From 2ba53f1490e9d288020d4af8fa79f2e1b8a277c6 Mon Sep 17 00:00:00 2001
From: Nick Huang <nick@langchain.dev>
Date: Wed, 5 Nov 2025 23:57:24 -0500
Subject: [PATCH 1/4] Deepagents JS docs

---
 src/docs.json                               |  27 +-
 src/oss/deepagents/backends.mdx             |  99 ++++++-
 src/oss/deepagents/customization.mdx        |  72 ++++-
 src/oss/deepagents/human-in-the-loop.mdx    | 175 ++++++++++-
 src/oss/deepagents/long-term-memory.mdx     | 313 +++++++++++---------
 src/oss/deepagents/middleware.mdx           | 160 +++++++++-
 src/oss/deepagents/quickstart.mdx           | 102 ++++++-
 src/oss/deepagents/subagents.mdx            | 252 +++++++++++++++-
 src/oss/reference/deepagents-javascript.mdx |   4 +
 9 files changed, 1026 insertions(+), 178 deletions(-)
 create mode 100644 src/oss/reference/deepagents-javascript.mdx

diff --git a/src/docs.json b/src/docs.json
index 3905df8dd8..f144d555b1 100644
--- a/src/docs.json
+++ b/src/docs.json
@@ -583,6 +583,30 @@
                       }
                     ]
                   },
+                  {
+                    "tab": "Deep Agents",
+                    "pages": [
+                      "oss/javascript/deepagents/overview",
+                      {
+                        "group": "Get started",
+                        "pages": [
+                          "oss/javascript/deepagents/quickstart",
+                          "oss/javascript/deepagents/customization"
+                        ]
+                      },
+                      {
+                        "group": "Core capabilities",
+                        "pages": [
+                          "oss/javascript/deepagents/harness",
+                          "oss/javascript/deepagents/backends",
+                          "oss/javascript/deepagents/subagents",
+                          "oss/javascript/deepagents/human-in-the-loop",
+                          "oss/javascript/deepagents/long-term-memory",
+                          "oss/javascript/deepagents/middleware"
+                        ]
+                      }
+                    ]
+                  },
                   {
                     "tab": "Integrations",
                     "pages": [
@@ -709,7 +733,8 @@
                         "group": "Reference",
                         "pages": [
                           "oss/javascript/reference/langchain-javascript",
-                          "oss/javascript/reference/langgraph-javascript"
+                          "oss/javascript/reference/langgraph-javascript",
+                          "oss/javascript/reference/deepagents-javascript"
                         ]
                       },
                       {
diff --git a/src/oss/deepagents/backends.mdx b/src/oss/deepagents/backends.mdx
index 5001d70970..2dcd90d210 100644
--- a/src/oss/deepagents/backends.mdx
+++ b/src/oss/deepagents/backends.mdx
@@ -37,6 +37,21 @@ agent = create_deep_agent(
 ```
 :::
 
+:::js
+```typescript
+import { createDeepAgent } from "deepagents";
+import { StateBackend } from "deepagents";
+
+// By default we provide a StateBackend
+const agent = createDeepAgent();
+
+// Under the hood, it looks like
+const agent2 = createDeepAgent({
+  backend: (rt) => new StateBackend(rt),   // Note that the tools access State through the runtime.state
+});
+```
+:::
+
 **How it works:**
 - Stores files in LangGraph agent state for the current thread.
 - Persists across multiple agent turns on the same thread via checkpoints.
@@ -47,17 +62,28 @@ agent = create_deep_agent(
 
 ### FilesystemBackend (local disk)
 
+:::python
 ```python
 from deepagents.backends import FilesystemBackend
 
 agent = create_deep_agent(
-    backend=FilesystemBackend(root_dir="/Users/nh/Desktop/")
+    backend=FilesystemBackend(root_dir=".", virtual_mode=True)
 )
 ```
+:::
+
+:::js
+```typescript
+import { createDeepAgent, FilesystemBackend } from "deepagents";
+
+const agent = createDeepAgent({
+  backend: new FilesystemBackend({ rootDir: ".", virtualMode: true }),
+});
+```
+:::
 
 **How it works:**
 - Reads/writes real files under a configurable `root_dir`.
-- Note: `root_dir` must be an absolute path.
 - You can optionally set `virtual_mode=True` to sandbox and normalize paths under `root_dir`.
 - Uses secure path resolution, prevents unsafe symlink traversal when possible, can use ripgrep for fast `grep`.
 
@@ -68,13 +94,30 @@ agent = create_deep_agent(
 
 ### StoreBackend (LangGraph Store)
 
+:::python
 ```python
+from langgraph.store.memory import InMemoryStore
 from deepagents.backends import StoreBackend
 
 agent = create_deep_agent(
-    backend=(lambda rt: StoreBackend(rt))   # Note that the tools access Store through the runtime.store
+    backend=(lambda rt: StoreBackend(rt)),   # Note that the tools access Store through the runtime.store
+    store=InMemoryStore()
 )
 ```
+:::
+
+:::js
+```typescript
+import { createDeepAgent, StoreBackend } from "deepagents";
+import { InMemoryStore } from "@langchain/langgraph";
+
+const store = new InMemoryStore()
+const agent = createDeepAgent({
+  backend: (rt) => new StoreBackend(rt),
+  store
+});
+```
+:::
 
 **How it works:**
 - Stores files in a LangGraph `BaseStore` provided by the runtime, enabling cross‑thread durable storage.
@@ -89,18 +132,37 @@ agent = create_deep_agent(
 :::python
 ```python
 from deepagents import create_deep_agent
-from deepagents.backends import FilesystemBackend
-from deepagents.backends.composite import build_composite_state_backend
+from deepagents.backends import CompositeBackend, StateBackend, StoreBackend
+from langgraph.store.memory import InMemoryStore
 
 composite_backend = lambda rt: CompositeBackend(
-    default=StateBackend(rt)
+    default=StateBackend(rt),
     routes={
         "/memories/": StoreBackend(rt),
-        "/docs/": CustomBackend()
     }
 )
 
-agent = create_deep_agent(backend=composite_backend)
+agent = create_deep_agent(
+    backend=composite_backend,
+    store=InMemoryStore()  # Store passed to create_deep_agent, not backend
+)
+```
+:::
+
+:::js
+```typescript
+import { createDeepAgent, CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+import { InMemoryStore } from "@langchain/langgraph";
+
+const compositeBackend = (rt) => new CompositeBackend(
+  new StateBackend(rt),
+  {
+    "/memories/": new StoreBackend(rt),
+  }
+);
+
+const store = new InMemoryStore()
+const agent = createDeepAgent({ backend: compositeBackend, store });
 ```
 :::
 
@@ -129,12 +191,12 @@ Route parts of the namespace to different backends. Commonly used to persist `/m
 :::python
 ```python
 from deepagents import create_deep_agent
-from deepagents.backends import FilesystemBackend
-from deepagents.backends.composite import build_composite_state_backend
+from deepagents.backends import CompositeBackend, StateBackend, FilesystemBackend
 
 composite_backend = lambda rt: CompositeBackend(
+    default=StateBackend(rt),
     routes={
-        "/memories/": FilesystemBackend(root_dir="/deepagents/myagent"),
+        "/memories/": FilesystemBackend(root_dir="/deepagents/myagent", virtual_mode=True),
     },
 )
 
