@otskit/core

import { DetachedTimestampFile, OpSHA256, makePending } from '@otskit/core'
import { readFileSync, writeFileSync } from 'node:fs'

const content = new Uint8Array(readFileSync('document.pdf'))
const dtf = DetachedTimestampFile.fromBytes(new OpSHA256(), content)

dtf.timestamp.attestations.push(
  makePending('https://alice.btc.calendar.opentimestamps.org')
)

writeFileSync('document.pdf.ots', dtf.serializeToBytes())

import { DetachedTimestampFile } from '@otskit/core'

const otsBytes = new Uint8Array(readFileSync('document.pdf.ots'))
const dtf = DetachedTimestampFile.deserialize(otsBytes)

console.log('Hash op:  ', dtf.fileHashOp.tagName)
console.log('Digest:   ', Buffer.from(dtf.fileDigest()).toString('hex'))
console.log('Complete: ', dtf.timestamp.isTimestampComplete())

import { DetachedTimestampFile, verifyAgainstBlockheader } from '@otskit/core'

const dtf = DetachedTimestampFile.deserialize(new Uint8Array(readFileSync('document.pdf.ots')))

for (const { msg, attestation } of dtf.timestamp.allAttestations()) {
  if (attestation.tagName === 'bitcoin') {
    const ok = verifyAgainstBlockheader(msg, blockHeader)
    console.log('Bloque', attestation.height, ok ? '✓ verificado' : '✗ fallo')
  }
}

import { makeMerkleTree, makePending, DetachedTimestampFile, OpSHA256 } from '@otskit/core'

const files = ['a.pdf', 'b.pdf', 'c.pdf']
const dtfs = files.map(f =>
  DetachedTimestampFile.fromBytes(new OpSHA256(), new Uint8Array(readFileSync(f)))
)

// Un solo árbol Merkle — una sola ancla para todos
const root = makeMerkleTree(dtfs.map(d => d.timestamp))
root.attestations.push(makePending('https://alice.btc.calendar.opentimestamps.org'))

files.forEach((f, i) => writeFileSync(`${f}.ots`, dtfs[i].serializeToBytes()))