ClaudeのTypeScript SDKで実装するStreaming・Tool・MCPヘルパー

import Anthropic from "@anthropic-ai/sdk";
 
const client = new Anthropic({
  apiKey: process.env["ANTHROPIC_API_KEY"] // デフォルト値なので省略可能
});
 
const message = await client.messages.create({
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello, Claude" }],
  model: "claude-opus-5-5"
});
 
for (const block of message.content) {
  if (block.type === "text") {
    console.log(block.text);
  }
}

bad.ts(8,32): error TS2339: Property 'text' does not exist on type 'ContentBlock'.
  Property 'text' does not exist on type 'BashCodeExecutionToolResultBlock'.

const anthropic = new Anthropic();
 
const stream = anthropic.messages
  .stream({
    model: "claude-opus-5-5",
    max_tokens: 1024,
    messages: [{ role: "user", content: "Say hello there!" }]
  })
  .on("text", (text) => {
    console.log(text);
  });
 
const message = await stream.finalMessage();
console.log(message);

import { betaZodTool } from "@anthropic-ai/sdk/helpers/beta/zod";
import { z } from "zod";
 
const anthropic = new Anthropic();
 
const weatherTool = betaZodTool({
  name: "get_weather",
  inputSchema: z.object({
    location: z.string()
  }),
  description: "Get the current weather in a given location",
  run: (input) => {
    return `The weather in ${input.location} is foggy and 60°F`;
  }
});
 
const finalMessage = await anthropic.beta.messages.toolRunner({
  model: "claude-opus-5-5",
  max_tokens: 1000,
  messages: [{ role: "user", content: "What is the weather in San Francisco?" }],
  tools: [weatherTool]
});
 
console.log(finalMessage.content);

import { ToolError } from "@anthropic-ai/sdk/lib/tools/ToolError";
 
const screenshotTool = betaZodTool({
  name: "take_screenshot",
  inputSchema: z.object({ url: z.string() }),
  run: async (input) => {
    if (!isValidUrl(input.url)) {
      throw new ToolError(`Invalid URL: ${input.url}`);
    }
    const result = await takeScreenshot(input.url);
    if (result.error) {
      throw new ToolError([
        { type: "text", text: `Failed to load page: ${result.error}` },
        { type: "image", source: { type: "base64", data: result.screenshot, media_type: "image/png" } }
      ]);
    }
    return { type: "image", source: { type: "base64", data: result.screenshot, media_type: "image/png" } };
  }
});

import {
  mcpTools,
  mcpMessages,
  mcpResourceToContent,
  mcpResourceToFile
} from "@anthropic-ai/sdk/helpers/beta/mcp";
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
 
const anthropic = new Anthropic();
const transport = new StdioClientTransport({ command: "mcp-server", args: [] });
const mcpClient = new Client({ name: "my-client", version: "1.0.0" });
await mcpClient.connect(transport);
 
// MCPのプロンプトをそのままMessages APIへ渡す
const { messages } = await mcpClient.getPrompt({ name: "my-prompt" });
await anthropic.beta.messages.create({
  model: "claude-opus-5-5",
  max_tokens: 1024,
  messages: mcpMessages(messages)
});
 
// MCPのツール一覧をtoolRunnerにそのまま渡す
const { tools } = await mcpClient.listTools();
const finalMessage = await anthropic.beta.messages.toolRunner({
  model: "claude-opus-5-5",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Use the available tools" }],
  tools: mcpTools(tools, mcpClient)
});

const batch = await client.messages.batches.create({
  requests: [
    { custom_id: "my-first-request", params: { model: "claude-opus-5-5", max_tokens: 1024, messages: [{ role: "user", content: "Hello, world" }] } }
  ]
});
 
const results = await client.messages.batches.results(batch.id);
for await (const entry of results) {
  if (entry.result.type === "succeeded") {
    console.log(entry.result.message.content);
  }
}

async function fetchAllMessageBatches() {
  const allMessageBatches = [];
  for await (const messageBatch of client.messages.batches.list({ limit: 20 })) {
    allMessageBatches.push(messageBatch);
  }
  return allMessageBatches;
}

const client = new Anthropic();
const response = await client.beta.messages.create({
  model: "claude-opus-5-5",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello, Claude" }],
  betas: ["context-management-2025-06-27"]
});