{
  "height": 74,
  "block_hash": "fbf0cf9f83409d1933ad91b503f532951a9ad6735a56f639a167c2ae7e7372bf",
  "status": "confirmed",
  "bitcoin_block_height": 974880,
  "digest": {
    "alg": "sha256",
    "hex": "fbf0cf9f83409d1933ad91b503f532951a9ad6735a56f639a167c2ae7e7372bf",
    "preimage": "block:{\"at\":\"2026-11-07T02:09:15.224Z\",\"entry_count\":2,\"first_seq\":169,\"height\":74,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":170,\"merkle_root\":\"b03cb1aace9d53b000f706c9e6a5904bfeebcfb595915dd4f6390d4c3268e4e8\",\"prev_hash\":\"bb7eb2517d16ee5b4f074e5b76bb53621ddcf711d379f9357beb3d43cfad04f0\",\"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": "6aee8a842be9793c375fc14e85e888f7a2e858d7d2a7169b97a305eaa9387effb6f766cf25daa3f66f865a0f"
        },
        {
          "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": "6aee8a84b9207a37887b6a0cadbd4a2d2c8a924746711dd18fb629b0b2bcee0c31c7de1e8b67f09c06bb9ac6"
        },
        {
          "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": "6aee8a842421a3748e6d7b2217bc7f35695f8e6f3680091533923727aeccbf698ce08e2c2203075639c4990a"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/74/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."
}