{
  "height": 52,
  "block_hash": "00fc8a3061b0683c65f0e44656372507dbffd3560bfb48d666ff55ab5d22e90e",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "00fc8a3061b0683c65f0e44656372507dbffd3560bfb48d666ff55ab5d22e90e",
    "preimage": "block:{\"at\":\"2026-11-07T01:17:00.040Z\",\"entry_count\":1,\"first_seq\":136,\"height\":52,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":136,\"merkle_root\":\"0bfa18f2eddc31e652cd92b3e137d97eba325917a8bdbb916f60fc37f9502aa5\",\"prev_hash\":\"354d1b336ec3c825611b1cc3bd391d78f0a94c13a5c862b999c5021b9ccd6dad\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee7c764b0b6517b9f5d8231eb24951b03c70faa5f1c6f4c3941aab255d093f8650a9d8ba11112b8431124d"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee7c77fc3874225545ea6b10af130528ce6c3d90870101c1d2c41bd9a5181a8a23286e348a7b01941fde11"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee7c77b388290ed5456defaed3beacba5df775e233245aee9139c439116046d8e0b75690469eb7970eb54b"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/52/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."
}