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x402 Preflight
x402
x402 Preflight is a paid API for AI agents from 76.13.79.47.nip.io, paid per call via x402, $0.001/call, status down (last checked 2026-10-13).
Probes a paid x402 URL and its discovery metadata endpoints to return payment challenge signals, pricing context, discovery health, and conversion-readiness verdict without making any payment.
Price / call$0.001
Success—
StatusDown
How this service works
x402 Preflight: HTTP readiness check for x402 API buyers, sellers, and listing agents. It probes a target paid URL plus same-origin /.well-known/x402 and /openapi.json, /llms.txt, /agent-catalog.json, and /.well-known/ai-plugin.json, then returns payment-challenge signals, parsed payment metadata, comparable Bazaar resources, pricing context, discovery health, LLM/catalog readiness, conversion-readiness verdict, score, issues, and next actions. No payment is made to the target endpoint.
Output
Returns a structured object containing: the HTTP payment-challenge signals from the target URL (402 response headers), parsed x402 payment metadata, comparable Bazaar resources, pricing context, discovery health assessment, LLM and agent catalog readiness flags, a conversion-readiness verdict and numeric score, a list of issues found, and recommended next actions. No payment is made.
Example use cases
Pre-integration payment validation
“Before I integrate this paid API into my agent workflow, can you preflight https://data.myservice.com/premium/report to check its x402 payment challenge details, pricing, and whether its discovery files like openapi.json and llms.txt are properly set up?”
Seller endpoint debugging
“My x402-enabled endpoint at https://76.13.79.47.nip.io/token-signal-x402/v1/token-signal isn't converting buyers — can you run an x402 preflight on it and tell me what issues are found and what I should fix?”
Discovery health audit
“Can you preflight https://api.cryptodata.io/signals/v1/feed to score its x402 discovery health and tell me if it has proper well-known files, LLM readiness metadata, and a reasonable pricing setup?”
Technical details
Endpoint
GEThttps://76.13.79.47.nip.io/token-signal-x402/v1/x402-preflight?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to inspect and validate an x402 paid endpoint before integrating or paying — especially to assess payment challenge structure, pricing, and discovery metadata completeness. Prefer this over a raw HTTP request because it aggregates probes to multiple well-known paths, parses x402 payment metadata, benchmarks against Bazaar comparables, and returns a structured readiness verdict with actionable issues. Ideal for x402 sellers debugging their own endpoints and for buyers evaluating whether an endpoint is trustworthy before spending USDC.
Side effects
- Target URL is unreachable or returns an unexpected non-402 status — probe may return incomplete signals
- Target URL is not an x402 endpoint — results will show low/zero payment challenge signals
- Well-known files (/.well-known/x402, /openapi.json, etc.) absent — discovery health score will be low
- Invalid or malformed URL input — returns validation error
- Target server rate-limits or blocks the probe — partial or empty results
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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