{
  "height": 12,
  "block_hash": "4b05c697d239585dac61706307dfab182e8a46cecb2593c909fea6afb2311ad0",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "4b05c697d239585dac61706307dfab182e8a46cecb2593c909fea6afb2311ad0",
    "preimage": "block:{\"at\":\"2026-11-06T23:05:18.589Z\",\"entry_count\":2,\"first_seq\":68,\"height\":12,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":69,\"merkle_root\":\"593f711b9c8aa09c628e5c21d47a8c6179a82aff2bb7c29bb020b8438314526a\",\"prev_hash\":\"55c169560b3da22c9790809f174d29d031a4217b8a7b938425e27d5dc4568d13\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:14:47.915Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee5f681847fc00f40a7d7638aae65ccc044e338594310b260b7598470ab735ba3da1b0af7a26c0a7fc5df1"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:14:47.915Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee5f6929b1a2e17e157b53585ae51b23f2a80c189b89bc33101ba6223629f93445a2556836c4f7e887fe3c"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-06T23:14:47.915Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee5f6843bca825f89e5cdb4576eed10259ce574894e5e7a752ee1738e5096e51c351a7e79b07f5c8c6ea5f"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/12/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."
}