Hello. This is Klaytn API Service team.
Please refer to the following information on how to check the KLAY balance through API.
When checking your account’s KLAY balance, please use Node API instead of Token History API. For more detailed information on Node API, make sure to check out the KAS document.
As shown in the example below, by utilizing the JSON RPC call, you can check your account’s KLAY balance with KAS API. To do so, enter the method string as "klay_getBalance" and the params as the account you want to check.
Klaytn API Service team.