🧠 Sequential Thinking MCP Server

A Remote MCP Server implementation for dynamic and reflective problem-solving through structured thinking. Built with the official @vercel/mcp-adapter for seamless Vercel deployment with Streamable HTTP transport.

✨ Features

• 🔄 Streamable HTTP Transport - Modern, efficient transport (recommended by MCP spec March 2025)

• 🌐 SSE Support - Backward compatibility with Server-Sent Events

• 📦 Vercel Native - One-click deployment with @vercel/mcp-adapter

• 🔀 Branching Logic - Explore alternative thinking paths

• 📝 Revision Tracking - Refine and improve previous thoughts

• 💾 Session Management - Persistent thinking across interactions

• 🏷️ Auto-Classification - Automatic thought type detection

Related MCP server: UltraThink

🚀 Quick Deploy

Deploy to Vercel (Recommended)

After deployment, your MCP server will be available at:

• Streamable HTTP: https://your-app.vercel.app/mcp

• SSE: https://your-app.vercel.app/sse

Local Development

# Clone the repository
git clone https://github.com/sheikhcoders/sequential-thinking-mcp.git
cd sequential-thinking-mcp

# Install dependencies
npm install

# Build
npm run build

# Run stdio mode (for MCP clients)
npm start

# Run HTTP mode (for development)
npm run start:http

📡 Transport Modes

Streamable HTTP (Recommended)

The latest MCP transport specification. Eliminates persistent connections for better scalability.

POST https://your-app.vercel.app/mcp

Server-Sent Events (SSE)

Legacy transport for backward compatibility.

GET https://your-app.vercel.app/sse

Standard IO (stdio)

For local MCP clients like Claude Desktop.

node dist/index.js

🔧 Configuration

Claude Desktop

Add to ~/.claude/claude_desktop_config.json:

{
  "mcpServers": {
    "sequential-thinking": {
      "url": "https://your-app.vercel.app/mcp"
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "sequential-thinking": {
      "url": "https://your-app.vercel.app/mcp"
    }
  }
}

Cline (Streamable HTTP)

Add to cline_mcp_settings.json:

{
  "mcpServers": {
    "sequential-thinking": {
      "command": "npx",
      "args": ["mcp-remote", "https://your-app.vercel.app/mcp"],
      "transportType": "Streamable HTTP"
    }
  }
}

For stdio (Local)

{
  "mcpServers": {
    "sequential-thinking": {
      "command": "npx",
      "args": ["sequential-thinking-mcp"]
    }
  }
}

🛠️ Available Tools

sequential_thinking

The main tool for step-by-step problem solving with dynamic thought management.

Parameters:

get_thinking_summary

Get a comprehensive summary of a thinking session.

list_thinking_sessions

List all available thinking sessions.

switch_thinking_branch

Switch between different thinking branches.

complete_thinking_session

Mark a session as completed with optional final conclusion.

📊 Thought Types

Thoughts are automatically classified:

🏗️ Project Structure

sequential-thinking-mcp/
├── api/
│   └── [transport]/
│       └── route.ts       # Vercel serverless handler
├── src/
│   ├── index.ts           # CLI entry point (stdio mode)
│   ├── server.ts          # MCP stdio server
│   ├── http-transport.ts  # Express HTTP server
│   ├── thinking-session.ts # Session management
│   └── types.ts           # TypeScript definitions
├── package.json
├── tsconfig.json
├── vercel.json            # Vercel configuration
└── README.md

🔒 Production Considerations

Session Persistence

For production with persistent sessions, integrate Vercel KV or Upstash Redis:

import { kv } from '@vercel/kv';

// Store session
await kv.set(`session:${sessionId}`, session);

// Retrieve session
const session = await kv.get(`session:${sessionId}`);

Authentication

Add OAuth or API key authentication for production:

// In your handler
const authHeader = request.headers.get('Authorization');
if (!validateToken(authHeader)) {
  return new Response('Unauthorized', { status: 401 });
}

📄 API Reference

Health Check

curl https://your-app.vercel.app/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "method": "initialize", "id": 1}'

Call Tool

curl https://your-app.vercel.app/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "sequential_thinking",
      "arguments": {
        "thought": "Let me analyze this problem step by step",
        "nextThoughtNeeded": true,
        "thoughtNumber": 1,
        "totalThoughts": 5
      }
    },
    "id": 1
  }'

📚 Resources

• MCP Specification

• Vercel MCP Adapter

• Deploy MCP Servers to Vercel

• Building Efficient MCP Servers

📝 License

MIT License - see LICENSE for details.

🤝 Contributing

Contributions welcome! Please read our contributing guidelines and submit PRs.

Built with ❤️ using the Model Context Protocol