{
  "height": 19,
  "block_hash": "5de41f7e9becddd0ca9af3e2c9f70630c3962415cf83f6fe30966bc151b7227d",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "5de41f7e9becddd0ca9af3e2c9f70630c3962415cf83f6fe30966bc151b7227d",
    "preimage": "block:{\"at\":\"2026-11-06T23:43:33.701Z\",\"entry_count\":2,\"first_seq\":83,\"height\":19,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":84,\"merkle_root\":\"003fc94d3fbbe49d3e46b888ebe95ab434190f2971b1611d8e92f2e4db1cd5ea\",\"prev_hash\":\"a923ee75eef62aa9b2035884401378d0411106b03678fed83dc26e5284b7ad6d\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:53:03.605Z",
      "updated_at": "2026-11-07T02:58:43.471Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee6860ba6e204fe1aff901e184d85048d7a5a7fb53b30ad996ac9b92478c3133d1659fe9fb6028960c546f"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:53:03.605Z",
      "updated_at": "2026-11-07T03:58:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee68621f1499350e7f52633dd24abfb82add5ba13849f4edc4223b25fab3b8687786f085c96457bc81a0d8"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:53:03.605Z",
      "updated_at": "2026-11-07T03:58:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee686039e324f6e999c8731266031413a93dc851962d8a34e7b9399f2c26bddc613aad0171ad11943672c2"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/19/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."
}