{"uid":"cap_IVssBPy5akhPNTmNIYvi2","slug":"selectarank-x402-preflight-checker-81c129b9","name":"SelectaRank x402 Preflight Checker","description":"Pay-per-call access to public-domain data (USGS earthquakes, NOAA/NWS forecasts, World Bank indicators) plus an x402 endpoint pre-payment checker over x402 on Base USDC. No account or API key.","url":"https://selectarank-data.vercel.app/v1/preflight?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["url"],"properties":{"url":{"type":"string","description":"https URL of the x402-protected endpoint to check (port 443, public host)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"url":"https://example.com/paid-endpoint","accepts":[],"verdict":"ok","transport":"header","isStatus402":true}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_wWc9RMg-lNqN3Y85WFHnz","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a given HTTPS URL is protected by x402 and returns its payment requirements before attempting a paid call","exampleAgentPrompt":"Before I call that paid data endpoint, can you run a preflight check on https://selectarank-data.vercel.app/v1/earthquakes to see if it's x402-protected and what payment options it accepts?","exampleUseCases":[{"title":"Pre-call x402 payment discovery","prompt":"Can you check https://some-api.example.com/v1/data before I try to call it — I want to know if it needs x402 payment and what USDC options it accepts?"},{"title":"Validate x402 endpoint configuration","prompt":"I just deployed my x402-protected API at https://myservice.vercel.app/v1/reports — can you do a preflight check to confirm it's correctly returning 402 and advertising its payment requirements?"},{"title":"Agent workflow payment routing","prompt":"Before my agent tries to fetch data from https://selectarank-data.vercel.app/v1/worldbank, check whether it's x402-protected and what transport method it uses for payment, so I can wire up the right payment handler."}],"resultDescription":"Returns a JSON object with the target URL, an array of accepted payment methods, a verdict string (e.g. 'ok'), the payment transport method (e.g. 'header'), and a boolean flag indicating whether the endpoint truly returns a 402 status. This lets callers understand payment requirements before committing funds.","failureModes":["Non-HTTPS or non-port-443 URL returns a validation error","Endpoint is not publicly reachable, resulting in a connection error","URL is not x402-protected, returning isStatus402: false with an empty accepts array","Malformed URL input causes a 400-level error","Timeout if the target endpoint is slow to respond"],"whenToPreferThis":"Use this endpoint when you need to programmatically discover whether a remote HTTPS endpoint requires x402 micropayment and what currencies/transport methods it accepts — especially before attempting an actual paid call. Prefer this over direct calling when you want to avoid unexpected payment failures or need to dynamically route payment logic in an agent workflow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T04:33:27.696Z","isFirstParty":false,"canonicalSlug":"selectarank-x402-preflight-checker-81c129b9"}