5. API & SDK Reference
5.1. SDKs
The GA functionality is encapsulated within the -ext SDKs, which extend the functionality of ethers.js and web3.js. For detailed API references, please see the repositories.
Kaia Ethers-ext SDK
- Repo: GitHub
- Code Example: gasless.js
- Code Example with Tutorial
- Key Methods:
gasless.getGaslessSwapRouter,gasless.getAmountRepay,gasless.getMinAmountOut,gasless.getAmountIn,gasless.getApproveTx,gasless.getSwapTx.
Kaia Web3js-ext SDK
- Repo: GitHub
- Code Example: gasless.js
- Code Example with Tutorial
- Key Methods:
web3.gasless.getGaslessSwapRouter,web3.gasless.getAmountRepay,web3.gasless.getMinAmountOut,web3.gasless.getAmountIn,web3.gasless.getApproveTx,web3.gasless.getSwapTx.
5.2. JSON-RPC API
kaia_sendRawTransactions accepts an array of signed, RLP-encoded raw transactions whose type byte is one of the Ethereum family (0x00 Legacy, 0x01 EIP-2930, 0x02 EIP-1559, 0x04 Blob). Use it for the GA pair ApproveTx + SwapTx, which are ordinary EVM types.
Kaia-specific types such as 0x30 (Smart-Contract Execution) must still be broadcast with the old single-tx method klay_sendRawTransaction.
Typical flow:
- Build and sign
ApproveTx+SwapTx→ send with kaia_sendRawTransactions - Build and sign the user’s AppTx → send with eth_sendRawTransaction or klay_sendRawTransaction depending on the transaction type
Because transactions are ordered by nonce, the AppTx will be executed right after the bundle even though it was sent through a separate endpoint.
If you only have one transaction to send (i.e. SwapTx), you can always fall back to eth_sendRawTransaction.