{"uid":"cap_FJkN2yZulbK7fpdDQ7CnS","slug":"multi-rail-x402-payment-flow-protocol-classification-procedure-a347d534","name":"Multi-rail x402 Payment Flow Protocol Classification Procedure","description":"Decision procedure for an agent that hits an unfamiliar paid endpoint and must identify which payment flow it speaks before paying. Classifies Base x402 challenge (WWW-Authenticate Payment, eip155: 8453, USDC), Solana CIRC Token-2022 quote-transfer-resend flow, MPP Tempo gateway challenge, and gateway-wrapper endpoints (which hide a flow behind another host). Returns protocol id, required headers, token/network, resend semantics, single-use flag, and the exact ordered steps to settle. Includes","url":"https://k2so.wrong.systems/api/services/multi-rail-x402-payment-flow-protocol-classifica?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"Multi-rail x402 payment flow protocol classification procedure paid response","$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":"multi-rail-x402-payment-flow-protocol-classifica","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"multi-rail-x402-payment-flow-protocol-classifica","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":"down","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_dJGEEzsAnkrqqnXSGRwod","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 decision procedure for identifying which x402 payment flow protocol an unfamiliar paid endpoint speaks and what steps are required to pay it","exampleAgentPrompt":"I just hit an unfamiliar paid endpoint that returned a 402 and I need to figure out which x402 payment flow it speaks — Base challenge, Solana CIRC Token-2022, MPP Tempo, or gateway wrapper — and what steps I need to take before I can pay it. Can you get me the decision procedure for classifying multi-rail x402 payment flows?","exampleUseCases":[{"title":"Identifying unknown 402 endpoint payment flow","prompt":"My agent just got a 402 response from an endpoint I've never seen before and I have no idea if it's Base x402, Solana CIRC Token-2022, or something else — can you give me the step-by-step decision procedure to figure out which payment protocol it's using?"},{"title":"Building an autonomous agent payment router","prompt":"I'm building an autonomous agent that needs to pay across multiple rails and I need a blunt classification schema so it can detect whether a new endpoint uses Base x402 challenge, MPP Tempo challenge, or a gateway wrapper before attempting payment — fetch me that decision procedure."},{"title":"Debugging a failed multi-rail payment attempt","prompt":"My agent tried to pay an endpoint and failed because it guessed the wrong x402 flow — can you pull the protocol classification procedure so I can work out whether it should have used Base x402 challenge, Solana CIRC quote-transfer-resend, or a gateway wrapper path?"}],"resultDescription":"A structured JSON response containing a prose decision procedure (brief field) describing how to classify x402 payment flow protocols across rails (Base x402 challenge, Solana CIRC Token-2022 quote-transfer-resend, MPP Tempo challenge, gateway wrapper), along with the topic, service slug, generation source (llm/reasoning/deterministic), and ISO-8601 timestamp of generation.","failureModes":["Payment not completed — endpoint returns 402 challenge requiring $0.002 USDC before content is delivered","Invalid method — only GET/HEAD/DELETE accepted","Upstream LLM generation failure — result.ok may be false with no brief returned","Topic override produces out-of-scope result if topic param is unrelated to x402 flows"],"whenToPreferThis":"Use this endpoint when an AI agent encounters an unfamiliar paid endpoint returning a 402 and needs to programmatically determine which x402 payment flow protocol it implements before attempting payment. Prefer this over generic documentation searches when you need a blunt, agent-executable decision procedure specifically covering Base x402 challenge, Solana CIRC Token-2022, MPP Tempo challenge, and gateway wrapper flows in a single authoritative brief.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-18T21:28:12.227Z","isFirstParty":false,"canonicalSlug":"multi-rail-x402-payment-flow-protocol-classification-procedure-a347d534"}