@@ -142,6 +204,21 @@ agent = create_deep_agent(backend=composite_backend)
 ```
 :::
 
+:::js
+```typescript
+import { createDeepAgent, CompositeBackend, FilesystemBackend, StateBackend } from "deepagents";
+
+const compositeBackend = (rt) => new CompositeBackend(
+  new StateBackend(rt),
+  {
+    "/memories/": new FilesystemBackend({ rootDir: "/deepagents/myagent", virtualMode: true }),
+  },
+);
+
+const agent = createDeepAgent({ backend: compositeBackend });
+```
+:::
+
 Behavior:
 - `/workspace/plan.md` → StateBackend (ephemeral)
 - `/memories/agent.md` → FilesystemBackend under `/deepagents/myagent`
diff --git a/src/oss/deepagents/customization.mdx b/src/oss/deepagents/customization.mdx
index 92d2542661..6e50bbf008 100644
--- a/src/oss/deepagents/customization.mdx
+++ b/src/oss/deepagents/customization.mdx
@@ -24,7 +24,25 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { ChatAnthropic } from "@langchain/anthropic";
+import { ChatOpenAI } from "@langchain/openai";
+import { createDeepAgent } from "deepagents";
+
+// Using Anthropic
+const agent = createDeepAgent({
+  model: new ChatAnthropic({
+    model: "claude-sonnet-4-20250514",
+    temperature: 0,
+  }),
+});
+
+// Using OpenAI
+const agent2 = createDeepAgent({
+  model: new ChatOpenAI({
+    model: "gpt-5",
+    temperature: 0,
+  }),
+});
 ```
 :::
 
@@ -51,7 +69,13 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createDeepAgent } from "deepagents";
+
+const researchInstructions = `You are an expert researcher. Your job is to conduct thorough research, and then write a polished report.`;
+
+const agent = createDeepAgent({
+  systemPrompt: researchInstructions,
+});
 ```
 :::
 
@@ -90,7 +114,49 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { tool } from "langchain";
+import { TavilySearch } from "@langchain/tavily";
+import { createDeepAgent } from "deepagents";
+import { z } from "zod";
+
+const internetSearch = tool(
+  async ({
+    query,
+    maxResults = 5,
+    topic = "general",
+    includeRawContent = false,
+  }: {
+    query: string;
+    maxResults?: number;
+    topic?: "general" | "news" | "finance";
+    includeRawContent?: boolean;
+  }) => {
+    const tavilySearch = new TavilySearch({
+      maxResults,
+      tavilyApiKey: process.env.TAVILY_API_KEY,
+      includeRawContent,
+      topic,
+    });
+    return await tavilySearch._call({ query });
+  },
+  {
+    name: "internet_search",
+    description: "Run a web search",
+    schema: z.object({
+      query: z.string().describe("The search query"),
+      maxResults: z.number().optional().default(5),
+      topic: z
+        .enum(["general", "news", "finance"])
+        .optional()
+        .default("general"),
+      includeRawContent: z.boolean().optional().default(false),
+    }),
+  },
+);
+
+const agent = createDeepAgent({
+  tools: [internetSearch],
+});
 ```
 :::
 
diff --git a/src/oss/deepagents/human-in-the-loop.mdx b/src/oss/deepagents/human-in-the-loop.mdx
index 5e96a27ee4..c1b68270f2 100644
--- a/src/oss/deepagents/human-in-the-loop.mdx
+++ b/src/oss/deepagents/human-in-the-loop.mdx
@@ -52,7 +52,53 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { tool } from "langchain";
+import { createDeepAgent } from "deepagents";
+import { MemorySaver } from "@langchain/langgraph";
+import { z } from "zod";
+import { v4 as uuidv4 } from 'uuid'; // install uuid package: npm install uuid
+
+const deleteFile = tool(
+  async ({ path }: { path: string }) => {
+    return `Deleted ${path}`;
+  },
+  {
+    name: "delete_file",
+    description: "Delete a file from the filesystem.",
+    schema: z.object({
+      path: z.string(),
+    }),
+  },
+);
+
+const sendEmail = tool(
+  async ({ to, subject, body }: { to: string; subject: string; body: string }) => {
+    return `Sent email to ${to}`;
+  },
+  {
+    name: "send_email",
+    description: "Send an email.",
+    schema: z.object({
+      to: z.string(),
+      subject: z.string(),
+      body: z.string(),
+    }),
+  },
+);
+
+// Checkpointer is REQUIRED for human-in-the-loop
+const checkpointer = new MemorySaver();
+
+const agent = createDeepAgent({
+  model: "claude-sonnet-4-5-20250929",
+  tools: [deleteFile, sendEmail],
+  interruptOn: {
+    delete_file: true,  // Default: approve, edit, reject
+    read_file: false,   // No interrupts needed
+    send_email: { allowedDecisions: ["approve", "reject"] },  // No editing
+  },
+  checkpointer,  // Required!
+});
 ```
 :::
 
@@ -83,7 +129,16 @@ interrupt_on = {
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const interruptOn = {
+  // Sensitive operations: allow all options
+  delete_file: { allowedDecisions: ["approve", "edit", "reject"] },
+
+  // Moderate risk: approval or rejection only
+  write_file: { allowedDecisions: ["approve", "reject"] },
+
+  // Must approve (no rejection allowed)
+  critical_operation: { allowedDecisions: ["approve"] },
+};
 ```
 :::
 
