{
  "height": 61,
  "block_hash": "bb7edad7238c4b4536f3e8e642dfb44c0e231d75fb032a454899ee1c1ce5cb49",
  "status": "confirmed",
  "bitcoin_block_height": 974877,
  "digest": {
    "alg": "sha256",
    "hex": "bb7edad7238c4b4536f3e8e642dfb44c0e231d75fb032a454899ee1c1ce5cb49",
    "preimage": "block:{\"at\":\"2026-11-07T01:39:15.145Z\",\"entry_count\":2,\"first_seq\":150,\"height\":61,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":151,\"merkle_root\":\"021a1a1275c8f88c0742b94d0ebb7e44ab5bc59bcbd48529aeeec8b3d7551da3\",\"prev_hash\":\"290ad3de1a469069af4c0556708b5eeb2605fb89b2c2a3ae2950f406ab8bbb26\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T03:48:43.477Z",
      "bitcoin_block_height": 974880,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee837b6b340a99bce8292fb830eacbb528cb954955659248f2d55ed627a4b482ea18fdc3bd61295775b911"
        },
        {
          "type": "bitcoin",
          "block_height": 974880,
          "merkle_root": "e20917e92c25ba0bebbc60b5b7fe48f0ee84f05c3eb4987c3107d249f2c7113d"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T04:48:43.485Z",
      "bitcoin_block_height": 974883,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee837c3d5cb9d9d99be52723d30480a4fb2b8f49d7a1d5c6f821a827b8f8dec3efb248d31d0172ff800110"
        },
        {
          "type": "bitcoin",
          "block_height": 974883,
          "merkle_root": "79abb9dd33baad0a1ff37045cc779f6fe1b133a7037999fbd2c996ad78e43b90"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:48:43.461Z",
      "updated_at": "2026-11-07T03:48:43.477Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee837ccb3566e60917e43207b566a54337be00ea9f30dc381a8fedf069649ecce91c961b298f7582685cae"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/61/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."
}