{
  "height": 15,
  "block_hash": "5a59150baff15e47a5804a9223b813a5a285bb144fb084f194cfb290a5ac2889",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "5a59150baff15e47a5804a9223b813a5a285bb144fb084f194cfb290a5ac2889",
    "preimage": "block:{\"at\":\"2026-11-06T23:20:18.692Z\",\"entry_count\":3,\"first_seq\":74,\"height\":15,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":76,\"merkle_root\":\"bfad432b291562d1776ecd0a258ab670fa25981d3cbe8afe4ad3adc2581e6186\",\"prev_hash\":\"4f074183ca945fd43bf666780b348daca82e8e4d21606a521f4a30b23fda5f08\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:23:33.611Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee6177067e101062f770c0e75119c9792f2485a1232dd29baf3ce98259abac8ab1069b8046858c0f0b3cd0"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:23:33.611Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee61770339961dc1a839dd95a25eb68133efe6315b260f0bec295d7e6cbd1128e0552379a48253ecc744a4"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:23:33.611Z",
      "updated_at": "2026-11-07T03:28:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee6177d82b9dd215a38b7ffb842c0e19feaab14cdfd39a537e8cd1d1563610f4131e4d280481ca882bf726"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/15/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."
}