{"uid":"cap_aXbOX7jDWNZEjzssjTFqc","slug":"delx-commerce-x402-payment-replay-key-9fd3d128","name":"Delx Commerce X402 Payment Replay Key","description":"Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.","url":"https://commerce.delx.ai/api/v1/x402/x402-payment-replay-key?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"nonce":{"type":"string","maxLength":8192,"description":"Nonce supplied to X402 Payment Replay Key; used only for this bounded calculation and processed in memory without retention."},"payer":{"type":"string","maxLength":8192,"description":"Payer supplied to X402 Payment Replay Key; used only for this bounded calculation and processed in memory without retention."},"resource":{"type":"string","maxLength":8192,"description":"Resource supplied to X402 Payment Replay Key; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"key":"e3cc8d847b2f88337939a2fab5ac3409aebfe27f223855a64805eba4ea53a947","fields":["nonce","payer","resource"],"secret":false},"schema":"delx/util-x402-payment-replay-key/v1","status":"pass","evidence":{"retained":false,"input_sha256":"07fbf5ea1e08edc254770787f1273ba864ab5603eb570e42969f774e980e8a0e","external_calls":0},"operation":"delivery_contract:x402_payment_replay_key"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_GZJryXeqNW0MLNDkdrgRe","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Generates a deterministic replay key from nonce, payer, and resource inputs for verifying and deduplicating x402 micropayments without retaining any data.","exampleAgentPrompt":"Compute an x402 payment replay key for nonce 'abc123', payer '0xDeadBeef...', and resource '/api/v1/data' so I can verify this payment hasn't been replayed.","exampleUseCases":[{"title":"Prevent duplicate agent micropayments","prompt":"I need to check whether this x402 payment was already processed — generate a replay key for nonce 'nonce-7f3a', payer '0x1234abcd...', and resource '/api/v1/search' so I can compare it against my records."},{"title":"Audit trail for USDC payment flows","prompt":"Derive a deterministic replay key for the transaction with nonce 'pay-99z', payer 'solana:FxkQ...', and resource '/api/v1/weather' so I can log it as a verifiable delivery reference."},{"title":"Deduplication key for agent payment middleware","prompt":"My payment middleware needs a replay key — compute one from nonce 'req-001', payer '0xABCDef...', and resource '/api/v1/inference' to ensure the same request can't be billed twice."}],"resultDescription":"Returns a deterministic 64-character hex replay key derived from the provided nonce, payer, and resource fields, along with the field list used, a SHA-256 hash of the input (for auditability), confirmation that no data was retained, and the operation name 'delivery_contract:x402_payment_replay_key'.","failureModes":["Missing required fields (nonce, payer, resource) result in a validation error","Inputs exceeding 8192 characters may be rejected","Malformed JSON body returns a parse error","Network timeout or service unavailability returns a 5xx error"],"whenToPreferThis":"Use this endpoint when you need a lightweight, stateless, verifiable deduplication key for x402 protocol micropayments — particularly when you want in-memory-only computation with no server-side data retention and a cryptographically auditable SHA-256 input hash. Prefer this over custom hashing logic when operating within the x402/USDC-on-Base or Solana payment ecosystem.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T00:54:03.956Z","isFirstParty":false,"canonicalSlug":"delx-commerce-x402-payment-replay-key-9fd3d128"}