Nexus MCP Server

🔍 Nexus MCP Server

AI integration without the complexity

Intelligent AI model search and discovery with zero-install simplicity

Quick Start • Features • Documentation • Contributing

🚀 What is Nexus?

Nexus is a production-ready Model Context Protocol (MCP) server that brings AI-powered web search directly into your development environment. Get intelligent search results with proper citations in Claude Desktop, Cursor, or any MCP-compatible client - all with a single command.

Why Nexus?

• 🎯 Zero Setup: Ready in 30 seconds with npx - no installation, no configuration
• 🧠 AI-Powered: Uses Perplexity Sonar models for intelligent, current web search
• 📚 Source Citations: Get authoritative sources with every search result
• 🔧 Developer-First: Built for developers who want AI capabilities without complexity
• ⚡ Production-Ready: Enterprise-grade reliability with comprehensive error handling

✨ Features

🚀 Zero-Install Simplicity

• Ready in 30 seconds with npx
• No dependencies or build steps
• Cross-platform compatibility
• Always up-to-date

🧠 AI-Powered Intelligence

• Perplexity Sonar model integration
• Real-time web content search
• Context-aware result ranking
• Multiple model options

📚 Professional Quality

• Source citations and metadata
• Comprehensive error handling
• Production-grade reliability
• TypeScript implementation

🔧 Developer Experience

• MCP protocol compliance
• Extensive documentation
• Configurable parameters
• Community support

🏃‍♂️ Quick Start

🚀 Zero-install setup - Ready in 30 seconds!

Prerequisites

• Node.js 16 or higher
• An OpenRouter API key (get one at OpenRouter)

Zero-Config Installation

No build steps, no dependencies, no setup required:

That's it! The server is now running and ready for MCP client connections.

Testing the NPX Installation

Alternative: Local Development Installation

For local development or customization:

1. Clone the repository:

2. Install dependencies:

3. Build the server:

4. Configure your OpenRouter API key:

5. Test the server:

Integration with MCP Clients

🚀 Quick Setup with NPX (Recommended)

The easiest way to integrate with any MCP client is using NPX:

Claude Code

Add this server to your Claude Code MCP settings:

1. Open your MCP settings file (usually ~/.claude/mcp_settings.json)
2. Add the server configuration using NPX:

3. Restart Claude Code

That's it! No installation, no build steps, no path configuration required.

Cursor

Configure the server in Cursor's MCP settings:

1. Open Cursor settings and navigate to MCP servers
2. Add a new server with:
   • Name: nexus
   • Command: npx
   • Args: ["nexus-mcp", "--stdio"]
   • Environment Variables:
     • OPENROUTER_API_KEY: your-api-key-here
3. Restart Cursor

Other MCP Clients

For any MCP-compatible client, use these connection details:

• Transport: stdio
• Command: npx
• Args: ["nexus-mcp", "--stdio"]
• Environment Variables: OPENROUTER_API_KEY=your-api-key-here

Alternative: Local Installation

If you prefer using a local installation (after following the local development setup):

Usage

Once integrated, you can use the search tool in your MCP client:

Basic Search

Advanced Search with Parameters

Available Tools

search

The main search tool that provides AI-powered web search capabilities.

Parameters:

• query (required): Search query (1-2000 characters)
• model (optional): Perplexity model to use (default: "perplexity/sonar")
• maxTokens (optional): Maximum response tokens (1-4000, default: 1000)
• temperature (optional): Response randomness (0-2, default: 0.7)

Example Response:

Configuration

Environment Variables

• OPENROUTER_API_KEY (required): Your OpenRouter API key
• NODE_ENV (optional): Environment setting (development, production, test)
• LOG_LEVEL (optional): Logging level (debug, info, warn, error)

Advanced Configuration

The server supports additional configuration through environment variables:

• OPENROUTER_TIMEOUT_MS: Request timeout in milliseconds (default: 30000)
• OPENROUTER_MAX_RETRIES: Maximum retry attempts (default: 3)
• OPENROUTER_BASE_URL: Custom OpenRouter API base URL

Resources

The server provides a configuration status resource at config://status that shows:

• Server health status
• Configuration information (with masked API key)
• Search tool availability
• Server uptime and version

Troubleshooting

NPX-Specific Issues

"npx: command not found"

• Ensure Node.js 16+ is installed: node --version
• Update npm: npm install -g npm@latest

"Cannot find package 'nexus-mcp'"

• The package may not be published yet. Use local installation instead
• Verify network connectivity for npm registry access

NPX takes a long time to start

• This is normal on first run as NPX downloads the package
• Subsequent runs will be faster due to caching
• For faster startup, use local installation instead

"Permission denied" errors with NPX

• Try: npx --yes nexus-mcp --stdio
• Or set npm permissions: npm config set user 0 && npm config set unsafe-perm true

Common Issues

"Search functionality is not available"

• Ensure OPENROUTER_API_KEY environment variable is set
• Verify your API key is valid at OpenRouter
• Check the server logs for initialization errors

"Authentication failed: Invalid API key"

• Double-check your API key format and validity
• Ensure the key has sufficient credits/permissions
• Test the key directly at OpenRouter dashboard

"Rate limit exceeded"

• Wait for the rate limit to reset (usually 1 minute)
• Consider upgrading your OpenRouter plan for higher limits
• Monitor usage in your OpenRouter dashboard

Connection timeouts

• Check your internet connection
• The server will automatically retry failed requests
• Increase timeout if needed: OPENROUTER_TIMEOUT_MS=60000

MCP client can't connect to server

• Verify the --stdio flag is included in your MCP configuration
• Check that Node.js 16+ is available in your MCP client's environment
• Ensure the API key is properly set in the environment variables

Debug Logging

Enable debug logging by:

For local development: Add LOG_LEVEL=debug to your .env file

For MCP clients: Add LOG_LEVEL: "debug" to the env section of your MCP configuration

This will provide detailed information about:

• Configuration loading
• API requests and responses
• Error details and stack traces
• Performance metrics

Testing Connection

You can test if the server is working by checking the configuration status resource in your MCP client, or by running a simple search query.

Development

For developers working on this server:

💰 API Credits and Costs

This server uses OpenRouter's API, which charges based on token usage:

• Perplexity Sonar models: Check current pricing at OpenRouter Models
• Usage monitoring: Track consumption through the OpenRouter dashboard
• Cost control: Set usage limits in your OpenRouter account
• Optimization: Nexus includes built-in rate limiting and intelligent caching

📚 Documentation

🤝 Contributing

We welcome contributions from developers of all experience levels!

🚀 Get Started

• Fork the repository
• Read our Contributing Guide
• Check out good first issues

🐛 Report Issues

• Bug Reports
• Feature Requests
• Ask Questions

💬 Join Community

• GitHub Discussions
• Code of Conduct
• Roadmap & Project Board

🌟 Recognition

Contributors are recognized in our:

• Contributors list
• Release notes for significant contributions
• Community spotlights and testimonials

🔗 Related Projects

• Model Context Protocol - The standard we implement
• OpenRouter - Our AI model provider
• Claude Desktop - Primary MCP client
• Cursor - AI-powered code editor with MCP support

📞 Support & Community

📄 License

MIT License - see LICENSE file for details.

Made with ❤️ by the open source community

⭐ Star us on GitHub • 📦 View on NPM • 📚 Read the Docs

Nexus: AI integration without the complexity