{"uid":"cap_6Ei4g44oprAxvjElODgFO","slug":"apiacre-com-x402-preflight-checker-bc7fa9d9","name":"apiacre.com x402 Preflight Checker","description":"Probe a public endpoint without paying, grade its x402 v2 challenge, check exact-host x402-list presence and traction, and optionally rank licensed market matches with buyer-concentration caveats.","url":"https://apiacre.com/v1/developer/x402-preflight","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string"},"body":{"anyOf":[{"type":"object"},{"type":"null"}]},"method":{"enum":["GET","POST"],"type":"string"},"market_limit":{"type":"integer"},"market_query":{"anyOf":[{"type":"string"},{"type":"null"}]}}},"responseSchema":{"type":"json","example":{"data":{"url":"https://apiacre.com/v1/developer/openapi-audit","grade":"A","score":100,"checks":[{"id":"http_402","passed":true,"message":"Return HTTP 402 before payment.","severity":"high"}],"method":"POST","payment":{"scheme":"exact","network":"eip155:8453","version":2,"acceptsCount":1},"finalUrl":"https://apiacre.com/v1/developer/openapi-audit","checkedAt":"2026-08-09T00:00:00+00:00","compliant":true,"elapsedMs":128,"statusCode":402,"limitations":"One unpaid target request only; 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It is the only known dedicated x402 compliance grading tool and provides both evidence and remediation, making it superior to manual header inspection.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:44:34.029Z","isFirstParty":false}