{
  "height": 13,
  "block_hash": "64a064e8c878c153c3c9c5c258d64cc5d10b42df1c7eadee427c5b309342b9c0",
  "status": "confirmed",
  "bitcoin_block_height": 972234,
  "digest": {
    "alg": "sha256",
    "hex": "64a064e8c878c153c3c9c5c258d64cc5d10b42df1c7eadee427c5b309342b9c0",
    "preimage": "block:{\"at\":\"2026-10-20T00:10:45.560Z\",\"entry_count\":1,\"first_seq\":15,\"height\":13,\"key_id\":\"key_41eb7b6d1b11968a\",\"last_seq\":15,\"merkle_root\":\"9d4c2f0075e5ae0e67edc024242e9ab7d0192d9ae0873c6d7f54de68b526c9b0\",\"prev_hash\":\"1c6f403c9eb8a7d17e62d6903fe7afb85c2f0a6991591ecb3f739ca2672e4f9f\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-20T00:15:14.143Z",
      "updated_at": "2026-10-20T02:15:14.172Z",
      "bitcoin_block_height": 972234,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6ad6b29338ea56d248506c485cdf162768e8acb76ef64921a9b1573b155f831228ecd6a5795653e09740c882"
        },
        {
          "type": "bitcoin",
          "block_height": 972234,
          "merkle_root": "7cef6f84a64954ca74d8f39f0cf266d02e7bb3385a0a2cdb587127d978fe6221"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-20T00:15:14.143Z",
      "updated_at": "2026-10-20T02:15:14.172Z",
      "bitcoin_block_height": 972234,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6ad6b2931732438e445bcaa6bfd249e244e21c958286a47d8e22cbad266f10482014b545c90d2cc84d8be713"
        },
        {
          "type": "bitcoin",
          "block_height": 972234,
          "merkle_root": "7cef6f84a64954ca74d8f39f0cf266d02e7bb3385a0a2cdb587127d978fe6221"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-10-20T00:15:14.143Z",
      "updated_at": "2026-10-20T02:15:14.172Z",
      "bitcoin_block_height": 972237,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6ad6b292c35a9b8873d07a7c31a6103573acc5459711769cd45f1d69157918c18f2af436fc20b83252782bb4"
        },
        {
          "type": "bitcoin",
          "block_height": 972237,
          "merkle_root": "5d433e97e6873bb59a2de2b84636e2303f5fd04a1a726158c1b428ef2710e9f3"
        }
      ]
    }
  ],
  "proof_url": "https://www.rightshold.com/v1/ledger/blocks/13/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."
}