{
  "height": 80,
  "block_hash": "c856b86c289adb02fc6f6f13c057c7673e60ebe8a159bc1dc462c7d683a4ae5d",
  "status": "confirmed",
  "bitcoin_block_height": 974880,
  "digest": {
    "alg": "sha256",
    "hex": "c856b86c289adb02fc6f6f13c057c7673e60ebe8a159bc1dc462c7d683a4ae5d",
    "preimage": "block:{\"at\":\"2026-11-07T02:24:15.277Z\",\"entry_count\":3,\"first_seq\":178,\"height\":80,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":180,\"merkle_root\":\"51e4b669e408467ac9505d466d82749dbd56c545344c5a6c9f96fc9010f6f7bd\",\"prev_hash\":\"4b65966ca977071c26b79caa38e5818b4305fe0eb9625c7994515338930d1391\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T02:28:43.466Z",
      "updated_at": "2026-11-07T04:28:43.481Z",
      "bitcoin_block_height": 974880,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee8cde4f49c4f8b0d6b3d06a6a9f9ff1003dfb892653a7ea2f2e03e004801fdb7c4ee222c4296d45bbd828"
        },
        {
          "type": "bitcoin",
          "block_height": 974880,
          "merkle_root": "e20917e92c25ba0bebbc60b5b7fe48f0ee84f05c3eb4987c3107d249f2c7113d"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T02:28:43.466Z",
      "updated_at": "2026-11-07T04:28:43.481Z",
      "bitcoin_block_height": 974883,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee8cde33694f596fbcf7d84309a7c85911c9d14fa1bb3b2c7b59df526d1e668cfbf7424548d3384bec734d"
        },
        {
          "type": "bitcoin",
          "block_height": 974883,
          "merkle_root": "79abb9dd33baad0a1ff37045cc779f6fe1b133a7037999fbd2c996ad78e43b90"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "pending",
      "submitted_at": "2026-11-07T02:28:43.466Z",
      "updated_at": "2026-11-07T02:28:43.466Z",
      "bitcoin_block_height": null,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee8cdeee20e225f591985641bd2c55091c0c228541e1432aba1410af89a2d4d42b7d67c5cdf9c7d7e96d9e"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/80/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."
}