{"uid":"cap_eIHhDh5nZy86XsXB8cr84","slug":"stampthisfile-opentimestamps-bitcoin-stamping-05d0702d","name":"StampThisFile OpenTimestamps Bitcoin Stamping","description":"Timestamp SHA-256 hashes in Bitcoin with OpenTimestamps: returns a standard .ots proof per hash (pending, complete within hours), verifiable without us","url":"https://stampthisfile.com/v1/stamps?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"hashes":{"type":"array","items":{"type":"string","pattern":"^[0-9a-fA-F]{64}$","description":"SHA-256 of the file, hex"},"maxItems":100,"minItems":1,"description":"Each hash costs the unit price; send each once"},"webhook":{"type":"object","required":["url"],"properties":{"url":{"type":"string","format":"uri","description":"https URL that receives stamps.completed / stamps.failed"},"signing_key":{"type":"string","description":"Optional Standard Webhooks secret (whsec_…) to also sign deliveries with HMAC (v1)"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ygTqcMBG956-iFvHufYIS","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Timestamps one or more SHA-256 file hashes on the Bitcoin blockchain via OpenTimestamps, returning a .ots proof file per hash","exampleAgentPrompt":"Please timestamp this file for me — its SHA-256 hash is a3b4c5d6e7f8901234567890abcdef1234567890abcdef1234567890abcdef12 — and send the completed .ots proof to my webhook at https://myapp.example.com/timestamps when it's ready.","exampleUseCases":[{"title":"Legal document existence proof","prompt":"I need to prove this contract existed before we signed it — its SHA-256 hash is f1e2d3c4b5a6978869504132abcdef9876543210fedcba9876543210fedcba98 — can you anchor it to Bitcoin and get me a .ots proof file?"},{"title":"Batch media asset notarization","prompt":"I have three creative files I need notarized on the blockchain — their SHA-256 hashes are aa11bb22cc33dd44ee55ff66001122334455667788990011aabbccddeeff0011, 1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef, and fedcba9876543210fedcba9876543210fedcba9876543210fedcba9876543210 — please stamp them all and notify my webhook at https://studio.example.com/proofs when done."},{"title":"Software release integrity attestation","prompt":"Before I publish this software release, I want to timestamp its SHA-256 hash 0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f0a1b2c3d4e5f6a7b8c9d0e1f2a on Bitcoin so users can independently verify it existed at release time — can you do that for me?"}],"resultDescription":"For each submitted hash, the endpoint returns a standard OpenTimestamps .ots proof file (initially in 'pending' state, upgraded to a full Bitcoin attestation within hours). The proof is independently verifiable using the open-source OpenTimestamps client without relying on this service. If a webhook URL was provided, a stamps.completed or stamps.failed event is delivered when the Bitcoin confirmation is finalized.","failureModes":["Invalid hash format (not 64 hex characters) returns a validation error","Exceeding 100 hashes per request returns a 400 error","Webhook URL unreachable results in stamps.failed event","Payment failure (insufficient USDC balance) blocks the request","Bitcoin network congestion may delay confirmation beyond the typical hours window"],"whenToPreferThis":"Choose this endpoint when you need a decentralized, independently verifiable timestamp proof anchored to Bitcoin — particularly for legal, compliance, or audit scenarios where you cannot rely on a centralized authority. Ideal for proving document existence before a deadline, notarizing creative works, or attesting software release integrity. Prefer this over centralized timestamping services when the verifier must be able to check the proof without trusting this service at all.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T06:34:18.566Z","isFirstParty":false,"canonicalSlug":"stampthisfile-opentimestamps-bitcoin-stamping-05d0702d"}