Endpoint Node is needed to connect to the Klaytn network and to issue an API call or send a transaction.
ken CLI comes with several utility and node management functions.
Smart Contract Development
Klaytn IDE - A browser-based compiler and IDE for the Klaytn smart contracts.
Truffle - An open-source tool for developing smart contracts in Solidity.
caver-java : A Java library that implements the Klaytn JSON-RPC APIs.