@@ -139,7 +194,51 @@ print(result["messages"][-1]["content"])
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { v4 as uuidv4 } from "uuid";
+import { Command } from "@langchain/langgraph";
+
+// Create config with thread_id for state persistence
+const config = { configurable: { thread_id: uuidv4() } };
+
+// Invoke the agent
+let result = await agent.invoke({
+  messages: [{ role: "user", content: "Delete the file temp.txt" }],
+}, config);
+
+// Check if execution was interrupted
+if (result.__interrupt__) {
+  // Extract interrupt information
+  const interrupts = result.__interrupt__[0].value;
+  const actionRequests = interrupts.actionRequests;
+  const reviewConfigs = interrupts.reviewConfigs;
+
+  // Create a lookup map from tool name to review config
+  const configMap = Object.fromEntries(
+    reviewConfigs.map((cfg) => [cfg.actionName, cfg])
+  );
+
+  // Display the pending actions to the user
+  for (const action of actionRequests) {
+    const reviewConfig = configMap[action.name];
+    console.log(`Tool: ${action.name}`);
+    console.log(`Arguments: ${JSON.stringify(action.args)}`);
+    console.log(`Allowed decisions: ${reviewConfig.allowedDecisions}`);
+  }
+
+  // Get user decisions (one per actionRequest, in order)
+  const decisions = [
+    { type: "approve" }  // User approved the deletion
+  ];
+
+  // Resume execution with decisions
+  result = await agent.invoke(
+    new Command({ resume: { decisions } }),
+    config  // Must use the same config!
+  );
+}
+
+// Process final result
+console.log(result.messages[result.messages.length - 1].content);
 ```
 :::
 
@@ -180,7 +279,33 @@ if result.get("__interrupt__"):
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const config = { configurable: { thread_id: uuidv4() } };
+
+let result = await agent.invoke({
+  messages: [{
+    role: "user",
+    content: "Delete temp.txt and send an email to admin@example.com"
+  }]
+}, config);
+
+if (result.__interrupt__) {
+  const interrupts = result.__interrupt__[0].value;
+  const actionRequests = interrupts.actionRequests;
+
+  // Two tools need approval
+  console.assert(actionRequests.length === 2);
+
+  // Provide decisions in the same order as actionRequests
+  const decisions = [
+    { type: "approve" },  // First tool: delete_file
+    { type: "reject" }    // Second tool: send_email
+  ];
+
+  result = await agent.invoke(
+    new Command({ resume: { decisions } }),
+    config
+  );
+}
 ```
 :::
 
@@ -215,7 +340,27 @@ if result.get("__interrupt__"):
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+if (result.__interrupt__) {
+  const interrupts = result.__interrupt__[0].value;
+  const actionRequest = interrupts.actionRequests[0];
+
+  // Original args from the agent
+  console.log(actionRequest.args);  // { to: "everyone@company.com", ... }
+
+  // User decides to edit the recipient
+  const decisions = [{
+    type: "edit",
+    editedAction: {
+      name: actionRequest.name,  // Must include the tool name
+      args: { to: "team@company.com", subject: "...", body: "..." }
+    }
+  }];
+
+  result = await agent.invoke(
+    new Command({ resume: { decisions } }),
+    config
+  );
+}
 ```
 :::
 
@@ -249,7 +394,25 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const agent = createDeepAgent({
+  tools: [deleteFile, readFile],
+  interruptOn: {
+    delete_file: true,
+    read_file: false,
+  },
+  subagents: [{
+    name: "file-manager",
+    description: "Manages file operations",
+    systemPrompt: "You are a file management assistant.",
+    tools: [deleteFile, readFile],
+    interruptOn: {
+      // Override: require approval for reads in this subagent
+      delete_file: true,
+      read_file: true,  // Different from main agent!
+    }
+  }],
+  checkpointer
+});
 ```
 :::
 
diff --git a/src/oss/deepagents/long-term-memory.mdx b/src/oss/deepagents/long-term-memory.mdx
index 7594eac82a..001f5e12dd 100644
--- a/src/oss/deepagents/long-term-memory.mdx
+++ b/src/oss/deepagents/long-term-memory.mdx
@@ -3,51 +3,70 @@ title: Long-term memory
 description: Learn how to extend deep agents with persistent memory across threads
 ---
 
-Deep agents come with a local filesystem to offload memory. This filesystem is stored in state and is therefore **transient to a single thread**—files are lost when the conversation ends.
+Deep agents come with a local filesystem to offload memory. By default, this filesystem is stored in agent state and is **transient to a single thread**—files are lost when the conversation ends.
 
-You can extend deep agents with **long-term memory** by providing a LangGraph `Store` and setting `use_longterm_memory=True`. This enables persistent storage that survives across threads and conversations.
+You can extend deep agents with **long-term memory** by using a **CompositeBackend** that routes specific paths to persistent storage. This enables hybrid storage where some files persist across threads while others remain ephemeral.
 
 ## Setup
 
+Configure long-term memory by using a `CompositeBackend` that routes the `/memories/` path to a `StoreBackend`:
+
 :::python
 ```python
 from deepagents import create_deep_agent
+from deepagents.backends import CompositeBackend, StateBackend, StoreBackend
 from langgraph.store.memory import InMemoryStore
 
-store = InMemoryStore()  # Or any other Store object
+def make_backend(runtime):
+    return CompositeBackend(
+        default=StateBackend(runtime),  # Ephemeral storage
+        routes={
+            "/memories/": StoreBackend(runtime)  # Persistent storage
+        }
+    )
+
 agent = create_deep_agent(
-    store=store,
-    use_longterm_memory=True
+    store=InMemoryStore(),  # Required for StoreBackend
+    backend=make_backend
 )
 ```
 :::
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createDeepAgent } from "deepagents";
+import { CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+import { InMemoryStore } from "@langchain/langgraph-checkpoint";
+
+const agent = createDeepAgent({
+  store: new InMemoryStore(),  // Required for StoreBackend
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),  // Ephemeral storage
+    { "/memories/": new StoreBackend(config) }  // Persistent storage
+  ),
+});
 ```
 :::
 
 ## How it works
 
-When long-term memory is enabled, deep agents maintain **two separate filesystems**:
+When using `CompositeBackend`, deep agents maintain **two separate filesystems**:
 
 ### 1. Short-term (transient) filesystem
-- Stored in the agent's state
+- Stored in the agent's state (via `StateBackend`)
 - Persists only within a single thread
 - Files are lost when the thread ends
-- Accessed through standard paths: `/notes.txt`
+- Accessed through standard paths: `/notes.txt`, `/workspace/draft.md`
 
 ### 2. Long-term (persistent) filesystem
-- Stored in a LangGraph Store
+- Stored in a LangGraph Store (via `StoreBackend`)
 - Persists across all threads and conversations
-- Files survive indefinitely
-- Accessed through the special prefix: `/memories/notes.txt`
-
-## The /memories/ path convention
+- Survives agent restarts
+- Accessed through paths prefixed with `/memories/`: `/memories/preferences.txt`
 
-**The key to long-term memory is the `/memories/` path prefix:**
+### Path routing
 
+The `CompositeBackend` routes file operations based on path prefixes:
 - Files with paths starting with `/memories/` are stored in the Store (persistent)
 - Files without this prefix remain in transient state
 - All filesystem tools (`ls`, `read_file`, `write_file`, `edit_file`) work with both
@@ -68,7 +87,15 @@ agent.invoke({
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+// Transient file (lost after thread ends)
+await agent.invoke({
+  messages: [{ role: "user", content: "Write draft to /draft.txt" }],
+});
+
+// Persistent file (survives across threads)
+await agent.invoke({
+  messages: [{ role: "user", content: "Save final report to /memories/report.txt" }],
+});
 ```
 :::
 
