{
  "height": 21,
  "block_hash": "99f56bdd0b27dbb75314ddbf2f60ab57435cfe5460f3501a701f026b2d94d16b",
  "status": "confirmed",
  "bitcoin_block_height": 972865,
  "digest": {
    "alg": "sha256",
    "hex": "99f56bdd0b27dbb75314ddbf2f60ab57435cfe5460f3501a701f026b2d94d16b",
    "preimage": "block:{\"at\":\"2026-10-24T02:49:44.257Z\",\"entry_count\":1,\"first_seq\":23,\"height\":21,\"key_id\":\"key_41eb7b6d1b11968a\",\"last_seq\":23,\"merkle_root\":\"964a5dc4235b01d9562b30689ded9ed5157deea7e84701ac548515dd2af8901d\",\"prev_hash\":\"6080e68206301c750044f731de8b7e98a9019d068377f042323658812b1572ca\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-24T02:56:29.156Z",
      "updated_at": "2026-10-24T04:03:42.394Z",
      "bitcoin_block_height": 972865,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6adc1e5e224b013c876e7ba2d65b904e46a454a839872536080bab6dbea9ff0d2292d1621d2bd97b0a11d394"
        },
        {
          "type": "bitcoin",
          "block_height": 972865,
          "merkle_root": "57d9a5b6d4f551ac33c023dbe0347020362d0ddee5474034a2c6f16d7e8c451e"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-24T02:56:29.156Z",
      "updated_at": "2026-10-24T04:03:42.394Z",
      "bitcoin_block_height": 972866,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6adc1e5ed25999a1563c06572c18ea6eb5938551f1fbff14fc6acad30bfb2e15cfc8fca2f4316821faf6e65d"
        },
        {
          "type": "bitcoin",
          "block_height": 972866,
          "merkle_root": "b8f6b16743fc18bdfa2d20c8e8483ade7e2959b9b0cda86929c08b6295111cf0"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-10-24T02:56:29.156Z",
      "updated_at": "2026-10-24T05:03:42.413Z",
      "bitcoin_block_height": 972871,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6adc1e5e030d4cd9f59071176d87294a17912e9d16ef22e2ddc72bd05fb76c670f1aec30f98d68e4713fcd5f"
        },
        {
          "type": "bitcoin",
          "block_height": 972871,
          "merkle_root": "96023e29396199d7f998b73198fe082536fa2b29b84bd1f8307762231f94e59d"
        }
      ]
    }
  ],
  "proof_url": "https://www.rightshold.com/v1/ledger/blocks/21/anchor.ots",
  "how_to_verify": "Download the .ots proof and run `ots verify -d <block_hash> <file>.ots` with the OpenTimestamps client, which checks the Bitcoin attestation against Bitcoin block headers. The digest is the block hash: sha256 of digest.preimage, the text \"block:\" followed by the canonical block header, which is the same header the issuer signs."
}