{
  "height": 28,
  "block_hash": "74fda32609f3d186ca8ef8f8a8f27828e130de238152a43db40cd95cf3c99973",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "74fda32609f3d186ca8ef8f8a8f27828e130de238152a43db40cd95cf3c99973",
    "preimage": "block:{\"at\":\"2026-11-07T00:10:58.527Z\",\"entry_count\":1,\"first_seq\":98,\"height\":28,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":98,\"merkle_root\":\"bc07f738da372827fd8564182685dcf0df5f0c31b31d8a9fc2460d3fc4e2a229\",\"prev_hash\":\"59dfdb3f7765d121ca0df789908ff56481878803d2c9a63d61985eec1f9dd9a2\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:18:43.452Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee6e658a95e9bd1961ade8e4795234987ed3c9279bf040ca6c4ecaec2cc52bf29024899ed0112525732dc9"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:18:43.452Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee6e65969ce50a255ca2202a9c4ee506f309abac0f853c810130686827e3dbe47916dc3b5e6ba507ac0aa6"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:18:43.452Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee6e6582699db7ca311f45755fc12e50ed752e36b0132ff9bef05fbfb3c81806c95533ad894f80273533f5"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/28/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."
}