{
  "height": 42,
  "block_hash": "eb368a4b22bdf9cc3d5f98e6b8324505c401f3a9f5322adc4440c03d93e97f6e",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "eb368a4b22bdf9cc3d5f98e6b8324505c401f3a9f5322adc4440c03d93e97f6e",
    "preimage": "block:{\"at\":\"2026-11-07T00:51:59.915Z\",\"entry_count\":1,\"first_seq\":121,\"height\":42,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":121,\"merkle_root\":\"5ee9adf4bc83aed228f8a701306b6c8271c64f215872e10833af12fce46bfef4\",\"prev_hash\":\"eb5dccf6f00a5a26cc442f12378d31ac5a1572fb0370cf57643b70719ae244c5\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:58:43.456Z",
      "updated_at": "2026-11-07T02:58:43.471Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee77c5f8ab745b4b3104e138de636a8bd24cdc5e71f9afa27fd96c2de1c12bf090962cd680499ee2122f2d"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:58:43.456Z",
      "updated_at": "2026-11-07T03:58:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee77c5654a44648458b26e21f0b3259ad2bcdfc58e7688768e71e101f59e419c6214c6836be7b3f13fe437"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T00:58:43.456Z",
      "updated_at": "2026-11-07T03:58:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee77c40f34147cc237d4fca3e81ec36e0f19834b064fd38c6088789584ee5f5a9b3915ca38c7688f2ed734"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/42/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."
}