{
  "height": 49,
  "block_hash": "437975afe33df92552aef17ba0f1fa06089d0b9a13a556e79a2324d71b6577e8",
  "status": "confirmed",
  "bitcoin_block_height": 974874,
  "digest": {
    "alg": "sha256",
    "hex": "437975afe33df92552aef17ba0f1fa06089d0b9a13a556e79a2324d71b6577e8",
    "preimage": "block:{\"at\":\"2026-11-07T01:09:15.002Z\",\"entry_count\":2,\"first_seq\":131,\"height\":49,\"key_id\":\"key_a521921c2ba20669\",\"last_seq\":132,\"merkle_root\":\"df9be73a324f44b1c00f9afaf930fc69849d15c9b7679be114d239730bdb4ae6\",\"prev_hash\":\"afc6c374694fd10db604a50db2d7f6b8c68b6201355e05d879be14881bc3d620\",\"v\":1}"
  },
  "calendars": [
    {
      "calendar": "https://a.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974874,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://alice.btc.calendar.opentimestamps.org",
          "commitment": "6aee7c73ec285ae918349057ddd37ece6dcefbcd5f47920206c42c9fa33a0ceb3e5a5d85bcc8c13bac2cc958"
        },
        {
          "type": "bitcoin",
          "block_height": 974874,
          "merkle_root": "fa522f272a37cb03554d5be30f11a1564362627a0d248c198befb5a303c3a302"
        }
      ]
    },
    {
      "calendar": "https://b.pool.opentimestamps.org",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://bob.btc.calendar.opentimestamps.org",
          "commitment": "6aee7c740caa147a2f5964ee45be7e8cd19d2befbef6de33f43f4446330b0e5ca1f1589cc8854e264c16146c"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    },
    {
      "calendar": "https://finney.calendar.eternitywall.com",
      "status": "confirmed",
      "submitted_at": "2026-11-07T01:18:43.458Z",
      "updated_at": "2026-11-07T03:18:43.476Z",
      "bitcoin_block_height": 974877,
      "attestations": [
        {
          "type": "pending",
          "uri": "https://finney.calendar.eternitywall.com",
          "commitment": "6aee7c73686bc7f7516aeb320f1c307484a192d16949c598fb0180bd934924d5ca471980be2ed4ccdbc08b65"
        },
        {
          "type": "bitcoin",
          "block_height": 974877,
          "merkle_root": "dee625f48434576e86df10e80f2912b1c31b96672232e47e103806c1faef5814"
        }
      ]
    }
  ],
  "proof_url": "https://www.a2ally.com/v1/ledger/blocks/49/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."
}