Changelog

September 26, 2025

MCP (Model Control Protocol) & Experimental ToolRouter

Composio now introduces comprehensive MCP (Model Control Protocol) support and an experimental ToolRouter for creating isolated, scoped sessions with advanced toolkit management. These features enable seamless integration with modern AI frameworks and provide powerful session-based tool routing capabilities.

Why Use MCP & ToolRouter?

  • Framework Integration: Native MCP support for Vercel AI, Mastra, OpenAI Agents, and LangChain
  • Session Isolation: Create isolated sessions with specific toolkit configurations
  • Advanced Authentication: Flexible auth config management per toolkit
  • Scoped Access: Control which tools are available within each session
  • Multi-Service Workflows: Route tool calls efficiently across different services
  • Development & Testing: Perfect for testing and development with scoped MCP server access

TypeScript SDK (v0.1.53)

Added: MCP API

Core MCP Features:

  • MCP Server Creation: Create and manage MCP server configurations
  • User-Specific URLs: Generate unique MCP server URLs for individual users
  • Toolkit Configuration: Support for multiple toolkits with custom auth configs
  • Tool Filtering: Specify allowed tools per configuration
  • Connection Management: Choose between manual and automatic account management

Basic Usage:

1import { Composio } from '@composio/core';
2
3const composio = new Composio({
4  apiKey: process.env.COMPOSIO_API_KEY,
5});
6
7// Create MCP configuration
8const mcpConfig = await composio.mcp.create('my-server-name', {
9  toolkits: [
10    { toolkit: 'github', authConfigId: 'ac_233434343' },
11    { toolkit: 'gmail', authConfigId: 'ac_567890123' }
12  ],
13  allowedTools: ['GITHUB_CREATE_ISSUE', 'GMAIL_SEND_EMAIL'],
14  manuallyManageConnections: false,
15});
16
17// Generate server instance for a user
18const serverInstance = await composio.mcp.generate('user123', mcpConfig.id);
19console.log('MCP URL:', serverInstance.url);

Framework Integration Examples:

1// Vercel AI Integration
2import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
3import { experimental_createMCPClient as createMCPClient } from 'ai';
4
5const mcpClient = await createMCPClient({
6  name: 'composio-mcp-client',
7  transport: new SSEClientTransport(new URL(serverInstance.url)),
8});
9
10// Mastra Integration
11import { MCPClient as MastraMCPClient } from '@mastra/mcp';
12
13const mcpClient = new MastraMCPClient({
14  servers: {
15    composio: { url: new URL(mcpSession.url) },
16  },
17});
18
19// OpenAI Agents Integration
20import { hostedMcpTool } from '@openai/agents';
21
22const tools = [
23  hostedMcpTool({
24    serverLabel: 'composio',
25    serverUrl: mcpSession.url,
26  }),
27];

Added: Experimental ToolRouter

Core ToolRouter Features:

  • Session-Based Routing: Create isolated sessions for specific users and toolkit combinations
  • Dynamic Configuration: Configure toolkits and auth configs per session
  • MCP Server URLs: Each session gets a unique MCP server endpoint
  • Flexible Toolkit Management: Support for string names or detailed toolkit configurations
  • Connection Control: Manual or automatic connection management per session

Basic Usage:

1// Create session with simple toolkit names
2const session = await composio.experimental.toolRouter.createSession('user_123', {
3  toolkits: ['gmail', 'slack', 'github'],
4});
5
6// Create session with auth configs
7const session = await composio.experimental.toolRouter.createSession('user_456', {
8  toolkits: [
9    { toolkit: 'gmail', authConfigId: 'ac_gmail_work' },
10    { toolkit: 'slack', authConfigId: 'ac_slack_team' },
11    { toolkit: 'github', authConfigId: 'ac_github_personal' },
12  ],
13  manuallyManageConnections: true,
14});
15
16console.log('Session ID:', session.sessionId);
17console.log('MCP URL:', session.url);

Advanced Multi-Service Integration:

1// Complex workflow session
2const integrationSession = await composio.experimental.toolRouter.createSession('user_789', {
3  toolkits: [
4    { toolkit: 'gmail', authConfigId: 'ac_gmail_work' },
5    { toolkit: 'slack', authConfigId: 'ac_slack_team' },
6    { toolkit: 'github', authConfigId: 'ac_github_personal' },
7    { toolkit: 'notion', authConfigId: 'ac_notion_workspace' },
8    { toolkit: 'calendar', authConfigId: 'ac_gcal_primary' },
9  ],
10});
11
12// Use with any MCP client
13const mcpClient = new MCPClient(integrationSession.url);