@@ -97,7 +124,20 @@ agent.invoke({
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { v4 as uuidv4 } from "uuid";
+
+// Thread 1: Write to long-term memory
+const config1 = { configurable: { thread_id: uuidv4() } };
+await agent.invoke({
+  messages: [{ role: "user", content: "Save my preferences to /memories/preferences.txt" }],
+}, config1);
+
+// Thread 2: Read from long-term memory (different conversation!)
+const config2 = { configurable: { thread_id: uuidv4() } };
+await agent.invoke({
+  messages: [{ role: "user", content: "What are my preferences?" }],
+}, config2);
+// Agent can read /memories/preferences.txt from the first thread
 ```
 :::
 
@@ -110,8 +150,11 @@ Store user preferences that persist across sessions:
 :::python
 ```python
 agent = create_deep_agent(
-    store=store,
-    use_longterm_memory=True,
+    store=InMemoryStore(),
+    backend=lambda rt: CompositeBackend(
+        default=StateBackend(rt),
+        routes={"/memories/": StoreBackend(rt)}
+    ),
     system_prompt="""When users tell you their preferences, save them to
     /memories/user_preferences.txt so you remember them in future conversations."""
 )
@@ -120,7 +163,14 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const agent = createDeepAgent({
+  store: new InMemoryStore(),
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),
+    { "/memories/": new StoreBackend(config) }
+  ),
+  systemPrompt: `When users tell you their preferences, save them to /memories/user_preferences.txt so you remember them in future conversations.`,
+});
 ```
 :::
 
@@ -131,8 +181,11 @@ An agent can update its own instructions based on feedback:
 :::python
 ```python
 agent = create_deep_agent(
-    store=store,
-    use_longterm_memory=True,
+    store=InMemoryStore(),
+    backend=lambda rt: CompositeBackend(
+        default=StateBackend(rt),
+        routes={"/memories/": StoreBackend(rt)}
+    ),
     system_prompt="""You have a file at /memories/instructions.txt with additional
     instructions and preferences.
 
@@ -146,7 +199,18 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const agent = createDeepAgent({
+  store: new InMemoryStore(),
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),
+    { "/memories/": new StoreBackend(config) }
+  ),
+  systemPrompt: `You have a file at /memories/instructions.txt with additional instructions and preferences.
+
+  Read this file at the start of conversations to understand user preferences.
+
+  When users provide feedback like "please always do X" or "I prefer Y", update /memories/instructions.txt using the edit_file tool.`,
+});
 ```
 :::
 
@@ -173,7 +237,16 @@ agent.invoke({
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+// Conversation 1: Learn about a project
+await agent.invoke({
+  messages: [{ role: "user", content: "We're building a web app with React. Save project notes." }],
+});
+
+// Conversation 2: Use that knowledge
+await agent.invoke({
+  messages: [{ role: "user", content: "What framework are we using?" }],
+});
+// Agent reads /memories/project_notes.txt from previous conversation
 ```
 :::
 
@@ -184,8 +257,11 @@ Maintain research state across sessions:
 :::python
 ```python
 research_agent = create_deep_agent(
-    store=store,
-    use_longterm_memory=True,
+    store=InMemoryStore(),
+    backend=lambda rt: CompositeBackend(
+        default=StateBackend(rt),
+        routes={"/memories/": StoreBackend(rt)}
+    ),
     system_prompt="""You are a research assistant.
 
     Save your research progress to /memories/research/:
@@ -200,7 +276,21 @@ research_agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const researchAgent = createDeepAgent({
+  store: new InMemoryStore(),
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),
+    { "/memories/": new StoreBackend(config) }
+  ),
+  systemPrompt: `You are a research assistant.
+
+  Save your research progress to /memories/research/:
+  - /memories/research/sources.txt - List of sources found
+  - /memories/research/notes.txt - Key findings and notes
+  - /memories/research/report.md - Final report draft
+
+  This allows research to continue across multiple sessions.`,
+});
 ```
 :::
 
@@ -217,13 +307,29 @@ Good for testing and development, but data is lost on restart:
 from langgraph.store.memory import InMemoryStore
 
 store = InMemoryStore()
-agent = create_deep_agent(store=store, use_longterm_memory=True)
+agent = create_deep_agent(
+    store=store,
+    backend=lambda rt: CompositeBackend(
+        default=StateBackend(rt),
+        routes={"/memories/": StoreBackend(rt)}
+    )
+)
 ```
 :::
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { InMemoryStore } from "@langchain/langgraph-checkpoint";
+import { createDeepAgent, CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+
+const store = new InMemoryStore();
+const agent = createDeepAgent({
+  store,
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),
+    { "/memories/": new StoreBackend(config) }
+  ),
+});
 ```
 :::
 
@@ -237,13 +343,31 @@ from langgraph.store.postgres import PostgresStore
 import os
 
 store = PostgresStore(connection_string=os.environ["DATABASE_URL"])
-agent = create_deep_agent(store=store, use_longterm_memory=True)
+agent = create_deep_agent(
+    store=store,
+    backend=lambda rt: CompositeBackend(
+        default=StateBackend(rt),
+        routes={"/memories/": StoreBackend(rt)}
+    )
+)
 ```
 :::
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { PostgresStore } from "@langchain/langgraph-checkpoint-postgres";
+import { createDeepAgent, CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+
+const store = new PostgresStore({
+  connectionString: process.env.DATABASE_URL,
+});
+const agent = createDeepAgent({
+  store,
+  backend: (config) => new CompositeBackend(
+    new StateBackend(config),
+    { "/memories/": new StoreBackend(config) }
+  ),
+});
 ```
 :::
 
@@ -251,125 +375,32 @@ agent = create_deep_agent(store=store, use_longterm_memory=True)
 
 ### Use descriptive paths
 
-Organize long-term files with clear, hierarchical paths:
-
-:::python
-```python
-# ✅ Good: Organized and descriptive
-/memories/user_preferences/language.txt
-/memories/projects/project_alpha/status.txt
-/memories/research/quantum_computing/sources.txt
-
-# ❌ Bad: Generic and unorganized
-/memories/temp.txt
-/memories/data.txt
-/memories/file1.txt
-```
-:::
-
-### Document what gets persisted
-
-In system prompts, clarify when to use long-term vs short-term storage:
-
-:::python
-```python
-system_prompt="""You have access to two types of storage:
-
-SHORT-TERM (paths without /memories/):
-- Current conversation notes
-- Temporary scratch work
-- Draft documents
-
-LONG-TERM (paths starting with /memories/):
-- User preferences and settings
-- Completed reports and documents
-- Knowledge that should persist across conversations
-- Project state and progress
-
-Always use /memories/ for information that should survive beyond this conversation."""
-```
-:::
-
-### Isolate storage by assistant ID
-
-For multi-tenant applications, provide an `assistant_id` to isolate storage:
+Organize persistent files with clear paths:
 
-:::python
-```python
-config = {
-    "configurable": {
-        "thread_id": "thread-123",
-    },
-    "metadata": {
-        "assistant_id": "user-456"  # Namespace isolation
-    }
-}
-
-agent.invoke({"messages": [...]}, config=config)
 ```
-:::
-
-Each assistant gets its own namespace in the Store, preventing cross-contamination.
-
-### Use persistent stores in production
-
-:::python
-```python
-# ❌ Development only - data lost on restart
-store = InMemoryStore()
-
-# ✅ Production - data persists
-from langgraph.store.postgres import PostgresStore
-store = PostgresStore(connection_string=os.environ["DATABASE_URL"])
+/memories/user_preferences.txt
+/memories/research/topic_a/sources.txt
+/memories/research/topic_a/notes.txt
+/memories/project/requirements.md
 ```
-:::
-
-## Listing files
 
