toolinput", callback);
-  }
+  // ── Notification on* setters (DOM-style) ──────────────────────────────────
 
-  /**
-   * Convenience handler for receiving streaming partial tool input from the host.
-   *
-   * Set this property to register a handler that will be called as the host
-   * streams partial tool arguments during tool call initialization. This enables
-   * progressive rendering of tool arguments before they're complete.
-   *
-   * **Important:** Partial arguments are "healed" JSON — the host closes unclosed
-   * brackets/braces to produce valid JSON. This means objects may be incomplete
-   * (e.g., the last item in an array may be truncated). Use partial data only
-   * for preview UI, not for critical operations.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   * Use {@link addEventListener `addEventListener`} to attach multiple listeners
-   * without replacing.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing notifications.
-   *
-   * @example Progressive rendering of tool arguments
-   * ```ts source="./app.examples.ts#App_ontoolinputpartial_progressiveRendering"
-   * const codePreview = document.querySelector<HTMLPreElement>("#code-preview")!;
-   * const canvas = document.querySelector<HTMLCanvasElement>("#canvas")!;
-   *
-   * app.ontoolinputpartial = (params) => {
-   *   codePreview.textContent = (params.arguments?.code as string) ?? "";
-   *   codePreview.style.display = "block";
-   *   canvas.style.display = "none";
-   * };
-   *
-   * app.ontoolinput = (params) => {
-   *   codePreview.style.display = "none";
-   *   canvas.style.display = "block";
-   *   render(params.arguments?.code as string);
-   * };
-   * ```
-   *
-   * @deprecated Use {@link addEventListener `addEventListener("toolinputpartial", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   * @see {@link McpUiToolInputPartialNotification `McpUiToolInputPartialNotification`} for the notification structure
-   * @see {@link ontoolinput `ontoolinput`} for the complete tool input handler
-   */
-  get ontoolinputpartial():
-    | ((params: McpUiToolInputPartialNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("toolinputpartial");
-  }
-  set ontoolinputpartial(
-    callback:
-      | ((params: McpUiToolInputPartialNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("toolinputpartial", callback);
-  }
+  get ontoolinput() { return this.getEventHandler("toolinput"); }
+  set ontoolinput(h) { this.setEventHandler("toolinput", h); }
 
-  /**
-   * Convenience handler for receiving tool execution results from the host.
-   *
-   * Set this property to register a handler that will be called when the host
-   * sends the result of a tool execution. This is sent after the tool completes
-   * on the MCP server, allowing your app to display the results or update its state.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   * Use {@link addEventListener `addEventListener`} to attach multiple listeners
-   * without replacing.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing notifications.
-   *
-   * @example Display tool execution results
-   * ```ts source="./app.examples.ts#App_ontoolresult_displayResults"
-   * app.ontoolresult = (params) => {
-   *   if (params.isError) {
-   *     console.error("Tool execution failed:", params.content);
-   *   } else if (params.content) {
-   *     console.log("Tool output:", params.content);
-   *   }
-   * };
-   * ```
-   *
-   * @deprecated Use {@link addEventListener `addEventListener("toolresult", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   * @see {@link McpUiToolResultNotification `McpUiToolResultNotification`} for the notification structure
-   * @see {@link ontoolinput `ontoolinput`} for the initial tool input handler
-   */
-  get ontoolresult():
-    | ((params: McpUiToolResultNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("toolresult");
-  }
-  set ontoolresult(
-    callback:
-      | ((params: McpUiToolResultNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("toolresult", callback);
-  }
+  get ontoolinputpartial() { return this.getEventHandler("toolinputpartial"); }
+  set ontoolinputpartial(h) { this.setEventHandler("toolinputpartial", h); }
 
-  /**
-   * Convenience handler for receiving tool cancellation notifications from the host.
-   *
-   * Set this property to register a handler that will be called when the host
-   * notifies that tool execution was cancelled. This can occur for various reasons
-   * including user action, sampling error, classifier intervention, or other
-   * interruptions. Apps should update their state and display appropriate feedback.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   * Use {@link addEventListener `addEventListener`} to attach multiple listeners
-   * without replacing.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing notifications.
-   *
-   * @example Handle tool cancellation
-   * ```ts source="./app.examples.ts#App_ontoolcancelled_handleCancellation"
-   * app.ontoolcancelled = (params) => {
-   *   console.log("Tool cancelled:", params.reason);
-   *   // Update your UI to show cancellation state
-   * };
-   * ```
-   *
-   * @deprecated Use {@link addEventListener `addEventListener("toolcancelled", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   * @see {@link McpUiToolCancelledNotification `McpUiToolCancelledNotification`} for the notification structure
-   * @see {@link ontoolresult `ontoolresult`} for successful tool completion
-   */
-  get ontoolcancelled():
-    | ((params: McpUiToolCancelledNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("toolcancelled");
-  }
-  set ontoolcancelled(
-    callback:
-      | ((params: McpUiToolCancelledNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("toolcancelled", callback);
-  }
+  get ontoolresult() { return this.getEventHandler("toolresult"); }
+  set ontoolresult(h) { this.setEventHandler("toolresult", h); }
 
-  /**
-   * Convenience handler for host context changes (theme, locale, etc.).
-   *
-   * Set this property to register a handler that will be called when the host's
-   * context changes, such as theme switching (light/dark), locale changes, or
-   * other environmental updates. Apps should respond by updating their UI
-   * accordingly.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   * Use {@link addEventListener `addEventListener`} to attach multiple listeners
-   * without replacing.
-   *
-   * Notification params are automatically merged into the internal host context
-   * via {@link onEventDispatch `onEventDispatch`} before any handler or listener
-   * fires. This means {@link getHostContext `getHostContext`} will return the
-   * updated values even before your callback runs.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing notifications.
-   *
-   * @example Respond to theme changes
-   * ```ts source="./app.examples.ts#App_onhostcontextchanged_respondToTheme"
-   * app.onhostcontextchanged = (ctx) => {
-   *   if (ctx.theme === "dark") {
-   *     document.body.classList.add("dark-theme");
-   *   } else {
-   *     document.body.classList.remove("dark-theme");
-   *   }
-   * };
-   * ```
-   *
-   * @deprecated Use {@link addEventListener `addEventListener("hostcontextchanged", handler)`} instead — it composes with other listeners and supports cleanup via {@link removeEventListener `removeEventListener`}.
-   * @see {@link McpUiHostContextChangedNotification `McpUiHostContextChangedNotification`} for the notification structure
-   * @see {@link McpUiHostContext `McpUiHostContext`} for the full context structure
-   */
-  get onhostcontextchanged():
-    | ((params: McpUiHostContextChangedNotification["params"]) => void)
-    | undefined {
-    return this.getEventHandler("hostcontextchanged");
-  }
-  set onhostcontextchanged(
-    callback:
-      | ((params: McpUiHostContextChangedNotification["params"]) => void)
-      | undefined,
-  ) {
-    this.setEventHandler("hostcontextchanged", callback);
-  }
+  get ontoolcancelled() { return this.getEventHandler("toolcancelled"); }
+  set ontoolcancelled(h) { this.setEventHandler("toolcancelled", h); }
+
+  get onhostcontextchanged() { return this.getEventHandler("hostcontextchanged"); }
+  set onhostcontextchanged(h) { this.setEventHandler("hostcontextchanged", h); }
+
+  // ── Request on* setters ───────────────────────────────────────────────────
 
-  /**
-   * Convenience handler for graceful shutdown requests from the host.
-   *
-   * Set this property to register a handler that will be called when the host
-   * requests the app to prepare for teardown. This allows the app to perform
-   * cleanup operations (save state, close connections, etc.) before being unmounted.
-   *
-   * The handler can be sync or async. The host will wait for the returned promise
-   * to resolve before proceeding with teardown.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing requests.
-   *
-   * @param callback - Function called when teardown is requested.
-   *   Must return `McpUiResourceTeardownResult` (can be an empty object `{}`) or a Promise resolving to it.
-   *
-   * @example Perform cleanup before teardown
-   * ```ts source="./app.examples.ts#App_onteardown_performCleanup"
-   * app.onteardown = async () => {
-   *   await saveState();
-   *   closeConnections();
-   *   console.log("App ready for teardown");
-   *   return {};
-   * };
-   * ```
-   *
-   * @see {@link McpUiResourceTeardownRequest `McpUiResourceTeardownRequest`} for the request structure
-   */
   private _onteardown?: (
     params: McpUiResourceTeardownRequest["params"],
     extra: RequestHandlerExtra,
-  ) => McpUiResourceTeardownResult | Promise<McpUiResourceTeardownResult>;
-  get onteardown() {
-    return this._onteardown;
-  }
-  set onteardown(
-    callback:
-      | ((
-          params: McpUiResourceTeardownRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => McpUiResourceTeardownResult | Promise<McpUiResourceTeardownResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced("onteardown", this._onteardown, callback);
-    this._onteardown = callback;
-    this.replaceRequestHandler(
-      McpUiResourceTeardownRequestSchema,
-      (request, extra) => {
-        if (!this._onteardown) throw new Error("No onteardown handler set");
-        return this._onteardown(request.params, extra);
-      },
-    );
-  }
-
+  ) => Promise<McpUiResourceTeardownResult> | McpUiResourceTeardownResult;
   /**
-   * Convenience handler for tool call requests from the host.
-   *
-   * Set this property to register a handler that will be called when the host
-   * requests this app to execute a tool. This enables apps to provide their own
-   * tools that can be called by the host or LLM.
-   *
-   * The app must declare tool capabilities in the constructor to use this handler.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing requests.
-   *
-   * @param callback - Async function that executes the tool and returns the result.
-   *   The callback will only be invoked if the app declared tool capabilities
-   *   in the constructor.
-   *
-   * @example Handle tool calls from the host
-   * ```ts source="./app.examples.ts#App_oncalltool_handleFromHost"
-   * app.oncalltool = async (params, extra) => {
-   *   if (params.name === "greet") {
-   *     const name = params.arguments?.name ?? "World";
-   *     return { content: [{ type: "text", text: `Hello, ${name}!` }] };
-   *   }
-   *   throw new Error(`Unknown tool: ${params.name}`);
-   * };
-   * ```
+   * Handler for `ui/resource-teardown` — called by the host before the iframe
+   * is unmounted. Return after any cleanup is complete.
    */
+  get onteardown() { return this._onteardown; }
+  set onteardown(cb) {
+    this.warnIfRequestHandlerReplaced("onteardown", this._onteardown, cb);
+    this._onteardown = cb;
+  }
+
   private _oncalltool?: (
     params: CallToolRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<CallToolResult>;
-  get oncalltool() {
-    return this._oncalltool;
-  }
-  set oncalltool(
-    callback:
-      | ((
-          params: CallToolRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<CallToolResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced("oncalltool", this._oncalltool, callback);
-    this._oncalltool = callback;
-    this.replaceRequestHandler(CallToolRequestSchema, (request, extra) => {
-      if (!this._oncalltool) throw new Error("No oncalltool handler set");
-      return this._oncalltool(request.params, extra);
-    });
-  }
-
   /**
-   * Convenience handler for listing available tools.
-   *
-   * Set this property to register a handler that will be called when the host
-   * requests a list of tools this app provides. This enables dynamic tool
-   * discovery by the host or LLM.
-   *
-   * The app must declare tool capabilities in the constructor to use this handler.
-   *
-   * Assigning replaces the previous handler; assigning `undefined` clears it.
-   *
-   * Register handlers before calling {@link connect `connect`} to avoid missing requests.
-   *
-   * @param callback - Async function that returns a {@link ListToolsResult `ListToolsResult`}.
-   *   Registration is always allowed; capability validation occurs when handlers
-   *   are invoked.
+   * Handler for tools the **iframe** exposes to the host (e.g.,
+   * `get_current_selection`). The host calls these via
+   * {@link app-bridge!AppBridge.callTool `AppBridge.callTool`}.
    *
-   * @example Return available tools
-   * ```ts source="./app.examples.ts#App_onlisttools_returnTools"
-   * app.onlisttools = async (params, extra) => {
-   *   return {
-   *     tools: [
-   *       { name: "greet", inputSchema: { type: "object" as const } },
-   *       { name: "calculate", inputSchema: { type: "object" as const } },
-   *       { name: "format", inputSchema: { type: "object" as const } },
-   *     ],
-   *   };
-   * };
-   * ```
-   *
-   * @see {@link oncalltool `oncalltool`} for handling tool execution
+   * Wire method: `ui/call-view-tool` (renamed from `tools/call` in v2; not part
+   * of SEP-1865's standard-MCP-messages set).
    */
+  get oncalltool() { return this._oncalltool; }
+  set oncalltool(cb) {
+    this.warnIfRequestHandlerReplaced("oncalltool", this._oncalltool, cb);
+    this._oncalltool = cb;
+  }
+
   private _onlisttools?: (
     params: ListToolsRequest["params"],
     extra: RequestHandlerExtra,
   ) => Promise<ListToolsResult>;
-  get onlisttools() {
-    return this._onlisttools;
-  }
-  set onlisttools(
-    callback:
-      | ((
-          params: ListToolsRequest["params"],
-          extra: RequestHandlerExtra,
-        ) => Promise<ListToolsResult>)
-      | undefined,
-  ) {
-    this.warnIfRequestHandlerReplaced(
-      "onlisttools",
-      this._onlisttools,
-      callback,
-    );
-    this._onlisttools = callback;
-    this.replaceRequestHandler(ListToolsRequestSchema, (request, extra) => {
-      if (!this._onlisttools) throw new Error("No onlisttools handler set");
-      return this._onlisttools(request.params, extra);
-    });
-  }
-
-  /**
-   * Verify that the host supports the capability required for the given request method.
-   * @internal
-   */
-  assertCapabilityForMethod(method: AppRequest["method"]): void {
-    // TODO
-  }
-
-  /**
-   * Verify that the app declared the capability required for the given request method.
-   * @internal
-   */
-  assertRequestHandlerCapability(method: AppRequest["method"]): void {
-    switch (method) {
-      case "tools/call":
-      case "tools/list":
-        if (!this._capabilities.tools) {
-          throw new Error(
-            `Client does not support tool capability (required for ${method})`,
-          );
-        }
-        return;
-      case "ping":
-      case "ui/resource-teardown":
-        return;
-      default:
-        throw new Error(`No handler for method ${method} registered`);
-    }
-  }
-
   /**
-   * Verify that the app supports the capability required for the given notification method.
-   * @internal
+   * Handler that lists tools the **iframe** exposes. See {@link oncalltool}.
+   *
+   * Wire method: `ui/list-view-tools` (renamed from `tools/list` in v2).
    */
-  assertNotificationCapability(method: AppNotification["method"]): void {
-    // TODO
+  get onlisttools() { return this._onlisttools; }
+  set onlisttools(cb) {
+    this.warnIfRequestHandlerReplaced("onlisttools", this._onlisttools, cb);
+    this._onlisttools = cb;
   }
 
-  /**
-   * Verify that task creation is supported for the given request method.
-   * @internal
-   */
-  protected assertTaskCapability(_method: string): void {
-    throw new Error("Tasks are not supported in MCP Apps");
-  }
-
-  /**
-   * Verify that task handler is supported for the given method.
-   * @internal
-   */
-  protected assertTaskHandlerCapability(_method: string): void {
-    throw new Error("Task handlers are not supported in MCP Apps");
-  }
+  // ── Outbound: standard MCP (proxied through host to real server) ──────────
 