Framework-Specific Examples:

1// Mastra Integration
2const mcpSession = await composio.experimental.toolRouter.createSession(userId, {
3  toolkits: ["gmail"],
4  manuallyManageConnections: true,
5});
6
7const agent = new MastraAgent({
8  name: 'Gmail Assistant',
9  model: openai('gpt-4o-mini'),
10  tools: await mcpClient.getTools(),
11});
12
13// OpenAI Agents Integration
14const tools = [
15  hostedMcpTool({
16    serverLabel: 'composio tool router',
17    serverUrl: mcpSession.url,
18    requireApproval: {
19      never: { toolNames: ['GMAIL_FETCH_EMAILS'] },
20    },
21  }),
22];

Python SDK (v0.8.12)

Added: MCP Support

Core MCP Features:

  • Server Configuration: Create and manage MCP server configurations
  • Toolkit Management: Support for both simple toolkit names and detailed configurations
  • Authentication Control: Per-toolkit auth config specification
  • Tool Filtering: Specify allowed tools across all toolkits
  • User Instance Generation: Generate user-specific MCP server instances

Basic Usage:

1from composio import Composio
2
3composio = Composio()
4
5# Create MCP server with toolkit configurations
6server = composio.mcp.create(
7    'personal-mcp-server',
8    toolkits=[
9        {
10            'toolkit': 'github',
11            'auth_config_id': 'ac_xyz',
12        },
13        {
14            'toolkit': 'slack', 
15            'auth_config_id': 'ac_abc',
16        },
17    ],
18    allowed_tools=['GITHUB_CREATE_ISSUE', 'SLACK_SEND_MESSAGE'],
19    manually_manage_connections=False
20)
21
22# Generate server instance for a user
23mcp_instance = server.generate('user_12345')
24print(f"MCP URL: {mcp_instance['url']}")

Simple Toolkit Usage:

1# Using simple toolkit names
2server = composio.mcp.create(
3    'simple-mcp-server',
4    toolkits=['composio_search', 'text_to_pdf'],
5    allowed_tools=['COMPOSIO_SEARCH_DUCK_DUCK_GO_SEARCH', 'TEXT_TO_PDF_CONVERT_TEXT_TO_PDF']
6)
7
8# All tools from toolkits (default behavior)
9server = composio.mcp.create(
10    'all-tools-server',
11    toolkits=['composio_search', 'text_to_pdf']
12    # allowed_tools=None means all tools from these toolkits
13)

LangChain Integration:

1import asyncio
2from composio import Composio
3from langchain_mcp_adapters.client import MultiServerMCPClient
4from langgraph.prebuilt import create_react_agent
5
6composio = Composio()
7
8mcp_config = composio.mcp.create(
9    name="langchain-slack-mcp",
10    toolkits=[{"toolkit": "slack", "auth_config_id": "<auth-config-id>"}],
11)
12
13mcp_server = mcp_config.generate(user_id='<user-id>')
14
15client = MultiServerMCPClient({
16    "composio": {
17        "url": mcp_server["url"],
18        "transport": "streamable_http",
19    }
20})
21
22async def langchain_mcp(message: str):
23    tools = await client.get_tools()
24    agent = create_react_agent("openai:gpt-4.1", tools)
25    response = await agent.ainvoke({"messages": message})
26    return response
27
28response = asyncio.run(langchain_mcp("Show me 20 most used slack channels"))

Migration Guide

TypeScript SDK: Migrating to New MCP API

The new MCP API provides enhanced functionality and better integration patterns. Here’s how to migrate from the previous MCP implementation:

Before (Legacy MCP)

1// Legacy MCP approach (still accessible via deprecated.mcp)
2import { Composio } from '@composio/core';
3
4const composio = new Composio();
5
6// Old MCP server creation
7const legacyMCP = await composio.deprecated.mcp.createServer({
8  name: 'my-server',
9  toolkits: ['github', 'gmail'],
10});
11
12// Direct URL usage
13const mcpUrl = legacyMCP.url;

After (New MCP API)

