Purpose: Provide a static, machine-readable catalog of x402 pay-per-call services for AI agents, along with factual results from automated checks. Services can be found by task and price ceiling, with results sorted by known answer pass rate from recent paid calls, then by price, and accompanied by Base chain settlement receipts.
Main capabilities: Provide the /v1/lookup query interface, supporting parameters such as task, max_price, and n; provide the /v1/tasks task list; provide a remote MCP server (Streamable HTTP, stateless JSON-RPC, no key required), containing the three tools search_catalog, get_service, and lookup, consistent with the results of mcp/server.py. Catalog files include catalog.json, services/<id>.json, llms.txt, .well-known/agent-card.json, etc.; check results and evidence are stored in the results/ directory, and receipts.json records each paid call.
Usage: The free quota is 5 queries per client per UTC day. The client identifier is the passed-in client value; otherwise it is a salted hash of the IP (the raw IP is not stored). The count resets at 00:00 UTC. Beyond that, each query costs 0.02 USDC (Base chain), paid via x402: if unpaid, it returns HTTP 402 with a v2 PAYMENT-REQUIRED header (exact scheme, eip155:8453, USDC, payTo 0x37cfCC8a29e9ff9458902B29E31E42dc7B718674); on retry, include the PAYMENT-SIGNATURE or X-PAYMENT header, and it is verified and settled via the PayAI x402 facilitator. The settlement transaction is returned in the PAYMENT-RESPONSE header and the response access block. There is also an always-paid endpoint /v1/lookup/paid, with the same parameters and results, costing 0.02 USDC each time, with no free quota.
Use cases: Scenarios where you need to select reliable x402 services for agents, compare prices and pass rates, and obtain verifiable settlement receipts.
Limitations: Payment only purchases query access and does not affect results, ranking, or inclusion; free, paidand exempt queries use the same code and data, with consistent results, and sellers cannot pay to obtain ranking. Paid digital downloads (such as the Overnight Chief of Staff Setup Pack, 9 USDC) are always paid and are not eligible for the free quota. Paid checks are off by default and require --pay, an external wallet file, and dependencies, and have hard limits (0.10 USD per time, 1.00 USD per UTC day, 20.00 USD lifetime), and only sign the exact scheme for USDC on Base. The project only publishes facts and does not provide ratings, does not hold customer funds, and is not a party to seller transactions; disputes about results can be raised via a GitHub issue. The license is MIT.
