Docs
Every door into the office.
The service does one thing: it commits a SHA-256 fingerprint to a Bitcoin block and hands back a receipt that outlives us. What follows are the ways to reach it — a browser, a library, a terminal, an HTTP call, or an agent. Each path produces the same instrument, and a receipt issued through one is verifiable through any of the others.
New here? Start with the quickstart — it needs nothing installed and takes about five minutes. Everything else on this page is for repeated, automated, or offline use.
Start here
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Quickstart
Drop a file, save a URL, settle the argument later. No account, no install, no payment.
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Install
The five entry points side by side — website, Python, Node, offline verifier, MCP — and how to choose between them.
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Verify a receipt
Check a receipt against the Bitcoin blockchain, including with this service switched off permanently.
Build against it
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HTTP API
Anchor, fetch a receipt, re-verify, request an inclusion proof. Plain JSON over HTTPS; no SDK required.
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SDKs
Python and TypeScript bindings over the same API. File bytes never leave the machine.
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Command line
Anchor and verify a folder from a terminal or a cron job. One line of JSON per invocation.
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Webhooks
Get called when an anchor confirms, instead of polling for it.
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MCP server
Give an AI agent the ability to anchor and verify its own outputs. Published to PyPI and the MCP registry.
Understand it
The documentation above tells you how to call the service. If you would rather know why any of it is trustworthy, the method pages carry the argument: the architecture, what a Bitcoin attestation actually proves, folder anchoring by Merkle root, and how the receipt behaves as evidence.
The verifier is MIT-licensed and reads a receipt without contacting us at all — annotated line by line.