-The `ls` tool shows files from both filesystems:
+### Document the memory structure
 
-:::python
-```python
-agent.invoke({
-    "messages": [{"role": "user", "content": "List all files"}]
-})
+Tell the agent what's stored where in your system prompt:
 
-# Example output:
-# Transient files:
-# - /draft.txt
-# - /temp_notes.txt
-#
-# Long-term files:
-# - /memories/user_preferences.txt
-# - /memories/project_status.txt
 ```
-:::
-
-Files from the Store are prefixed with `/memories/` in listings.
-
-## Limitations
-
-### Store is required
-
-You must provide a Store when enabling long-term memory:
-
-:::python
-```python
-# ❌ This will error
-agent = create_deep_agent(use_longterm_memory=True)  # Missing store!
-
-# ✅ Correct
-agent = create_deep_agent(
-    use_longterm_memory=True,
-    store=InMemoryStore()
-)
+Your persistent memory structure:
+- /memories/preferences.txt: User preferences and settings
+- /memories/context/: Long-term context about the user
+- /memories/knowledge/: Facts and information learned over time
 ```
-:::
 
-### Agents must use correct paths
+### Prune old data
 
-The agent must learn to use the `/memories/` prefix for persistence. The system prompt teaches this, but the agent must follow the instructions.
+Implement periodic cleanup of outdated persistent files to keep storage manageable.
 
-### No automatic cleanup
+### Choose the right storage
 
-Long-term files persist indefinitely. There's no built-in TTL or automatic cleanup. You'll need to implement cleanup strategies if needed.
+- **Development**: Use `InMemoryStore` for quick iteration
+- **Production**: Use `PostgresStore` or other persistent stores
+- **Multi-tenant**: Consider using assistant_id-based namespacing in your store
diff --git a/src/oss/deepagents/middleware.mdx b/src/oss/deepagents/middleware.mdx
index 253003f86c..c6677e5ded 100644
--- a/src/oss/deepagents/middleware.mdx
+++ b/src/oss/deepagents/middleware.mdx
@@ -43,7 +43,19 @@ agent = create_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createAgent, todoListMiddleware } from "langchain";
+
+// todoListMiddleware is included by default in createDeepAgent
+// You can customize it if building a custom agent
+const agent = createAgent({
+  model: "claude-sonnet-4-5-20250929",
+  middleware: [
+    todoListMiddleware({
+      // Optional: Custom addition to the system prompt
+      systemPrompt: "Use the write_todos tool to...",
+    }),
+  ],
+});
 ```
 :::
 
@@ -58,6 +70,7 @@ Context engineering is a main challenge in building effective agents. This is pa
 - **write_file**: Write a new file to the filesystem
 - **edit_file**: Edit an existing file in the filesystem
 
+:::python
 ```python
 from langchain.agents import create_agent
 from deepagents.middleware.filesystem import FilesystemMiddleware
@@ -68,7 +81,7 @@ agent = create_agent(
     model="claude-sonnet-4-5-20250929",
     middleware=[
         FilesystemMiddleware(
-            long_term_memory=False,  # Enables access to long-term memory, defaults to False. You must attach a store to use long-term memory.
+            backend=None,  # Optional: custom backend (defaults to StateBackend)
             system_prompt="Write to the filesystem when...",  # Optional custom addition to the system prompt
             custom_tool_descriptions={
                 "ls": "Use the ls tool when...",
@@ -78,15 +91,40 @@ agent = create_agent(
     ],
 )
 ```
+:::
+
+:::js
+```typescript
+import { createAgent } from "langchain";
+import { createFilesystemMiddleware } from "deepagents";
+
+// FilesystemMiddleware is included by default in createDeepAgent
+// You can customize it if building a custom agent
+const agent = createAgent({
+  model: "claude-sonnet-4-5-20250929",
+  middleware: [
+    createFilesystemMiddleware({
+      backend: undefined,  // Optional: custom backend (defaults to StateBackend)
+      systemPrompt: "Write to the filesystem when...",  // Optional custom system prompt override
+      customToolDescriptions: {
+        ls: "Use the ls tool when...",
+        read_file: "Use the read_file tool to...",
+      },  // Optional: Custom descriptions for filesystem tools
+    }),
+  ],
+});
+```
+:::
 
 ### Short-term vs. long-term filesystem
 
-By default, these tools write to a local "filesystem" in your graph state. If you provide a `Store` object to your agent runtime, you can also enable saving to long-term memory, which persists **across** different threads of your agent.
+By default, these tools write to a local "filesystem" in your graph state. To enable persistent storage across threads, configure a `CompositeBackend` that routes specific paths (like `/memories/`) to a `StoreBackend`.
 
 :::python
 ```python
 from langchain.agents import create_agent
 from deepagents.middleware import FilesystemMiddleware
+from deepagents.backends import CompositeBackend, StateBackend, StoreBackend
 from langgraph.store.memory import InMemoryStore
 
