🧠 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

🚀 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:

Parameter	Type	Required	Description
thought	string	✅	Your current thinking step
nextThoughtNeeded	boolean	✅	Whether another thought is needed
thoughtNumber	number	✅	Current thought number (1-indexed)
totalThoughts	number	✅	Estimated total thoughts needed
isRevision	boolean	❌	Whether this revises previous thinking
revisesThought	number	❌	Which thought number is being revised
branchFromThought	number	❌	Create branch from this thought
branchId	string	❌	Branch identifier
sessionId	string	❌	Session ID for persistence

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:

Type	Detected When
question	Contains ?, starts with what/how/why
observation	Contains "I notice", "I see", "observe"
hypothesis	Contains "perhaps", "maybe", "hypothesis"
verification	Contains "verify", "test", "check"
insight	Contains "insight", "realize", "aha"
conclusion	Contains "therefore", "in conclusion"
refinement	Contains "refine", "improve", "better"
reflection	Contains "reflect", "thinking about"
analysis	Default for analytical statements

🏗️ 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