curl --request GET \
  --url https://xbt-mainnet.gomaestro-api.org/v0/rpc/mempool/transactions \
  --header 'api-key: <api-key>'

{
  "data": {
    "mempool_sequence": 123,
    "txids": [
      "<string>"
    ]
  },
  "last_updated": {
    "block_hash": "<string>",
    "block_height": 123
  }
}