{
  "height": 13,
  "block_hash": "54b5847dbd04a08b258af1c6f6f5cdca7bff14305a122b64981c7940ede293d2",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "54b5847dbd04a08b258af1c6f6f5cdca7bff14305a122b64981c7940ede293d2",
    "preimage": "block:{\"at\":\"2026-11-06T23:10:18.618Z\",\"entry_count\":2,\"first_seq\":70,\"height\":13,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":71,\"merkle_root\":\"b0112f50baf89431c16f03e173e3dd0f365ea178c04e35db29511b6d0a374f4e\",\"prev_hash\":\"4b05c697d239585dac61706307dfab182e8a46cecb2593c909fea6afb2311ad0\",\"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": "6aee5f69abb9a1528f47e7d67e9c637ef8faaf08872ff0a6d304ce8416c58e48ede13c789dafc3d70b697039"
        },
        {
          "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": "6aee5f6a836b69e4a84cc12130047c057677cad8cd899e8688c12847c83f0a3412909f238a75c8f46763fd96"
        },
        {
          "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": "6aee5f69136dcd02945c73d1a189fe4d98d5ce8dc93c5bd126a0f916c78b00d1f22c4cc8840769d7102a53af"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.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."
}