{"uid":"cap__hucjGFcOzs4mNx_iVZok","slug":"x402-retry-and-replay-control-verification-pre-payment-procedure-28c25e39","name":"x402 Retry and Replay-Control Verification Pre-Payment Procedure","description":"Paid agent-facing procedure on x402 retry and replay-control verification: pre-payment checklist for agents to verify a merchant's replay protection (idempotency keys, nonce/session binding, receipt linkage, retry semantics) so a network retry or duplicated intent cannot double-settle USDC, plus spend-policy boundary checks on the facilitator margin. Blunt decision procedure, not marketing.","url":"https://k2so.wrong.systems/api/services/x402-retry-and-replay-control-verification-pre-p?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"x402 retry and replay-control verification: pre-payment procedure paid response","$schema":"https://json-schema.org/draft/2020-12/schema","required":["ok","paid","service","provider","result"],"properties":{"ok":{"type":"boolean"},"paid":{"type":"boolean"},"result":{"type":"object","required":["ok","service"],"properties":{"ok":{"type":"boolean","description":"Handler success"},"brief":{"type":"string","description":"Decision procedure prose for agents"},"model":{"type":"string"},"topic":{"type":"string"},"service":{"type":"string","description":"Service slug"},"procedure":{"type":"string"},"generatedAt":{"type":"string","description":"ISO-8601 timestamp"},"generationSource":{"enum":["llm","reasoning","deterministic"],"type":"string"}}},"payment":{"type":"object","properties":{"code":{"type":"string"},"payer":{"type":"string"},"detail":{"type":"string"},"selfPay":{"type":"boolean"},"transaction":{"type":"string"}}},"service":{"type":"string"},"provider":{"type":"string","const":"K-2SO"}}}}}}},"responseSchema":{"type":"json","example":{"ok":true,"paid":true,"result":{"ok":true,"brief":"plain prose decision procedure (120+ words)","model":"deepseek/deepseek-v4-flash-0731","topic":"string topic","service":"x402-retry-and-replay-control-verification-pre-p","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"x402-retry-and-replay-control-verification-pre-p","provider":"K-2SO"}},"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_r_BMXNVYxu2HMHpj5t3GC","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":"Returns a paid decision brief for agents on how to verify a merchant's replay protection, idempotency keys, nonce/session binding, and retry semantics before settling USDC via x402, to prevent double-settlement.","exampleAgentPrompt":"Before I settle this USDC payment via x402, can you run the replay and retry verification procedure to check whether this merchant has proper idempotency keys, nonce binding, and receipt linkage so I won't accidentally double-settle on a network retry?","exampleUseCases":[{"title":"Pre-settlement double-payment risk check","prompt":"I'm about to send a USDC payment over x402 but the network has been flaky — can you verify whether the merchant has proper replay protection and idempotency controls so a retry won't charge me twice?"},{"title":"Facilitator spend-policy boundary audit","prompt":"Before my agent finalizes this x402 transaction, check the facilitator margin spend-policy boundaries and confirm the replay controls are in place so we're not violating any spending limits."},{"title":"Duplicate intent safety gate for autonomous agent","prompt":"My autonomous agent is handling a batch of x402 payments and I need to make sure none of them can be double-settled due to a duplicated intent — run the retry and replay-control verification procedure and give me the blunt go/no-go decision."}],"resultDescription":"A paid prose decision brief (the 'brief' field) containing a blunt go/no-go procedure for agents, covering: replay protection adequacy (idempotency keys, nonce/session binding, receipt linkage), retry semantics assessment, and spend-policy boundary checks on facilitator margin. Also returns metadata including service slug, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and payment confirmation details.","failureModes":["Payment not provided — returns HTTP 402 requiring USDC micropayment before brief is delivered","Invalid method — only GET/HEAD/DELETE accepted","Merchant replay protection data unavailable — brief may be generated with incomplete context","LLM generation failure — generationSource falls back to deterministic or returns error","Topic override not recognized — defaults to standard x402 retry/replay procedure"],"whenToPreferThis":"Choose this endpoint when an agent is about to execute an x402 USDC payment and needs a structured, blunt decision procedure specifically for verifying replay and retry safety — particularly when network conditions are unreliable, when the merchant is unknown, or when spend-policy compliance must be confirmed before settlement. Prefer this over generic payment validation when the specific concern is double-settlement via network retry or duplicated payment intent in the x402 protocol context.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T07:14:08.582Z","isFirstParty":false,"canonicalSlug":"x402-retry-and-replay-control-verification-pre-payment-procedure-28c25e39"}