feat(anthropic): implement Anthropic memory tool in provider package (#9406)

Author: christian-bromann

libs/providers/langchain-anthropic/README.md

@@ -75,6 +75,65 @@ const response = await model.stream({
 });
 ```
 
+## Tools
+
+This package provides LangChain-compatible wrappers for Anthropic's built-in tools. These tools can be bound to `ChatAnthropic` using `bindTools()` or any [`ReactAgent`](https://docs.langchain.com/oss/javascript/langchain/agents).
+
+### Memory Tool
+
+The memory tool (`memory_20250818`) enables Claude to store and retrieve information across conversations through a memory file directory. Claude can create, read, update, and delete files that persist between sessions, allowing it to build knowledge over time without keeping everything in the context window.
+
+```typescript
+import { ChatAnthropic, tools } from "@langchain/anthropic";
+
+// Create a simple in-memory file store (or use your own persistence layer)
+const files = new Map<string, string>();
+
+const memory = tools.memory_20250818({
+  execute: async (command) => {
+    switch (command.command) {
+      case "view":
+        if (!command.path || command.path === "/") {
+          return Array.from(files.keys()).join("\n") || "Directory is empty.";
+        }
+        return (
+          files.get(command.path) ?? `Error: File not found: ${command.path}`
+        );
+      case "create":
+        files.set(command.path!, command.file_text ?? "");
+        return `Successfully created file: ${command.path}`;
+      case "str_replace":
+        const content = files.get(command.path!);
+        if (content && command.old_str) {
+          files.set(
+            command.path!,
+            content.replace(command.old_str, command.new_str ?? "")
+          );
+        }
+        return `Successfully replaced text in: ${command.path}`;
+      case "delete":
+        files.delete(command.path!);
+        return `Successfully deleted: ${command.path}`;
+      // Handle other commands: insert, rename
+      default:
+        return `Unknown command`;
+    }
+  },
+});
+
+const llm = new ChatAnthropic({
+  model: "claude-sonnet-4-5-20250929",
+});
+
+const llmWithMemory = llm.bindTools([memory]);
+
+const response = await llmWithMemory.invoke(
+  "Remember that my favorite programming language is TypeScript"
+);
+```
+
+For more information, see [Anthropic's Memory Tool documentation](https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/memory-tool).
+
 ## Development
 
 To develop the Anthropic package, you'll need to follow these instructions:
@@ -103,8 +162,8 @@ Test files should live within a `tests/` file in the `src/` folder. Unit tests s
 end in `.int.test.ts`:
 
 ```bash
-$ pnpm test
-$ pnpm test:int
+pnpm test
+pnpm test:int
 ```
 
 ### Lint & Format
@@ -124,5 +183,5 @@ If you add a new file to be exported, either import & re-export from `src/index.
 After running `pnpm build`, publish a new version with:
 
 ```bash
-$ npm publish
+npm publish
 ```

libs/providers/langchain-anthropic/package.json

@@ -75,6 +75,7 @@
     "vectorstores"
   ],
   "main": "./dist/index.cjs",
+  "module": "./dist/index.js",
   "types": "./dist/index.d.cts",
   "exports": {
     ".": {
@@ -95,6 +96,5 @@
     "CHANGELOG.md",
     "README.md",
     "LICENSE"
-  ],
-  "module": "./dist/index.js"
+  ]
 }

libs/providers/langchain-anthropic/src/index.ts

@@ -1,3 +1,4 @@
 export * from "./chat_models.js";
 export { convertPromptToAnthropic } from "./utils/prompts.js";
 export { type ChatAnthropicContentBlock } from "./types.js";
+export * from "./tools/index.js";

libs/providers/langchain-anthropic/src/tools/index.ts

@@ -0,0 +1,2 @@
+export { memory_20250818 } from "./memory.js";
+export type * from "./types.js";

libs/providers/langchain-anthropic/src/tools/memory.ts

@@ -0,0 +1,78 @@
+import { tool } from "@langchain/core/tools";
+import type { DynamicStructuredTool, ToolRuntime } from "@langchain/core/tools";
+
+import type { MemoryTool20250818Options } from "./types.js";
+
+/**
+ * Creates an Anthropic memory tool that can be used with ChatAnthropic.
+ *
+ * The memory tool enables Claude to store and retrieve information across conversations
+ * through a memory file directory. Claude can create, read, update, and delete files that
+ * persist between sessions, allowing it to build knowledge over time without keeping
+ * everything in the context window.
+ *
+ * @example
+ * ```typescript
+ * import { ChatAnthropic, memory_20250818 } from "@langchain/anthropic";
+ *
+ * const llm = new ChatAnthropic({
+ *   model: "claude-sonnet-4-5-20250929"
+ * });
+ *
+ * const memory = memory_20250818({
+ *   execute: async (args) => {
+ *     // handle memory command execution
+ *     // ...
+ *   },
+ * });
+ * const llmWithMemory = llm.bindTools([memory]);
+ *
+ * const response = await llmWithMemory.invoke("Remember that I like Python");
+ * ```
+ *
+ * @param options - Optional configuration for the memory tool (currently unused)
+ * @param options.execute - Optional execute function that handles memory command execution.
+ * @returns The memory tool object that can be passed to `bindTools`
+ *
+ * @see https://docs.anthropic.com/en/docs/agents-and-tools/tool-use/memory-tool
+ */
+export function memory_20250818(
+  options?: MemoryTool20250818Options
+): DynamicStructuredTool {
+  const memoryTool = tool(
+    options?.execute as (
+      input: unknown,
+      runtime: ToolRuntime<unknown, unknown>
+    ) => string | Promise<string>,
+    {
+      name: "memory",
+      schema: {
+        type: "object",
+        properties: {
+          command: {
+            type: "string",
+            enum: [
+              "view",
+              "create",
+              "str_replace",
+              "insert",
+              "delete",
+              "rename",
+            ],
+          },
+        },
+        required: ["command"],
+      },
+    }
+  );
+
+  memoryTool.extras = {
+    ...(memoryTool.extras ?? {}),
+    providerToolDefinition: {
+      type: "memory_20250818",
+      name: "memory",
+    },
+  };
+
+  return memoryTool;
+}