{
  "height": 56,
  "block_hash": "e83386a58cb7d7a1d64817e541f8d0784e6ae7911e6a015bd9d016d53859421f",
  "status": "confirmed",
  "bitcoin_block_height": 974877,
  "digest": {
    "alg": "sha256",
    "hex": "e83386a58cb7d7a1d64817e541f8d0784e6ae7911e6a015bd9d016d53859421f",
    "preimage": "block:{\"at\":\"2026-11-07T01:25:45.087Z\",\"entry_count\":1,\"first_seq\":143,\"height\":56,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":143,\"merkle_root\":\"b905d6cff9a7870dc68a85de02c8d953611a040011dd865cf8354fbfc13f5b91\",\"prev_hash\":\"592285687a8cfa9dd1a3b74e35bd5084e1a34d14fa9436e72835227155faceff\",\"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": "6aee7ecf35bd04fb46e71708fabbe5e0b022fab71a01ad633603e00a392fa621192bd41cec256ff772353176"
        },
        {
          "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": "6aee7ecf6bfc91b1e7cd1c6083dedbb501fcbc492440fcc4a5ebe954863beb058be2fadf8869abbc70f29e98"
        },
        {
          "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": "6aee7ece6c9d7347533d4f6ee427390fd881efc7d0601819e1ebd5e75282c84fc3840481bebc33d3a6baa6be"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/56/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."
}