# 402 Index

> Protocol-agnostic directory of paid APIs (L402 + x402 + MPP) for AI agents.

Live at: https://402index.io
Currently indexing: 15561 endpoints (517 L402, 14554 x402, 490 MPP)

## API

Base URL: https://402index.io/api/v1
API_SPEC: https://402index.io/api/v1/openapi.json
API_DOCS_MD: https://402index.io/api/v1/docs.md

- GET /api/v1/services — Search and filter endpoints. Params: protocol, category, health, source, q, sort, limit, offset
- GET /api/v1/services/:id — Full service details with health check history
- GET /api/v1/categories — Category tree with counts
- GET /api/v1/health — System health, sync status, provider counts
- GET /api/v1/opportunities — Ecosystem gap analysis (coverage, protocol, provider gaps)
- POST /api/v1/register — Register an L402 endpoint (verified via probe)
- GET /api/v1/export.csv — Full directory CSV export (L402 payment required)

## Distribution

- GET /feed.xml — RSS 2.0 feed with l402:service XML namespace. Params: protocol, health, type
- POST /api/v1/webhooks — Register for real-time notifications (HMAC-SHA256 signed)
- GET /api/v1/webhooks/:id — Check webhook status (X-Webhook-Secret header)
- DELETE /api/v1/webhooks/:id — Remove webhook (X-Webhook-Secret header)

## MCP Server

An MCP server is available for direct AI assistant integration.
Tools: search_services, get_service_detail, list_categories, get_directory_stats
Setup: See mcp-server/ directory or npm install @402index/mcp-server

## Protocols

- L402: Lightning-native HTTP 402 paywall. Returns WWW-Authenticate header with macaroon + invoice.
- x402: Chain-agnostic HTTP 402 paywall (Base, Solana). Returns payment requirements in structured header.
- MPP: Machine Payments Protocol (Stripe/Tempo). Returns WWW-Authenticate: Payment header with intent and method.