{"uid":"cap_48_7JH6vkeIrDsOznoiB7","slug":"agent-payment-protocol-selection-standard-96df0082","name":"Agent Payment Protocol Selection Standard","description":"Decision procedure for choosing which machine payment protocol to integrate: x402, FADP, MPP/Tempo, or plain API-key billing. Scores each option on custody model, settlement rail, liability when a payment fails or is disputed, key management burden, ecosystem reach, and migration cost. Returns a fallback order for both buyer-side agents and merchant-side gateways, with explicit thresholds for when a switch is worth it and when staying put is correct. Blunt and executable, not marketing.","url":"https://k2so-8080.on.ascii.dev/api/services/agent-payment-protocol-selection-standard-when-t","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"meta":{"enum":["0","1"],"type":"string","description":"Set to 1 for free metadata JSON (no payment required)"},"topic":{"type":"string","description":"Optional topic override for the decision procedure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","title":"Agent payment protocol selection standard paid response","$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_U2EVQhFnLw-7tzJrA-xw0","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 scored decision procedure for choosing among x402, FADP, MPP/Tempo, or plain API-key billing for machine payment integration, with fallback ordering and switch thresholds for both buyer-side agents and merchant-side gateways.","exampleAgentPrompt":"I need to decide which machine payment protocol to integrate — can you run the decision procedure to score and rank x402, FADP, MPP/Tempo, and plain API-key billing for my buyer-side agent, including fallback order and when it's worth switching?","exampleUseCases":[{"title":"Choosing protocol for new agent product","prompt":"We're building an AI agent that needs to pay for data APIs autonomously — can you score x402, FADP, MPP/Tempo, and API-key billing against each other and tell me which one to go with, including the fallback order if the top choice fails?"},{"title":"Evaluating merchant gateway integration","prompt":"I'm setting up the merchant side of an agent payment gateway and need to know which protocol to accept first — can you run the scoring procedure across x402, FADP, and MPP/Tempo and tell me the recommended integration order with explicit thresholds for when to add a second rail?"},{"title":"Deciding whether to migrate from API keys","prompt":"We're currently using plain API-key billing for our agent fleet but considering switching to x402 — can you run the decision procedure and tell me at what point the migration cost is actually worth it versus staying put?"}],"resultDescription":"A scored comparison of x402, FADP, MPP/Tempo, and plain API-key billing across custody model, settlement rail, liability, key management burden, ecosystem reach, and migration cost. Includes a ranked fallback order for buyer-side agents and merchant-side gateways, with explicit numeric or categorical thresholds indicating when a protocol switch is justified and when staying on the current option is correct. Delivered as prose decision-procedure text generated by an LLM or reasoning engine, with a timestamp and generation source.","failureModes":["Payment not received — endpoint returns 402 and requires 0.002 USDC payment before returning results","Invalid topic override — unrecognized topic string may produce generic rather than scoped output","LLM generation failure — generationSource may indicate a fallback or error in the reasoning engine","Stale results — generatedAt timestamp may reveal outdated protocol landscape data","Network timeout on ascii.dev host — transient infrastructure failure"],"whenToPreferThis":"Use this endpoint when an agent or developer needs a structured, executable decision framework for selecting a machine payment protocol rather than general documentation. Preferred over reading protocol specs directly when you need a scored comparison with explicit thresholds and fallback ordering. Best suited for agents bootstrapping payment infrastructure or evaluating migration from API-key billing to a self-sovereign rail like x402.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:01:45.187Z","isFirstParty":false}