feat(langchain): add a big tool middleware

examples/package.json

@@ -52,7 +52,7 @@
     "@langchain/google-vertexai": "workspace:*",
     "@langchain/google-vertexai-web": "workspace:*",
     "@langchain/groq": "workspace:*",
-    "@langchain/langgraph": "alpha",
+    "@langchain/langgraph": "next",
     "@langchain/mistralai": "workspace:*",
     "@langchain/mongodb": "workspace:*",
     "@langchain/nomic": "workspace:*",

examples/src/createAgent/middleware/bigTool.ts

@@ -0,0 +1,100 @@
+import * as z from "zod";
+import { createAgent, HumanMessage, AIMessage, tool } from "langchain";
+import { bigToolMiddleware } from "langchain/middleware";
+import { ChatAnthropic } from "@langchain/anthropic";
+
+/**
+ * Capture the raw requests to verify the tools are being selected correctly
+ */
+const requestBodies: any[] = [];
+const llm = new ChatAnthropic({
+  apiKey: process.env.ANTHROPIC_API_KEY,
+  model: "claude-sonnet-4-20250514",
+  clientOptions: {
+    fetch: (url, options) => {
+      requestBodies.push(JSON.parse(options?.body as string));
+      return fetch(url, options);
+    },
+  },
+});
+
+// Example usage
+const agent = createAgent({
+  llm,
+  tools: [
+    tool(
+      ({ a, b, operation }: { a: number; b: number; operation: string }) => {
+        if (operation === "add") {
+          return a + b;
+        } else if (operation === "multiply") {
+          return a * b;
+        } else if (operation === "subtract") {
+          return a - b;
+        } else if (operation === "divide") {
+          return a / b;
+        } else {
+          return "Unknown operation";
+        }
+      },
+      {
+        name: "calculator",
+        description: "Perform basic math operations",
+        schema: z.object({
+          a: z.number(),
+          b: z.number(),
+          operation: z.enum(["add", "multiply", "subtract", "divide"]),
+        }),
+      }
+    ),
+    tool(
+      () => {
+        return "Database query result: 42";
+      },
+      {
+        name: "database",
+        description: "Query a database",
+        schema: z.object({
+          query: z.string(),
+        }),
+      }
+    ),
+  ],
+  middleware: [
+    bigToolMiddleware({
+      strategy: "custom",
+      customSelector: (tools, query) => {
+        if (query.includes("calculator")) {
+          return tools.filter((tool) => tool.name === "calculator");
+        } else if (query.includes("database")) {
+          return tools.filter((tool) => tool.name === "database");
+        }
+
+        return [];
+      },
+      maxTools: 1,
+    }),
+  ] as const,
+});
+
+// Usage example with a long chat history for testing caching
+const result = await agent.invoke({
+  messages: [new HumanMessage("Calculate 10 + 20")],
+});
+console.log(
+  "Calculate 10 + 20\nAgent response:",
+  result.messages.at(-1)?.content,
+  `\nAll available tools: ${requestBodies
+    .pop()
+    .tools.map((tool: { name: string }) => tool.name)}`
+);
+
+const result2 = await agent.invoke({
+  messages: [new HumanMessage("Query the database for 42")],
+});
+console.log(
+  "\nQuery the database for 42\nAgent response:",
+  result2.messages.at(-1)?.content,
+  `\nAll available tools: ${requestBodies
+    .pop()
+    .tools.map((tool: { name: string }) => tool.name)}`
+);

internal/eslint/package.json

@@ -4,8 +4,8 @@
   "description": "Shared ESLint configuration for LangChain.js projects",
   "author": "LangChain",
   "license": "MIT",
-  "main": "./index.ts",
-  "types": "./index.ts",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
   "type": "module",
   "keywords": [
     "eslint",

