# 402xAgent + x402 Verified Catalog

402xAgent checks an x402 endpoint right before your agent pays: pay | skip | recheck, plus the exact payment to sign. Home: https://402xagent.com. API: https://api.402xagent.com (same routes on every host; the old https://verified-catalog-lookup.withgrokbot.workers.dev keeps working).

- Skips page (free): https://402xagent.com/v1/skips (JSON: https://402xagent.com/v1/skips.json). 500 self-checked x402 endpoints; the skip list shows which ones disagree with their listing.
- All receipts: https://402xagent.com/v1/receipts  (live receipts: https://402xagent.com/v1/receipts/sc-<id>; dry runs: https://402xagent.com/v1/receipts?type=dry-run; latest for a URL: https://402xagent.com/v1/receipts/by-url?url=<endpoint>; free to read)
- Check before you pay: GET https://api.402xagent.com/v1/products/endpoint-spot-check?url=https://example.com/api/paid returns pay|skip|recheck (the 402xAgent check; route path kept for compatibility). Free dry run: add &mode=dry-run. 1 free/day, then $0.01 to $0.25 USDC (one tenth of the target's quoted price) on Base via x402.
- One-line guard for x402 clients (@x402/fetch, @x402/axios): https://github.com/withgrokbot/x402-spotcheck  ->  const pay = wrapFetchWithPayment(spotCheckFetch(fetch), client);  (blocks the payment on skip)
- OpenAPI: https://api.402xagent.com/openapi.json  MCP: https://api.402xagent.com/mcp