{"uid":"cap_fY5OiC8x_am_eqqOE4TBL","slug":"x402-preflight-endpoint-validator-8c22b112","name":"x402 Preflight Endpoint Validator","description":"x402 pre-listing QA probe: validate your endpoint's 402 challenge, header sizes, and payment schema before listing","url":"https://predator-ubuntu.taild9a745.ts.net/v1/preflight?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","format":"uri"},"body":{"type":"object"},"method":{"enum":["GET","POST"],"type":"string"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_H2Jl8GUd5GEVztHmC1K3c","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates an endpoint's 402 challenge response, payment schema, and header sizes before listing it on x402-compatible marketplaces","exampleAgentPrompt":"Run a preflight check on my endpoint at https://api.example.com/data using a GET request to make sure its 402 challenge, headers, and payment schema are all valid before I list it.","exampleUseCases":[{"title":"Pre-listing QA for paid API","prompt":"Before I submit my new API to the x402 marketplace, can you run a preflight probe on https://myapi.example.com/analyze with a POST method to verify the 402 challenge and payment schema look correct?"},{"title":"Debugging malformed 402 response","prompt":"My x402 endpoint at https://service.example.com/v1/query keeps getting rejected at listing — can you run a preflight check on it with a GET request and tell me what's wrong with the 402 headers or payment schema?"},{"title":"CI validation before deployment","prompt":"As part of my deploy pipeline, run a preflight validation against https://staging.myservice.com/api/report using POST to confirm the 402 challenge and header sizes are within spec before it goes live."}],"resultDescription":"Returns a structured report indicating whether the target endpoint correctly issues a 402 Payment Required challenge, whether the payment schema fields are valid and complete, and whether response headers are within acceptable size limits — surfacing any issues before the endpoint is listed on an x402 marketplace.","failureModes":["Target URL is unreachable or times out","Target endpoint does not return a 402 status at all","Payment schema fields are malformed or missing required properties","Response headers exceed size limits","Invalid URL format provided as input","Target endpoint returns unexpected redirects"],"whenToPreferThis":"Use this endpoint when you are a developer or agent preparing to list an x402-enabled API on a marketplace and need to validate that the 402 challenge, payment schema, and headers are correctly configured before submission. Prefer this over manual testing when you want a structured, automated report of compliance issues.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-20T12:33:34.161Z","isFirstParty":false,"canonicalSlug":"x402-preflight-endpoint-validator-8c22b112"}