 store = InMemoryStore()
@@ -96,7 +134,10 @@ agent = create_agent(
     store=store,
     middleware=[
         FilesystemMiddleware(
-            long_term_memory=True,
+            backend=lambda rt: CompositeBackend(
+                default=StateBackend(rt),
+                routes={"/memories/": StoreBackend(rt)}
+            ),
             custom_tool_descriptions={
                 "ls": "Use the ls tool when...",
                 "read_file": "Use the read_file tool to..."
@@ -109,11 +150,34 @@ agent = create_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createAgent } from "langchain";
+import { createFilesystemMiddleware } from "deepagents";
+import { CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+import { InMemoryStore } from "@langchain/langgraph-checkpoint";
+
+const store = new InMemoryStore();
+
+const agent = createAgent({
+  model: "claude-sonnet-4-5-20250929",
+  store,
+  middleware: [
+    createFilesystemMiddleware({
+      backend: (config) => new CompositeBackend(
+        new StateBackend(config),
+        { "/memories/": new StoreBackend(config) }
+      ),
+      systemPrompt: "Write to the filesystem when...", // Optional custom system prompt override
+      customToolDescriptions: {
+        ls: "Use the ls tool when...",
+        read_file: "Use the read_file tool to...",
+      }, // Optional: Custom descriptions for filesystem tools
+    }),
+  ],
+});
 ```
 :::
 
-If you enable `use_longterm_memory=True` and provide a `Store` in your agent runtime, then any files prefixed with **/memories/** are saved to the long-term memory store. Note that any agents deployed on LangGraph Platform are automatically provided with a long-term memory store.
+When you configure a `CompositeBackend` with a `StoreBackend` for `/memories/`, any files prefixed with **/memories/** are saved to persistent storage and survive across different threads. Files without this prefix remain in ephemeral state storage.
 
 ## Subagent middleware
 
@@ -121,6 +185,7 @@ Handing off tasks to subagents isolates context, keeping the main (supervisor) a
 
 The subagents middleware allows you to supply subagents through a `task` tool.
 
+:::python
 ```python
 from langchain_core.tools import tool
 from langchain.agents import create_agent
@@ -144,7 +209,7 @@ agent = create_agent(
                     "description": "This subagent can get weather in cities.",
                     "system_prompt": "Use the get_weather tool to get the weather in a city.",
                     "tools": [get_weather],
-                    "model": "gpt-4.1",
+                    "model": "gpt-4o",
                     "middleware": [],
                 }
             ],
@@ -152,6 +217,49 @@ agent = create_agent(
     ],
 )
 ```
+:::
+
+:::js
+```typescript
+import { tool } from "langchain";
+import { createAgent } from "langchain";
+import { createSubAgentMiddleware } from "deepagents";
+import { z } from "zod";
+
+const getWeather = tool(
+  async ({ city }: { city: string }) => {
+    return `The weather in ${city} is sunny.`;
+  },
+  {
+    name: "get_weather",
+    description: "Get the weather in a city.",
+    schema: z.object({
+      city: z.string(),
+    }),
+  },
+);
+
+const agent = createAgent({
+  model: "claude-sonnet-4-5-20250929",
+  middleware: [
+    createSubAgentMiddleware({
+      defaultModel: "claude-sonnet-4-5-20250929",
+      defaultTools: [],
+      subagents: [
+        {
+          name: "weather",
+          description: "This subagent can get weather in cities.",
+          systemPrompt: "Use the get_weather tool to get the weather in a city.",
+          tools: [getWeather],
+          model: "gpt-4o",
+          middleware: [],
+        },
+      ],
+    }),
+  ],
+});
+```
+:::
 
 A subagent is defined with a **name**, **description**, **system prompt**, and **tools**. You can also provide a subagent with a custom **model**, or with additional **middleware**. This can be particularly useful when you want to give the subagent an additional state key to share with the main agent.
 
@@ -194,7 +302,43 @@ agent = create_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { tool } from "langchain";
+import { createAgent } from "langchain";
+import { createSubAgentMiddleware, type SubAgent } from "deepagents";
+import { z } from "zod";
+
+const getWeather = tool(
+  async ({ city }: { city: string }) => {
+    return `The weather in ${city} is sunny.`;
+  },
+  {
+    name: "get_weather",
+    description: "Get the weather in a city.",
+    schema: z.object({
+      city: z.string(),
+    }),
+  },
+);
+
+const weatherSubagent: SubAgent = {
+  name: "weather",
+  description: "This subagent can get weather in cities.",
+  systemPrompt: "Use the get_weather tool to get the weather in a city.",
+  tools: [getWeather],
+  model: "gpt-4o",
+  middleware: [],
+};
+
+const agent = createAgent({
+  model: "claude-sonnet-4-5-20250929",
+  middleware: [
+    createSubAgentMiddleware({
+      defaultModel: "claude-sonnet-4-5-20250929",
+      defaultTools: [],
+      subagents: [weatherSubagent],
+    }),
+  ],
+});
 ```
 :::
 
diff --git a/src/oss/deepagents/quickstart.mdx b/src/oss/deepagents/quickstart.mdx
index 2a60af41ed..97d51ae980 100644
--- a/src/oss/deepagents/quickstart.mdx
+++ b/src/oss/deepagents/quickstart.mdx
@@ -11,6 +11,7 @@ Before you begin, make sure you have an API key from a model provider (e.g., Ant
 
 ### Step 1: Install dependencies
 
+:::python
 <CodeGroup>
     ```bash pip
     pip install deepagents tavily-python
@@ -24,6 +25,23 @@ Before you begin, make sure you have an API key from a model provider (e.g., Ant
     poetry add deepagents tavily-python
     ```
 </CodeGroup>
+:::
+
+:::js
+<CodeGroup>
+    ```bash npm
+    npm install deepagents @langchain/tavily
+    ```
+
+    ```bash yarn
+    yarn add deepagents @langchain/tavily
+    ```
+
+    ```bash pnpm
+    pnpm add deepagents @langchain/tavily
+    ```
+</CodeGroup>
+:::
 
 ### Step 2: Set up your API keys
 
@@ -61,12 +79,59 @@ def internet_search(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { tool } from "langchain";
+import { TavilySearch } from "@langchain/tavily";
+import { z } from "zod";
+
+const internetSearch = tool(
+  async ({
+    query,
+    maxResults = 5,
+    topic = "general",
+    includeRawContent = false,
+  }: {
+    query: string;
+    maxResults?: number;
+    topic?: "general" | "news" | "finance";
+    includeRawContent?: boolean;
+  }) => {
+    const tavilySearch = new TavilySearch({
+      maxResults,
+      tavilyApiKey: process.env.TAVILY_API_KEY,
+      includeRawContent,
+      topic,
+    });
+    return await tavilySearch._call({ query });
+  },
+  {
+    name: "internet_search",
+    description: "Run a web search",
+    schema: z.object({
+      query: z.string().describe("The search query"),
+      maxResults: z
+        .number()
+        .optional()
+        .default(5)
+        .describe("Maximum number of results to return"),
+      topic: z
+        .enum(["general", "news", "finance"])
+        .optional()
+        .default("general")
+        .describe("Search topic category"),
+      includeRawContent: z
+        .boolean()
+        .optional()
+        .default(false)
+        .describe("Whether to include raw content"),
+    }),
+  },
+);
 ```
 :::
 
 ### Step 4: Create a deep agent
 
+:::python
 ```python
 # System prompt to steer the agent to be an expert researcher
 research_instructions = """You are an expert researcher. Your job is to conduct thorough research and then write a polished report.
@@ -83,15 +148,50 @@ agent = create_deep_agent(
     system_prompt=research_instructions
 )
 ```
+:::
+
+:::js
+```typescript
+import { createDeepAgent } from "deepagents";
+
+// System prompt to steer the agent to be an expert researcher
+const researchInstructions = `You are an expert researcher. Your job is to conduct thorough research and then write a polished report.
+
+You have access to an internet search tool as your primary means of gathering information.
+
+## \`internet_search\`
+
+Use this to run an internet search for a given query. You can specify the max number of results to return, the topic, and whether raw content should be included.
+`;
+
+const agent = createDeepAgent({
+  tools: [internetSearch],
+  systemPrompt: researchInstructions,
+});
+```
+:::
 
 ### Step 5: Run the agent
 
+:::python
 ```python
 result = agent.invoke({"messages": [{"role": "user", "content": "What is langgraph?"}]})
 