   /**
    * Call a tool on the originating MCP server (proxied through the host).
    *
-   * Apps can call tools to fetch fresh data or trigger server-side actions.
-   * The host proxies the request to the actual MCP server and returns the result.
-   *
-   * @param params - Tool name and arguments
-   * @param options - Request options (timeout, etc.)
-   * @returns Tool execution result
-   *
-   * @throws {Error} If the tool does not exist on the server
-   * @throws {Error} If the request times out or the connection is lost
-   * @throws {Error} If the host rejects the request
-   *
-   * Note: Tool-level execution errors are returned in the result with `isError: true`
-   * rather than throwing exceptions. Always check `result.isError` to distinguish
-   * between transport failures (thrown) and tool execution failures (returned).
-   *
-   * @example Fetch updated weather data
-   * ```ts source="./app.examples.ts#App_callServerTool_fetchWeather"
-   * try {
-   *   const result = await app.callServerTool({
-   *     name: "get_weather",
-   *     arguments: { location: "Tokyo" },
-   *   });
-   *   if (result.isError) {
-   *     console.error("Tool returned error:", result.content);
-   *   } else {
-   *     console.log(result.content);
-   *   }
-   * } catch (error) {
-   *   console.error("Tool call failed:", error);
-   * }
+   * @example
+   * ```ts
+   * const result = await app.callServerTool({
+   *   name: "search",
+   *   arguments: { query: "weather" },
+   * });
    * ```
    */
   async callServerTool(
@@ -857,652 +367,205 @@ export class App extends ProtocolWithEvents<
           `Did you mean: callServerTool({ name: "${params}", arguments: { ... } })?`,
       );
     }
-    return await this.request(
-      { method: "tools/call", params },
-      CallToolResultSchema,
-      options,
-    );
+    return this.client.callTool(params, options) as Promise<CallToolResult>;
   }
 
-  /**
-   * Read a resource from the originating MCP server (proxied through the host).
-   *
-   * Apps can read resources to access files, data, or other content provided by
-   * the MCP server. Resources are identified by URI (e.g., `file:///path/to/file`
-   * or custom schemes like `videos://bunny-1mb`). The host proxies the request to
-   * the actual MCP server and returns the resource content.
-   *
-   * @param params - Resource URI to read
-   * @param options - Request options (timeout, etc.)
-   * @returns Resource content with URI, name, description, mimeType, and contents array
-   *
-   * @throws {Error} If the resource does not exist on the server
-   * @throws {Error} If the request times out or the connection is lost
-   * @throws {Error} If the host rejects the request
-   *
-   * @example Read a video resource and play it
-   * ```ts source="./app.examples.ts#App_readServerResource_playVideo"
-   * try {
-   *   const result = await app.readServerResource({
-   *     uri: "videos://bunny-1mb",
-   *   });
-   *   const content = result.contents[0];
-   *   if (content && "blob" in content) {
-   *     const binary = Uint8Array.from(atob(content.blob), (c) =>
-   *       c.charCodeAt(0),
-   *     );
-   *     const url = URL.createObjectURL(
-   *       new Blob([binary], { type: content.mimeType || "video/mp4" }),
-   *     );
-   *     videoElement.src = url;
-   *     videoElement.play();
-   *   }
-   * } catch (error) {
-   *   console.error("Failed to read resource:", error);
-   * }
-   * ```
-   *
-   * @see {@link listServerResources `listServerResources`} to discover available resources
-   */
+  /** Read a resource from the originating MCP server (proxied through the host). */
   async readServerResource(
     params: ReadResourceRequest["params"],
     options?: RequestOptions,
   ): Promise<ReadResourceResult> {
-    return await this.request(
-      { method: "resources/read", params },
-      ReadResourceResultSchema,
-      options,
-    );
+    return this.client.readResource(params, options);
   }
 
-  /**
-   * List available resources from the originating MCP server (proxied through the host).
-   *
-   * Apps can list resources to discover what content is available on the MCP server.
-   * This enables dynamic resource discovery and building resource browsers or pickers.
-   * The host proxies the request to the actual MCP server and returns the resource list.
-   *
-   * Results may be paginated using the `cursor` parameter for servers with many resources.
-   *
-   * @param params - Optional parameters (omit for all resources, or `{ cursor }` for pagination)
-   * @param options - Request options (timeout, etc.)
-   * @returns List of resources with their URIs, names, descriptions, mimeTypes, and optional pagination cursor
-   *
-   * @throws {Error} If the request times out or the connection is lost
-   * @throws {Error} If the host rejects the request
-   *
-   * @example Discover available videos and build a picker UI
-   * ```ts source="./app.examples.ts#App_listServerResources_buildPicker"
-   * try {
-   *   const result = await app.listServerResources();
-   *   const videoResources = result.resources.filter((r) =>
-   *     r.mimeType?.startsWith("video/"),
-   *   );
-   *   videoResources.forEach((resource) => {
-   *     const option = document.createElement("option");
-   *     option.value = resource.uri;
-   *     option.textContent = resource.description || resource.name;
-   *     selectElement.appendChild(option);
-   *   });
-   * } catch (error) {
-   *   console.error("Failed to list resources:", error);
-   * }
-   * ```
-   *
-   * @see {@link readServerResource `readServerResource`} to read a specific resource
-   */
+  /** List resources from the originating MCP server (proxied through the host). */
   async listServerResources(
     params?: ListResourcesRequest["params"],
     options?: RequestOptions,
   ): Promise<ListResourcesResult> {
-    return await this.request(
-      { method: "resources/list", params },
-      ListResourcesResultSchema,
-      options,
-    );
+    return this.client.listResources(params, options);
   }
 
+  // ── Outbound: ui/* requests ───────────────────────────────────────────────
+
   /**
-   * Send a message to the host's chat interface.
-   *
-   * Enables the app to add messages to the conversation thread. Useful for
-   * user-initiated messages or app-to-conversation communication.
-   *
-   * @param params - Message role and content
-   * @param options - Request options (timeout, etc.)
-   * @returns Result with optional `isError` flag indicating host rejection
-   *
-   * @throws {Error} If the request times out or the connection is lost
-   *
-   * @example Send a text message from user interaction
-   * ```ts source="./app.examples.ts#App_sendMessage_textFromInteraction"
-   * try {
-   *   const result = await app.sendMessage({
-   *     role: "user",
-   *     content: [{ type: "text", text: "Show me details for item #42" }],
-   *   });
-   *   if (result.isError) {
-   *     console.error("Host rejected the message");
-   *     // Handle rejection appropriately for your app
-   *   }
-   * } catch (error) {
-   *   console.error("Failed to send message:", error);
-   *   // Handle transport/protocol error
-   * }
-   * ```
-   *
-   * @example Send follow-up message after offloading large data to model context
-   * ```ts source="./app.examples.ts#App_sendMessage_withLargeContext"
-   * const markdown = `---
-   * word-count: ${fullTranscript.split(/\s+/).length}
-   * speaker-names: ${speakerNames.join(", ")}
-   * ---
-   *
-   * ${fullTranscript}`;
-   *
-   * // Offload long transcript to model context
-   * await app.updateModelContext({ content: [{ type: "text", text: markdown }] });
-   *
-   * // Send brief trigger message
-   * await app.sendMessage({
-   *   role: "user",
-   *   content: [{ type: "text", text: "Summarize the key points" }],
-   * });
-   * ```
-   *
-   * @see {@link McpUiMessageRequest `McpUiMessageRequest`} for request structure
+   * Send a message to the host that should be treated as if the user typed it.
+   * Typically pre-fills or submits the chat input.
    */
-  sendMessage(params: McpUiMessageRequest["params"], options?: RequestOptions) {
-    return this.request(
-      <McpUiMessageRequest>{
-        method: "ui/message",
-        params,
-      },
+  sendMessage(
+    params: McpUiMessageRequest["params"],
+    options?: RequestOptions,
+  ) {
+    return this.ui.sendRequest(
+      "ui/message",
+      params,
       McpUiMessageResultSchema,
       options,
     );
   }
 
   /**
-   * Send log messages to the host for debugging and telemetry.
+   * Send a log message to the host.
    *
-   * Logs are not added to the conversation but may be recorded by the host
-   * for debugging purposes.
-   *
-   * @param params - Log level and message
-   *
-   * @example Log app state for debugging
-   * ```ts source="./app.examples.ts#App_sendLog_debugState"
-   * app.sendLog({
-   *   level: "info",
-   *   data: "Weather data refreshed",
-   *   logger: "WeatherApp",
-   * });
-   * ```
-   *
-   * @returns Promise that resolves when the log notification is sent
+   * Wire method: `ui/log` (renamed from `notifications/message` in v2; the v1
+   * direction conflicted with core MCP semantics).
    */
   sendLog(params: LoggingMessageNotification["params"]) {
-    return this.notification(<LoggingMessageNotification>{
-      method: "notifications/message",
-      params,
-    });
+    return this.ui.sendNotification("ui/log", params);
   }
 
   /**
-   * Update the host's model context with app state.
-   *
-   * Context updates are intended to be available to the model in future
-   * turns, without triggering an immediate model response (unlike {@link sendMessage `sendMessage`}).
-   *
-   * The host will typically defer sending the context to the model until the
-   * next user message — either from the actual user or via `sendMessage`. Only
-   * the last update is sent; each call overwrites any previous context.
-   *
-   * @param params - Context content and/or structured content
-   * @param options - Request options (timeout, etc.)
-   *
-   * @throws {Error} If the host rejects the context update (e.g., unsupported content type)
-   * @throws {Error} If the request times out or the connection is lost
-   *
-   * @example Update model context with current app state
-   * ```ts source="./app.examples.ts#App_updateModelContext_appState"
-   * const markdown = `---
-   * item-count: ${itemList.length}
-   * total-cost: ${totalCost}
-   * currency: ${currency}
-   * ---
-   *
-   * User is viewing their shopping cart with ${itemList.length} items selected:
-   *
-   * ${itemList.map((item) => `- ${item}`).join("\n")}`;
-   *
-   * await app.updateModelContext({
-   *   content: [{ type: "text", text: markdown }],
-   * });
-   * ```
-   *
-   * @example Report runtime error to model
-   * ```ts source="./app.examples.ts#App_updateModelContext_reportError"
-   * try {
-   *   const _stream = await navigator.mediaDevices.getUserMedia({ audio: true });
-   *   // ... use _stream for transcription
-   * } catch (err) {
-   *   // Inform the model that the app is in a degraded state
-   *   await app.updateModelContext({
-   *     content: [
-   *       {
-   *         type: "text",
-   *         text: "Error: transcription unavailable",
-   *       },
-   *     ],
-   *   });
-   * }
-   * ```
-   *
-   * @returns Promise that resolves when the context update is acknowledged
+   * Update the host's model context with app state. The host stashes this and
+   * includes it in the next prompt turn.
    */
   updateModelContext(
     params: McpUiUpdateModelContextRequest["params"],
     options?: RequestOptions,
   ) {
-    return this.request(
-      <McpUiUpdateModelContextRequest>{
-        method: "ui/update-model-context",
-        params,
-      },
-      EmptyResultSchema,
+    return this.ui.sendRequest(
+      "ui/update-model-context",
+      params,
+      specTypeSchema("EmptyResult"),
       options,
     );
   }
 
-  /**
-   * Request the host to open an external URL in the default browser.
-   *
-   * The host may deny this request based on user preferences or security policy.
-   * Apps should handle rejection gracefully by checking `result.isError`.
-   *
-   * @param params - URL to open
-   * @param options - Request options (timeout, etc.)
-   * @returns Result with `isError: true` if the host denied the request (e.g., blocked domain, user cancelled)
-   *
-   * @throws {Error} If the request times out or the connection is lost
-   *
-   * @example Open documentation link
-   * ```ts source="./app.examples.ts#App_openLink_documentation"
-   * const { isError } = await app.openLink({ url: "https://docs.example.com" });
-   * if (isError) {
-   *   // Host denied the request (e.g., blocked domain, user cancelled)
-   *   // Optionally show fallback: display URL for manual copy
-   *   console.warn("Link request denied");
-   * }
-   * ```
-   *
-   * @see {@link McpUiOpenLinkRequest `McpUiOpenLinkRequest`} for request structure
-   * @see {@link McpUiOpenLinkResult `McpUiOpenLinkResult`} for result structure
-   */
-  openLink(params: McpUiOpenLinkRequest["params"], options?: RequestOptions) {
-    return this.request(
-      <McpUiOpenLinkRequest>{
-        method: "ui/open-link",
-        params,
-      },
+  /** Ask the host to open a URL in the user's browser. */
+  openLink(
+    params: McpUiOpenLinkRequest["params"],
+    options?: RequestOptions,
+  ) {
+    return this.ui.sendRequest(
+      "ui/open-link",
+      params,
       McpUiOpenLinkResultSchema,
       options,
     );
   }
+  /** @deprecated Use {@link openLink `openLink`}. */
+  get sendOpenLink() { return this.openLink; }
 
-  /** @deprecated Use {@link openLink `openLink`} instead */
-  sendOpenLink: App["openLink"] = this.openLink;
-
-  /**
-   * Request the host to download a file.
-   *
-   * Since MCP Apps run in sandboxed iframes where direct downloads are blocked,
-   * this provides a host-mediated mechanism for file exports. The host will
-   * typically show a confirmation dialog before initiating the download.
-   *
-   * Uses standard MCP resource types: `EmbeddedResource` for inline content
-   * and `ResourceLink` for content the host can fetch directly.
-   *
-   * @param params - Resource contents to download
-   * @param options - Request options (timeout, etc.)
-   * @returns Result with `isError: true` if the host denied the request (e.g., user cancelled)
-   *
-   * @throws {Error} If the request times out or the connection is lost
-   *
-   * @example Download a JSON file (embedded text resource)
-   * ```ts
-   * const data = JSON.stringify({ items: selectedItems }, null, 2);
-   * const { isError } = await app.downloadFile({
-   *   contents: [{
-   *     type: "resource",
-   *     resource: {
-   *       uri: "file:///export.json",
-   *       mimeType: "application/json",
-   *       text: data,
-   *     },
-   *   }],
-   * });
-   * if (isError) {
-   *   console.warn("Download denied or cancelled");
-   * }
-   * ```
-   *
-   * @example Download binary content (embedded blob resource)
-   * ```ts
-   * const { isError } = await app.downloadFile({
-   *   contents: [{
-   *     type: "resource",
-   *     resource: {
-   *       uri: "file:///image.png",
-   *       mimeType: "image/png",
-   *       blob: base64EncodedPng,
-   *     },
-   *   }],
-   * });
-   * ```
-   *
-   * @example Download via resource link (host fetches)
-   * ```ts
-   * const { isError } = await app.downloadFile({
-   *   contents: [{
-   *     type: "resource_link",
-   *     uri: "https://api.example.com/reports/q4.pdf",
-   *     name: "Q4 Report",
-   *     mimeType: "application/pdf",
-   *   }],
-   * });
-   * ```
-   *
-   * @see {@link McpUiDownloadFileRequest `McpUiDownloadFileRequest`} for request structure
-   * @see {@link McpUiDownloadFileResult `McpUiDownloadFileResult`} for result structure
-   */
+  /** Ask the host to download a file to the user's machine. */
   downloadFile(
     params: McpUiDownloadFileRequest["params"],
     options?: RequestOptions,
   ) {
-    return this.request(
-      <McpUiDownloadFileRequest>{
-        method: "ui/download-file",
-        params,
-      },
+    return this.ui.sendRequest(
+      "ui/download-file",
+      params,
       McpUiDownloadFileResultSchema,
       options,
     );
   }
 
