From 6050ccf2afc02b3a9ec6b08423991751d397075c Mon Sep 17 00:00:00 2001
From: Andrew Harvard <aharvard@squareup.com>
Date: Tue, 3 Jun 2025 13:37:12 -0400
Subject: [PATCH 1/3] fix typescript types to be compatible with MCP SDK

---
 packages/server/src/index.ts | 41 ++++++++++++++++++++++--------------
 packages/server/src/types.ts | 22 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 17 deletions(-)

diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index b69eb0b1..566c1272 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -4,17 +4,17 @@
  */
 
 // Import types first
-import { CreateHtmlResourceOptions } from './types.js';
+import {
+  Base64BlobContent,
+  CreateHtmlResourceOptions,
+  HtmlTextContent,
+  mimeType,
+} from './types.js';
 
-export interface HtmlResourceBlock {
+export type HtmlResourceBlock = {
   type: 'resource';
-  resource: {
-    uri: string; // Primary identifier. Starts with "ui://"
-    mimeType: 'text/html' | 'text/uri-list'; // text/html for rawHtml content, text/uri-list for externalUrl content
-    text?: string; // HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
-    blob?: string; // Base64 encoded HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
-  };
-}
+  resource: HtmlTextContent | Base64BlobContent;
+};
 
 /**
  * Robustly encodes a UTF-8 string to Base64.
@@ -60,7 +60,7 @@ export function createHtmlResource(
   options: CreateHtmlResourceOptions,
 ): HtmlResourceBlock {
   let actualContentString: string;
-  let mimeType: 'text/html' | 'text/uri-list';
+  let mimeType: mimeType;
 
   if (options.content.type === 'rawHtml') {
     if (!options.uri.startsWith('ui://')) {
@@ -96,18 +96,27 @@ export function createHtmlResource(
     );
   }
 
-  const resource: HtmlResourceBlock['resource'] = {
-    uri: options.uri,
-    mimeType: mimeType,
-  };
+  let resource: HtmlResourceBlock['resource'];
 
   switch (options.delivery) {
     case 'text':
-      resource.text = actualContentString;
+      resource = {
+        uri: options.uri,
+        mimeType: mimeType,
+        text: actualContentString,
+      };
       break;
     case 'blob':
-      resource.blob = robustUtf8ToBase64(actualContentString);
+      resource = {
+        uri: options.uri,
+        mimeType: mimeType,
+        blob: robustUtf8ToBase64(actualContentString),
+      };
       break;
+    default:
+      // Exhaustive check
+      const exhaustiveCheck: never = options.delivery;
+      throw new Error(`Invalid delivery type: ${exhaustiveCheck}`);
   }
 
   return {
diff --git a/packages/server/src/types.ts b/packages/server/src/types.ts
index 893f216c..a796e811 100644
--- a/packages/server/src/types.ts
+++ b/packages/server/src/types.ts
@@ -1,9 +1,29 @@
+// Primary identifier for the resource. Starts with ui://`
+export type URI = `ui://${string}`;
+
+// text/html for rawHtml content, text/uri-list for externalUrl content
+export type mimeType = 'text/html' | 'text/uri-list';
+
+export type HtmlTextContent = {
+  uri: URI;
+  mimeType: mimeType;
+  text: string; // HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
+  blob?: never;
+};
+
+export type Base64BlobContent = {
+  uri: URI;
+  mimeType: mimeType;
+  blob: string; //  Base64 encoded HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
+  text?: never;
+};
+
 export type ResourceContentPayload =
   | { type: 'rawHtml'; htmlString: string }
   | { type: 'externalUrl'; iframeUrl: string };
 
 export interface CreateHtmlResourceOptions {
-  uri: string; // REQUIRED. Must start with "ui://" if content.type is "rawHtml",
+  uri: URI; // REQUIRED. Must start with "ui://" if content.type is "rawHtml",
   // or "ui-app://" if content.type is "externalUrl".
   content: ResourceContentPayload; // REQUIRED. The actual content payload.
   delivery: 'text' | 'blob'; // REQUIRED. How the content string (htmlString or iframeUrl) should be packaged.