 # Print the agent's response
 print(result["messages"][-1].content)
 ```
+:::
+
+:::js
+```typescript
+const result = await agent.invoke({
+  messages: [{ role: "user", content: "What is langgraph?" }],
+});
+
+// Print the agent's response
+console.log(result.messages[result.messages.length - 1].content);
+```
+:::
 
 ## What happened?
 
diff --git a/src/oss/deepagents/subagents.mdx b/src/oss/deepagents/subagents.mdx
index e2d1169507..19e0b07480 100644
--- a/src/oss/deepagents/subagents.mdx
+++ b/src/oss/deepagents/subagents.mdx
@@ -50,6 +50,7 @@ For complex workflows, use a pre-built LangGraph graph:
 
 ## Using SubAgent
 
+:::python
 ```python
 import os
 from typing import Literal
@@ -86,6 +87,66 @@ agent = create_deep_agent(
     subagents=subagents
 )
 ```
+:::
+
+:::js
+```typescript
+import { tool } from "langchain";
+import { TavilySearch } from "@langchain/tavily";
+import { createDeepAgent } from "deepagents";
+import { ChatAnthropic } from "@langchain/anthropic";
+import { z } from "zod";
+
+const internetSearch = tool(
+  async ({
+    query,
+    maxResults = 5,
+    topic = "general",
+    includeRawContent = false,
+  }: {
+    query: string;
+    maxResults?: number;
+    topic?: "general" | "news" | "finance";
+    includeRawContent?: boolean;
+  }) => {
+    const tavilySearch = new TavilySearch({
+      maxResults,
+      tavilyApiKey: process.env.TAVILY_API_KEY,
+      includeRawContent,
+      topic,
+    });
+    return await tavilySearch._call({ query });
+  },
+  {
+    name: "internet_search",
+    description: "Run a web search",
+    schema: z.object({
+      query: z.string().describe("The search query"),
+      maxResults: z.number().optional().default(5),
+      topic: z
+        .enum(["general", "news", "finance"])
+        .optional()
+        .default("general"),
+      includeRawContent: z.boolean().optional().default(false),
+    }),
+  },
+);
+
+const researchSubagent = {
+  name: "research-agent",
+  description: "Used to research more in depth questions",
+  systemPrompt: "You are a great researcher",
+  tools: [internetSearch],
+  model: new ChatAnthropic({model:"claude-sonnet-4-5-20250929"}),  // Optional override, defaults to main agent model
+};
+const subagents = [researchSubagent];
+
+const agent = createDeepAgent({
+  model: new ChatAnthropic({model:"claude-sonnet-4-5-20250929"}),
+  subagents: subagents,
+});
+```
+:::
 
 ## Using CompiledSubAgent
 
@@ -123,7 +184,31 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createDeepAgent, CompiledSubAgent } from "deepagents";
+import { createAgent } from "langchain";
+
+// Create a custom agent graph
+const customGraph = createAgent({
+  model: yourModel,
+  tools: specializedTools,
+  prompt: "You are a specialized agent for data analysis...",
+});
+
+// Use it as a custom subagent
+const customSubagent: CompiledSubAgent = {
+  name: "data-analyzer",
+  description: "Specialized agent for complex data analysis tasks",
+  runnable: customGraph,
+};
+
+const subagents = [customSubagent];
+
+const agent = createDeepAgent({
+  model: "claude-sonnet-4-5-20250929",
+  tools: [internetSearch],
+  systemPrompt: researchInstructions,
+  subagents: subagents,
+});
 ```
 :::
 
@@ -181,7 +266,24 @@ research_subagent = {
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const researchSubagent = {
+  name: "research-agent",
+  description: "Conducts in-depth research using web search and synthesizes findings",
+  systemPrompt: `You are a thorough researcher. Your job is to:
+
+  1. Break down the research question into searchable queries
+  2. Use internet_search to find relevant information
+  3. Synthesize findings into a comprehensive but concise summary
+  4. Cite sources when making claims
+
+  Output format:
+  - Summary (2-3 paragraphs)
+  - Key findings (bullet points)
+  - Sources (with URLs)
+
+  Keep your response under 500 words to maintain clean context.`,
+  tools: [internetSearch],
+};
 ```
 :::
 
@@ -207,7 +309,17 @@ email_agent = {
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+// ✅ Good: Focused tool set
+const emailAgent = {
+  name: "email-sender",
+  tools: [sendEmail, validateEmail],  // Only email-related
+};
+
+// ❌ Bad: Too many tools
+const emailAgentBad = {
+  name: "email-sender",
+  tools: [sendEmail, webSearch, databaseQuery, fileUpload],  // Unfocused
+};
 ```
 :::
 
@@ -230,7 +342,7 @@ subagents = [
         "description": "Analyzes financial data and market trends",
         "system_prompt": "You are an expert financial analyst...",
         "tools": [get_stock_price, analyze_fundamentals],
-        "model": "openai:gpt-4o",  # Better for numerical analysis
+        "model": "openai:gpt-5",  # Better for numerical analysis
     },
 ]
 ```
@@ -238,7 +350,22 @@ subagents = [
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const subagents = [
+  {
+    name: "contract-reviewer",
+    description: "Reviews legal documents and contracts",
+    systemPrompt: "You are an expert legal reviewer...",
+    tools: [readDocument, analyzeContract],
+    model: "claude-sonnet-4-5-20250929",  // Large context for long documents
+  },
+  {
+    name: "financial-analyst",
+    description: "Analyzes financial data and market trends",
+    systemPrompt: "You are an expert financial analyst...",
+    tools: [getStockPrice, analyzeFundamentals],
+    model: "gpt-5",  // Better for numerical analysis
+  },
+];
 ```
 :::
 
@@ -266,7 +393,19 @@ data_analyst = {
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+const dataAnalyst = {
+  systemPrompt: `Analyze the data and return:
+  1. Key insights (3-5 bullet points)
+  2. Overall confidence score
+  3. Recommended next actions
+
+  Do NOT include:
+  - Raw data
+  - Intermediate calculations
+  - Detailed tool outputs
+
+  Keep response under 300 words.`,
+};
 ```
 :::
 
@@ -311,7 +450,34 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-// TODO: Add JS implementation
+import { createDeepAgent } from "deepagents";
+
+const subagents = [
+  {
+    name: "data-collector",
+    description: "Gathers raw data from various sources",
+    systemPrompt: "Collect comprehensive data on the topic",
+    tools: [webSearch, apiCall, databaseQuery],
+  },
+  {
+    name: "data-analyzer",
+    description: "Analyzes collected data for insights",
+    systemPrompt: "Analyze data and extract key insights",
+    tools: [statisticalAnalysis],
+  },
+  {
+    name: "report-writer",
+    description: "Writes polished reports from analysis",
+    systemPrompt: "Create professional reports from insights",
+    tools: [formatDocument],
+  },
+];
+
+const agent = createDeepAgent({
+  model: "claude-sonnet-4-5-20250929",
+  systemPrompt: "You coordinate data analysis and reporting. Use subagents for specialized tasks.",
+  subagents: subagents,
+});
 ```
 :::
 
@@ -333,6 +499,8 @@ Each subagent works with clean context focused only on its task.
 **Solutions**:
 