-  /**
-   * Request the host to tear down this app.
-   *
-   * Apps call this method to request that the host tear them down. The host
-   * decides whether to proceed - if approved, the host will send
-   * `ui/resource-teardown` to allow the app to perform gracefull termination before being
-   * unmounted. This piggybacks on the existing teardown mechanism, ensuring
-   * the app only needs a single shutdown procedure (via {@link onteardown `onteardown`})
-   * regardless of whether the teardown was initiated by the app or the host.
-   *
-   * This is a fire-and-forget notification - no response is expected.
-   * If the host approves, the app will receive a `ui/resource-teardown`
-   * request via the {@link onteardown `onteardown`} handler to persist unsaved state.
-   *
-   * @param params - Empty params object (reserved for future use)
-   * @returns Promise that resolves when the notification is sent
-   *
-   * @example App-initiated teardown after user action
-   * ```typescript
-   * // User clicks "Done" button in the app
-   * async function handleDoneClick() {
-   *   // Request the host to tear down the app
-   *   await app.requestTeardown();
-   *   // If host approves, onteardown handler will be called for termination
-   * }
-   *
-   * // Set up teardown handler (called for both app-initiated and host-initiated teardown)
-   * app.onteardown = async () => {
-   *   await saveState();
-   *   closeConnections();
-   *   return {};
-   * };
-   * ```
-   *
-   * @see {@link McpUiRequestTeardownNotification `McpUiRequestTeardownNotification`} for notification structure
-   * @see {@link onteardown `onteardown`} for the graceful termination handler
-   */
-  requestTeardown(params: McpUiRequestTeardownNotification["params"] = {}) {
-    return this.notification(<McpUiRequestTeardownNotification>{
-      method: "ui/notifications/request-teardown",
-      params,
-    });
-  }
-
-  /**
-   * Request a change to the display mode.
-   *
-   * Requests the host to change the UI container to the specified display mode
-   * (e.g., "inline", "fullscreen", "pip"). The host will respond with the actual
-   * display mode that was set, which may differ from the requested mode if
-   * the requested mode is not available (check `availableDisplayModes` in host context).
-   *
-   * @param params - The display mode being requested
-   * @param options - Request options (timeout, etc.)
-   * @returns Result containing the actual display mode that was set
-   *
-   * @example Toggle display mode
-   * ```ts source="./app.examples.ts#App_requestDisplayMode_toggle"
-   * const container = document.getElementById("main")!;
-   * const ctx = app.getHostContext();
-   * const newMode = ctx?.displayMode === "inline" ? "fullscreen" : "inline";
-   * if (ctx?.availableDisplayModes?.includes(newMode)) {
-   *   const result = await app.requestDisplayMode({ mode: newMode });
-   *   container.classList.toggle("fullscreen", result.mode === "fullscreen");
-   * }
-   * ```
-   *
-   * @see {@link McpUiRequestDisplayModeRequest `McpUiRequestDisplayModeRequest`} for request structure
-   * @see {@link McpUiHostContext `McpUiHostContext`} for checking availableDisplayModes
-   */
+  /** Ask the host to change the iframe's display mode (inline ↔ fullscreen ↔ pip). */
   requestDisplayMode(
     params: McpUiRequestDisplayModeRequest["params"],
     options?: RequestOptions,
   ) {
-    return this.request(
-      <McpUiRequestDisplayModeRequest>{
-        method: "ui/request-display-mode",
-        params,
-      },
+    return this.ui.sendRequest(
+      "ui/request-display-mode",
+      params,
       McpUiRequestDisplayModeResultSchema,
       options,
     );
   }
 
-  /**
-   * Notify the host of UI size changes.
-   *
-   * Apps can manually report size changes to help the host adjust the container.
-   * If `autoResize` is enabled (default), this is called automatically.
-   *
-   * @param params - New width and height in pixels
-   *
-   * @example Manually notify host of size change
-   * ```ts source="./app.examples.ts#App_sendSizeChanged_manual"
-   * app.sendSizeChanged({
-   *   width: 400,
-   *   height: 600,
-   * });
-   * ```
-   *
-   * @returns Promise that resolves when the notification is sent
-   *
-   * @see {@link McpUiSizeChangedNotification `McpUiSizeChangedNotification`} for notification structure
-   */
+  // ── Outbound: ui/* notifications ──────────────────────────────────────────
+
+  /** Ask the host to tear down this view (e.g., user clicked a close button). */
+  requestTeardown(
+    params?: McpUiRequestTeardownNotification["params"],
+  ) {
+    return this.ui.sendNotification("ui/notifications/request-teardown", params);
+  }
+
+  /** Notify the host that the iframe's content size changed. */
   sendSizeChanged(params: McpUiSizeChangedNotification["params"]) {
-    return this.notification(<McpUiSizeChangedNotification>{
-      method: "ui/notifications/size-changed",
-      params,
-    });
+    return this.ui.sendNotification("ui/notifications/size-changed", params);
   }
+  /** @deprecated Use {@link sendSizeChanged `sendSizeChanged`}. */
+  get notifySizeChanged() { return this.sendSizeChanged; }
 
   /**
-   * Set up automatic size change notifications using ResizeObserver.
-   *
-   * Observes both `document.documentElement` and `document.body` for size changes
-   * and automatically sends `ui/notifications/size-changed` notifications to the host.
-   * The notifications are debounced using requestAnimationFrame to avoid duplicates.
-   *
-   * Note: This method is automatically called by `connect()` if the `autoResize`
-   * option is true (default). You typically don't need to call this manually unless
-   * you disabled autoResize and want to enable it later.
-   *
-   * @returns Cleanup function to disconnect the observer
-   *
-   * @example Manual setup for custom scenarios
-   * ```ts source="./app.examples.ts#App_setupAutoResize_manual"
-   * const app = new App(
-   *   { name: "MyApp", version: "1.0.0" },
-   *   {},
-   *   { autoResize: false },
-   * );
-   * await app.connect(transport);
-   *
-   * // Later, enable auto-resize manually
-   * const cleanup = app.setupSizeChangedNotifications();
-   *
-   * // Clean up when done
-   * cleanup();
-   * ```
+   * Start observing document size and emitting size-changed notifications.
+   * Called automatically by {@link connect `connect`} when
+   * `options.autoResize` is true.
    */
-  setupSizeChangedNotifications() {
-    let scheduled = false;
-    let lastWidth = 0;
-    let lastHeight = 0;
-
-    const sendBodySizeChanged = () => {
-      if (scheduled) {
-        return;
-      }
-      scheduled = true;
-      requestAnimationFrame(() => {
-        scheduled = false;
-        const html = document.documentElement;
-
-        // Measure actual content height by temporarily overriding html sizing.
-        // Height uses max-content because fit-content would clamp to the viewport
-        // height when content is taller than the iframe, causing internal scrolling.
-        //
-        // Width uses window.innerWidth instead of measuring via fit-content.
-        // Setting html.style.width to fit-content forces a synchronous reflow at
-        // 0px width for responsive apps (whose content derives width from the
-        // container rather than having intrinsic width). This causes the browser
-        // to clamp scrollLeft on any horizontal scroll containers to 0, permanently
-        // destroying their scroll positions.
-        const originalHeight = html.style.height;
-        html.style.height = "max-content";
-        const height = Math.ceil(html.getBoundingClientRect().height);
-        html.style.height = originalHeight;
-
-        const width = Math.ceil(window.innerWidth);
-
-        // Only send if size actually changed (prevents feedback loops from style changes)
-        if (width !== lastWidth || height !== lastHeight) {
-          lastWidth = width;
-          lastHeight = height;
-          this.sendSizeChanged({ width, height });
-        }
+  setupSizeChangedNotifications(): void {
+    if (typeof ResizeObserver === "undefined" || this._resizeObserver) return;
+    this._resizeObserver = new ResizeObserver(() => {
+      void this.sendSizeChanged({
+        width: document.documentElement.scrollWidth,
+        height: document.documentElement.scrollHeight,
       });
-    };
-
-    sendBodySizeChanged();
-
-    const resizeObserver = new ResizeObserver(sendBodySizeChanged);
-    // Observe both html and body to catch all size changes
-    resizeObserver.observe(document.documentElement);
-    resizeObserver.observe(document.body);
-
-    return () => resizeObserver.disconnect();
+    });
+    this._resizeObserver.observe(document.documentElement);
   }
 
+  // ── Lifecycle ─────────────────────────────────────────────────────────────
+
   /**
-   * Establish connection with the host and perform initialization handshake.
-   *
-   * This method performs the following steps:
-   * 1. Connects the transport layer
-   * 2. Sends `ui/initialize` request with app info and capabilities
-   * 3. Receives host capabilities and context in response
-   * 4. Sends `ui/notifications/initialized` notification
-   * 5. Sets up auto-resize using {@link setupSizeChangedNotifications `setupSizeChangedNotifications`} if enabled (default)
+   * Connect to the host.
    *
-   * If initialization fails, the connection is automatically closed and an error
-   * is thrown.
+   * Performs the MCP `initialize` handshake (which carries
+   * `capabilities.extensions[io.modelcontextprotocol/ui]`), then a slimmed
+   * `ui/initialize` to receive the initial `hostContext`, then
+   * `ui/notifications/initialized`.
    *
-   * @param transport - Transport layer (typically {@link PostMessageTransport `PostMessageTransport`})
-   * @param options - Request options for the initialize request
-   *
-   * @throws {Error} If initialization fails or connection is lost
-   *
-   * @example Connect with PostMessageTransport
-   * ```ts source="./app.examples.ts#App_connect_withPostMessageTransport"
-   * const app = new App({ name: "MyApp", version: "1.0.0" }, {});
-   *
-   * try {
-   *   await app.connect(new PostMessageTransport(window.parent, window.parent));
-   *   console.log("Connected successfully!");
-   * } catch (error) {
-   *   console.error("Failed to connect:", error);
-   * }
-   * ```
-   *
-   * @see {@link McpUiInitializeRequest `McpUiInitializeRequest`} for the initialization request structure
-   * @see {@link McpUiInitializedNotification `McpUiInitializedNotification`} for the initialized notification
-   * @see {@link PostMessageTransport `PostMessageTransport`} for the typical transport implementation
+   * @param transport - Defaults to a `PostMessageTransport` to `window.parent`.
    */
-  override async connect(
+  async connect(
     transport: Transport = new PostMessageTransport(
       window.parent,
       window.parent,
     ),
     options?: RequestOptions,
   ): Promise<void> {
-    if (this.transport) {
+    if (this.client.transport) {
       throw new Error(
         "App is already connected. Call close() before connecting again.",
       );
     }
-    await super.connect(transport);
+    await this.client.connect(transport, options);
 
     try {
-      const result = await this.request(
-        <McpUiInitializeRequest>{
-          method: "ui/initialize",
-          params: {
-            appCapabilities: this._capabilities,
-            appInfo: this._appInfo,
-            protocolVersion: LATEST_PROTOCOL_VERSION,
-          },
+      const result = await this.ui.sendRequest(
+        "ui/initialize",
+        {
+          appCapabilities: this._capabilities,
+          appInfo: this._appInfo,
+          protocolVersion: LATEST_PROTOCOL_VERSION,
         },
         McpUiInitializeResultSchema,
         options,
       );
-
       if (result === undefined) {
-        throw new Error(`Server sent invalid initialize result: ${result}`);
+        throw new Error(`Host sent invalid ui/initialize result: ${result}`);
       }
+      this._hostInfo = result.hostInfo as Implementation;
+      this._hostContext = (result.hostContext ?? {}) as McpUiHostContext;
 
-      this._hostCapabilities = result.hostCapabilities;
-      this._hostInfo = result.hostInfo;
-      this._hostContext = result.hostContext;
-
-      await this.notification(<McpUiInitializedNotification>{
-        method: "ui/notifications/initialized",
-      });
+      await this.ui.sendNotification("ui/notifications/initialized", undefined);
 
       if (this.options?.autoResize) {
         this.setupSizeChangedNotifications();
       }
     } catch (error) {
-      // Disconnect if initialization fails.
       void this.close();
       throw error;
     }
   }
+
+  /** Close the connection and release resources. */
+  async close(): Promise<void> {
+    this._resizeObserver?.disconnect();
+    this._resizeObserver = undefined;
+    return this.client.close();
+  }
+
+  /** Underlying transport (for diagnostics). */
+  get transport(): Transport | undefined {
+    return this.client.transport;
+  }
 }
diff --git a/src/events.ts b/src/events.ts
index 4d17ca4f2..251ea9183 100644
--- a/src/events.ts
+++ b/src/events.ts
@@ -1,13 +1,3 @@
-import { Protocol } from "@modelcontextprotocol/sdk/shared/protocol.js";
-import {
-  Request,
-  Notification,
-  Result,
-} from "@modelcontextprotocol/sdk/types.js";
-import { ZodLiteral, ZodObject } from "zod/v4";
-
-type MethodSchema = ZodObject<{ method: ZodLiteral<string> }>;
-
 /**
  * Per-event state: a singular `on*` handler (replace semantics) plus a
  * listener array (`addEventListener` semantics), mirroring the DOM model
@@ -19,13 +9,9 @@ interface EventSlot<T = unknown> {
 }
 
 /**
- * Intermediate base class that adds DOM-style event support on top of the
- * MCP SDK's `Protocol`.
+ * Standalone DOM-style event dispatcher base class.
  *
- * The base `Protocol` class stores one handler per method:
- * `setRequestHandler()` and `setNotificationHandler()` replace any existing
- * handler for the same method silently. This class introduces a two-channel
- * event model inspired by the DOM:
+ * Provides a two-channel event model:
  *
  * ### Singular `on*` handler (like `el.onclick`)
  *
@@ -42,41 +28,26 @@ interface EventSlot<T = unknown> {
  *
  * ### Dispatch order
  *
- * When a notification arrives for a mapped event:
+ * When {@link dispatchEvent `dispatchEvent`} is called for a mapped event:
  * 1. {@link onEventDispatch `onEventDispatch`} (subclass side-effects)
  * 2. The singular `on*` handler (if set)
  * 3. All `addEventListener` listeners in insertion order
  *
- * ### Double-set protection
- *
- * Direct calls to {@link setRequestHandler `setRequestHandler`} /
- * {@link setNotificationHandler `setNotificationHandler`} throw if a handler
- * for the same method has already been registered (through any path), so
- * accidental overwrites surface as errors instead of silent bugs.
+ * Unlike the v1 `ProtocolWithEvents`, this class has no coupling to the MCP
+ * SDK. Subclasses are responsible for wiring incoming notifications to
+ * {@link dispatchEvent `dispatchEvent`} themselves (typically via
+ * `ExtensionHandle.setNotificationHandler`).
  *
  * @typeParam EventMap - Maps event names to the listener's `params` type.
  */
-export abstract class ProtocolWithEvents<
-  SendRequestT extends Request,
-  SendNotificationT extends Notification,
-  SendResultT extends Result,
+export abstract class EventDispatcher<
   EventMap extends Record<string, unknown>,
-> extends Protocol<SendRequestT, SendNotificationT, SendResultT> {
-  private _registeredMethods = new Set<string>();
+> {
   private _eventSlots = new Map<keyof EventMap, EventSlot>();
 
   /**
-   * Event name → notification schema. Subclasses populate this so that
-   * the event system can lazily register a dispatcher with the correct
-   * schema on first use.
-   */
-  protected abstract readonly eventSchemas: {
-    [K in keyof EventMap]: MethodSchema;
-  };
-
-  /**
-   * Called once per incoming notification, before any handlers or listeners
-   * fire. Subclasses may override to perform side effects such as merging
+   * Called once per dispatch, before any handlers or listeners fire.
+   * Subclasses may override to perform side effects such as merging
    * notification params into cached state.
    */
   protected onEventDispatch<K extends keyof EventMap>(
@@ -87,9 +58,7 @@ export abstract class ProtocolWithEvents<
   // ── Event system (DOM model) ────────────────────────────────────────
 
