curl --request GET \
  --url https://api.coingecko.com/api/v3/global \
  --header 'x-cg-demo-api-key: <api-key>'

{
  "data": {
    "active_cryptocurrencies": 17397,
    "upcoming_icos": 0,
    "ongoing_icos": 49,
    "ended_icos": 3376,
    "markets": 1476,
    "total_market_cap": {
      "btc": 34570737.199462704,
      "eth": 1259418635.423994,
      "usd": 2621040321355.0405
    },
    "total_volume": {
      "btc": 1254779.1727158197,
      "eth": 45711847.69194817,
      "usd": 95133256404.37308
    },
    "market_cap_percentage": {
      "btc": 57.9539332566265,
      "eth": 9.58227145398409,
      "usdt": 7.223241338072757
    },
    "market_cap_change_percentage_24h_usd": -1.6081983639177684,
    "volume_change_percentage_24h_usd": 33.064521460740046,
    "updated_at": 1779878351
  }
}