add integration test

Author: christian-bromann

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

@@ -173,12 +173,13 @@ function isBuiltinTool(tool: unknown): tool is AnthropicBuiltInToolUnion {
     "code_execution_",
     "memory_",
     "tool_search_",
+    "mcp_toolset",
   ];
   return (
     typeof tool === "object" &&
     tool !== null &&
     "type" in tool &&
-    "name" in tool &&
+    ("name" in tool || "mcp_server_name" in tool) &&
     typeof tool.type === "string" &&
     builtInToolPrefixes.some(
       (prefix) => typeof tool.type === "string" && tool.type.startsWith(prefix)
@@ -1067,6 +1068,7 @@ export class ChatAnthropicMessages<
       container: options?.container,
       betas: _combineBetas(this.betas, options?.betas, toolBetas ?? []),
       output_format: options?.output_format,
+      mcp_servers: options?.mcp_servers,
     };
 
     if (this.thinking.type === "enabled") {

libs/providers/langchain-anthropic/src/tools/tests/mcpToolset.int.test.ts

@@ -0,0 +1,53 @@
+import { expect, it, describe } from "vitest";
+import { HumanMessage } from "@langchain/core/messages";
+import { ContentBlock } from "@langchain/core/messages";
+
+import { ChatAnthropic } from "../../chat_models.js";
+import { tools } from "../index.js";
+
+const createModel = () =>
+  new ChatAnthropic({
+    model: "claude-sonnet-4-5-20250929",
+    temperature: 0,
+  });
+
+describe("Anthropic MCP Toolset Integration Tests", () => {
+  it("mcpToolset can connect to MCP server and run a tool", async () => {
+    const llm = createModel();
+
+    const mcpToolset = tools.mcpToolset_20251120({
+      serverName: "test-server",
+    });
+
+    const llmWithTools = llm.bindTools([mcpToolset]);
+
+    const response = await llmWithTools.invoke(
+      [
+        new HumanMessage(
+          "Please use any available tool from the MCP server to demonstrate it works."
+        ),
+      ],
+      {
+        mcp_servers: [
+          {
+            type: "url",
+            url: "https://docs.mcp.cloudflare.com/mcp",
+            name: "test-server",
+          },
+        ],
+      }
+    );
+
+    expect(Array.isArray(response.content)).toBe(true);
+    expect(
+      (response.content as ContentBlock.Multimodal.Data[]).find(
+        (block) => block.type === "mcp_tool_use"
+      )
+    ).toBeDefined();
+    expect(
+      (response.content as ContentBlock.Multimodal.Data[]).find(
+        (block) => block.type === "mcp_tool_result"
+      )
+    ).toBeDefined();
+  }, 60000);
+});