curl --request GET \
  --url https://xbt-mainnet.gomaestro-api.org/v0/mempool/addresses/{address}/balance \
  --header 'api-key: <api-key>'

{
  "data": "695100",
  "indexer_info": {
    "chain_tip": {
      "block_hash": "000000000000000000012c80ffd2f0bd17f1f92a0bb4c098236d7108f727bfe5",
      "block_height": 874584
    },
    "estimated_blocks": [
      {
        "block_height": 874585,
        "sats_per_vb": {
          "max": 504,
          "median": 8,
          "min": 1
        }
      }
    ],
    "mempool_timestamp": "2025-01-06 16:43:32"
  }
}