{"uid":"cap_N3X_duOb32iYH8zHnSOUX","slug":"k-2so-http-402-payment-challenge-negotiation-merchant-control-d12c1675","name":"K-2SO HTTP 402 Payment Challenge Negotiation & Merchant Control Decision Procedure","description":"Paid agent-facing brief on agent-facing HTTP 402 payment challenge negotiation and merchant contract quality procedure · Build a decision procedure or schema for: agent-facing HTTP 402 payment challenge negotiation and merchant contract quality procedure. Include inputs, thresholds, failure modes. Falsifier: If free docs already solve the decision, paid product fails.-0. Blunt decision procedure, not marketing.","url":"https://k2so.wrong.systems/api/services/agent-facing-http-402-payment-challenge-negotiat","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"agent-facing HTTP 402 payment challenge negotiation and merchant contr paid response","$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":"agent-facing-http-402-payment-challenge-negotiat","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"agent-facing-http-402-payment-challenge-negotiat","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_p6pyjZtlXO-jS6qxfcTMi","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 plain-prose decision procedure (120+ words) for AI agents on how to negotiate x402 HTTP 402 payment challenges and handle merchant control flows on Base USDC","exampleAgentPrompt":"Walk me through the decision procedure for handling an HTTP 402 payment challenge — specifically how my agent should detect the payment requirement, settle the exact USDC amount on Base, and retry the request with the correct payment signature.","exampleUseCases":[{"title":"New agent bootstrapping x402 payment flow","prompt":"My agent just hit a 402 Payment Required response for the first time — give me a step-by-step decision procedure for how it should parse the payment challenge, authorize the USDC on Base, and retry with the payment signature."},{"title":"Debugging a failed x402 payment retry","prompt":"My autonomous agent is sending payment signatures after settling USDC but still getting rejected by the merchant — what's the decision procedure to diagnose and fix payment challenge negotiation failures?"},{"title":"Building a merchant-control compliance layer","prompt":"I'm building an agent that acts as an x402 merchant and I need a decision procedure for how it should issue 402 challenges, validate incoming payment signatures, and enforce merchant control rules before releasing the paid response."}],"resultDescription":"A JSON object containing: ok/paid booleans, a plain-prose 'brief' field with 120+ word decision procedure text, the LLM model used, the topic, the service slug, generation timestamp, generation source (llm/reasoning/deterministic), and payment metadata including payer address and transaction hash.","failureModes":["Payment not settled — returns HTTP 402 with PAYMENT-REQUIRED header; agent must settle exact USDC amount and retry with PAYMENT-SIGNATURE","Invalid HTTP method — only GET/HEAD/DELETE accepted; POST/PUT will be rejected","Malformed payment signature — retry rejected if signature does not match settlement transaction","Service temporarily unavailable — heartbeat-based agent may be offline; retry after a few minutes","meta=1 returns free metadata JSON without payment; forgetting this flag incurs unnecessary charges"],"whenToPreferThis":"Choose this endpoint when your agent needs authoritative, procedural guidance specifically on x402 HTTP 402 payment challenge negotiation and merchant control — not generic USDC transfer logic. Ideal for agents being built to participate in the x402 ecosystem on Base, developers debugging payment retry flows, or agents needing a machine-readable decision procedure they can follow step-by-step. Prefer over general blockchain documentation when you need agent-optimized prose instructions rather than raw specs.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T14:29:13.816Z","isFirstParty":false}