402xAgent MCP server

Verified Pay-Per-Call Catalog

A static, machine-readable catalog of pay-per-call (x402) services for AI agents, with factual results of our own automated checks. Published by @WithGrokBot.

Try it in one line

Which x402 web-search endpoint delivered on our last paid calls, at $0.01 or less? No key; 5 free lookups per client per UTC day:

curl -s "https://verified-catalog-lookup.withgrokbot.workers.dev/v1/lookup?task=web-search&max_price=0.01&ref=via-readme"

const r = await (await fetch("https://verified-catalog-lookup.withgrokbot.workers.dev/v1/lookup?task=web-search&max_price=0.01&ref=via-readme")).json();

Results are sorted by known-answer pass rate over our last paid calls, then price, each with its Base settlement receipts. Other tasks: /v1/tasks. Optional client=; ref only says where you found the link.

Pricing

• 5 free lookups per client per UTC day. The client is your client value when you send one, otherwise a salted hash of your IP (raw IPs are never stored). The counter resets at 00:00 UTC. Only /v1/lookup is metered; /v1/tasks, /openapi.json and the static catalog files stay free.
• After that, $0.02 USDC on Base per lookup via x402. The lookup answers HTTP 402 with a v2 PAYMENT-REQUIRED header (exact scheme, eip155:8453, USDC, payTo 0x37cfCC8a29e9ff9458902B29E31E42dc7B718674). Retry with a PAYMENT-SIGNATURE (or X-PAYMENT) header; the payment is verified and settled through the public PayAI x402 facilitator, and the settlement tx comes back in the PAYMENT-RESPONSE header and the response's access block.
• Payment never changes results, sort order or listings. It buys query access only. Free, paid and exempt lookups run the same code on the same data and get identical results; no seller can pay for placement, and no check result or known-answer outcome depends on who paid. Every lookup response repeats this in payment_policy.

Remote MCP server (free)

https://verified-catalog-lookup.withgrokbot.workers.dev/mcp (Streamable HTTP, stateless JSON-RPC, no key). Same 3 tools and results as mcp/server.py: searchcatalog, getservice and lookup. lookup uses the client name vc-mcp, so it shares that client's 5 free lookups per UTC day; after that it reports the 402 and does not pay. Registry name: io.github.withgrokbot/verified-catalog (server.json).

Always-paid endpoint (x402)

GET https://verified-catalog-lookup.withgrokbot.workers.dev/v1/lookup/paid?task=web-search&max_price=0.01 takes the same parameters and returns the same result as /v1/lookup, for $0.02 USDC on Base per call with no free quota. Its 402 carries x402 Bazaar discovery metadata (extensions.bazaar); it is also listed in /openapi.json (x-payment-info) and /.well-known/x402. Bad parameters get a 400 before anything is settled.

Files

Shortened. The full README is on GitHub.