{
  "height": 54,
  "block_hash": "fecec13e7488c03b673de1e3b6a93fe55ec4b217003bb366fa7cf4c2296b4b80",
  "status": "confirmed",
  "bitcoin_block_height": 974877,
  "digest": {
    "alg": "sha256",
    "hex": "fecec13e7488c03b673de1e3b6a93fe55ec4b217003bb366fa7cf4c2296b4b80",
    "preimage": "block:{\"at\":\"2026-11-07T01:21:15.060Z\",\"entry_count\":1,\"first_seq\":139,\"height\":54,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":139,\"merkle_root\":\"a5ef039e6b59ac3c1ccf439860f075115eec5b4b7c8aac8fb6df924db6d782a1\",\"prev_hash\":\"fe2d87aae3979159b364742489bc3277e19f33c2679255d2b915178a96a7cce9\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:28:43.459Z",
      "updated_at": "2026-11-07T04:28:43.481Z",
      "bitcoin_block_height": 974880,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee7ecd5879f0b581efa730ad51150159d28174b113a1ba1f1e16246170b97f946a01ceb1010cfaaf96108f"
        },
        {
          "type": "bitcoin",
          "block_height": 974880,
          "merkle_root": "e20917e92c25ba0bebbc60b5b7fe48f0ee84f05c3eb4987c3107d249f2c7113d"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:28:43.459Z",
      "updated_at": "2026-11-07T04:28:43.481Z",
      "bitcoin_block_height": 974883,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee7ecd0aa45bca471a3f8f07066ff9722b33f6fb568f130584032a49b7a1eef78f9ee9250b09fcad9f9061"
        },
        {
          "type": "bitcoin",
          "block_height": 974883,
          "merkle_root": "79abb9dd33baad0a1ff37045cc779f6fe1b133a7037999fbd2c996ad78e43b90"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:28:43.459Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee7ecccaaa28fb993ecf947b8067dde7d83f401e4de5d59c3914c949a0b20cf1cb1eae3e4c6c59bb5e426c"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/54/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."
}