{
  "height": 63,
  "block_hash": "e4b7e2b1f56a8e1f2e622b17ec1f45958681d00e12a0e1ed0a109b1ea25c9dba",
  "status": "confirmed",
  "bitcoin_block_height": 974877,
  "digest": {
    "alg": "sha256",
    "hex": "e4b7e2b1f56a8e1f2e622b17ec1f45958681d00e12a0e1ed0a109b1ea25c9dba",
    "preimage": "block:{\"at\":\"2026-11-07T01:42:45.158Z\",\"entry_count\":1,\"first_seq\":153,\"height\":63,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":153,\"merkle_root\":\"2e798529c6a3aadefdc5546605ed285d24776844c5543a0a15143a0287cfa6a0\",\"prev_hash\":\"27a5ac77eba4b89643c4a8f75e22d275ff752b76ca65a751a541b2425fa6006f\",\"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": "6aee837dedb5b77b0e0091bf9418cfcc7c80d3b85156e1323649de2ae4053632d5ff15b381c71ec2d7e2b331"
        },
        {
          "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": "6aee837e6e8d364a72c17106cfe42dbad72c6fb85abc3f2e69934e0e0c4b364f0cea607eb34f6054a6c5a608"
        },
        {
          "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": "6aee837e1fd9d7125f33665e9859dc224652a79b666703808392a39a3acda7935d7f4654f28657206cae6227"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/63/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."
}