{"uid":"cap_XRJcqO7w0W2K79TjBqkXT","slug":"penny-engine-ai-agent-outcome-guard-ffac1b70","name":"Penny Engine — AI Agent Outcome Guard","description":"Machine-to-machine result validation via x402. One structured call, deterministic PASS or FAIL and SHA-256 fingerprint, $0.001 USDC on Base.","url":"https://penny-paid-batch-production.up.railway.app/api/proof-gate?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"result":{"type":"object"},"expectations":{"type":"object","properties":{"equals":{"type":"object"},"numberRanges":{"type":"object"},"nonEmptyPaths":{"type":"array","items":{"type":"string"}},"requiredPaths":{"type":"array","items":{"type":"string"}}}}}},"responseSchema":{"type":"json","example":{"passed":true,"service":"M2M Agent Outcome Guard","verdict":"PASS","evidence":{"algorithm":"SHA-256","resultSha256":"example_only"},"checksTotal":4}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ESxKD-2LQS8FnIKPBmLol","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates AI agent output against declared expectations, returning a deterministic PASS/FAIL verdict and SHA-256 fingerprint of the result.","exampleAgentPrompt":"Check if this agent result passes my expectations — it should have a non-empty 'summary' field, a 'confidence' value between 0.8 and 1.0, and the 'status' field should equal 'completed'. Give me a PASS or FAIL and the SHA-256 fingerprint.","exampleUseCases":[{"title":"Guard a research agent's summary output","prompt":"My research agent just returned a result — validate that it has a non-empty 'findings' field, that 'confidence' is between 0.75 and 1.0, and that 'status' equals 'done'. I need a PASS or FAIL before I hand this off to the next step."},{"title":"Audit a pricing agent before executing a trade","prompt":"Before I act on this pricing agent output, check that 'price' is between 99.5 and 102.0, 'ticker' equals 'AAPL', and 'timestamp' is non-empty. Return the verdict and the SHA-256 fingerprint so I can log it."},{"title":"Validate customer-facing AI response quality","prompt":"I have an AI-generated customer reply — verify that 'tone' equals 'professional', the 'body' path is non-empty, and 'wordCount' is between 50 and 300. Tell me if it passes and give me the result hash."}],"resultDescription":"Returns a JSON object with a boolean 'passed' field, a 'verdict' string ('PASS' or 'FAIL'), an 'evidence' object containing the hashing algorithm name ('SHA-256') and the SHA-256 hash of the submitted result, and a 'checksTotal' integer indicating how many validation checks were evaluated.","failureModes":["Missing or malformed 'result' object causes validation to fail with an error response","Empty or invalid 'expectations' object may result in zero checks and an ambiguous outcome","Payment failure via x402 returns HTTP 402 and no validation is performed","Malformed JSON in the request body returns an HTTP 400 error","Network timeout or Railway infrastructure unavailability returns HTTP 5xx"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-call, cryptographically auditable quality gate for structured AI agent outputs — especially in automated M2M pipelines where you need a tamper-evident fingerprint alongside a binary verdict. It is ideal when you want deterministic validation rules (field existence, value equality, numeric ranges) rather than semantic or LLM-based evaluation. At $0.001 USDC per call it is cost-effective for high-frequency agent monitoring.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-23T18:35:04.743Z","isFirstParty":false,"canonicalSlug":"penny-engine-ai-agent-outcome-guard-ffac1b70"}