From 3e9824a51627927da116d449f6293325e59e1c00 Mon Sep 17 00:00:00 2001
From: Andrew Harvard <aharvard@squareup.com>
Date: Tue, 3 Jun 2025 13:56:51 -0400
Subject: [PATCH 2/3] update mimeType to MimeType

---
 packages/server/src/index.ts | 14 ++++++--------
 packages/server/src/types.ts | 13 +++++++++----
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index 359e126a..26434af6 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -8,13 +8,13 @@ import {
   Base64BlobContent,
   CreateHtmlResourceOptions,
   HtmlTextContent,
-  mimeType,
+  MimeType,
   UiActionResult,
   UiActionResultLink,
   UiActionResultNotification,
   UiActionResultPrompt,
   UiActionResultIntent,
-  UiActionResultToolCall
+  UiActionResultToolCall,
 } from './types.js';
 
 export type HtmlResourceBlock = {
@@ -66,7 +66,7 @@ export function createHtmlResource(
   options: CreateHtmlResourceOptions,
 ): HtmlResourceBlock {
   let actualContentString: string;
-  let mimeType: mimeType;
+  let mimeType: MimeType;
 
   if (options.content.type === 'rawHtml') {
     if (!options.uri.startsWith('ui://')) {
@@ -173,9 +173,7 @@ export function uiActionResultToolCall(
   };
 }
 
-export function uiActionResultPrompt(
-  prompt: string,
-): UiActionResultPrompt {
+export function uiActionResultPrompt(prompt: string): UiActionResultPrompt {
   return {
     type: 'prompt',
     payload: {
@@ -209,10 +207,10 @@ export function uiActionResultIntent(
 export function uiActionResultNotification(
   message: string,
 ): UiActionResultNotification {
-  return {  
+  return {
     type: 'notification',
     payload: {
       message,
     },
   };
-}
\ No newline at end of file
+}
diff --git a/packages/server/src/types.ts b/packages/server/src/types.ts
index 2e7adad1..b921e6ad 100644
--- a/packages/server/src/types.ts
+++ b/packages/server/src/types.ts
@@ -2,18 +2,18 @@
 export type URI = `ui://${string}`;
 
 // text/html for rawHtml content, text/uri-list for externalUrl content
-export type mimeType = 'text/html' | 'text/uri-list';
+export type MimeType = 'text/html' | 'text/uri-list';
 
 export type HtmlTextContent = {
   uri: URI;
-  mimeType: mimeType;
+  mimeType: MimeType;
   text: string; // HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
   blob?: never;
 };
 
 export type Base64BlobContent = {
   uri: URI;
-  mimeType: mimeType;
+  mimeType: MimeType;
   blob: string; //  Base64 encoded HTML content (for mimeType `text/html`), or iframe URL (for mimeType `text/uri-list`)
   text?: never;
 };
@@ -29,7 +29,12 @@ export interface CreateHtmlResourceOptions {
   delivery: 'text' | 'blob'; // REQUIRED. How the content string (htmlString or iframeUrl) should be packaged.
 }
 
-export type UiActionType = 'tool' | 'prompt' | 'link' | 'intent' | 'notification';
+export type UiActionType =
+  | 'tool'
+  | 'prompt'
+  | 'link'
+  | 'intent'
+  | 'notification';
 
 export type UiActionResultToolCall = {
   type: 'tool';

From 0ad7fddee8f4918f3c91c31d121699b951aef480 Mon Sep 17 00:00:00 2001
From: Andrew Harvard <aharvard@squareup.com>
Date: Mon, 9 Jun 2025 08:20:29 -0400
Subject: [PATCH 3/3] fix lint unexpected lexical declaration lint error

---
 packages/server/src/index.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index 26434af6..d4f5897d 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -121,8 +121,10 @@ export function createHtmlResource(
       break;
     default:
       // Exhaustive check
-      const exhaustiveCheck: never = options.delivery;
-      throw new Error(`Invalid delivery type: ${exhaustiveCheck}`);
+      (() => {
+        const exhaustiveCheck: never = options.delivery;
+        throw new Error(`Invalid delivery type: ${exhaustiveCheck}`);
+      })();
   }
 
   return {