ViemSigner

Signer adapter that wraps a viem WalletClient for wallet operations.

Signer adapter that wraps a viem WalletClient for wallet operations. Implements GenericSigner.

Import

import { ViemSigner } from "@zama-fhe/sdk/viem";

Usage

import { createWalletClient, custom } from "viem";
import { sepolia } from "viem/chains";
import { ViemSigner } from "@zama-fhe/sdk/viem";

const walletClient = createWalletClient({ chain: sepolia, transport: custom(window.ethereum!) });

const signer = new ViemSigner({ walletClient, ethereum: window.ethereum });

You rarely need to instantiate ViemSigner directly. The viem createConfig builds one from the walletClient you pass. Use this class when constructing ZamaSDK manually or when using the generic createConfig.

Constructor

walletClient

WalletClient

Viem wallet client for signing transactions and typed data.

const signer = new ViemSigner({ walletClient });

---

ethereum

EIP1193Provider | undefined

Raw EIP-1193 provider for wallet lifecycle event subscriptions. When provided, the signer emits wallet account transitions on disconnect, account change, and chain change. Omit if you handle lifecycle events manually.

const signer = new ViemSigner({ walletClient, ethereum: window.ethereum });

Methods

All methods are inherited from GenericSigner.

Method	Behavior
walletAccount store	Sync observable store
requireWalletAccount()	From wallet client
signTypedData()	Via wallet client
writeContract()	Via wallet client

Wallet account transitions are only emitted when you pass the ethereum option. Without it, the SDK still works but credentials are not automatically cleared when users switch accounts.

Related

• GenericSigner -- interface this class implements

• ViemProvider -- companion provider adapter

• EthersSigner -- ethers alternative

• Configuration guide -- full setup walkthrough