{"uid":"cap_gm89owztcPYXqOaN6Y8BI","slug":"overwing-preflight-for-x402-f9208b80","name":"Overwing Preflight for x402","description":"Overwing Preflight for x402: should an agent sign this payment? POST the PAYMENT-REQUIRED terms and your policy; get allow, review or refuse with reasons: terms vs policy, payee vs the x402 directory and the server's own manifest, price vs the record. $0.002 USDC, no account.","url":"https://overwing.ai/api/x402/preflight/x402?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"policy":{"type":"object","description":"max_per_call_usd (default 0.05), new_payee_max_usd (0.01), allowed_networks, allowed_payees, blocked_payees, allow_testnets (false), max_price_drift (0.25)"},"network":{"type":"string","description":"The CAIP-2 network the agent would pay on, when the terms offer several"},"fresh_quote":{"type":"boolean","description":"Also fetch the resource unpaid and compare its quote with the terms given"},"requested_url":{"type":"string","description":"The URL the agent asked for; checked against the resource in the terms"},"payment_required":{"description":"The PAYMENT-REQUIRED header value (base64 JSON) or the decoded x402 v2 object {x402Version, resource, accepts[]}"}}},"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_2Tz2JD0q_MvIN8jqZUpMz","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":"Evaluates an x402 payment-required challenge against an agent's spending policy and the x402 payee directory, returning allow/review/refuse with detailed reasons.","exampleAgentPrompt":"Before paying this x402 API challenge, run a preflight check against my policy — max $0.05 per call, no testnets, only USDC on base — and tell me if I should allow, review, or refuse it.","exampleUseCases":[{"title":"Guard agent from unexpected payee","prompt":"I got a payment-required response from an API I haven't used before. Check if the payee is in the x402 directory and whether the price is within my limit of $0.01 for new payees before I sign anything."},{"title":"Enforce per-call spending cap","prompt":"My agent is about to pay an x402 fee — run a preflight check on the payment terms and make sure it's under $0.05 per call and the payee matches what the server's manifest says."},{"title":"Verify price hasn't drifted","prompt":"Fetch the resource unpaid and compare the fresh quote against the payment-required terms I was given — I want to know if the price has drifted more than 25% before my agent pays."}],"resultDescription":"A structured decision object containing one of: allow, review, or refuse; accompanied by specific reasons covering policy compliance (max per call, allowed networks, allowed/blocked payees, testnet flag, price drift), payee verification against the x402 directory and server manifest, and optionally a fresh-quote price comparison.","failureModes":["Malformed or undecodable PAYMENT-REQUIRED header returns a parsing error","Unknown or unregistered payee returns a refuse with directory-miss reason","Network not in allowed_networks list returns a refuse with network policy reason","Price exceeds max_per_call_usd returns refuse with price policy reason","Fresh quote fetch fails if requested_url is unreachable","Policy object missing required fields may use defaults silently"],"whenToPreferThis":"Use this endpoint when an AI agent encounters an x402 PAYMENT-REQUIRED response and must decide whether to sign and forward payment before proceeding. It is specifically suited for x402 v2 protocol challenges and provides directory-backed payee verification that generic policy checks cannot offer. Prefer it over manual policy evaluation when you need cross-referencing against the x402 payee registry and server manifest in a single low-cost call ($0.002 USDC, no account required).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-14T06:30:29.433Z","isFirstParty":false,"canonicalSlug":"overwing-preflight-for-x402-f9208b80"}