1// New MCP API approach
2import { Composio } from '@composio/core';
3
4const composio = new Composio({
5  apiKey: process.env.COMPOSIO_API_KEY,
6});
7
8// Step 1: Create MCP configuration
9const mcpConfig = await composio.mcp.create('my-server', {
10  toolkits: [
11    { toolkit: 'github', authConfigId: 'ac_github_123' },
12    { toolkit: 'gmail', authConfigId: 'ac_gmail_456' }
13  ],
14  allowedTools: ['GITHUB_CREATE_ISSUE', 'GMAIL_SEND_EMAIL'],
15  manuallyManageConnections: false,
16});
17
18// Step 2: Generate user-specific server instance
19const serverInstance = await composio.mcp.generate('user_123', mcpConfig.id);
20const mcpUrl = serverInstance.url;

Key Migration Changes

  1. Two-Step Process:

    • Before: Single step server creation
    • After: Create configuration, then generate user instances

  2. Enhanced Configuration:

    • Before: Simple toolkit names only
    • After: Detailed toolkit configs with auth, tool filtering, connection management

  3. User-Specific URLs:

    • Before: Single server URL for all users
    • After: Unique URLs per user for better isolation

  4. Backward Compatibility:

    • Legacy Access: Old MCP functionality remains available via composio.deprecated.mcp
    • Gradual Migration: Migrate at your own pace without breaking existing implementations

Migration Benefits

  • Better Security: User-specific sessions with isolated access
  • Enhanced Control: Fine-grained toolkit and tool management
  • Framework Integration: Native support for modern AI frameworks
  • Scalability: Better resource management and user isolation

Migration Timeline

  • Phase 1: New MCP API available alongside legacy implementation
  • Phase 2: Legacy MCP accessible via deprecated.mcp namespace
  • Phase 3: Full deprecation (timeline to be announced)

Recommendation: Start new projects with the new MCP API and gradually migrate existing implementations to benefit from enhanced features and better framework integration.

Key Benefits & Use Cases

Development & Testing

  • Isolated Environments: Test different toolkit combinations without affecting production
  • Scoped Access: Limit tool access for security and testing purposes
  • Framework Flexibility: Works with any MCP-compatible client or framework

Production Workflows

  • Multi-Service Integration: Seamlessly combine tools from different services
  • User-Specific Sessions: Each user gets their own isolated session with appropriate permissions
  • Authentication Management: Fine-grained control over authentication per toolkit

Framework Compatibility

  • Vercel AI: Native integration with Vercel AI SDK
  • Mastra: Full support for Mastra agents and workflows
  • OpenAI Agents: Direct integration with OpenAI’s agent framework
  • LangChain: Complete LangGraph and LangChain compatibility
  • Custom Clients: Works with any MCP-compatible client

Enterprise Features

  • Session Management: Track and manage multiple user sessions
  • Resource Control: Limit concurrent sessions and resource usage
  • Audit Trail: Full logging and monitoring of tool usage
  • Security: Isolated sessions prevent cross-user data access

Migration & Compatibility

Both MCP and ToolRouter features are designed to complement existing Composio functionality:

1// Can be used alongside regular tool management
2const regularTools = await composio.tools.get({ toolkits: ['github'] });
3const mcpSession = await composio.experimental.toolRouter.createSession(userId, {
4  toolkits: ['gmail', 'slack']
5});
6
7// Both approaches can coexist and serve different purposes

The experimental ToolRouter API provides a preview of advanced session management capabilities, while the MCP API offers production-ready Model Control Protocol support for modern AI frameworks.

Bug Fixes

Fixed: Missing Descriptions in Auth Config Fields

Python SDK (v0.8.12) & TypeScript SDK (v0.1.53)

Issue Fixed:

  • Auth Config Connection Fields: Added missing descriptions to toolkit auth configuration connection fields
  • Auth Config Creation Fields: Added missing descriptions to toolkit auth configuration creation fields
  • Field Documentation: Improved field documentation and help text for better developer experience

Details: Previously, when developers were setting up auth configurations for toolkits, many fields lacked proper descriptions, making it difficult to understand what information was required. This fix ensures all auth config fields now include:

  • Clear, descriptive field labels
  • Helpful placeholder text where appropriate
  • Detailed explanations of field requirements

This improvement affects all toolkits and makes the authentication setup process more intuitive and error-free.