curl --request GET \
  --url https://tonapi.io/v2/liteserver/get_block_proof

{
  "complete": true,
  "from": {
    "workchain": 4294967295,
    "shard": "800000000000000",
    "seqno": 30699640,
    "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
    "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
  },
  "to": {
    "workchain": 4294967295,
    "shard": "800000000000000",
    "seqno": 30699640,
    "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
    "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
  },
  "steps": [
    {
      "lite_server_block_link_back": {
        "to_key_block": false,
        "from": {
          "workchain": 4294967295,
          "shard": "800000000000000",
          "seqno": 30699640,
          "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
          "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
        },
        "to": {
          "workchain": 4294967295,
          "shard": "800000000000000",
          "seqno": 30699640,
          "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
          "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
        },
        "dest_proof": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
        "proof": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
        "state_proof": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85"
      },
      "lite_server_block_link_forward": {
        "to_key_block": false,
        "from": {
          "workchain": 4294967295,
          "shard": "800000000000000",
          "seqno": 30699640,
          "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
          "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
        },
        "to": {
          "workchain": 4294967295,
          "shard": "800000000000000",
          "seqno": 30699640,
          "root_hash": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
          "file_hash": "A6A0BD6608672B11B79538A50B2204E748305C12AA0DED9C16CF0006CE3AF8DB"
        },
        "dest_proof": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
        "config_proof": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
        "signatures": {
          "validator_set_hash": 123,
          "catchain_seqno": 123,
          "signatures": [
            {
              "node_id_short": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85",
              "signature": "131D0C65055F04E9C19D687B51BC70F952FD9CA6F02C2801D3B89964A779DF85"
            }
          ]
        }
      }
    }
  ]
}

{
  "error": "<string>",
  "error_code": 123
}