HTTP 402 AI Tollbooth

Agent-ready developer troubleshooting data, sold per request over Bitcoin Lightning.

Live: https://http-402-ai-tollbooth.rsaun-lightning.workers.dev

HTTP 402 AI Tollbooth gives developers and AI agents three useful records free, then unlocks complete structured datasets with a BOLT11 Lightning payment. There are no accounts, subscriptions, credit cards, or API keys.

This is a public, documentation and example repository. The production Worker implementation remains private and is not included here.

Try it now

List the complete catalog:

curl -sS https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/catalog

Preview exactly three records without payment:

curl -sS https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/preview/api-error-fixes

Request the full product and receive an HTTP 402 Lightning challenge:

curl -i https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/api/data/api-error-fixes

The last command creates an invoice. Do not run it unless you intentionally want a payment challenge; simply requesting it does not spend sats.

Related MCP server: Kairos Signal MCP Server

Why agents use it

• 203 products across DevOps, APIs, ML/AI, Web/Frontend, and Databases

• Entry, Standard, and Premium datasets with 50, 100, or 200 records

• Exactly three free records per product for try-before-you-buy discovery

• Stable error_code, description, and programmatic_fix fields

• HTTP 402 and Bitcoin Lightning payments without user accounts

• OpenAPI 3.1, MCP discovery metadata, and llms.txt

• Deterministic fallback generation for resilient dataset delivery

• Durable one-time redemption and replay protection

• Future x402 settlement is documented but remains disabled pending verification

Architecture

AI agent / developer
        |
        | HTTPS: catalog, preview, paid dataset
        v
Cloudflare Worker
   |         |                    |
   |         |                    +--> Alby --> Bitcoin Lightning invoice
   |         |
   |         +--> Durable Objects --> atomic redemption + counters
   |
   +--> Workers KV --> invoice challenges + generated dataset cache

Pricing

See the pricing rationale, including the live-verified 2,000-sat receiving floor.

How to pay

1. Request a paid product endpoint.

2. Receive 402 Payment Required with a BOLT11 invoice and payment hash.

3. Pay the invoice in a Lightning wallet.

4. Retry the same endpoint with X-Payment-Hash and X-Payment-Preimage.

5. Receive the full dataset once; replayed proofs are rejected.

Never publish or share a payment preimage before using it for its intended redemption. Future Solana USDC/x402 support is disabled until its manual verification process is completed.

Discovery documents

• Smithery server card

• OpenAPI 3.1 document

• llms.txt

• Billboard integration summary

• Official MCP Registry readiness

Integrations

• MCP metadata: tool descriptions for catalog, preview, and purchase discovery

• MCP transport: a live Streamable HTTP JSON-RPC endpoint at /mcp with four read-only tools

• OpenAPI: complete HTTP endpoint descriptions for agent frameworks

• LLMs.txt: concise machine-readable project and payment guidance

Connect an MCP client to https://http-402-ai-tollbooth.rsaun-lightning.workers.dev/mcp. The server supports list_products, preview_product, list_payment_methods, and buy_product. The last tool only returns payment directions and an HTTP 402 challenge; it never pays an invoice or creates a purchase on the caller's behalf.

For a complete no-payment example, see the Node agent recovery sample.

Runnable free sample

The sample shows how an agent can inspect malformed JSON, retry a transient 429 once after Retry-After, and safely stop when a response is not recoverable. It uses Node 22+ built-ins only:

cd examples/node-agent-recovery
npm test
npm start

The demo calls only the public three-record preview endpoint. It does not call a paid route, create an invoice, or automatically replay a payment proof.

License

The documentation in this billboard repository is available under the MIT License. The private production source code is not covered by this repository or license.