 1. **Make descriptions more specific:**
+
+   :::python
    ```python
    # ✅ Good
    {"name": "research-specialist", "description": "Conducts in-depth research on specific topics using web search. Use when you need detailed information that requires multiple searches."}
@@ -340,8 +508,21 @@ Each subagent works with clean context focused only on its task.
    # ❌ Bad
    {"name": "helper", "description": "helps with stuff"}
    ```
+   :::
+
+   :::js
+   ```typescript
+   // ✅ Good
+   { name: "research-specialist", description: "Conducts in-depth research on specific topics using web search. Use when you need detailed information that requires multiple searches." }
+
+   // ❌ Bad
+   { name: "helper", description: "helps with stuff" }
+   ```
+   :::
 
 2. **Instruct main agent to delegate:**
+
+   :::python
    ```python
    agent = create_deep_agent(
        system_prompt="""...your instructions...
@@ -351,6 +532,19 @@ Each subagent works with clean context focused only on its task.
        subagents=[...]
    )
    ```
+   :::
+
+   :::js
+   ```typescript
+   const agent = createDeepAgent({
+     systemPrompt: `...your instructions...
+
+     IMPORTANT: For complex tasks, delegate to your subagents using the task() tool.
+     This keeps your context clean and improves results.`,
+     subagents: [...]
+   });
+   ```
+   :::
 
 ### Context still getting bloated
 
@@ -359,6 +553,8 @@ Each subagent works with clean context focused only on its task.
 **Solutions**:
 
 1. **Instruct subagent to return concise results:**
+
+   :::python
    ```python
    system_prompt="""...
 
@@ -366,8 +562,21 @@ Each subagent works with clean context focused only on its task.
    Do NOT include raw data, intermediate search results, or detailed tool outputs.
    Your response should be under 500 words."""
    ```
+   :::
+
+   :::js
+   ```typescript
+   systemPrompt: `...
+
+   IMPORTANT: Return only the essential summary.
+   Do NOT include raw data, intermediate search results, or detailed tool outputs.
+   Your response should be under 500 words.`
+   ```
+   :::
 
 2. **Use filesystem for large data:**
+
+   :::python
    ```python
    system_prompt="""When you gather large amounts of data:
    1. Save raw data to /data/raw_results.txt
@@ -376,6 +585,18 @@ Each subagent works with clean context focused only on its task.
 
    This keeps context clean."""
    ```
+   :::
+
+   :::js
+   ```typescript
+   systemPrompt: `When you gather large amounts of data:
+   1. Save raw data to /data/raw_results.txt
+   2. Process and analyze the data
+   3. Return only the analysis summary
+
+   This keeps context clean.`
+   ```
+   :::
 
 ### Wrong subagent being selected
 
@@ -383,6 +604,7 @@ Each subagent works with clean context focused only on its task.
 
 **Solution**: Differentiate subagents clearly in descriptions:
 
+:::python
 ```python
 subagents = [
     {
@@ -395,3 +617,19 @@ subagents = [
     }
 ]
 ```
+:::
+
+:::js
+```typescript
+const subagents = [
+  {
+    name: "quick-researcher",
+    description: "For simple, quick research questions that need 1-2 searches. Use when you need basic facts or definitions.",
+  },
+  {
+    name: "deep-researcher",
+    description: "For complex, in-depth research requiring multiple searches, synthesis, and analysis. Use for comprehensive reports.",
+  }
+];
+```
+:::
diff --git a/src/oss/reference/deepagents-javascript.mdx b/src/oss/reference/deepagents-javascript.mdx
new file mode 100644
index 0000000000..bd59558703
--- /dev/null
+++ b/src/oss/reference/deepagents-javascript.mdx
@@ -0,0 +1,4 @@
+---
+title: Deep Agents
+url: https://reference.langchain.com/javascript/deepagents/
+---

From 300778970486cc12cc18843c381733b8e430bb28 Mon Sep 17 00:00:00 2001
From: nhuang-lc <nick@langchain.dev>
Date: Thu, 6 Nov 2025 06:59:22 -0800
Subject: [PATCH 2/4] Update src/oss/deepagents/middleware.mdx

Co-authored-by: Christian Bromann <git@bromann.dev>
---
 src/oss/deepagents/middleware.mdx | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/oss/deepagents/middleware.mdx b/src/oss/deepagents/middleware.mdx
index c6677e5ded..4aa6112eda 100644
--- a/src/oss/deepagents/middleware.mdx
+++ b/src/oss/deepagents/middleware.mdx
@@ -151,8 +151,7 @@ agent = create_agent(
 :::js
 ```typescript
 import { createAgent } from "langchain";
-import { createFilesystemMiddleware } from "deepagents";
-import { CompositeBackend, StateBackend, StoreBackend } from "deepagents";
+import { createFilesystemMiddleware, CompositeBackend, StateBackend, StoreBackend } from "deepagents";
 import { InMemoryStore } from "@langchain/langgraph-checkpoint";
 
 const store = new InMemoryStore();

From 7b8bfc00bb143dd4c93262caf6b5ff529ab29f5d Mon Sep 17 00:00:00 2001
From: nhuang-lc <nick@langchain.dev>
Date: Thu, 6 Nov 2025 06:59:28 -0800
Subject: [PATCH 3/4] Update src/oss/deepagents/middleware.mdx

Co-authored-by: Christian Bromann <git@bromann.dev>
---
 src/oss/deepagents/middleware.mdx | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/oss/deepagents/middleware.mdx b/src/oss/deepagents/middleware.mdx
index 4aa6112eda..759b35d3cf 100644
--- a/src/oss/deepagents/middleware.mdx
+++ b/src/oss/deepagents/middleware.mdx
@@ -301,8 +301,7 @@ agent = create_agent(
 
 :::js
 ```typescript
-import { tool } from "langchain";
-import { createAgent } from "langchain";
+import { tool, createAgent } from "langchain";
 import { createSubAgentMiddleware, type SubAgent } from "deepagents";
 import { z } from "zod";
 

From 5a428b84dcf54003b34a210e24381b974b52fd75 Mon Sep 17 00:00:00 2001
From: nhuang-lc <nick@langchain.dev>
Date: Thu, 6 Nov 2025 06:59:33 -0800
Subject: [PATCH 4/4] Update src/oss/deepagents/backends.mdx

Co-authored-by: Christian Bromann <git@bromann.dev>
---
 src/oss/deepagents/backends.mdx | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/oss/deepagents/backends.mdx b/src/oss/deepagents/backends.mdx
index 2dcd90d210..1d1c2d56bc 100644
--- a/src/oss/deepagents/backends.mdx
+++ b/src/oss/deepagents/backends.mdx
@@ -39,8 +39,7 @@ agent = create_deep_agent(
 
 :::js
 ```typescript
-import { createDeepAgent } from "deepagents";
-import { StateBackend } from "deepagents";
+import { createDeepAgent, StateBackend } from "deepagents";
 
 // By default we provide a StateBackend
 const agent = createDeepAgent();