   /**
-   * Lazily create the event slot and register a single dispatcher with the
-   * base `Protocol`. The dispatcher fans out to the `on*` handler and all
-   * `addEventListener` listeners.
+   * Lazily create the event slot for a given event name.
    */
   private _ensureEventSlot<K extends keyof EventMap>(
     event: K,
@@ -98,31 +67,32 @@ export abstract class ProtocolWithEvents<
       | EventSlot<EventMap[K]>
       | undefined;
     if (!slot) {
-      const schema = this.eventSchemas[event];
-      if (!schema) {
-        throw new Error(`Unknown event: ${String(event)}`);
-      }
       slot = { listeners: [] };
       this._eventSlots.set(event, slot as EventSlot);
-
-      // Claim this method so direct setNotificationHandler calls throw.
-      const method = schema.shape.method.value;
-      this._registeredMethods.add(method);
-
-      const s = slot; // stable reference for the closure
-      super.setNotificationHandler(schema, (n) => {
-        const params = (n as { params: EventMap[K] }).params;
-        this.onEventDispatch(event, params);
-        // 1. Singular on* handler
-        s.onHandler?.(params);
-        // 2. addEventListener listeners — snapshot to tolerate removal during
-        //    dispatch (e.g., a listener that calls removeEventListener on itself)
-        for (const l of [...s.listeners]) l(params);
-      });
     }
     return slot;
   }
 
+  /**
+   * Dispatch an event to its `on*` handler and all `addEventListener`
+   * listeners. Subclasses call this when a mapped notification arrives.
+   */
+  protected dispatchEvent<K extends keyof EventMap>(
+    event: K,
+    params: EventMap[K],
+  ): void {
+    this.onEventDispatch(event, params);
+    const slot = this._eventSlots.get(event) as
+      | EventSlot<EventMap[K]>
+      | undefined;
+    if (!slot) return;
+    // 1. Singular on* handler
+    slot.onHandler?.(params);
+    // 2. addEventListener listeners — snapshot to tolerate removal during
+    //    dispatch (e.g., a listener that calls removeEventListener on itself)
+    for (const l of [...slot.listeners]) l(params);
+  }
+
   /**
    * Set or clear the singular `on*` handler for an event.
    *
@@ -160,11 +130,7 @@ export abstract class ProtocolWithEvents<
    *
    * Unlike the singular `on*` handler, calling this multiple times appends
    * listeners rather than replacing them. All registered listeners fire in
-   * insertion order after the `on*` handler when the notification arrives.
-   *
-   * Registration is lazy: the first call (for a given event, from either
-   * this method or the `on*` setter) registers a dispatcher with the base
-   * `Protocol`.
+   * insertion order after the `on*` handler when the event is dispatched.
    *
    * @param event - Event name (a key of the `EventMap` type parameter).
    * @param handler - Listener invoked with the notification `params`.
@@ -177,9 +143,7 @@ export abstract class ProtocolWithEvents<
   }
 
   /**
-   * Remove a previously registered event listener. The dispatcher stays
-   * registered even if the listener array becomes empty; future
-   * notifications simply have no listeners to call.
+   * Remove a previously registered event listener.
    */
   removeEventListener<K extends keyof EventMap>(
     event: K,
@@ -193,46 +157,7 @@ export abstract class ProtocolWithEvents<
     if (idx !== -1) slot.listeners.splice(idx, 1);
   }
 
-  // ── Handler registration with double-set protection ─────────────────
-
-  // The two overrides below are arrow-function class fields rather than
-  // prototype methods so that Protocol's constructor — which registers its
-  // own ping/cancelled/progress handlers via `this.setRequestHandler`
-  // before our fields initialize — hits the base implementation and skips
-  // tracking. Converting these to proper methods would crash with
-  // `_registeredMethods` undefined during super().
-
-  /**
-   * Registers a request handler. Throws if a handler for the same method
-   * has already been registered — use the `on*` setter (replace semantics)
-   * or `addEventListener` (multi-listener) for notification events.
-   *
-   * @throws {Error} if a handler for this method is already registered.
-   */
-  override setRequestHandler: Protocol<
-    SendRequestT,
-    SendNotificationT,
-    SendResultT
-  >["setRequestHandler"] = (schema, handler) => {
-    this._assertMethodNotRegistered(schema, "setRequestHandler");
-    super.setRequestHandler(schema, handler);
-  };
-
-  /**
-   * Registers a notification handler. Throws if a handler for the same
-   * method has already been registered — use the `on*` setter (replace
-   * semantics) or `addEventListener` (multi-listener) for mapped events.
-   *
-   * @throws {Error} if a handler for this method is already registered.
-   */
-  override setNotificationHandler: Protocol<
-    SendRequestT,
-    SendNotificationT,
-    SendResultT
-  >["setNotificationHandler"] = (schema, handler) => {
-    this._assertMethodNotRegistered(schema, "setNotificationHandler");
-    super.setNotificationHandler(schema, handler);
-  };
+  // ── Compat shim for request-handler `on*` setters ──────────────────
 
