{
  "height": 31,
  "block_hash": "a57457b6e050675c0b9f249c0acf26b2e2b863741e422aaf60b8b8e66562e656",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "a57457b6e050675c0b9f249c0acf26b2e2b863741e422aaf60b8b8e66562e656",
    "preimage": "block:{\"at\":\"2026-11-07T00:24:14.275Z\",\"entry_count\":3,\"first_seq\":103,\"height\":31,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":105,\"merkle_root\":\"8753bdad603752c7f233030bea60bcd8623774a000a41256d8757e2b4abb0fd3\",\"prev_hash\":\"fa9b208f81668a1481bb737be8b9fbad6186bca8f9b2bbc4b4cc7bc99ff64a9f\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:28:43.454Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee70bdd2d0288ad6df5784ccf4450ca626a0205be8c9525cbbf1e594327392ff0facb0ffeaf26f598bdf74"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:28:43.454Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee70bde2b5e7fbd95e816ba02b4fd2f1f9983500d3ab445e76f56bd26404cabcedf714adf3665fe99349c2"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:28:43.454Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee70bd64f63306528e60c9da7d7aa35cb526aa21ec605335b6b857e78e4ac96d9edd9625a1b3812934855a"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/31/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."
}