@umarise/anchor

Anchor any file to Bitcoin with one API call. Hash-in, proof-out.

artifact → artifact.proof

Zero dependencies. Node.js 18+.

Install

npm install @umarise/anchor

Anchor a file

import { UmariseCore, hashBytes } from '@umarise/anchor';
import { readFile } from 'fs/promises';

const core = new UmariseCore({ apiKey: process.env.UMARISE_API_KEY });

const bytes = await readFile('./release.tar.gz');
const hash = await hashBytes(bytes);
const origin = await core.attest(hash);

console.log(origin.origin_id); // done

Verify a file (no API key needed)

const core = new UmariseCore();

const bytes = await readFile('./release.tar.gz');
const hash = await hashBytes(bytes);
const result = await core.verify(hash);

if (result) {
  console.log('Existed since:', result.captured_at);
}

Verification is public. No account, no API key, no vendor dependency.

CLI

npx @umarise/cli anchor release.tar.gz
# → release.tar.gz.proof

Verify offline:

npx @umarise/cli verify release.tar.gz.proof
# Hash Match ✓ | Bitcoin Block #881234 | 2026-03-05 | VALID

API

Method	Auth	Description
health()	Public	API health check
resolve({ originId })	Public	Lookup by origin ID
resolve({ hash })	Public	Lookup by hash
verify(hash)	Public	Check if hash is anchored
proof(originId)	Public	Download .ots proof
attest(hash)	API Key	Create anchor

hashBytes(data)

SHA-256 hash of a Buffer or Uint8Array. Bytes never leave your system.

import { hashBytes } from '@umarise/anchor';
const hash = await hashBytes(fileBuffer);
// "sha256:a1b2c3..."

Error Handling

import { UmariseCoreError } from '@umarise/anchor';

try {
  await core.attest(hash);
} catch (err) {
  if (err instanceof UmariseCoreError) {
    console.log(err.code);       // 'RATE_LIMIT_EXCEEDED'
    console.log(err.statusCode); // 429
  }
}

CI/CD

Use the GitHub Action for automated anchoring:

- uses: AnchoringTrust/anchor-action@v1
  with:
    file: build.tar.gz
  env:
    UMARISE_API_KEY: ${{ secrets.UMARISE_API_KEY }}

Every build gets a .proof file. Verifiable offline, independent of Umarise.

Links

• Get API key
• API Reference
• Independent Verifier
• Anchoring Specification

License

Unlicense (Public Domain)