How to integrate Openrouter MCP with Claude Agent SDK

This guide walks you through connecting Openrouter to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Openrouter agent that can generate python code from this prompt, summarize this article using claude-3, list all available llama-3 model endpoints through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Openrouter account through Composio's Openrouter MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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OpenRouter is a unified API platform for accessing language models from various providers. It lets you easily integrate and switch between multiple LLMs with a single API.

13 Tools

Introduction

This guide walks you through connecting Openrouter to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Openrouter agent that can generate python code from this prompt, summarize this article using claude-3, list all available llama-3 model endpoints through natural language commands.

This guide will help you understand how to give your Claude Agent SDK agent real control over a Openrouter account through Composio's Openrouter MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Openrouter with

ChatGPTOpenAI Agents SDKClaude CodeClaude CoworkCodexOpenCodeCursorVS CodeOpenClawHermesCLIGoogle ADKLangChainVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get and set up your Claude/Anthropic and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for Openrouter
  • Configure an AI agent that can use Openrouter as a tool
  • Run a live chat session where you can ask the agent to perform Openrouter operations

What is Claude Agent SDK?

The Claude Agent SDK is Anthropic's official framework for building AI agents powered by Claude. It provides a streamlined interface for creating agents with MCP tool support and conversation management.

Key features include:

  • Native MCP Support: Built-in support for Model Context Protocol servers
  • Permission Modes: Control tool execution permissions
  • Streaming Responses: Real-time response streaming for interactive applications
  • Context Manager: Clean async context management for sessions

What is the Openrouter MCP server, and what's possible with it?

The Openrouter MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Openrouter account. It provides structured and secure access to a wide range of large language models, so your agent can generate completions, manage model access, check credits, and retrieve generation details seamlessly on your behalf.

  • Unified model completions: Let your agent generate chat-based or text completions using any model available through Openrouter, perfect for conversation or content creation tasks.
  • Model catalog and provider discovery: Ask your agent to list all available AI models and providers, helping you compare capabilities, endpoints, and pricing in real time.
  • Credit monitoring and usage tracking: Have your agent fetch your current API credit balance, so you always know your usage limits before starting new tasks.
  • Generation result retrieval: Direct your agent to pull detailed metadata for any previous generation, including token counts, costs, and latency for analysis or auditing.
  • Endpoint and configuration info: Empower your agent to fetch the latest model endpoints and supported parameters, making it easy to fine-tune routing and optimize performance.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and Claude/Anthropic API Key
  • Primary know-how of Claude Agents SDK
  • A Openrouter account
  • Some knowledge of Python
2

Getting API Keys for Claude/Anthropic and Composio

Claude/Anthropic API Key
  • Go to the Anthropic Console and create an API key. You'll need credits to use the models.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

npm install @anthropic-ai/claude-agent-sdk @composio/core dotenv

Install the Composio SDK and the Claude Agents SDK.

What's happening:

  • @composio/core provides Composio integration for Anthropic
  • @anthropic-ai/claude-agent-sdk is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
ANTHROPIC_API_KEY=your_anthropic_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates with Composio
  • USER_ID identifies the user for session management
  • ANTHROPIC_API_KEY authenticates with Anthropic/Claude
5

Import dependencies

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

dotenv.config();
What's happening:
  • We're importing all necessary libraries including the Claude Agent SDK and Composio
  • The dotenv.config() function loads environment variables from your .env file
  • This setup prepares the foundation for connecting Claude with Openrouter functionality
6

Create a Composio instance and Tool Router session

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });

  // Create Tool Router session for Openrouter
  const session = await composio.create(USER_ID, {
    toolkits: ['openrouter'],
  });
  const mcpUrl = session?.mcp.url;
What's happening:
  • The function checks for the required COMPOSIO_API_KEY environment variable
  • We're creating a Composio instance using our API key
  • The create method creates a Tool Router session for Openrouter
  • The returned url is the MCP server URL that your agent will use
7

