{
  "height": 78,
  "block_hash": "77e2c501c67098511d57d53cf6593e9e1e7c6004e136f370b7b05ddd98408f8d",
  "status": "confirmed",
  "bitcoin_block_height": 974880,
  "digest": {
    "alg": "sha256",
    "hex": "77e2c501c67098511d57d53cf6593e9e1e7c6004e136f370b7b05ddd98408f8d",
    "preimage": "block:{\"at\":\"2026-11-07T02:19:15.265Z\",\"entry_count\":2,\"first_seq\":175,\"height\":78,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":176,\"merkle_root\":\"98c087f69b4b2fedf3e384592380b6db7012bb16ea4d78fd1c5ef38c5376ffe1\",\"prev_hash\":\"ecf7c240b9edfc8f546f3da1cbc20d957b0fcf4e5242f030066277fdde340043\",\"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": "6aee8cdc96578f25afb9c8b0a12d5396aa351bc79c8d5189f198a1d0283fa59c2b192a7b6e4f152de8e14da2"
        },
        {
          "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": "6aee8cdceb8faa9299258589b6cbc1f3cccd50ebc44358f9554bd1ee7f5c9f6e031232bab17017c00b28d339"
        },
        {
          "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": "6aee8cdc19f42d8f1e4dcf1148dd0ac572a3495eca518208759b8d1f952b3ca2be648d2c1de00c71fbad0c75"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/78/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."
}