libs/langchain-community/src/load/import_map.ts

@@ -82,7 +82,37 @@ export * as llms__togetherai from "../llms/togetherai.js";
 export * as llms__watsonx_ai from "../llms/watsonx_ai.js";
 export * as llms__writer from "../llms/writer.js";
 export * as llms__yandex from "../llms/yandex.js";
+export * as llms__layerup_security from "../llms/layerup_security.js";
+export * as vectorstores__analyticdb from "../vectorstores/analyticdb.js";
+export * as vectorstores__astradb from "../vectorstores/astradb.js";
+export * as vectorstores__azion_edgesql from "../vectorstores/azion_edgesql.js";
+export * as vectorstores__azure_aisearch from "../vectorstores/azure_aisearch.js";
+export * as vectorstores__azure_cosmosdb from "../vectorstores/azure_cosmosdb.js";
+export * as vectorstores__cassandra from "../vectorstores/cassandra.js";
+export * as vectorstores__chroma from "../vectorstores/chroma.js";
+export * as vectorstores__clickhouse from "../vectorstores/clickhouse.js";
+export * as vectorstores__closevector__node from "../vectorstores/closevector/node.js";
+export * as vectorstores__closevector__web from "../vectorstores/closevector/web.js";
+export * as vectorstores__cloudflare_vectorize from "../vectorstores/cloudflare_vectorize.js";
+export * as vectorstores__convex from "../vectorstores/convex.js";
 export * as vectorstores__couchbase_search from "../vectorstores/couchbase_search.js";
+export * as vectorstores__elasticsearch from "../vectorstores/elasticsearch.js";
+export * as vectorstores__faiss from "../vectorstores/faiss.js";
+export * as vectorstores__googlevertexai from "../vectorstores/googlevertexai.js";
+export * as vectorstores__hnswlib from "../vectorstores/hnswlib.js";
+export * as vectorstores__hanavector from "../vectorstores/hanavector.js";
+export * as vectorstores__lancedb from "../vectorstores/lancedb.js";
+export * as vectorstores__libsql from "../vectorstores/libsql.js";
+export * as vectorstores__mariadb from "../vectorstores/mariadb.js";
+export * as vectorstores__milvus from "../vectorstores/milvus.js";
+export * as vectorstores__momento_vector_index from "../vectorstores/momento_vector_index.js";
+export * as vectorstores__mongodb_atlas from "../vectorstores/mongodb_atlas.js";
+export * as vectorstores__myscale from "../vectorstores/myscale.js";
+export * as vectorstores__neo4j_vector from "../vectorstores/neo4j_vector.js";
+export * as vectorstores__neon from "../vectorstores/neon.js";
+export * as vectorstores__opensearch from "../vectorstores/opensearch.js";
+export * as vectorstores__pgvector from "../vectorstores/pgvector.js";
+export * as vectorstores__pinecone from "../vectorstores/pinecone.js";
 export * as vectorstores__prisma from "../vectorstores/prisma.js";
 export * as vectorstores__qdrant from "../vectorstores/qdrant.js";
 export * as vectorstores__redis from "../vectorstores/redis.js";

libs/langchain-core/src/messages/index.ts

@@ -9,16 +9,7 @@ export * from "./transformers.js";
 export * from "./metadata.js";
 export * from "./message.js";
 export * from "./modifier.js";
-// TODO: Use a star export when we deprecate the
-// existing "ToolCall" type in "base.js".
-export {
-  type ToolMessageFields,
-  ToolMessage,
-  ToolMessageChunk,
-  type InvalidToolCall,
-  isToolMessage,
-  isToolMessageChunk,
-} from "./tool.js";
+export * from "./tool.js";
 
 // This is an old export for backwards compatibility with existing multimodal content blocks
 // TODO: remove this in v2

libs/langchain/package.json

@@ -79,7 +79,7 @@
   },
   "dependencies": {
     "@langchain/textsplitters": "workspace:*",
-    "@langchain/langgraph": "^1.0.0-alpha",
+    "@langchain/langgraph": "next",
     "@langchain/langgraph-checkpoint": "^0.1.1",
     "js-yaml": "^4.1.0",
     "jsonpointer": "^5.0.1",

libs/langchain/src/agents/interrupt.ts

@@ -1,5 +1,19 @@
 export { interrupt } from "@langchain/langgraph";
 
+/**
+ * Represents information about an interrupt.
+ */
+export interface Interrupt<TValue = unknown> {
+  /**
+   * The ID of the interrupt.
+   */
+  id: string;
+  /**
+   * The requests for human input.
+   */
+  value: TValue;
+}
+
 /**
  * Configuration interface that defines what actions are allowed for a human interrupt.
  * This controls the available interaction options when the graph is paused for human input.