   /**
    * Warn if a request handler `on*` setter is replacing a previously-set
@@ -250,30 +175,11 @@ export abstract class ProtocolWithEvents<
       );
     }
   }
-
-  /**
-   * Replace a request handler, bypassing double-set protection. Used by
-   * `on*` request-handler setters that need replace semantics.
-   */
-  protected replaceRequestHandler: Protocol<
-    SendRequestT,
-    SendNotificationT,
-    SendResultT
-  >["setRequestHandler"] = (schema, handler) => {
-    const method = (schema as MethodSchema).shape.method.value;
-    this._registeredMethods.add(method);
-    super.setRequestHandler(schema, handler);
-  };
-
-  private _assertMethodNotRegistered(schema: unknown, via: string): void {
-    const method = (schema as MethodSchema).shape.method.value;
-    if (this._registeredMethods.has(method)) {
-      throw new Error(
-        `Handler for "${method}" already registered (via ${via}). ` +
-          `Use addEventListener() to attach multiple listeners, ` +
-          `or the on* setter for replace semantics.`,
-      );
-    }
-    this._registeredMethods.add(method);
-  }
 }
+
+/**
+ * @deprecated Renamed to {@link EventDispatcher `EventDispatcher`} in v2.
+ * This alias is kept for source-level compatibility and will be removed in a
+ * future release.
+ */
+export const ProtocolWithEvents = EventDispatcher;
diff --git a/src/generated/schema.json b/src/generated/schema.json
index d66e55760..bfc9ef3a0 100644
--- a/src/generated/schema.json
+++ b/src/generated/schema.json
@@ -63,6 +63,9 @@
       },
       "additionalProperties": false
     },
+    "McpUiContentBlock": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema"
+    },
     "McpUiDisplayMode": {
       "$schema": "https://json-schema.org/draft/2020-12/schema",
       "anyOf": [
@@ -95,182 +98,7 @@
             "contents": {
               "type": "array",
               "items": {
-                "anyOf": [
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "resource"
-                      },
-                      "resource": {
-                        "anyOf": [
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "text": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "text"],
-                            "additionalProperties": false
-                          },
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "blob": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "blob"],
-                            "additionalProperties": false
-                          }
-                        ]
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "resource"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "name": {
-                        "type": "string"
-                      },
-                      "title": {
-                        "type": "string"
-                      },
-                      "icons": {
-                        "type": "array",
-                        "items": {
-                          "type": "object",
-                          "properties": {
-                            "src": {
-                              "type": "string"
-                            },
-                            "mimeType": {
-                              "type": "string"
-                            },
-                            "sizes": {
-                              "type": "array",
-                              "items": {
-                                "type": "string"
-                              }
-                            },
-                            "theme": {
-                              "type": "string",
-                              "enum": ["light", "dark"]
-                            }
-                          },
-                          "required": ["src"],
-                          "additionalProperties": false
-                        }
-                      },
-                      "uri": {
-                        "type": "string"
-                      },
-                      "description": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "size": {
-                        "type": "number"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "properties": {},
-                        "additionalProperties": {}
-                      },
-                      "type": {
-                        "type": "string",
-                        "const": "resource_link"
-                      }
-                    },
-                    "required": ["name", "uri", "type"],
-                    "additionalProperties": false
-                  }
-                ]
+                "anyOf": [{}, {}]
               },
               "description": "Resource contents to download — embedded (inline data) or linked (host fetches). Uses standard MCP resource types."
             }
@@ -503,7 +331,8 @@
           "additionalProperties": false
         }
       },
-      "additionalProperties": false
+      "additionalProperties": false,
+      "description": "Capabilities supported by the host application."
     },
     "McpUiHostContextChangedNotification": {
       "$schema": "https://json-schema.org/draft/2020-12/schema",
@@ -521,145 +350,9 @@
               "type": "object",
               "properties": {
                 "id": {
-                  "description": "JSON-RPC id of the tools/call request.",
-                  "anyOf": [
-                    {
-                      "type": "string"
-                    },
-                    {
-                      "type": "integer",
-                      "minimum": -9007199254740991,
-                      "maximum": 9007199254740991
-                    }
-                  ]
+                  "description": "JSON-RPC id of the tools/call request."
                 },
                 "tool": {
-                  "type": "object",
-                  "properties": {
-                    "name": {
-                      "type": "string"
-                    },
-                    "title": {
-                      "type": "string"
-                    },
-                    "icons": {
-                      "type": "array",
-                      "items": {
-                        "type": "object",
-                        "properties": {
-                          "src": {
-                            "type": "string"
-                          },
-                          "mimeType": {
-                            "type": "string"
-                          },
-                          "sizes": {
-                            "type": "array",
-                            "items": {
-                              "type": "string"
-                            }
-                          },
-                          "theme": {
-                            "type": "string",
-                            "enum": ["light", "dark"]
-                          }
-                        },
-                        "required": ["src"],
-                        "additionalProperties": false
-                      }
-                    },
-                    "description": {
-                      "type": "string"
-                    },
-                    "inputSchema": {
-                      "type": "object",
-                      "properties": {
-                        "type": {
-                          "type": "string",
-                          "const": "object"
-                        },
-                        "properties": {
-                          "type": "object",
-                          "propertyNames": {
-                            "type": "string"
-                          },
-                          "additionalProperties": {}
-                        },
-                        "required": {
-                          "type": "array",
-                          "items": {
-                            "type": "string"
-                          }
-                        }
-                      },
-                      "required": ["type"],
-                      "additionalProperties": {}
-                    },
-                    "outputSchema": {
-                      "type": "object",
-                      "properties": {
-                        "type": {
-                          "type": "string",
-                          "const": "object"
-                        },
-                        "properties": {
-                          "type": "object",
-                          "propertyNames": {
-                            "type": "string"
-                          },
-                          "additionalProperties": {}
-                        },
-                        "required": {
-                          "type": "array",
-                          "items": {
-                            "type": "string"
-                          }
-                        }
-                      },
-                      "required": ["type"],
-                      "additionalProperties": {}
-                    },
-                    "annotations": {
-                      "type": "object",
-                      "properties": {
-                        "title": {
-                          "type": "string"
-                        },
-                        "readOnlyHint": {
-                          "type": "boolean"
-                        },
-                        "destructiveHint": {
-                          "type": "boolean"
-                        },
-                        "idempotentHint": {
-                          "type": "boolean"
-                        },
-                        "openWorldHint": {
-                          "type": "boolean"
-                        }
-                      },
-                      "additionalProperties": false
-                    },
-                    "execution": {
-                      "type": "object",
-                      "properties": {
-                        "taskSupport": {
-                          "type": "string",
-                          "enum": ["required", "optional", "forbidden"]
-                        }
-                      },
-                      "additionalProperties": false
-                    },
-                    "_meta": {
-                      "type": "object",
-                      "propertyNames": {
-                        "type": "string"
-                      },
-                      "additionalProperties": {}
-                    }
-                  },
-                  "required": ["name", "inputSchema"],
-                  "additionalProperties": false,
                   "description": "Tool definition including name, inputSchema, etc."
                 }
               },
@@ -1284,145 +977,9 @@
           "type": "object",
           "properties": {
             "id": {
-              "description": "JSON-RPC id of the tools/call request.",
-              "anyOf": [
-                {
-                  "type": "string"
-                },
-                {
-                  "type": "integer",
-                  "minimum": -9007199254740991,
-                  "maximum": 9007199254740991
-                }
-              ]
+              "description": "JSON-RPC id of the tools/call request."
             },
             "tool": {
-              "type": "object",
-              "properties": {
-                "name": {
-                  "type": "string"
-                },
-                "title": {
-                  "type": "string"
-                },
-                "icons": {
-                  "type": "array",
-                  "items": {
-                    "type": "object",
-                    "properties": {
-                      "src": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "sizes": {
-                        "type": "array",
-                        "items": {
-                          "type": "string"
-                        }
-                      },
-                      "theme": {
-                        "type": "string",
-                        "enum": ["light", "dark"]
-                      }
-                    },
-                    "required": ["src"],
-                    "additionalProperties": false
-                  }
-                },
-                "description": {
-                  "type": "string"
-                },
-                "inputSchema": {
-                  "type": "object",
-                  "properties": {
-                    "type": {
-                      "type": "string",
-                      "const": "object"
-                    },
-                    "properties": {
-                      "type": "object",
-                      "propertyNames": {
-                        "type": "string"
-                      },
-                      "additionalProperties": {}
-                    },
-                    "required": {
-                      "type": "array",
-                      "items": {
-                        "type": "string"
-                      }
-                    }
-                  },
-                  "required": ["type"],
-                  "additionalProperties": {}
-                },
-                "outputSchema": {
-                  "type": "object",
-                  "properties": {
-                    "type": {
-                      "type": "string",
-                      "const": "object"
-                    },
-                    "properties": {
-                      "type": "object",
-                      "propertyNames": {
-                        "type": "string"
-                      },
-                      "additionalProperties": {}
-                    },
-                    "required": {
-                      "type": "array",
-                      "items": {
-                        "type": "string"
-                      }
-                    }
-                  },
-                  "required": ["type"],
-                  "additionalProperties": {}
-                },
-                "annotations": {
-                  "type": "object",
-                  "properties": {
-                    "title": {
-                      "type": "string"
-                    },
-                    "readOnlyHint": {
-                      "type": "boolean"
-                    },
-                    "destructiveHint": {
-                      "type": "boolean"
-                    },
-                    "idempotentHint": {
-                      "type": "boolean"
-                    },
-                    "openWorldHint": {
-                      "type": "boolean"
-                    }
-                  },
-                  "additionalProperties": false
-                },
-                "execution": {
-                  "type": "object",
-                  "properties": {
-                    "taskSupport": {
-                      "type": "string",
-                      "enum": ["required", "optional", "forbidden"]
-                    }
-                  },
-                  "additionalProperties": false
-                },
-                "_meta": {
-                  "type": "object",
-                  "propertyNames": {
-                    "type": "string"
-                  },
-                  "additionalProperties": {}
-                }
-              },
-              "required": ["name", "inputSchema"],
-              "additionalProperties": false,
               "description": "Tool definition including name, inputSchema, etc."
             }
           },
@@ -2472,52 +2029,6 @@
           "type": "object",
           "properties": {
             "appInfo": {
-              "type": "object",
-              "properties": {
-                "name": {
-                  "type": "string"
-                },
-                "title": {
-                  "type": "string"
-                },
-                "icons": {
-                  "type": "array",
-                  "items": {
-                    "type": "object",
-                    "properties": {
-                      "src": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "sizes": {
-                        "type": "array",
-                        "items": {
-                          "type": "string"
-                        }
-                      },
-                      "theme": {
-                        "type": "string",
-                        "enum": ["light", "dark"]
-                      }
-                    },
-                    "required": ["src"],
-                    "additionalProperties": false
-                  }
-                },
-                "version": {
-                  "type": "string"
-                },
-                "websiteUrl": {
-                  "type": "string"
-                },
-                "description": {
-                  "type": "string"
-                }
-              },
-              "required": ["name", "version"],
-              "additionalProperties": false,
               "description": "App identification (name and version)."
             },
             "appCapabilities": {
@@ -2586,52 +2097,6 @@
           "description": "Negotiated protocol version string (e.g., \"2025-11-21\")."
         },
         "hostInfo": {
-          "type": "object",
-          "properties": {
-            "name": {
-              "type": "string"
-            },
-            "title": {
-              "type": "string"
-            },
-            "icons": {
-              "type": "array",
-              "items": {
-                "type": "object",
-                "properties": {
-                  "src": {
-                    "type": "string"
-                  },
-                  "mimeType": {
-                    "type": "string"
-                  },
-                  "sizes": {
-                    "type": "array",
-                    "items": {
-                      "type": "string"
-                    }
-                  },
-                  "theme": {
-                    "type": "string",
-                    "enum": ["light", "dark"]
-                  }
-                },
-                "required": ["src"],
-                "additionalProperties": false
-              }
-            },
-            "version": {
-              "type": "string"
-            },
-            "websiteUrl": {
-              "type": "string"
-            },
-            "description": {
-              "type": "string"
-            }
-          },
-          "required": ["name", "version"],
-          "additionalProperties": false,
           "description": "Host application identification and version."
         },
         "hostCapabilities": {
@@ -2854,145 +2319,9 @@
               "type": "object",
               "properties": {
                 "id": {
-                  "description": "JSON-RPC id of the tools/call request.",
-                  "anyOf": [
-                    {
-                      "type": "string"
-                    },
-                    {
-                      "type": "integer",
-                      "minimum": -9007199254740991,
-                      "maximum": 9007199254740991
-                    }
-                  ]
+                  "description": "JSON-RPC id of the tools/call request."
                 },
                 "tool": {
-                  "type": "object",
-                  "properties": {
-                    "name": {
-                      "type": "string"
-                    },
-                    "title": {
-                      "type": "string"
-                    },
-                    "icons": {
-                      "type": "array",
-                      "items": {
-                        "type": "object",
-                        "properties": {
-                          "src": {
-                            "type": "string"
-                          },
-                          "mimeType": {
-                            "type": "string"
-                          },
-                          "sizes": {
-                            "type": "array",
-                            "items": {
-                              "type": "string"
-                            }
-                          },
-                          "theme": {
-                            "type": "string",
-                            "enum": ["light", "dark"]
-                          }
-                        },
-                        "required": ["src"],
-                        "additionalProperties": false
-                      }
-                    },
-                    "description": {
-                      "type": "string"
-                    },
-                    "inputSchema": {
-                      "type": "object",
-                      "properties": {
-                        "type": {
-                          "type": "string",
-                          "const": "object"
-                        },
-                        "properties": {
-                          "type": "object",
-                          "propertyNames": {
-                            "type": "string"
-                          },
-                          "additionalProperties": {}
-                        },
-                        "required": {
-                          "type": "array",
-                          "items": {
-                            "type": "string"
-                          }
-                        }
-                      },
-                      "required": ["type"],
-                      "additionalProperties": {}
-                    },
-                    "outputSchema": {
-                      "type": "object",
-                      "properties": {
-                        "type": {
-                          "type": "string",
-                          "const": "object"
-                        },
-                        "properties": {
-                          "type": "object",
-                          "propertyNames": {
-                            "type": "string"
-                          },
-                          "additionalProperties": {}
-                        },
-                        "required": {
-                          "type": "array",
-                          "items": {
-                            "type": "string"
-                          }
-                        }
-                      },
-                      "required": ["type"],
-                      "additionalProperties": {}
-                    },
-                    "annotations": {
-                      "type": "object",
-                      "properties": {
-                        "title": {
-                          "type": "string"
-                        },
-                        "readOnlyHint": {
-                          "type": "boolean"
-                        },
-                        "destructiveHint": {
-                          "type": "boolean"
-                        },
-                        "idempotentHint": {
-                          "type": "boolean"
-                        },
-                        "openWorldHint": {
-                          "type": "boolean"
-                        }
-                      },
-                      "additionalProperties": false
-                    },
-                    "execution": {
-                      "type": "object",
-                      "properties": {
-                        "taskSupport": {
-                          "type": "string",
-                          "enum": ["required", "optional", "forbidden"]
-                        }
-                      },
-                      "additionalProperties": false
-                    },
-                    "_meta": {
-                      "type": "object",
-                      "propertyNames": {
-                        "type": "string"
-                      },
-                      "additionalProperties": {}
-                    }
-                  },
-                  "required": ["name", "inputSchema"],
-                  "additionalProperties": false,
                   "description": "Tool definition including name, inputSchema, etc."
                 }
               },
@@ -3648,322 +2977,7 @@
             },
             "content": {
               "type": "array",
-              "items": {
-                "anyOf": [
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "text"
-                      },
-                      "text": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "text"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "image"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "audio"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "name": {
-                        "type": "string"
-                      },
-                      "title": {
-                        "type": "string"
-                      },
-                      "icons": {
-                        "type": "array",
-                        "items": {
-                          "type": "object",
-                          "properties": {
-                            "src": {
-                              "type": "string"
-                            },
-                            "mimeType": {
-                              "type": "string"
-                            },
-                            "sizes": {
-                              "type": "array",
-                              "items": {
-                                "type": "string"
-                              }
-                            },
-                            "theme": {
-                              "type": "string",
-                              "enum": ["light", "dark"]
-                            }
-                          },
-                          "required": ["src"],
-                          "additionalProperties": false
-                        }
-                      },
-                      "uri": {
-                        "type": "string"
-                      },
-                      "description": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "size": {
-                        "type": "number"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "properties": {},
-                        "additionalProperties": {}
-                      },
-                      "type": {
-                        "type": "string",
-                        "const": "resource_link"
-                      }
-                    },
-                    "required": ["name", "uri", "type"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "resource"
-                      },
-                      "resource": {
-                        "anyOf": [
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "text": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "text"],
-                            "additionalProperties": false
-                          },
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "blob": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "blob"],
-                            "additionalProperties": false
-                          }
-                        ]
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "resource"],
-                    "additionalProperties": false
-                  }
-                ]
-              },
+              "items": {},
               "description": "Message content blocks (text, image, etc.)."
             }
           },
@@ -4130,7 +3144,8 @@
           }
         }
       },
-      "additionalProperties": false
+      "additionalProperties": false,
+      "description": "Content Security Policy configuration for UI resources.\n\nServers declare which origins their UI requires. Hosts use this to enforce appropriate CSP headers.\n\n> [!IMPORTANT]\n> MCP App HTML runs in a sandboxed iframe with no same-origin server.\n> **All** origins must be declared—including where your bundled JS/CSS is\n> served from (`localhost` in dev, your CDN in production)."
     },
     "McpUiResourceMeta": {
       "$schema": "https://json-schema.org/draft/2020-12/schema",
@@ -4242,7 +3257,8 @@
           "additionalProperties": false
         }
       },
-      "additionalProperties": false
+      "additionalProperties": false,
+      "description": "Sandbox permissions requested by the UI resource.\n\nServers declare which browser capabilities their UI needs.\nHosts MAY honor these by setting appropriate iframe `allow` attributes.\nApps SHOULD NOT assume permissions are granted; use JS feature detection as fallback."
     },
     "McpUiResourceTeardownRequest": {
       "$schema": "https://json-schema.org/draft/2020-12/schema",
@@ -5287,369 +4303,6 @@
           "const": "ui/notifications/tool-result"
         },
         "params": {
-          "type": "object",
-          "properties": {
-            "_meta": {
-              "type": "object",
-              "properties": {
-                "progressToken": {
-                  "anyOf": [
-                    {
-                      "type": "string"
-                    },
-                    {
-                      "type": "integer",
-                      "minimum": -9007199254740991,
-                      "maximum": 9007199254740991
-                    }
-                  ]
-                },
-                "io.modelcontextprotocol/related-task": {
-                  "type": "object",
-                  "properties": {
-                    "taskId": {
-                      "type": "string"
-                    }
-                  },
-                  "required": ["taskId"],
-                  "additionalProperties": false
-                }
-              },
-              "additionalProperties": {}
-            },
-            "content": {
-              "default": [],
-              "type": "array",
-              "items": {
-                "anyOf": [
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "text"
-                      },
-                      "text": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "text"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "image"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "audio"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "name": {
-                        "type": "string"
-                      },
-                      "title": {
-                        "type": "string"
-                      },
-                      "icons": {
-                        "type": "array",
-                        "items": {
-                          "type": "object",
-                          "properties": {
-                            "src": {
-                              "type": "string"
-                            },
-                            "mimeType": {
-                              "type": "string"
-                            },
-                            "sizes": {
-                              "type": "array",
-                              "items": {
-                                "type": "string"
-                              }
-                            },
-                            "theme": {
-                              "type": "string",
-                              "enum": ["light", "dark"]
-                            }
-                          },
-                          "required": ["src"],
-                          "additionalProperties": false
-                        }
-                      },
-                      "uri": {
-                        "type": "string"
-                      },
-                      "description": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "size": {
-                        "type": "number"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "properties": {},
-                        "additionalProperties": {}
-                      },
-                      "type": {
-                        "type": "string",
-                        "const": "resource_link"
-                      }
-                    },
-                    "required": ["name", "uri", "type"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "resource"
-                      },
-                      "resource": {
-                        "anyOf": [
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "text": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "text"],
-                            "additionalProperties": false
-                          },
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "blob": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "blob"],
-                            "additionalProperties": false
-                          }
-                        ]
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "resource"],
-                    "additionalProperties": false
-                  }
-                ]
-              }
-            },
-            "structuredContent": {
-              "type": "object",
-              "propertyNames": {
-                "type": "string"
-              },
-              "additionalProperties": {}
-            },
-            "isError": {
-              "type": "boolean"
-            }
-          },
-          "required": ["content"],
-          "additionalProperties": {},
           "description": "Standard MCP tool execution result."
         }
       },
@@ -5684,322 +4337,7 @@
             "content": {
               "description": "Context content blocks (text, image, etc.).",
               "type": "array",
-              "items": {
-                "anyOf": [
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "text"
-                      },
-                      "text": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "text"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "image"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "audio"
-                      },
-                      "data": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "data", "mimeType"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "name": {
-                        "type": "string"
-                      },
-                      "title": {
-                        "type": "string"
-                      },
-                      "icons": {
-                        "type": "array",
-                        "items": {
-                          "type": "object",
-                          "properties": {
-                            "src": {
-                              "type": "string"
-                            },
-                            "mimeType": {
-                              "type": "string"
-                            },
-                            "sizes": {
-                              "type": "array",
-                              "items": {
-                                "type": "string"
-                              }
-                            },
-                            "theme": {
-                              "type": "string",
-                              "enum": ["light", "dark"]
-                            }
-                          },
-                          "required": ["src"],
-                          "additionalProperties": false
-                        }
-                      },
-                      "uri": {
-                        "type": "string"
-                      },
-                      "description": {
-                        "type": "string"
-                      },
-                      "mimeType": {
-                        "type": "string"
-                      },
-                      "size": {
-                        "type": "number"
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "properties": {},
-                        "additionalProperties": {}
-                      },
-                      "type": {
-                        "type": "string",
-                        "const": "resource_link"
-                      }
-                    },
-                    "required": ["name", "uri", "type"],
-                    "additionalProperties": false
-                  },
-                  {
-                    "type": "object",
-                    "properties": {
-                      "type": {
-                        "type": "string",
-                        "const": "resource"
-                      },
-                      "resource": {
-                        "anyOf": [
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "text": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "text"],
-                            "additionalProperties": false
-                          },
-                          {
-                            "type": "object",
-                            "properties": {
-                              "uri": {
-                                "type": "string"
-                              },
-                              "mimeType": {
-                                "type": "string"
-                              },
-                              "_meta": {
-                                "type": "object",
-                                "propertyNames": {
-                                  "type": "string"
-                                },
-                                "additionalProperties": {}
-                              },
-                              "blob": {
-                                "type": "string"
-                              }
-                            },
-                            "required": ["uri", "blob"],
-                            "additionalProperties": false
-                          }
-                        ]
-                      },
-                      "annotations": {
-                        "type": "object",
-                        "properties": {
-                          "audience": {
-                            "type": "array",
-                            "items": {
-                              "type": "string",
-                              "enum": ["user", "assistant"]
-                            }
-                          },
-                          "priority": {
-                            "type": "number",
-                            "minimum": 0,
-                            "maximum": 1
-                          },
-                          "lastModified": {
-                            "type": "string",
-                            "format": "date-time",
-                            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
-                          }
-                        },
-                        "additionalProperties": false
-                      },
-                      "_meta": {
-                        "type": "object",
-                        "propertyNames": {
-                          "type": "string"
-                        },
-                        "additionalProperties": {}
-                      }
-                    },
-                    "required": ["type", "resource"],
-                    "additionalProperties": false
-                  }
-                ]
-              }
+              "items": {}
             },
             "structuredContent": {
               "description": "Structured content for machine-readable context data.",
diff --git a/src/generated/schema.test.ts b/src/generated/schema.test.ts
index 57d989fd0..298d066b6 100644
--- a/src/generated/schema.test.ts
+++ b/src/generated/schema.test.ts
@@ -167,6 +167,10 @@ export type McpUiInitializeResultSchemaInferredType = z.infer<
   typeof generated.McpUiInitializeResultSchema
 >;
 
+export type McpUiContentBlockSchemaInferredType = z.infer<
+  typeof generated.McpUiContentBlockSchema
+>;
+
 expectType<spec.McpUiTheme>({} as McpUiThemeSchemaInferredType);
 expectType<McpUiThemeSchemaInferredType>({} as spec.McpUiTheme);
 expectType<spec.McpUiDisplayMode>({} as McpUiDisplayModeSchemaInferredType);
@@ -361,3 +365,5 @@ expectType<spec.McpUiInitializeResult>(
 expectType<McpUiInitializeResultSchemaInferredType>(
   {} as spec.McpUiInitializeResult,
 );
+expectType<spec.McpUiContentBlock>({} as McpUiContentBlockSchemaInferredType);
+expectType<McpUiContentBlockSchemaInferredType>({} as spec.McpUiContentBlock);
diff --git a/src/generated/schema.ts b/src/generated/schema.ts
index aed1f9651..5fcc39681 100644
--- a/src/generated/schema.ts
+++ b/src/generated/schema.ts
@@ -2,15 +2,16 @@
 // Post-processed for Zod v3/v4 compatibility and MCP SDK integration
 // Run: npm run generate:schemas
 import { z } from "zod/v4";
-import {
-  ContentBlockSchema,
-  CallToolResultSchema,
-  EmbeddedResourceSchema,
-  ImplementationSchema,
-  RequestIdSchema,
-  ResourceLinkSchema,
-  ToolSchema,
-} from "@modelcontextprotocol/sdk/types.js";
+import { isSpecType } from "@modelcontextprotocol/client";
+import type {
+  ContentBlock,
+  CallToolResult,
+  EmbeddedResource,
+  Implementation,
+  RequestId,
+  ResourceLink,
+  Tool,
+} from "@modelcontextprotocol/client";
 
