{
  "height": 18,
  "block_hash": "de1a5dd1067d32d4930794bea615cb1b918042db829fb6500ed1a821e4c90c38",
  "status": "confirmed",
  "bitcoin_block_height": 972829,
  "digest": {
    "alg": "sha256",
    "hex": "de1a5dd1067d32d4930794bea615cb1b918042db829fb6500ed1a821e4c90c38",
    "preimage": "block:{\"at\":\"2026-10-23T19:46:17.984Z\",\"entry_count\":1,\"first_seq\":20,\"height\":18,\"key_id\":\"key_41eb7b6d1b11968a\",\"last_seq\":20,\"merkle_root\":\"7f590f8d93c577cc3c2dfaa8e55e5ca64d50e7aa0823cd7909426af6574297b0\",\"prev_hash\":\"0921cb42020a493930de746b2d2a978179d999b628e8a54712d8e7aee749c77b\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-23T19:53:02.956Z",
      "updated_at": "2026-10-23T21:53:02.963Z",
      "bitcoin_block_height": 972829,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6adbbb1951c0f5162eaa2dc176e0cd1b19ba79284c55f8d4be37c841f0dd581a2c187052d5a458ff0daa3b30"
        },
        {
          "type": "bitcoin",
          "block_height": 972829,
          "merkle_root": "673c0a2d93c20d9f3e747a7cd364a345df6ad18c383ad2de4ca38a0475507297"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-10-23T19:53:02.956Z",
      "updated_at": "2026-10-23T23:31:30.983Z",
      "bitcoin_block_height": 972835,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6adbbb1fb0881f28248eb3333b76f798b8276901931dfbc06c35bf367b9591713581d29518ba50bc5c672da9"
        },
        {
          "type": "bitcoin",
          "block_height": 972835,
          "merkle_root": "f24c17844238ebd6a2ef74e30715008f07ec90774762b16319248169cf634a1a"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-10-23T19:53:02.956Z",
      "updated_at": "2026-10-23T23:31:30.983Z",
      "bitcoin_block_height": 972835,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6adbbb1f150682a3a2e715c15db586ad39bef183e14048a4f191095761d7f0dd3890becd8423ec17066510cd"
        },
        {
          "type": "bitcoin",
          "block_height": 972835,
          "merkle_root": "f24c17844238ebd6a2ef74e30715008f07ec90774762b16319248169cf634a1a"
        }
      ]
    }
  ],
  "proof_url": "https://www.rightshold.com/v1/ledger/blocks/18/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."
}