{
  "height": 64,
  "block_hash": "bf84ecc8b2fa59d6e6a09f563c4e890cb1458610527130f28a703e3d859bf63a",
  "status": "confirmed",
  "bitcoin_block_height": 974877,
  "digest": {
    "alg": "sha256",
    "hex": "bf84ecc8b2fa59d6e6a09f563c4e890cb1458610527130f28a703e3d859bf63a",
    "preimage": "block:{\"at\":\"2026-11-07T01:44:15.162Z\",\"entry_count\":2,\"first_seq\":154,\"height\":64,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":155,\"merkle_root\":\"29661dcf9dbb2e16e37dbdd948760155adeb0cf964b2230d6d610bbc719511e4\",\"prev_hash\":\"e4b7e2b1f56a8e1f2e622b17ec1f45958681d00e12a0e1ed0a109b1ea25c9dba\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T03:48:43.477Z",
      "bitcoin_block_height": 974880,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee837eab6bc572eb77cc19ea5a22c1d702d486f1a3f8c4663e8716bd4195594c315126a3b8505e20eac9b1"
        },
        {
          "type": "bitcoin",
          "block_height": 974880,
          "merkle_root": "e20917e92c25ba0bebbc60b5b7fe48f0ee84f05c3eb4987c3107d249f2c7113d"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T04:48:43.485Z",
      "bitcoin_block_height": 974883,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee837f90d0fd86c58d6d689962c02598b4d0614ea6be97a82a954f4acd0195f0ccedc85355dd739bbfc121"
        },
        {
          "type": "bitcoin",
          "block_height": 974883,
          "merkle_root": "79abb9dd33baad0a1ff37045cc779f6fe1b133a7037999fbd2c996ad78e43b90"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T03:48:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee837f32f45214e689b58652f9c3f5b0c5138a50d580c5984a0a4f0d71aa69a937e321c2ee274673ed2b24"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/64/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."
}