{"uid":"cap_hkQRfU8EbzCT6zGStC4pI","slug":"x402-preflight-90f02660","name":"x402 Preflight","description":"Check an x402 seller before you pay it. Probes the endpoint now, checks that its payment can actually succeed (token EIP-712 domain, payTo), and adds its 30-day uptime from our monitor of paid Bazaar listings, how many distinct buyers paid it, and how its price compares with similar listings, with cheaper well-used alternatives. Returns a verdict (ok, caution, avoid) with the reasons.","url":"https://preflight.kagurazaka.dev/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","maxLength":2048,"description":"https URL of the x402 endpoint you are about to pay"},"method":{"enum":["GET","POST"],"type":"string","description":"method you will call it with (default GET)"},"max_price_usd":{"type":"number","description":"the most you are willing to pay per call; a higher price gives the verdict avoid"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["url","verdict","reasons"],"properties":{"now":{"type":"object","description":"the live probe: method, status, latency, protocol version, price, networks, payTo"},"url":{"type":"string"},"bazaar":{"type":"object","description":"the CDP Bazaar listing: distinct payers and calls in 30 days"},"market":{"type":"object","description":"median price of similar listings and cheaper alternatives with payers and uptime"},"history":{"type":"object","description":"our monitor's 30-day record: probes, uptime (0-1), median latency, last failure, price changes; null when not monitored"},"reasons":{"type":"array","description":"why the verdict is not ok; empty when it is"},"verdict":{"enum":["ok","caution","avoid"],"type":"string"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_8--PmlM1W313LsNaUps-A","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Probes an x402 payment endpoint before you pay it, returning a safety verdict (ok/caution/avoid) with uptime history, buyer statistics, and price comparisons against similar listings.","exampleAgentPrompt":"Before I pay it, can you run a preflight check on https://api.example.com/data to make sure it's legitimate, has good uptime, and isn't overpriced — flag it if it costs more than $0.01 per call?","exampleUseCases":[{"title":"Vet unknown x402 API before paying","prompt":"I found an x402 endpoint at https://somedata.dev/v1/prices — can you check if it's safe to pay, whether real users have paid it before, and how it compares in price to similar listings?"},{"title":"Guard agent against overspending","prompt":"Before my agent calls https://analytics.xyz/report, run a preflight and reject it if it costs more than $0.05 per call or gets a caution or avoid verdict."},{"title":"Find cheaper x402 alternatives","prompt":"Check https://premium.apiservice.io/summary with preflight and tell me if there are cheaper x402 endpoints that do the same thing with good uptime and real payers."}],"resultDescription":"A JSON object containing: a verdict string (ok, caution, or avoid); a reasons array explaining any issues; a live probe snapshot (HTTP status, latency, protocol version, price, networks, payTo address); a bazaar object with distinct payer count and call volume over 30 days; a history object with 30-day uptime ratio, median latency, last failure timestamp, and price changes; and a market object with the median price of similar listings and cheaper well-used alternatives.","failureModes":["Target URL is unreachable or times out — probe returns live failure details but verdict may be caution/avoid","EIP-712 domain or payTo address is malformed or missing — returned as a reason for caution/avoid","Endpoint not listed in Bazaar — bazaar and history fields may be null with reduced verdict confidence","URL parameter missing — request rejected with validation error","max_price_usd exceeded by actual price — verdict set to avoid regardless of other signals","Endpoint is valid but has no historical monitoring data — history field is null"],"whenToPreferThis":"Use this endpoint whenever an AI agent is about to make an x402 payment to an unknown or untrusted seller and needs a safety gate before committing funds. It is specifically designed for the x402 protocol ecosystem and provides richer signal than a generic HTTP health check by combining live probing, EIP-712 payment metadata validation, Bazaar buyer statistics, and price benchmarking in a single call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T12:33:09.601Z","isFirstParty":false,"canonicalSlug":"x402-preflight-90f02660"}