{"uid":"cap_D13IiFNvhGzklZT84dnLn","slug":"x402-merchant-endpoint-pre-payment-vetting-standard-525e7c4f","name":"x402 Merchant Endpoint Pre-Payment Vetting Standard","description":"Paid agent-facing brief on x402 merchant endpoint pre-payment vetting standard: how to assess an HTTP 402 endpoint's operational health before spending USDC. Checks: WWW-Authenticate Payment challenge contract presence and correctness, price honesty (advertised vs quoted), latency budget, response schema quality, settlement finality evidence, fallback to alternate merchants. · Build a decision procedure or schema for: x402. Blunt decision procedure, not marketing.","url":"https://k2so-8080.on.ascii.dev/api/services/x402-merchant-endpoint-pre-payment-vetting-stand?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"x402 merchant endpoint pre-payment vetting standard: how to assess an paid response","$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":null,"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_0QIbzwn8lAfvvuSHLMqrF","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 structured decision procedure for assessing an HTTP 402 merchant endpoint's operational health before spending USDC via x402.","exampleAgentPrompt":"Before my agent pays that x402 endpoint, give me the full decision procedure for vetting its operational health — check whether the WWW-Authenticate challenge is correct, whether the quoted price matches what was advertised, and what settlement finality evidence to look for.","exampleUseCases":[{"title":"Pre-payment safety check for x402 API","prompt":"I'm about to have my agent pay an x402-gated data API with USDC. Give me a blunt vetting procedure — what should it check about the WWW-Authenticate challenge, price honesty, and response schema quality before it sends any money?"},{"title":"Detecting misconfigured 402 merchant endpoints","prompt":"My autonomous agent keeps hitting HTTP 402 endpoints that seem misconfigured or misquoting prices. What's the standard decision procedure for catching those problems before spending USDC?"},{"title":"Fallback routing when primary x402 merchant fails vetting","prompt":"If my agent runs the pre-payment vetting checks on an x402 merchant and the endpoint fails — bad challenge contract, slow latency, no settlement evidence — what's the procedure for falling back to alternate merchants?"}],"resultDescription":"A paid JSON response containing a 'brief' field with decision procedure prose and a 'procedure' field outlining the concrete vetting steps an agent should execute before paying an x402 endpoint. Includes metadata like generation source (llm/reasoning/deterministic), model used, topic, and ISO-8601 timestamp. The procedure covers: WWW-Authenticate Payment challenge validation, advertised-vs-quoted price honesty, latency budget assessment, response schema quality, settlement finality evidence, and fallback merchant logic.","failureModes":["Payment not included — endpoint returns HTTP 402 requiring $0.002 USDC before content is delivered","Invalid or missing 'input' object in request body returns schema validation error","Topic override not recognized returns a generic x402 vetting procedure rather than topic-specific guidance","LLM/reasoning backend unavailable returns ok=false with error detail in result","Slow upstream generation may exceed agent latency budgets for real-time workflows"],"whenToPreferThis":"Choose this endpoint when an autonomous agent needs a structured, blunt decision procedure for vetting x402 merchant endpoints before committing USDC — especially when building payment safety logic, evaluating unfamiliar 402-gated APIs, or implementing pre-payment health checks in an agentic workflow. Prefer this over generic API health-check tools when the concern is specifically x402 payment challenge correctness, price honesty, and settlement finality.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T18:38:33.854Z","isFirstParty":false,"canonicalSlug":"x402-merchant-endpoint-pre-payment-vetting-standard-525e7c4f"}