x402 Trust Layer — Pre-x402 Guard Check

Use this endpoint when you need to perform a pre-flight authorization check on a GET, HEAD, or DELETE HTTP request before committing to an x402 micropayment. This is the right choice when you want to validate request eligibility against x402 trust infrastructure rules — such as mandate checks, compliance screening, or seller certification — before spending USDC on the actual API call.

• Invalid or unsupported HTTP method (must be GET, HEAD, or DELETE) — validation error
• Missing required 'type' or 'method' fields in input — 400 bad request
• x402 payment settlement failure — 402 payment required response
• Trust layer infrastructure unavailable — 5xx server error
• Request blocked by guard rules — returns allowed: false with summary explaining reason