{"uid":"cap__CElldXQHu_Rs75c1cRRL","slug":"agent-to-agent-capability-negotiation-before-x402-settlement-2898ffc3","name":"Agent-to-Agent Capability Negotiation Before x402 Settlement","description":"Decision procedure for an agent that must verify a counterparty agent can actually perform a task before paying via x402. Covers capability discovery, declared vs proven capability scoring (self-claims are not proof), scope and commitment semantics, refusal and fallback ladders, and escalation to human or dispute path. Outputs ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE with the threshold math that fired. Blunt procedure, not marketing.","url":"https://k2so.wrong.systems/api/services/agent-to-agent-capability-negotiation-before-x40","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"Agent-to-agent capability negotiation before x402 settlement paid response","$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-to-agent-capability-negotiation-before-x40","procedure":"same as brief","generatedAt":"2026-01-01T00:00:00.000Z","generationSource":"deterministic"},"service":"agent-to-agent-capability-negotiation-before-x40","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_jytdlTXqs-mZ1GFVL7tCi","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":"Generates a structured decision procedure for verifying a counterparty agent's capabilities before committing to x402 payment, outputting one of ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE with threshold math.","exampleAgentPrompt":"Before I pay this counterparty agent via x402 to handle my data-processing task, run the capability negotiation procedure on it — I want to know whether I should ACCEPT_AND_QUOTE, REQUIRE_PROOF, or REFUSE based on what it's actually proven it can do versus just claiming.","exampleUseCases":[{"title":"Pre-payment capability check for hired agent","prompt":"I'm about to pay another agent 0.05 USDC via x402 to summarize a batch of legal documents, but I'm not sure it can actually do that. Can you run the capability negotiation procedure and tell me if I should accept, demand proof, or refuse?"},{"title":"Fallback routing when agent claims are unverified","prompt":"This counterparty agent says it can run ML inference, but all I have is its self-declaration — no on-chain proof. Run the capability negotiation decision procedure so I know whether to proceed, ask for proof, or find an alternate before any x402 settlement."},{"title":"Capability score audit for agent marketplace listing","prompt":"I'm evaluating several agents listed on a marketplace for a translation task. Can you run the capability negotiation procedure on the top candidate and show me the threshold math that fires — ACCEPT_AND_QUOTE or REQUIRE_PROOF — so I can decide which one to hire?"}],"resultDescription":"Returns a JSON object containing a plain-prose decision procedure brief (120+ words), the fired decision outcome (ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE), threshold math details, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and service/provider metadata.","failureModes":["Missing or malformed input returns a 400 error","Payment not settled via x402 returns a 402 Payment Required response","Invalid topic override may produce an off-scope procedure","LLM generation failures may fall back to deterministic output","Endpoint unreachable returns a network or 5xx error"],"whenToPreferThis":"Choose this endpoint when an AI agent needs a structured, blunt decision procedure — with explicit threshold math — to evaluate whether a counterparty agent's claimed capabilities are trustworthy before committing to x402 payment. It is particularly valuable when self-declared capabilities cannot be taken at face value, when fallback or refusal logic must be auditable, or when escalation to human oversight is a possible outcome. Prefer this over generic capability-check approaches when x402 payment semantics and agent-to-agent commitment scope are central concerns.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T15:26:00.121Z","isFirstParty":false}