402 Index MCP Server

Search 15,000+ paid API endpoints across L402, x402, and MPP protocols with real-time health monitoring.

The 402 Index is the world's largest directory of paid API endpoints for AI agents. This MCP server gives your agent access to search, filter, and evaluate paid APIs before spending money.

Quick Start

npm install -g @402index/mcp-server
mcp-server

Installation

Claude Code

npm install -g @402index/mcp-server
claude mcp add 402index -- mcp-server

Claude Desktop

Install the server, then add to ~/Library/Application Support/Claude/claude_desktop_config.json:

npm install -g @402index/mcp-server

{
  "mcpServers": {
    "402index": {
      "command": "mcp-server"
    }
  }
}

Cursor

Install the server, then add to .cursor/mcp.json:

npm install -g @402index/mcp-server

{
  "mcpServers": {
    "402index": {
      "command": "mcp-server"
    }
  }
}

Cline

Install the server, then add to your Cline MCP settings:

npm install -g @402index/mcp-server

{
  "mcpServers": {
    "402index": {
      "command": "mcp-server"
    }
  }
}

Tools

Tool	Description
search_services	Search 15,000+ paid APIs by keyword, protocol (L402/x402/MPP), category, health status, price, and more
get_service_detail	Full details for a service including health history, latency, pricing, and payment verification
list_categories	Browse all API categories with per-protocol endpoint counts
get_directory_stats	Directory-wide health stats, protocol breakdown, and sync timestamps

Token-Optimized Defaults (v0.2.0)

Responses are compact by default to minimize token usage in agent workflows:

• search_services returns 10 results with 5 fields (name, url, protocol, price_sats, health_status) by default
  • fields — Comma-separated field names to return, or * for all 20 fields
  • format — json (default) or csv for tabular output (~29% fewer tokens)
  • limit — Results per page (default 10, max 200)
• list_categories returns a flat [{name, count}] array by default
  • summary — true (default) for compact output, false for full protocol breakdown

What Can Your Agent Discover?

• L402 (Lightning) — Self-custodial Bitcoin micropayments. 477 endpoints from providers like mutinynet faucet, sats4ai, LightningEnable.
• x402 (Coinbase/Solana) — USDC stablecoin payments on Base/Solana. 14,478 endpoints from Bazaar, Satring, Sponge.
• MPP (Stripe/Tempo) — Fiat-native machine payments. 488 endpoints from OpenAI, Anthropic, Google Gemini, Firecrawl, Replicate.

Every endpoint is health-checked hourly with latency measurements and reliability scoring.

Example Prompts

• "Find healthy L402 APIs for weather data under $0.01"
• "What paid inference APIs are available and which have the best uptime?"
• "Show me all podcast-related paid APIs"
• "Which API categories have the most endpoints?"
• "Get details on the sats4ai image generation endpoint"

Environment Variables

Variable	Default	Description
INDEX_URL	https://402index.io	Base URL of the 402 Index API

Links

• Website: https://402index.io
• API Docs: https://402index.io/api-docs
• OpenAPI Spec: https://402index.io/api/v1/openapi.json
• llms.txt: https://402index.io/llms.txt
• npm: https://www.npmjs.com/package/@402index/mcp-server

License

MIT