 /**
  * @description Color theme preference for the host environment.
@@ -212,77 +213,81 @@ export const McpUiSandboxProxyReadyNotificationSchema = z.object({
  * > **All** origins must be declared—including where your bundled JS/CSS is
  * > served from (`localhost` in dev, your CDN in production).
  */
-export const McpUiResourceCspSchema = z.object({
-  /**
-   * @description Origins for network requests (fetch/XHR/WebSocket).
-   *
-   * - Maps to CSP `connect-src` directive
-   * - Empty or omitted → no network connections (secure default)
-   *
-   * @example
-   * ```ts
-   * ["https://api.weather.com", "wss://realtime.service.com"]
-   * ```
-   */
-  connectDomains: z
-    .array(z.string())
-    .optional()
-    .describe(
-      "Origins for network requests (fetch/XHR/WebSocket).\n\n- Maps to CSP `connect-src` directive\n- Empty or omitted \u2192 no network connections (secure default)",
-    ),
-  /**
-   * @description Origins for static resources (images, scripts, stylesheets, fonts, media).
-   *
-   * - Maps to CSP `img-src`, `script-src`, `style-src`, `font-src`, `media-src` directives
-   * - Wildcard subdomains supported: `https://*.example.com`
-   * - Empty or omitted → no network resources (secure default)
-   *
-   * @example
-   * ```ts
-   * ["https://cdn.jsdelivr.net", "https://*.cloudflare.com"]
-   * ```
-   */
-  resourceDomains: z
-    .array(z.string())
-    .optional()
-    .describe(
-      "Origins for static resources (images, scripts, stylesheets, fonts, media).\n\n- Maps to CSP `img-src`, `script-src`, `style-src`, `font-src`, `media-src` directives\n- Wildcard subdomains supported: `https://*.example.com`\n- Empty or omitted \u2192 no network resources (secure default)",
-    ),
-  /**
-   * @description Origins for nested iframes.
-   *
-   * - Maps to CSP `frame-src` directive
-   * - Empty or omitted → no nested iframes allowed (`frame-src 'none'`)
-   *
-   * @example
-   * ```ts
-   * ["https://www.youtube.com", "https://player.vimeo.com"]
-   * ```
-   */
-  frameDomains: z
-    .array(z.string())
-    .optional()
-    .describe(
-      "Origins for nested iframes.\n\n- Maps to CSP `frame-src` directive\n- Empty or omitted \u2192 no nested iframes allowed (`frame-src 'none'`)",
-    ),
-  /**
-   * @description Allowed base URIs for the document.
-   *
-   * - Maps to CSP `base-uri` directive
-   * - Empty or omitted → only same origin allowed (`base-uri 'self'`)
-   *
-   * @example
-   * ```ts
-   * ["https://cdn.example.com"]
-   * ```
-   */
-  baseUriDomains: z
-    .array(z.string())
-    .optional()
-    .describe(
-      "Allowed base URIs for the document.\n\n- Maps to CSP `base-uri` directive\n- Empty or omitted \u2192 only same origin allowed (`base-uri 'self'`)",
-    ),
-});
+export const McpUiResourceCspSchema = z
+  .object({
+    /**
+     * @description Origins for network requests (fetch/XHR/WebSocket).
+     *
+     * - Maps to CSP `connect-src` directive
+     * - Empty or omitted → no network connections (secure default)
+     *
+     * @example
+     * ```ts
+     * ["https://api.weather.com", "wss://realtime.service.com"]
+     * ```
+     */
+    connectDomains: z
+      .array(z.string())
+      .optional()
+      .describe(
+        "Origins for network requests (fetch/XHR/WebSocket).\n\n- Maps to CSP `connect-src` directive\n- Empty or omitted \u2192 no network connections (secure default)",
+      ),
+    /**
+     * @description Origins for static resources (images, scripts, stylesheets, fonts, media).
+     *
+     * - Maps to CSP `img-src`, `script-src`, `style-src`, `font-src`, `media-src` directives
+     * - Wildcard subdomains supported: `https://*.example.com`
+     * - Empty or omitted → no network resources (secure default)
+     *
+     * @example
+     * ```ts
+     * ["https://cdn.jsdelivr.net", "https://*.cloudflare.com"]
+     * ```
+     */
+    resourceDomains: z
+      .array(z.string())
+      .optional()
+      .describe(
+        "Origins for static resources (images, scripts, stylesheets, fonts, media).\n\n- Maps to CSP `img-src`, `script-src`, `style-src`, `font-src`, `media-src` directives\n- Wildcard subdomains supported: `https://*.example.com`\n- Empty or omitted \u2192 no network resources (secure default)",
+      ),
+    /**
+     * @description Origins for nested iframes.
+     *
+     * - Maps to CSP `frame-src` directive
+     * - Empty or omitted → no nested iframes allowed (`frame-src 'none'`)
+     *
+     * @example
+     * ```ts
+     * ["https://www.youtube.com", "https://player.vimeo.com"]
+     * ```
+     */
+    frameDomains: z
+      .array(z.string())
+      .optional()
+      .describe(
+        "Origins for nested iframes.\n\n- Maps to CSP `frame-src` directive\n- Empty or omitted \u2192 no nested iframes allowed (`frame-src 'none'`)",
+      ),
+    /**
+     * @description Allowed base URIs for the document.
+     *
+     * - Maps to CSP `base-uri` directive
+     * - Empty or omitted → only same origin allowed (`base-uri 'self'`)
+     *
+     * @example
+     * ```ts
+     * ["https://cdn.example.com"]
+     * ```
+     */
+    baseUriDomains: z
+      .array(z.string())
+      .optional()
+      .describe(
+        "Allowed base URIs for the document.\n\n- Maps to CSP `base-uri` directive\n- Empty or omitted \u2192 only same origin allowed (`base-uri 'self'`)",
+      ),
+  })
+  .describe(
+    "Content Security Policy configuration for UI resources.\n\nServers declare which origins their UI requires. Hosts use this to enforce appropriate CSP headers.\n\n> [!IMPORTANT]\n> MCP App HTML runs in a sandboxed iframe with no same-origin server.\n> **All** origins must be declared\u2014including where your bundled JS/CSS is\n> served from (`localhost` in dev, your CDN in production).",
+  );
 
 /**
  * @description Sandbox permissions requested by the UI resource.
@@ -291,52 +296,56 @@ export const McpUiResourceCspSchema = z.object({
  * Hosts MAY honor these by setting appropriate iframe `allow` attributes.
  * Apps SHOULD NOT assume permissions are granted; use JS feature detection as fallback.
  */
-export const McpUiResourcePermissionsSchema = z.object({
-  /**
-   * @description Request camera access.
-   *
-   * Maps to Permission Policy `camera` feature.
-   */
-  camera: z
-    .object({})
-    .optional()
-    .describe(
-      "Request camera access.\n\nMaps to Permission Policy `camera` feature.",
-    ),
-  /**
-   * @description Request microphone access.
-   *
-   * Maps to Permission Policy `microphone` feature.
-   */
-  microphone: z
-    .object({})
-    .optional()
-    .describe(
-      "Request microphone access.\n\nMaps to Permission Policy `microphone` feature.",
-    ),
-  /**
-   * @description Request geolocation access.
-   *
-   * Maps to Permission Policy `geolocation` feature.
-   */
-  geolocation: z
-    .object({})
-    .optional()
-    .describe(
-      "Request geolocation access.\n\nMaps to Permission Policy `geolocation` feature.",
-    ),
-  /**
-   * @description Request clipboard write access.
-   *
-   * Maps to Permission Policy `clipboard-write` feature.
-   */
-  clipboardWrite: z
-    .object({})
-    .optional()
-    .describe(
-      "Request clipboard write access.\n\nMaps to Permission Policy `clipboard-write` feature.",
-    ),
-});
+export const McpUiResourcePermissionsSchema = z
+  .object({
+    /**
+     * @description Request camera access.
+     *
+     * Maps to Permission Policy `camera` feature.
+     */
+    camera: z
+      .object({})
+      .optional()
+      .describe(
+        "Request camera access.\n\nMaps to Permission Policy `camera` feature.",
+      ),
+    /**
+     * @description Request microphone access.
+     *
+     * Maps to Permission Policy `microphone` feature.
+     */
+    microphone: z
+      .object({})
+      .optional()
+      .describe(
+        "Request microphone access.\n\nMaps to Permission Policy `microphone` feature.",
+      ),
+    /**
+     * @description Request geolocation access.
+     *
+     * Maps to Permission Policy `geolocation` feature.
+     */
+    geolocation: z
+      .object({})
+      .optional()
+      .describe(
+        "Request geolocation access.\n\nMaps to Permission Policy `geolocation` feature.",
+      ),
+    /**
+     * @description Request clipboard write access.
+     *
+     * Maps to Permission Policy `clipboard-write` feature.
+     */
+    clipboardWrite: z
+      .object({})
+      .optional()
+      .describe(
+        "Request clipboard write access.\n\nMaps to Permission Policy `clipboard-write` feature.",
+      ),
+  })
+  .describe(
+    "Sandbox permissions requested by the UI resource.\n\nServers declare which browser capabilities their UI needs.\nHosts MAY honor these by setting appropriate iframe `allow` attributes.\nApps SHOULD NOT assume permissions are granted; use JS feature detection as fallback.",
+  );
 
 /**
  * @description Notification of UI size changes (View -> Host).
@@ -495,70 +504,72 @@ export const McpUiRequestTeardownNotificationSchema = z.object({
  * @description Capabilities supported by the host application.
  * @see {@link McpUiInitializeResult `McpUiInitializeResult`} for the initialization result that includes these capabilities
  */
-export const McpUiHostCapabilitiesSchema = z.object({
-  /** @description Experimental features (structure TBD). */
-  experimental: z
-    .object({})
-    .optional()
-    .describe("Experimental features (structure TBD)."),
-  /** @description Host supports opening external URLs. */
-  openLinks: z
-    .object({})
-    .optional()
-    .describe("Host supports opening external URLs."),
-  /** @description Host supports file downloads via ui/download-file. */
-  downloadFile: z
-    .object({})
-    .optional()
-    .describe("Host supports file downloads via ui/download-file."),
-  /** @description Host can proxy tool calls to the MCP server. */
-  serverTools: z
-    .object({
-      /** @description Host supports tools/list_changed notifications. */
-      listChanged: z
-        .boolean()
-        .optional()
-        .describe("Host supports tools/list_changed notifications."),
-    })
-    .optional()
-    .describe("Host can proxy tool calls to the MCP server."),
-  /** @description Host can proxy resource reads to the MCP server. */
-  serverResources: z
-    .object({
-      /** @description Host supports resources/list_changed notifications. */
-      listChanged: z
-        .boolean()
-        .optional()
-        .describe("Host supports resources/list_changed notifications."),
-    })
-    .optional()
-    .describe("Host can proxy resource reads to the MCP server."),
-  /** @description Host accepts log messages. */
-  logging: z.object({}).optional().describe("Host accepts log messages."),
-  /** @description Sandbox configuration applied by the host. */
-  sandbox: z
-    .object({
-      /** @description Permissions granted by the host (camera, microphone, geolocation). */
-      permissions: McpUiResourcePermissionsSchema.optional().describe(
-        "Permissions granted by the host (camera, microphone, geolocation).",
-      ),
-      /** @description CSP domains approved by the host. */
-      csp: McpUiResourceCspSchema.optional().describe(
-        "CSP domains approved by the host.",
+export const McpUiHostCapabilitiesSchema = z
+  .object({
+    /** @description Experimental features (structure TBD). */
+    experimental: z
+      .object({})
+      .optional()
+      .describe("Experimental features (structure TBD)."),
+    /** @description Host supports opening external URLs. */
+    openLinks: z
+      .object({})
+      .optional()
+      .describe("Host supports opening external URLs."),
+    /** @description Host supports file downloads via ui/download-file. */
+    downloadFile: z
+      .object({})
+      .optional()
+      .describe("Host supports file downloads via ui/download-file."),
+    /** @description Host can proxy tool calls to the MCP server. */
+    serverTools: z
+      .object({
+        /** @description Host supports tools/list_changed notifications. */
+        listChanged: z
+          .boolean()
+          .optional()
+          .describe("Host supports tools/list_changed notifications."),
+      })
+      .optional()
+      .describe("Host can proxy tool calls to the MCP server."),
+    /** @description Host can proxy resource reads to the MCP server. */
+    serverResources: z
+      .object({
+        /** @description Host supports resources/list_changed notifications. */
+        listChanged: z
+          .boolean()
+          .optional()
+          .describe("Host supports resources/list_changed notifications."),
+      })
+      .optional()
+      .describe("Host can proxy resource reads to the MCP server."),
+    /** @description Host accepts log messages. */
+    logging: z.object({}).optional().describe("Host accepts log messages."),
+    /** @description Sandbox configuration applied by the host. */
+    sandbox: z
+      .object({
+        /** @description Permissions granted by the host (camera, microphone, geolocation). */
+        permissions: McpUiResourcePermissionsSchema.optional().describe(
+          "Permissions granted by the host (camera, microphone, geolocation).",
+        ),
+        /** @description CSP domains approved by the host. */
+        csp: McpUiResourceCspSchema.optional().describe(
+          "CSP domains approved by the host.",
+        ),
+      })
+      .optional()
+      .describe("Sandbox configuration applied by the host."),
+    /** @description Host accepts context updates (ui/update-model-context) to be included in the model's context for future turns. */
+    updateModelContext:
+      McpUiSupportedContentBlockModalitiesSchema.optional().describe(
+        "Host accepts context updates (ui/update-model-context) to be included in the model's context for future turns.",
       ),
-    })
-    .optional()
-    .describe("Sandbox configuration applied by the host."),
-  /** @description Host accepts context updates (ui/update-model-context) to be included in the model's context for future turns. */
-  updateModelContext:
-    McpUiSupportedContentBlockModalitiesSchema.optional().describe(
-      "Host accepts context updates (ui/update-model-context) to be included in the model's context for future turns.",
+    /** @description Host supports receiving content messages (ui/message) from the view. */
+    message: McpUiSupportedContentBlockModalitiesSchema.optional().describe(
+      "Host supports receiving content messages (ui/message) from the view.",
     ),
-  /** @description Host supports receiving content messages (ui/message) from the view. */
-  message: McpUiSupportedContentBlockModalitiesSchema.optional().describe(
-    "Host supports receiving content messages (ui/message) from the view.",
-  ),
-});
+  })
+  .describe("Capabilities supported by the host application.");
 
 /**
  * @description Capabilities provided by the View ({@link app!App `App`}).
@@ -734,6 +745,30 @@ export const McpUiClientCapabilitiesSchema = z.object({
     ),
 });
 
+const EmbeddedResourceSchema = z.custom<EmbeddedResource>((v) =>
+  isSpecType("EmbeddedResource", v),
+);
+
+const ResourceLinkSchema = z.custom<ResourceLink>((v) =>
+  isSpecType("ResourceLink", v),
+);
+
+const ContentBlockSchema = z.custom<ContentBlock>((v) =>
+  isSpecType("ContentBlock", v),
+);
+
+const CallToolResultSchema = z.custom<CallToolResult>((v) =>
+  isSpecType("CallToolResult", v),
+);
+
+const RequestIdSchema = z.custom<RequestId>((v) => isSpecType("RequestId", v));
+
+const ToolSchema = z.custom<Tool>((v) => isSpecType("Tool", v));
+
+const ImplementationSchema = z.custom<Implementation>((v) =>
+  isSpecType("Implementation", v),
+);
+
 /**
  * @description Request to download a file through the host.
  *
@@ -1018,3 +1053,6 @@ export const McpUiInitializeResultSchema = z
     ),
   })
   .passthrough();
+
+/** Content block for ui/update-model-context. */
+export const McpUiContentBlockSchema = ContentBlockSchema;
diff --git a/src/message-transport.ts b/src/message-transport.ts
index 9d195435a..3cc5f797c 100644
--- a/src/message-transport.ts
+++ b/src/message-transport.ts
@@ -1,12 +1,9 @@
 import {
-  JSONRPCMessage,
-  JSONRPCMessageSchema,
-  MessageExtraInfo,
-} from "@modelcontextprotocol/sdk/types.js";
-import {
-  Transport,
-  TransportSendOptions,
-} from "@modelcontextprotocol/sdk/shared/transport.js";
+  type JSONRPCMessage,
+  parseJSONRPCMessage,
+  type Transport,
+  type TransportSendOptions,
+} from "@modelcontextprotocol/client";
 import { TOOL_INPUT_PARTIAL_METHOD } from "./spec.types";
 
