{"uid":"cap_dOl8IPmYCx006AFzVxAvF","slug":"x402-idempotency-check-7e06f314","name":"X402 Idempotency Check","description":"X402 Idempotency Check: X402 Idempotency Check compares payment and delivery idempotency keys for one operation from bounded caller-supplied values without an external provider. Call X402 Idempotency Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Idempotency Check as versioned deterministic…","url":"https://api.delx.ai/api/v1/x402/x402-idempotency-check?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"payment_key":{"type":"string","maxLength":8192,"description":"Payment Key supplied to X402 Idempotency Check; used only for this bounded calculation and processed in memory without retention."},"delivery_key":{"type":"string","maxLength":8192,"description":"Delivery Key supplied to X402 Idempotency Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"matched":true,"payment_key":"job-42","delivery_key":"job-42"},"schema":"delx/util-x402-idempotency-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"a9aa562b36a16cb899fdccfd5bcae9beef661bc9955a23c2dab0076b08c36ff5","external_calls":0},"operation":"delivery_contract:x402_idempotency_check"}},"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_mAbJpTjrkv8d8T2vqnLpq","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":"Compares payment and delivery idempotency keys for an x402 operation to detect duplicates and verify keys match before accepting or paying for agent-delivered results.","exampleAgentPrompt":"Before accepting this x402 agent delivery, check whether the payment key 'pay_abc123xyz' and delivery key 'del_xyz789abc' are consistent and there are no mismatches or duplicate operation signals.","exampleUseCases":[{"title":"Guard against duplicate x402 payments","prompt":"I'm about to pay for an x402 result — can you check the payment key 'pay_a1b2c3' and delivery key 'del_c3b2a1' to make sure this isn't a duplicate and the keys actually match?"},{"title":"Validate agent delivery before acceptance","prompt":"Before my agent accepts this delivery, verify that the payment idempotency key 'pay_qwerty123' and the delivery idempotency key 'del_qwerty456' are aligned and there's no mismatch reason flagged."},{"title":"Audit x402 operation key consistency","prompt":"Can you run an idempotency check on these two keys from an x402 operation — payment key 'pay_zz9900ff' and delivery key 'del_zz9900ff' — and tell me whether they're accepted or rejected and why?"}],"resultDescription":"Returns an explicit acceptance or rejection status for the operation, contract-specific validation checks, normalized evidence from the provided keys, and any mismatch reasons detected between the payment and delivery idempotency keys.","failureModes":["Missing or empty payment_key or delivery_key fields causes validation failure","Keys exceeding 8192 character limit are rejected","Mismatched keys return rejection status with detailed mismatch reasons","Malformed or non-string key values may result in error response"],"whenToPreferThis":"Use this endpoint when operating in the x402 payment protocol ecosystem and needing a deterministic, stateless check that payment and delivery idempotency keys correspond before committing to a payment or accepting an agent result. Prefer this over custom key comparison logic when you need normalized evidence and explicit accept/reject verdicts with mismatch explanations included.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-20T07:14:54.849Z","isFirstParty":false,"canonicalSlug":"x402-idempotency-check-7e06f314"}