{
  "height": 75,
  "block_hash": "c6e1d46395278236eefd3e57c88aca734c5b379de152660fdaf94515e4ddbd89",
  "status": "confirmed",
  "bitcoin_block_height": 974880,
  "digest": {
    "alg": "sha256",
    "hex": "c6e1d46395278236eefd3e57c88aca734c5b379de152660fdaf94515e4ddbd89",
    "preimage": "block:{\"at\":\"2026-11-07T02:12:15.238Z\",\"entry_count\":1,\"first_seq\":171,\"height\":75,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":171,\"merkle_root\":\"7e6a4c06f6cac7e793fe87a908168fd49f7dc3b3cbedbd4a430431789f8bedc9\",\"prev_hash\":\"fbf0cf9f83409d1933ad91b503f532951a9ad6735a56f639a167c2ae7e7372bf\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T02:18:43.465Z",
      "updated_at": "2026-11-07T04:18:43.479Z",
      "bitcoin_block_height": 974880,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee8a85f6e3c4cf728909b390128b3c21c75156016b006fd7970e53ae806b9c81e553260449a8c5dbf9b0d7"
        },
        {
          "type": "bitcoin",
          "block_height": 974880,
          "merkle_root": "e20917e92c25ba0bebbc60b5b7fe48f0ee84f05c3eb4987c3107d249f2c7113d"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T02:18:43.465Z",
      "updated_at": "2026-11-07T04:18:43.479Z",
      "bitcoin_block_height": 974883,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee8a8597d61aa689a1e9faf9f09069f196c29491542bf74e1993fc2586fc7ea99d7ef79e3fdc107c231a4c"
        },
        {
          "type": "bitcoin",
          "block_height": 974883,
          "merkle_root": "79abb9dd33baad0a1ff37045cc779f6fe1b133a7037999fbd2c996ad78e43b90"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "pending",
      "submitted_at": "2026-11-07T02:18:43.465Z",
      "updated_at": "2026-11-07T02:18:43.465Z",
      "bitcoin_block_height": null,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee8a85c7e55e64405c63cdf3507bc8958e63ef915a0d4b558af8a05111ef8f05d9c0a5f98b447fc3eb970c"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/75/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."
}