fix(anthropic): add support for container upload block type in message formatting

.changeset/tiny-falcons-joke.md

@@ -0,0 +1,5 @@
+---
+"@langchain/anthropic": patch
+---
+
+fix(anthropic): add support for container upload block type in message formatting

libs/providers/langchain-anthropic/src/tests/chat_models-code_execution.int.test.ts

@@ -0,0 +1,111 @@
+import { describe, it, expect } from "vitest";
+import Anthropic from "@anthropic-ai/sdk";
+import { HumanMessage, AIMessage } from "@langchain/core/messages";
+import { ChatAnthropic } from "../chat_models.js";
+import fs from "fs";
+import path from "path";
+import os from "os";
+
+describe("Files API with Code Execution", () => {
+  it("should handle createMessageWithFiles using container_upload blocks", async () => {
+    // Create Anthropic client for Files API
+    const anthropicClient = new Anthropic({
+      apiKey: process.env.ANTHROPIC_API_KEY,
+    });
+
+    // Create a temporary CSV file
+    const csvContent =
+      "name,age,city\nAlice,30,NYC\nBob,25,LA\nCharlie,35,Chicago";
+    const tmpDir = os.tmpdir();
+    const tmpFilePath = path.join(tmpDir, "test_data.csv");
+    fs.writeFileSync(tmpFilePath, csvContent);
+
+    try {
+      // Upload file using Anthropic Files API
+      const fileUpload = await anthropicClient.beta.files.upload({
+        file: fs.createReadStream(tmpFilePath),
+      });
+
+      // Create ChatAnthropic model with code execution beta header
+      const model = new ChatAnthropic({
+        model: "claude-3-5-haiku-20241022",
+        temperature: 0,
+        clientOptions: {
+          defaultHeaders: {
+            "anthropic-beta": "code-execution-2025-08-25,files-api-2025-04-14",
+          },
+        },
+      });
+
+      // Define the built-in code_execution tool
+      const codeExecutionTool = {
+        type: "code_execution_20250825" as const,
+        name: "code_execution",
+      };
+
+      // Create a message with container_upload block
+      const message = new HumanMessage({
+        content: [
+          {
+            type: "text",
+            text: "Analyze this CSV data and tell me the average age",
+          },
+          { type: "container_upload", file_id: fileUpload.id },
+        ],
+      });
+
+      // Invoke the model with the file
+      const result = await model.invoke([message], {
+        tools: [codeExecutionTool],
+      });
+
+      // Verify the result is an AIMessage
+      expect(result).toBeInstanceOf(AIMessage);
+
+      // The response should contain content blocks
+      const content = Array.isArray(result.content) ? result.content : [];
+      expect(content.length).toBeGreaterThan(0);
+
+      // Verify that code_execution tool was used (server_tool_use block)
+      expect(
+        content.some(
+          (block) =>
+            typeof block === "object" &&
+            "type" in block &&
+            block.type === "server_tool_use"
+        )
+      ).toBe(true);
+
+      // Verify that we got a code execution result
+      expect(
+        content.some(
+          (block) =>
+            typeof block === "object" &&
+            "type" in block &&
+            block.type === "bash_code_execution_tool_result"
+        )
+      ).toBe(true);
+
+      // The response should contain text with the calculated average
+      const textBlocks = content.filter(
+        (block) =>
+          typeof block === "object" && "type" in block && block.type === "text"
+      );
+      const responseText = textBlocks
+        .map((block) =>
+          typeof block === "object" && "text" in block ? block.text : ""
+        )
+        .join(" ")
+        .toLowerCase();
+
+      // The response should mention the average age (30)
+      expect(responseText).toMatch(/average|mean/i);
+      expect(responseText).toMatch(/30/);
+    } finally {
+      // Clean up temporary file
+      if (fs.existsSync(tmpFilePath)) {
+        fs.unlinkSync(tmpFilePath);
+      }
+    }
+  }, 60000);
+});

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

@@ -191,3 +191,52 @@ test("Can properly format anthropic messages when given two tool results", async
     system: undefined,
   });
 });
+
+test("Can properly format messages with container_upload blocks", async () => {
+  const messageHistory = [
+    new HumanMessage({
+      content: [
+        { type: "text", text: "Analyze this CSV data" },
+        { type: "container_upload", file_id: "file_abc123" },
+      ],
+    }),
+  ];
+
+  const formattedMessages = _convertMessagesToAnthropicPayload(messageHistory);
+
+  expect(formattedMessages).toEqual({
+    messages: [
+      {
+        role: "user",
+        content: [
+          { type: "text", text: "Analyze this CSV data" },
+          { type: "container_upload", file_id: "file_abc123" },
+        ],
+      },
+    ],
+    system: undefined,
+  });
+});
+
+test("Drop content blocks that we don't know how to handle", async () => {
+  const messageHistory = [
+    new HumanMessage({
+      content: [
+        { type: "text", text: "Hello" },
+        { type: "some-unexpected-block-type", some_unexpected_field: "abc123" },
+      ],
+    }),
+  ];
+
+  const formattedMessages = _convertMessagesToAnthropicPayload(messageHistory);
+
+  expect(formattedMessages).toEqual({
+    messages: [
+      {
+        role: "user",
+        content: [{ type: "text", text: "Hello" }],
+      },
+    ],
+    system: undefined,
+  });
+});

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

@@ -48,6 +48,8 @@ export type AnthropicWebSearchResultBlockParam =
 // TODO(hntrl): beta blocks should be separated
 export type AnthropicSearchResultBlockParam =
   Anthropic.Beta.BetaSearchResultBlockParam;
+export type AnthropicContainerUploadBlockParam =
+  Anthropic.Beta.BetaContainerUploadBlockParam;
 
 // Union of all possible content block types including server tool use
 export type ChatAnthropicContentBlock =
@@ -61,7 +63,8 @@ export type ChatAnthropicContentBlock =
   | AnthropicServerToolUseBlockParam
   | AnthropicWebSearchToolResultBlockParam
   | AnthropicWebSearchResultBlockParam
-  | AnthropicSearchResultBlockParam;
+  | AnthropicSearchResultBlockParam
+  | AnthropicContainerUploadBlockParam;
 
 export function isAnthropicImageBlockParam(
   block: unknown

libs/providers/langchain-anthropic/src/utils/message_inputs.ts

@@ -27,6 +27,7 @@ import {
   AnthropicWebSearchToolResultBlockParam,
   AnthropicSearchResultBlockParam,
   AnthropicToolResponse,
+  AnthropicContainerUploadBlockParam,
 } from "../types.js";
 import {
   _isAnthropicImageBlockParam,
@@ -271,7 +272,18 @@ function* _formatContentBlocks(
         ...(cacheControl ? { cache_control: cacheControl } : {}),
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
       } as any;
+    } else if (contentPart.type === "container_upload") {
+      yield {
+        ...contentPart,
+        ...(cacheControl ? { cache_control: cacheControl } : {}),
+      } as AnthropicContainerUploadBlockParam;
     }
+
+    // Note that we are intentionally dropping any blocks that we don't
+    // recognize. This is to allow for cross-compatibility between different
+    // providers that may have different block types. Ie if we take a message
+    // output from OpenAI and send it to Anthropic, we want to drop any blocks
+    // that Anthropic doesn't understand.
   }
 }