 /**
@@ -79,28 +76,29 @@ export class PostMessageTransport implements Transport {
         console.debug("Ignoring message from unknown source", event);
         return;
       }
-      const parsed = JSONRPCMessageSchema.safeParse(event.data);
-      if (parsed.success) {
-        console.debug("Parsed message", parsed.data);
-        this.onmessage?.(parsed.data);
-      } else if (event.data?.jsonrpc !== "2.0") {
-        // Not a JSON-RPC message at all (e.g. internal frames injected by
-        // the host environment). Ignore silently so the transport stays alive.
-        console.debug(
-          "Ignoring non-JSON-RPC message",
-          parsed.error.message,
-          event,
-        );
-      } else {
-        // Has jsonrpc: "2.0" but is otherwise malformed — surface as a real
-        // protocol error.
-        console.error("Failed to parse message", parsed.error.message, event);
-        this.onerror?.(
-          new Error(
-            "Invalid JSON-RPC message received: " + parsed.error.message,
-          ),
-        );
+      let parsed: JSONRPCMessage;
+      try {
+        parsed = parseJSONRPCMessage(event.data);
+      } catch (err) {
+        if (event.data?.jsonrpc !== "2.0") {
+          // Not a JSON-RPC message at all (e.g. internal frames injected by
+          // the host environment). Ignore silently so the transport stays alive.
+          console.debug("Ignoring non-JSON-RPC message", err, event);
+        } else {
+          // Has jsonrpc: "2.0" but is otherwise malformed — surface as a real
+          // protocol error.
+          console.error("Failed to parse message", err, event);
+          this.onerror?.(
+            new Error(
+              "Invalid JSON-RPC message received: " +
+                (err instanceof Error ? err.message : String(err)),
+            ),
+          );
+        }
+        return;
       }
+      console.debug("Parsed message", parsed);
+      this.onmessage?.(parsed);
     };
   }
 
@@ -166,9 +164,8 @@ export class PostMessageTransport implements Transport {
    * method must be called before messages will be received.
    *
    * @param message - The validated JSON-RPC message
-   * @param extra - Optional metadata about the message (unused in this transport)
    */
-  onmessage?: (message: JSONRPCMessage, extra?: MessageExtraInfo) => void;
+  onmessage?: (message: JSONRPCMessage) => void;
 
   /**
    * Optional session identifier for this transport connection.
diff --git a/src/react/useApp.tsx b/src/react/useApp.tsx
index d6dcfbb79..cfb624609 100644
--- a/src/react/useApp.tsx
+++ b/src/react/useApp.tsx
@@ -1,6 +1,5 @@
 import { useEffect, useState } from "react";
-import { Implementation } from "@modelcontextprotocol/sdk/types.js";
-import { Client } from "@modelcontextprotocol/sdk/client";
+import { Implementation } from "@modelcontextprotocol/client";
 import { App, McpUiAppCapabilities, PostMessageTransport } from "../app";
 export * from "../app";
 
diff --git a/src/server/index.examples.ts b/src/server/index.examples.ts
index d583ae85c..29442524d 100644
--- a/src/server/index.examples.ts
+++ b/src/server/index.examples.ts
@@ -13,7 +13,7 @@ import type {
   McpServer,
   ToolCallback,
   ReadResourceCallback,
-} from "@modelcontextprotocol/sdk/server/mcp.js";
+} from "@modelcontextprotocol/server";
 import { z } from "zod";
 import {
   registerAppTool,
@@ -74,7 +74,7 @@ function registerAppTool_basicUsage(server: McpServer) {
     {
       title: "Get Weather",
       description: "Get current weather for a location",
-      inputSchema: { location: z.string() },
+      inputSchema: z.object({ location: z.string() }),
       _meta: {
         ui: { resourceUri: "ui://weather/view.html" },
       },
@@ -122,7 +122,7 @@ function registerAppTool_appOnlyVisibility(server: McpServer) {
     "update-quantity",
     {
       description: "Update item quantity in cart",
-      inputSchema: { itemId: z.string(), quantity: z.number() },
+      inputSchema: z.object({ itemId: z.string(), quantity: z.number() }),
       _meta: {
         ui: {
           resourceUri: "ui://shop/cart.html",
diff --git a/src/server/index.test.ts b/src/server/index.test.ts
index 1853cc05a..47fd9a3b0 100644
--- a/src/server/index.test.ts
+++ b/src/server/index.test.ts
@@ -7,7 +7,7 @@ import {
   getUiCapability,
   EXTENSION_ID,
 } from "./index";
-import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import type { McpServer } from "@modelcontextprotocol/server";
 
 describe("registerAppTool", () => {
   it("should pass through config to server.registerTool", () => {
@@ -31,7 +31,7 @@ describe("registerAppTool", () => {
     });
 
     registerAppTool(
-      mockServer as unknown as Pick<McpServer, "registerTool">,
+      mockServer as unknown as McpServer,
       "my-tool",
       {
         title: "My Tool",
@@ -72,7 +72,7 @@ describe("registerAppTool", () => {
       };
 
       registerAppTool(
-        mockServer as unknown as Pick<McpServer, "registerTool">,
+        mockServer as unknown as McpServer,
         "my-tool",
         {
           _meta: {
@@ -107,7 +107,7 @@ describe("registerAppTool", () => {
       };
 
       registerAppTool(
-        mockServer as unknown as Pick<McpServer, "registerTool">,
+        mockServer as unknown as McpServer,
         "my-tool",
         {
           _meta: {
@@ -142,7 +142,7 @@ describe("registerAppTool", () => {
       };
 
       registerAppTool(
-        mockServer as unknown as Pick<McpServer, "registerTool">,
+        mockServer as unknown as McpServer,
         "my-tool",
         {
           _meta: {
@@ -176,7 +176,7 @@ describe("registerAppTool", () => {
       };
 
       registerAppTool(
-        mockServer as unknown as Pick<McpServer, "registerTool">,
+        mockServer as unknown as McpServer,
         "my-tool",
         {
           _meta: {
@@ -225,7 +225,7 @@ describe("registerAppResource", () => {
     });
 
     registerAppResource(
-      mockServer as unknown as Pick<McpServer, "registerResource">,
+      mockServer as unknown as McpServer,
       "My Resource",
       "ui://test/view.html",
       {
@@ -255,7 +255,7 @@ describe("registerAppResource", () => {
     };
 
     registerAppResource(
-      mockServer as unknown as Pick<McpServer, "registerResource">,
+      mockServer as unknown as McpServer,
       "My Resource",
       "ui://test/view.html",
       {
@@ -306,7 +306,7 @@ describe("registerAppResource", () => {
     const callback = mock(async () => expectedResult);
 
     registerAppResource(
-      mockServer as unknown as Pick<McpServer, "registerResource">,
+      mockServer as unknown as McpServer,
       "My Resource",
       "ui://test/view.html",
       { _meta: { ui: {} } },
diff --git a/src/server/index.ts b/src/server/index.ts
index 87209ef39..7d16f49ad 100644
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -32,45 +32,42 @@
  */
 
 import {
-  RESOURCE_URI_META_KEY,
-  RESOURCE_MIME_TYPE,
+  McpUiClientCapabilities,
   McpUiResourceCsp,
   McpUiResourceMeta,
   McpUiToolMeta,
-  McpUiClientCapabilities,
+  RESOURCE_MIME_TYPE,
+  RESOURCE_URI_META_KEY,
 } from "../app.js";
 import type {
-  BaseToolCallback,
+  ClientCapabilities,
   McpServer,
+  ReadResourceCallback,
+  ReadResourceResult,
+  RegisteredResource,
   RegisteredTool,
   ResourceMetadata,
-  ToolCallback,
-  ReadResourceCallback as _ReadResourceCallback,
-  RegisteredResource,
-} from "@modelcontextprotocol/sdk/server/mcp.js";
-import type {
-  AnySchema,
-  ZodRawShapeCompat,
-} from "@modelcontextprotocol/sdk/server/zod-compat.js";
-import type {
-  ClientCapabilities,
-  ReadResourceResult,
+  StandardSchemaWithJSON,
   ToolAnnotations,
-} from "@modelcontextprotocol/sdk/types.js";
+  ToolCallback,
+} from "@modelcontextprotocol/server";
 
 // Re-exports for convenience
-export { RESOURCE_URI_META_KEY, RESOURCE_MIME_TYPE };
+export { RESOURCE_MIME_TYPE, RESOURCE_URI_META_KEY };
 export type { ResourceMetadata, ToolCallback };
 
 /**
  * Base tool configuration matching the standard MCP server tool options.
  * Extended by {@link McpUiAppToolConfig `McpUiAppToolConfig`} to add UI metadata requirements.
  */
-export interface ToolConfig {
+export interface ToolConfig<
+  Input extends StandardSchemaWithJSON | undefined = undefined,
+  Output extends StandardSchemaWithJSON | undefined = undefined,
+> {
   title?: string;
   description?: string;
-  inputSchema?: ZodRawShapeCompat | AnySchema;
-  outputSchema?: ZodRawShapeCompat | AnySchema;
+  inputSchema?: Input;
+  outputSchema?: Output;
   annotations?: ToolAnnotations;
   _meta?: Record<string, unknown>;
 }
@@ -85,370 +82,136 @@ export interface ToolConfig {
  *
  * @see {@link registerAppTool `registerAppTool`} for the recommended way to register app tools
  */
-export interface McpUiAppToolConfig extends ToolConfig {
+export type McpUiAppToolConfig<
+  Input extends StandardSchemaWithJSON | undefined = undefined,
+  Output extends StandardSchemaWithJSON | undefined = undefined,
+> = ToolConfig<Input, Output> & {
   _meta: {
     [key: string]: unknown;
   } & (
-    | {
-        ui: McpUiToolMeta;
-      }
+    | { ui: McpUiToolMeta }
     | {
         /**
          * URI of the UI resource to display for this tool.
-         * This is converted to `_meta["ui/resourceUri"]`.
+         * Converted to `_meta["ui/resourceUri"]` for wire compat.
          *
          * @example "ui://weather/view.html"
-         *
          * @deprecated Use `_meta.ui.resourceUri` instead.
          */
-        [RESOURCE_URI_META_KEY]?: string;
+        [RESOURCE_URI_META_KEY]: string;
       }
   );
-}
+};
 
-/**
- * MCP App Resource configuration for {@link registerAppResource `registerAppResource`}.
- *
- * Extends the base MCP SDK `ResourceMetadata` with optional UI metadata
- * for configuring security policies and rendering preferences.
- *
- * The `_meta.ui` field here is included in the `resources/list` response and serves as
- * a static default for hosts to review at connection time. When the `resources/read`
- * content item also includes `_meta.ui`, the content-item value takes precedence.
- *
- * @see {@link registerAppResource `registerAppResource`} for usage
- */
-export interface McpUiAppResourceConfig extends ResourceMetadata {
-  /**
-   * Optional UI metadata for the resource.
-   *
-   * This appears on the resource entry in `resources/list` and acts as a listing-level
-   * fallback. Individual content items returned by `resources/read` may include their
-   * own `_meta.ui` which takes precedence over this value.
-   */
-  _meta?: {
-    /**
-     * UI-specific metadata including CSP configuration and rendering preferences.
-     */
-    ui?: McpUiResourceMeta;
-    // Allow additional metadata properties for extensibility.
-    [key: string]: unknown;
-  };
+function normalizeAppToolMeta(
+  meta: McpUiAppToolConfig["_meta"],
+): Record<string, unknown> {
+  const out: Record<string, unknown> = { ...meta };
+  const ui = { ...((meta as { ui?: McpUiToolMeta }).ui ?? {}) } as McpUiToolMeta;
+  const flat = out[RESOURCE_URI_META_KEY];
+  // Sync both directions so hosts checking either format see the resource URI.
+  if (ui.resourceUri && !(RESOURCE_URI_META_KEY in out)) {
+    out[RESOURCE_URI_META_KEY] = ui.resourceUri;
+  } else if (typeof flat === "string" && !ui.resourceUri) {
+    ui.resourceUri = flat;
+  }
+  out.ui = ui;
+  return out;
 }
 
 /**
- * Register an app tool with the MCP server.
- *
- * This is a convenience wrapper around `server.registerTool` that normalizes
- * UI metadata: if `_meta.ui.resourceUri` is set, the legacy `_meta["ui/resourceUri"]`
- * key is also populated (and vice versa) for compatibility with older hosts.
- *
- * @param server - The MCP server instance
- * @param name - Tool name/identifier
- * @param config - Tool configuration with `_meta` field containing UI metadata
- * @param cb - Tool handler function
- *
- * @example Basic usage
- * ```ts source="./index.examples.ts#registerAppTool_basicUsage"
- * registerAppTool(
- *   server,
- *   "get-weather",
- *   {
- *     title: "Get Weather",
- *     description: "Get current weather for a location",
- *     inputSchema: { location: z.string() },
- *     _meta: {
- *       ui: { resourceUri: "ui://weather/view.html" },
- *     },
- *   },
- *   async (args) => {
- *     const weather = await fetchWeather(args.location);
- *     return { content: [{ type: "text", text: JSON.stringify(weather) }] };
- *   },
- * );
- * ```
- *
- * @example Tool visible to model but not callable by UI
- * ```ts source="./index.examples.ts#registerAppTool_modelOnlyVisibility"
- * registerAppTool(
- *   server,
- *   "show-cart",
- *   {
- *     description: "Display the user's shopping cart",
- *     _meta: {
- *       ui: {
- *         resourceUri: "ui://shop/cart.html",
- *         visibility: ["model"],
- *       },
- *     },
- *   },
- *   async () => {
- *     const cart = await getCart();
- *     return { content: [{ type: "text", text: JSON.stringify(cart) }] };
- *   },
- * );
- * ```
- *
- * @example Tool hidden from model, only callable by UI
- * ```ts source="./index.examples.ts#registerAppTool_appOnlyVisibility"
- * registerAppTool(
- *   server,
- *   "update-quantity",
- *   {
- *     description: "Update item quantity in cart",
- *     inputSchema: { itemId: z.string(), quantity: z.number() },
- *     _meta: {
- *       ui: {
- *         resourceUri: "ui://shop/cart.html",
- *         visibility: ["app"],
- *       },
- *     },
- *   },
- *   async ({ itemId, quantity }) => {
- *     const cart = await updateCartItem(itemId, quantity);
- *     return { content: [{ type: "text", text: JSON.stringify(cart) }] };
- *   },
- * );
- * ```
+ * Register a tool whose result is rendered as an interactive App UI.
  *
- * @see {@link registerAppResource `registerAppResource`} to register the HTML resource referenced by the tool
+ * Thin wrapper over `McpServer.registerTool` that normalizes the
+ * `_meta.ui` block and ensures both nested and flat resource-URI keys are
+ * present for maximum host compatibility.
  */
 export function registerAppTool<
-  OutputArgs extends ZodRawShapeCompat | AnySchema,
-  InputArgs extends undefined | ZodRawShapeCompat | AnySchema = undefined,
+  Input extends StandardSchemaWithJSON | undefined = undefined,
+  Output extends StandardSchemaWithJSON | undefined = undefined,
 >(
-  server: Pick<McpServer, "registerTool">,
+  server: McpServer,
   name: string,
-  config: McpUiAppToolConfig & {
-    inputSchema?: InputArgs;
-    outputSchema?: OutputArgs;
-  },
-  cb: ToolCallback<InputArgs>,
+  config: McpUiAppToolConfig<Input, Output>,
+  callback: ToolCallback<Input>,
 ): RegisteredTool {
-  // Normalize metadata for backward compatibility:
-  // - If _meta.ui.resourceUri is set, also set the legacy flat key
-  // - If the legacy flat key is set, also set _meta.ui.resourceUri
-  const meta = config._meta;
-  const uiMeta = meta.ui as McpUiToolMeta | undefined;
-  const legacyUri = meta[RESOURCE_URI_META_KEY] as string | undefined;
-
-  let normalizedMeta = meta;
-  if (uiMeta?.resourceUri && !legacyUri) {
-    // New format -> also set legacy key
-    normalizedMeta = { ...meta, [RESOURCE_URI_META_KEY]: uiMeta.resourceUri };
-  } else if (legacyUri && !uiMeta?.resourceUri) {
-    // Legacy format -> also set new format
-    normalizedMeta = { ...meta, ui: { ...uiMeta, resourceUri: legacyUri } };
-  }
-
-  return server.registerTool(name, { ...config, _meta: normalizedMeta }, cb);
+  return server.registerTool(
+    name,
+    {
+      ...config,
+      _meta: normalizeAppToolMeta(config._meta),
+    } as Parameters<McpServer["registerTool"]>[1],
+    callback as Parameters<McpServer["registerTool"]>[2],
+  );
 }
 
