# HTTP 402 AI Tollbooth

> A Bitcoin Lightning HTTP 402 marketplace offering 203 machine-readable developer troubleshooting datasets across DevOps, APIs, ML/AI, Web/Frontend, and Databases.

## Discovery
- Catalog: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/catalog
- Categories: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/categories
- Free preview: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/preview/{product}
- OpenAPI 3.1: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/openapi.json
- MCP manifest: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/.well-known/mcp.json
- Payment guide: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/docs/payment-flow

## Payment model
Requesting a paid product returns HTTP 402 with a mainnet BOLT11 invoice, payment hash, price, preview URL, and instructions. After payment, retry once with X-Payment-Hash and X-Payment-Preimage. Entry products cost 2,000 sats for 50 records; Standard costs 5,000 sats for 100; Premium costs 10,000 sats for 200.

## Record contract
Every paid record contains non-empty error_code, description, and programmatic_fix strings. Free previews return exactly three records and never require payment.