viem

Create a PublicClient with createPublicClient, passing an explicit chain and http transport, then call readContract with the contract address, ABI, function name, and args. Define the ABI with an as const assertion so return values and arguments are fully typed.

viem uses native bigint instead of BigNumber, splits functionality into PublicClient and WalletClient instead of Provider and Signer, and requires explicit chain and transport configuration. ABIs need as const assertions for type inference, and simulation is separated from execution via simulateContract.

Call simulateContract first to catch reverts without spending gas, then pass the returned request object to walletClient.writeContract. Afterward, call waitForTransactionReceipt and check that receipt.status is not reverted before treating the transaction as successful.

Yes, client.multicall batches multiple read calls into a single RPC request through the Multicall3 contract. By default allowFailure is true, so each result includes a status field; set allowFailure to false to throw on the first failure.

viem returns bigint values, which JSON.stringify cannot serialize natively. Pass a replacer function that converts bigint values to strings, or convert values with toString or formatUnits before serializing.

Catch the error, check it is an instance of BaseError, then use err.walk with a predicate to find ContractFunctionRevertedError in the cause chain. The revert error exposes data.errorName and data.args for custom Solidity errors, or a reason string for require-style reverts.