-export type McpUiReadResourceResult = ReadResourceResult & {
+/**
+ * Metadata for an App UI resource. Adds the optional `_meta.ui` CSP/permissions
+ * block on top of {@link ResourceMetadata `ResourceMetadata`}.
+ */
+export type McpUiAppResourceMetadata = ResourceMetadata & {
   _meta?: {
-    ui?: McpUiResourceMeta;
     [key: string]: unknown;
+    ui?: McpUiResourceMeta;
   };
 };
-export type McpUiReadResourceCallback = (
-  uri: URL,
-  extra: Parameters<_ReadResourceCallback>[1],
-) => McpUiReadResourceResult | Promise<McpUiReadResourceResult>;
-export type ReadResourceCallback = McpUiReadResourceCallback;
 
 /**
- * Register an app resource with the MCP server.
- *
- * This is a convenience wrapper around `server.registerResource` that:
- * - Defaults the MIME type to {@link RESOURCE_MIME_TYPE `RESOURCE_MIME_TYPE`} (`"text/html;profile=mcp-app"`)
- * - Provides a cleaner API matching the SDK's callback signature
+ * Register an App UI resource (the `ui://` HTML the host renders in an iframe).
  *
- * @param server - The MCP server instance
- * @param name - Human-readable resource name
- * @param uri - Resource URI (should match the `_meta.ui` field in tool config)
- * @param config - Resource configuration
- * @param readCallback - Callback that returns the resource contents
- *
- * @example Basic usage
- * ```ts source="./index.examples.ts#registerAppResource_basicUsage"
- * registerAppResource(
- *   server,
- *   "Weather View",
- *   "ui://weather/view.html",
- *   {
- *     description: "Interactive weather display",
- *   },
- *   async () => ({
- *     contents: [
- *       {
- *         uri: "ui://weather/view.html",
- *         mimeType: RESOURCE_MIME_TYPE,
- *         text: await fs.readFile("dist/view.html", "utf-8"),
- *       },
- *     ],
- *   }),
- * );
- * ```
- *
- * @example With CSP configuration for network access
- * ```ts source="./index.examples.ts#registerAppResource_withCsp"
- * registerAppResource(
- *   server,
- *   "Music Player",
- *   "ui://music/player.html",
- *   {
- *     description: "Audio player with external soundfonts",
- *   },
- *   async () => ({
- *     contents: [
- *       {
- *         uri: "ui://music/player.html",
- *         mimeType: RESOURCE_MIME_TYPE,
- *         text: musicPlayerHtml,
- *         _meta: {
- *           ui: {
- *             csp: {
- *               resourceDomains: ["https://cdn.example.com"], // For scripts/styles/images
- *               connectDomains: ["https://api.example.com"], // For fetch/WebSocket
- *             },
- *           },
- *         },
- *       },
- *     ],
- *   }),
- * );
- * ```
- *
- * @example With stable origin for external API CORS allowlists
- * ```ts source="./index.examples.ts#registerAppResource_withDomain"
- * // Computes a stable origin from an MCP server URL for hosting in Claude.
- * function computeAppDomainForClaude(mcpServerUrl: string): string {
- *   const hash = crypto
- *     .createHash("sha256")
- *     .update(mcpServerUrl)
- *     .digest("hex")
- *     .slice(0, 32);
- *   return `${hash}.claudemcpcontent.com`;
- * }
- *
- * const APP_DOMAIN = computeAppDomainForClaude("https://example.com/mcp");
- *
- * registerAppResource(
- *   server,
- *   "Company Dashboard",
- *   "ui://dashboard/view.html",
- *   {
- *     description: "Internal dashboard with company data",
- *   },
- *   async () => ({
- *     contents: [
- *       {
- *         uri: "ui://dashboard/view.html",
- *         mimeType: RESOURCE_MIME_TYPE,
- *         text: dashboardHtml,
- *         _meta: {
- *           ui: {
- *             // CSP: tell browser the app is allowed to make requests
- *             csp: {
- *               connectDomains: ["https://api.example.com"],
- *             },
- *             // CORS: give app a stable origin for the API server to allowlist
- *             //
- *             // (Public APIs that use `Access-Control-Allow-Origin: *` or API
- *             // key auth don't need this.)
- *             domain: APP_DOMAIN,
- *           },
- *         },
- *       },
- *     ],
- *   }),
- * );
- * ```
- *
- * @see {@link McpUiResourceMeta `McpUiResourceMeta`} for `_meta.ui` configuration options
- * @see {@link McpUiResourceCsp `McpUiResourceCsp`} for CSP domain allowlist configuration
- * @see {@link registerAppTool `registerAppTool`} to register tools that reference this resource
+ * Thin wrapper over `McpServer.registerResource` that defaults `mimeType` to
+ * {@link RESOURCE_MIME_TYPE `RESOURCE_MIME_TYPE`} and ensures resource contents
+ * carry that MIME type.
  */
 export function registerAppResource(
-  server: Pick<McpServer, "registerResource">,
+  server: McpServer,
   name: string,
   uri: string,
-  config: McpUiAppResourceConfig,
-  readCallback: McpUiReadResourceCallback,
+  metadata: McpUiAppResourceMetadata,
+  readCallback: ReadResourceCallback,
 ): RegisteredResource {
+  const wrappedCallback: ReadResourceCallback = async (u, ctx) => {
+    const result = await readCallback(u, ctx);
+    return {
+      ...result,
+      contents: result.contents.map((c) => ({
+        mimeType: RESOURCE_MIME_TYPE,
+        ...c,
+      })),
+    } as ReadResourceResult;
+  };
   return server.registerResource(
     name,
     uri,
-    {
-      // Default MIME type for MCP App UI resources (can still be overridden by config below)
-      mimeType: RESOURCE_MIME_TYPE,
-      ...config,
-    },
-    readCallback,
+    { mimeType: RESOURCE_MIME_TYPE, ...metadata },
+    wrappedCallback,
   );
 }
 
 /**
- * Extension identifier for MCP Apps capability negotiation.
- *
- * Used as the key in `extensions` to advertise MCP Apps support.
+ * Type guard: returns true if `caps.extensions` declares MCP Apps support.
  */
+export function clientSupportsMcpApps(
+  caps: ClientCapabilities | undefined,
+): caps is ClientCapabilities & {
+  extensions: { "io.modelcontextprotocol/ui": McpUiClientCapabilities };
+} {
+  return !!caps?.extensions?.["io.modelcontextprotocol/ui"];
+}
+
+export type { McpUiResourceCsp, McpUiResourceMeta, McpUiToolMeta };
+
+/** SEP-2133 extension identifier for MCP Apps. Same value as MCP_APPS_EXTENSION_ID. */
 export const EXTENSION_ID = "io.modelcontextprotocol/ui";
 
 /**
- * Get MCP Apps capability settings from client capabilities.
- *
- * This helper retrieves the capability object from the `extensions` field
- * where MCP Apps advertises its support.
- *
- * Note: The `clientCapabilities` parameter extends the SDK's `ClientCapabilities`
- * type with an `extensions` field (pending SEP-1724). Once `extensions` is added
- * to the SDK, this can use `ClientCapabilities` directly.
- *
- * @param clientCapabilities - The client capabilities from the initialize response
- * @returns The MCP Apps capability settings, or `undefined` if not supported
- *
- * @example Check for MCP Apps support in server initialization
- * ```ts source="./index.examples.ts#getUiCapability_checkSupport"
- * server.server.oninitialized = () => {
- *   const clientCapabilities = server.server.getClientCapabilities();
- *   const uiCap = getUiCapability(clientCapabilities);
- *
- *   if (uiCap?.mimeTypes?.includes(RESOURCE_MIME_TYPE)) {
- *     // App-enhanced tool
- *     registerAppTool(
- *       server,
- *       "weather",
- *       {
- *         description: "Get weather information with interactive dashboard",
- *         _meta: { ui: { resourceUri: "ui://weather/dashboard" } },
- *       },
- *       weatherHandler,
- *     );
- *   } else {
- *     // Text-only fallback
- *     server.registerTool(
- *       "weather",
- *       {
- *         description: "Get weather information",
- *       },
- *       textWeatherHandler,
- *     );
- *   }
- * };
- * ```
+ * Returns the MCP Apps capability blob from ClientCapabilities.extensions, or
+ * undefined if the client does not declare MCP Apps support.
  */
 export function getUiCapability(
-  clientCapabilities:
-    | (ClientCapabilities & { extensions?: Record<string, unknown> })
-    | null
-    | undefined,
+  clientCapabilities: ClientCapabilities | undefined | null,
 ): McpUiClientCapabilities | undefined {
-  if (!clientCapabilities) {
-    return undefined;
-  }
-
-  return clientCapabilities.extensions?.[EXTENSION_ID] as
+  return clientCapabilities?.extensions?.[EXTENSION_ID] as
     | McpUiClientCapabilities
     | undefined;
 }
diff --git a/src/spec.types.ts b/src/spec.types.ts
index 9f83fa972..fe6c77af9 100644
--- a/src/spec.types.ts
+++ b/src/spec.types.ts
@@ -11,14 +11,14 @@
  */
 
 import type {
+  RequestId,
   CallToolResult,
   ContentBlock,
   EmbeddedResource,
   Implementation,
-  RequestId,
   ResourceLink,
   Tool,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/client";
 
 /**
  * Current protocol version supported by this SDK.
@@ -459,7 +459,7 @@ export interface McpUiResourceTeardownResult {
   [key: string]: unknown;
 }
 
-export interface McpUiSupportedContentBlockModalities {
+export type McpUiSupportedContentBlockModalities = {
   /** @description Host supports text content blocks. */
   text?: {};
   /** @description Host supports image content blocks. */
@@ -491,7 +491,7 @@ export interface McpUiRequestTeardownNotification {
  * @description Capabilities supported by the host application.
  * @see {@link McpUiInitializeResult `McpUiInitializeResult`} for the initialization result that includes these capabilities
  */
-export interface McpUiHostCapabilities {
+export type McpUiHostCapabilities = {
   /** @description Experimental features (structure TBD). */
   experimental?: {};
   /** @description Host supports opening external URLs. */
@@ -527,7 +527,7 @@ export interface McpUiHostCapabilities {
  * @description Capabilities provided by the View ({@link app!App `App`}).
  * @see {@link McpUiInitializeRequest `McpUiInitializeRequest`} for the initialization request that includes these capabilities
  */
-export interface McpUiAppCapabilities {
+export type McpUiAppCapabilities = {
   /** @description Experimental features (structure TBD). */
   experimental?: {};
   /** @description App exposes MCP-style tools that the host can call. */
@@ -594,7 +594,7 @@ export interface McpUiInitializedNotification {
  * > **All** origins must be declared—including where your bundled JS/CSS is
  * > served from (`localhost` in dev, your CDN in production).
  */
-export interface McpUiResourceCsp {
+export type McpUiResourceCsp = {
   /**
    * @description Origins for network requests (fetch/XHR/WebSocket).
    *
@@ -653,7 +653,7 @@ export interface McpUiResourceCsp {
  * Hosts MAY honor these by setting appropriate iframe `allow` attributes.
  * Apps SHOULD NOT assume permissions are granted; use JS feature detection as fallback.
  */
-export interface McpUiResourcePermissions {
+export type McpUiResourcePermissions = {
   /**
    * @description Request camera access.
    *
@@ -831,10 +831,13 @@ export const REQUEST_DISPLAY_MODE_METHOD: McpUiRequestDisplayModeRequest["method
  * capabilities during MCP initialization. Servers can check for MCP Apps
  * support using {@link server-helpers!getUiCapability}.
  */
-export interface McpUiClientCapabilities {
+export type McpUiClientCapabilities = {
   /**
    * @description Array of supported MIME types for UI resources.
    * Must include `"text/html;profile=mcp-app"` for MCP Apps support.
    */
   mimeTypes?: string[];
 }
+
+/** Content block for ui/update-model-context. */
+export type McpUiContentBlock = ContentBlock;
diff --git a/src/types.ts b/src/types.ts
index 24bffecee..fcec84c41 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -67,6 +67,7 @@ export {
   type McpUiToolVisibility,
   type McpUiToolMeta,
   type McpUiClientCapabilities,
+  type McpUiContentBlock,
 } from "./spec.types.js";
 
 // Import types needed for protocol type unions (not re-exported, just used internally)
@@ -156,7 +157,7 @@ import {
   ReadResourceResult,
   ResourceListChangedNotification,
   ToolListChangedNotification,
-} from "@modelcontextprotocol/sdk/types.js";
+} from "@modelcontextprotocol/client";
 
 /**
  * All request types in the MCP Apps protocol.
diff --git a/tsconfig.json b/tsconfig.json
index 08ff1103f..eb5eb7a44 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,10 @@
   "compilerOptions": {
     "target": "ES2020",
     "module": "ESNext",
-    "lib": ["ES2020", "DOM"],
+    "lib": [
+      "ES2020",
+      "DOM"
+    ],
     "jsx": "react-jsx",
     "declaration": true,
     "emitDeclarationOnly": true,
@@ -15,6 +18,16 @@
     "skipLibCheck": true,
     "resolveJsonModule": true
   },
-  "include": ["src/**/*.ts", "src/**/*.tsx", "docs/**/*.ts", "docs/**/*.tsx"],
-  "exclude": ["node_modules", "dist", "examples/**/*.ts"]
+  "include": [
+    "src/**/*.ts",
+    "src/**/*.tsx",
+    "docs/**/*.ts",
+    "docs/**/*.tsx"
+  ],
+  "exclude": [
+    "dist",
+    "examples",
+    "examples/**/*.ts",
+    "node_modules"
+  ]
 }
diff --git a/typedoc.config.mjs b/typedoc.config.mjs
index 5775caec7..c84ebd634 100644
--- a/typedoc.config.mjs
+++ b/typedoc.config.mjs
@@ -26,9 +26,17 @@ const config = {
     "src/message-transport.ts",
     "src/types.ts",
   ],
+  externalSymbolLinkMappings: {
+    "@modelcontextprotocol/client": {
+      "*": "https://modelcontextprotocol.github.io/typescript-sdk/",
+    },
+    "@modelcontextprotocol/server": {
+      "*": "https://modelcontextprotocol.github.io/typescript-sdk/",
+    },
+  },
   excludePrivate: true,
   excludeInternal: false,
-  intentionallyNotExported: ["AppOptions", "MethodSchema"],
+  intentionallyNotExported: [],
   blockTags: [...OptionDefaults.blockTags, "@description"],
   jsDocCompatibility: {
     exampleTag: false,