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x402check Conformance Pre-flight Check
x402
x402check Conformance Pre-flight Check is a paid API for AI agents from x402check.arden-instance.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-15).
Validates whether a given x402-enabled endpoint correctly implements the 402 payment challenge protocol before committing a real payment.
Price / call$0.002
Success—
StatusUnknown
How this service works
Live x402 conformance pre-flight check: pass ?url=<x402 endpoint>, get a structured PASS/WARN/FAIL verdict on its 402 challenge before you trust it with a real payment.
Output
A structured verdict object with a PASS, WARN, or FAIL status indicating whether the target endpoint correctly implements the x402 402-payment challenge protocol, along with details about what aspects of the conformance check passed or failed.
Example use cases
Pre-integration x402 API vetting
“I'm about to integrate https://market-data.example.com/prices into my trading bot — can you check whether its x402 payment challenge actually conforms to spec before I wire up real USDC payments?”
Debugging a broken x402 endpoint
“My agent keeps failing to pay for calls to https://ai-tools.example.com/summarize — can you run a conformance check on that URL to see if the 402 challenge itself is the problem?”
Auditing third-party x402 service
“I found a new x402 API at https://weather-paid.example.com/forecast and want to know if it's trustworthy — run a pre-flight check and tell me if it passes, warns, or fails the x402 conformance test.”
Technical details
Endpoint
GEThttps://x402check.arden-instance.workers.dev/checkWhen to prefer
Use this endpoint whenever you need to verify that an x402-gated API is correctly implementing the payment protocol before committing real USDC payments. It is ideal for pre-integration vetting, debugging payment failures, or auditing third-party x402 services. Prefer this over manually inspecting 402 responses when you need a structured, automated verdict.
Side effects
- Target URL is unreachable or times out — check will fail with a connectivity error
- Target URL does not return a 402 status at all — likely a FAIL verdict
- Malformed or missing ?url= query parameter — request rejected
- Target endpoint is not an x402 service — verdict will be FAIL
- Network errors from the Cloudflare Worker reaching the target URL
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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