{"uid":"cap_jdxfX1A8P0_1qbRXJaM_j","slug":"x402-unsupported-rail-triage-decision-procedure-e9f38ce9","name":"x402 Unsupported Rail Triage Decision Procedure","description":"Deterministic procedure for an agent that receives an HTTP 402 challenge on a rail or protocol version its payment client does not support. Inputs: rail identifier and version from the payment challenge headers, client support matrix, facilitator availability (PayAI, MPP gateway), budget floor. Decision: pay directly when the rail is supported, route through a facilitator when the rail is bridged and facilitator fee is under 15 percent of quote, upgrade client when the version gap is one minor","url":"https://k2so.wrong.systems/api/services/x402-unsupported-rail-triage-decision-procedure?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"x402 unsupported rail triage decision procedure paid response","$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-unsupported-rail-triage-decision-procedure","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"x402-unsupported-rail-triage-decision-procedure","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_AEfuYKmXYf2aDRGawfe9d","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 an AI-generated decision procedure brief helping agents triage and handle unsupported payment rails in the x402 protocol ecosystem","exampleAgentPrompt":"I got an unsupported rail error from an x402 payment endpoint — walk me through the triage decision procedure so I know whether to retry on a different rail, abort the transaction, or escalate.","exampleUseCases":[{"title":"Triage failed x402 rail mid-workflow","prompt":"My autonomous agent just hit an x402 unsupported rail error while trying to pay for a data API call — what's the step-by-step decision procedure I should follow to decide whether to retry, reroute, or abort?"},{"title":"Pre-flight policy check for new rail","prompt":"Before my agent starts calling a new set of x402 merchants, I want to know the triage procedure it should apply if any of them respond with an unsupported rail — can you fetch that decision brief?"},{"title":"Debugging x402 integration failures","prompt":"We're building an x402 agent and keep getting unsupported rail responses in staging — give me the official triage decision procedure so we can encode the right fallback logic into the agent."}],"resultDescription":"A JSON object containing a plain-prose decision procedure brief (120+ words) written for AI agents, covering how to triage unsupported payment rail situations in the x402 protocol. Includes the generating model name, topic string, service slug, ISO-8601 generation timestamp, and a generationSource field indicating whether the content came from an LLM, reasoning engine, or deterministic logic. Also returns payment confirmation fields (ok, paid, provider).","failureModes":["HTTP 402 returned if USDC payment not yet settled — agent must pay exact amount and retry with PAYMENT-SIGNATURE header","Payment signature mismatch or expired signature causes rejection","Topic override parameter may produce off-target brief if the string is ambiguous","LLM generation failure may fall back to deterministic source with reduced richness","Network timeout if the upstream LLM provider is slow"],"whenToPreferThis":"Choose this endpoint when an autonomous agent needs structured, prose-form policy guidance specifically for triage of unsupported payment rails in the x402 protocol — not for general x402 error handling, payment execution, or rail selection. Particularly useful when encoding fallback logic into an agent workflow or auditing agent behavior against a canonical decision procedure. Prefer over generic LLM prompts because it delivers a curated, versioned, agent-optimized brief with a stable schema.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T12:36:58.865Z","isFirstParty":false,"canonicalSlug":"x402-unsupported-rail-triage-decision-procedure-e9f38ce9"}