{"uid":"cap__J3dEPQQ6C0hCuxRqpWPz","slug":"x402-shizu-me-notarization-service-cd0c8aac","name":"x402.shizu.me Notarization Service","description":"Prove a piece of data existed at a point in time. POST {data} returns its sha256, a recorded timestamp, and an HMAC receipt; GET ?hash= tells you whether and when that hash was first notarized. An agent can hash data but cannot self-certify WHEN it existed to a third party — this is that proof.","url":"https://x402.shizu.me/notarize","method":"GET","headers":{},"bodySchema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"type":"object","required":["method"],"properties":{"method":{"const":"GET"},"queryParams":{"type":"object","required":["hash"],"properties":{"hash":{"type":"string"}}}}}}},"responseSchema":{"type":"json","example":{"ts":1784300000,"alg":"sha256","hash":"9f2b…","receipt":"c1a…","first_seen":true}},"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_XSl-a0sMya01yjrkYRzB_","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":"Records a SHA-256 hash of arbitrary data with a timestamp and HMAC receipt, or retrieves when a given hash was first notarized, providing third-party proof of data existence at a point in time.","exampleAgentPrompt":"Can you notarize this text for me — 'Q4 product roadmap draft v1: launch in March' — and give me a timestamped HMAC receipt proving it existed right now?","exampleUseCases":null,"resultDescription":"For POST (notarize): returns the SHA-256 hash of the submitted data, a server-recorded UTC timestamp, and an HMAC receipt that a third party can use to verify the data existed at that moment. For GET with ?hash=: returns whether that hash has been previously notarized and, if so, the earliest recorded timestamp.","failureModes":["Missing or malformed data payload returns an error with no hash or receipt","Hash not found in GET lookup returns a not-yet-notarized status","Network or payment failure results in no receipt being issued","Malformed hash query string returns a validation error","Server unavailability means timestamp cannot be certified"],"whenToPreferThis":"Use this endpoint when you need a cryptographically verifiable, third-party-attested proof that a piece of data existed at a specific moment in time — something an AI agent cannot self-certify. Prefer this over client-side hashing when the timestamp itself needs to be trusted by an external party, e.g. for intellectual property claims, audit trails, or dispute resolution.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:47:58.192Z","isFirstParty":false}