Configure Claude Agent with MCP

const options: Options = {
  permissionMode: 'bypassPermissions',
  mcpServers: {
    composio: {
      type: 'http',
      url: mcpUrl,
      headers: { 'x-api-key': COMPOSIO_API_KEY }
    }
  },
  systemPrompt: 'You are a helpful assistant with access to Openrouter tools via Composio.',
  maxTurns: 10,
};
What's happening:
  • We're configuring the Claude Agent options with the MCP server URL
  • permissionMode: 'bypassPermissions' allows the agent to execute operations without asking for permission each time
  • The system prompt instructs the agent that it has access to Openrouter
  • maxTurns: 10 limits the conversation length to prevent excessive API usage
8

Create client and start chat loop

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}
What's happening:
  • The readline interface is created to handle user input and output
  • The query function is used to send the user's input to the agent
  • The chat loop continues until the user types 'exit' or 'quit'
9

Run the application

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}
What's happening:
  • The chat function is the entry point for the application
  • The try-catch block is used to handle any errors that occur

Complete Code

Here's the complete code to get you started with Openrouter and Claude Agent SDK:

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });
  const session = await composio.create(USER_ID, {
    toolkits: ['openrouter']
  });
  const mcp_url = session?.mcp.url;

  const options: Options = {
    permissionMode: 'bypassPermissions',
    mcpServers: {
      composio: {
        type: 'http',
        url: mcp_url,
        headers: { 'x-api-key': COMPOSIO_API_KEY }
      }
    },
    systemPrompt: 'You are a helpful assistant with access to Openrouter tools via Composio.',
    maxTurns: 10,
  };

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}

Conclusion

You've successfully built a Claude Agent SDK agent that can interact with Openrouter through Composio's Tool Router.

Key features:

  • Native MCP support through Claude's agent framework
  • Streaming responses for real-time interaction
  • Permission bypass for smooth automated workflows
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

Every Openrouter action and event your agent gets out of the box.

Create Chat Completion

Tool to generate a chat-style completion.

Create Coinbase Charge

Tool to create a Coinbase charge for crypto payment to add credits to your OpenRouter account.

Create Message (Anthropic Format)

Tool to create a message using Anthropic Messages API format via OpenRouter.

Get Credits

Tool to get the current API credit balance for the authenticated user.

Get Current Key

Tool to get information about the currently authenticated API key.

Get Generation

Tool to retrieve a generation result by its unique ID.

Get Models Count

Tool to get the total count of available models on OpenRouter.

List Available Models

Tool to list available models via OpenRouter API.

List Embedding Models

Tool to list all available embeddings models via OpenRouter API.

OpenRouter List Model Endpoints

Tool to list endpoints for a specific model.

OpenRouter List Providers

Tool to list all AI model providers available through the OpenRouter API.

List User Models

Tool to list models filtered by user provider preferences, privacy settings, and guardrails.

OpenRouter List ZDR Endpoints

Tool to preview the impact of Zero Data Retention (ZDR) on the available endpoints.

FRAMEWORKS

How to build Openrouter MCP Agent with another framework

ChatGPT logo

ChatGPT

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OpenAI Agents SDK logo

OpenAI Agents SDK

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Claude Code logo

Claude Code

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Claude Cowork logo

Claude Cowork

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Codex logo

Codex

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Cursor logo

Cursor

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OpenClaw logo

OpenClaw

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Hermes logo

Hermes

Use Openrouter MCP with Hermes

CLI logo

CLI

Use Openrouter MCP with CLI

Google ADK logo

Google ADK

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LangChain logo

LangChain

Use Openrouter MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Openrouter MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Openrouter MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Openrouter MCP with LlamaIndex

CrewAI logo

CrewAI

Use Openrouter MCP with CrewAI

OpenCode logo

OpenCode

Use Openrouter MCP with OpenCode

VS Code logo

VS Code

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FAQ

Frequently asked questions

With a standalone Openrouter MCP server, the agents and LLMs can only access a fixed set of Openrouter tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Openrouter and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Claude Agent SDK fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Openrouter tools.

Yes, absolutely. You can configure which Openrouter scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Openrouter data and credentials are handled as safely as possible.

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