curl --request GET \
  --url https://mainnet.mirrornode.hedera.com/api/v1/topics/{topicId}/messages

{
  "messages": [
    {
      "chunk_info": {
        "initial_transaction_id": "0.0.10-1234567890-000000321",
        "nonce": 3,
        "number": 1,
        "total": 2,
        "scheduled": true
      },
      "consensus_timestamp": "1234567890.000000001",
      "message": "bWVzc2FnZQ==",
      "payer_account_id": "0.0.10",
      "running_hash": "cnVubmluZ19oYXNo",
      "running_hash_version": 2,
      "sequence_number": 1,
      "topic_id": "0.0.7"
    }
  ],
  "links": {
    "next": null
  }
}