getSlot

curl --request POST \
  --url 'https://mainnet.helius-rpc.com/?api-key=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": "1",
  "method": "getSlot",
  "params": [
    {
      "commitment": "finalized"
    }
  ]
}
'

{
  "jsonrpc": "2.0",
  "id": "1",
  "result": 1234
}