> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abs.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Viem

> Learn how to use the Viem library to build applications on Abstract.

The Viem library has first-class support for Abstract by providing a set of
extensions to interact with [paymasters](/how-abstract-works/native-account-abstraction/paymasters),
[smart contract wallets](/how-abstract-works/native-account-abstraction/smart-contract-wallets), and more.
This page will walk through how to configure Viem to utilize Abstract’s features.

<Accordion title="Prerequisites">
  Ensure you have the following installed on your machine:

  * [Node.js](https://nodejs.org/en/download/) v18.0.0 or later.
  * You’ve already created a JavaScript project,
    (e.g. using [CRA](https://create-react-app.dev/) or [Next.js](https://nextjs.org/)).
  * Viem library version 2.21.25 or later installed.
</Accordion>

## 1. Installation

Install the `viem` package.

```bash theme={null}
npm install viem
```

## 2. Client Configuration

Configure your Viem [client](https://viem.sh/zksync/client) using `abstractTestnet`
as the [chain](https://viem.sh/zksync/chains) and extend it with
[eip712WalletActions](https://viem.sh/zksync/client#eip712walletactions).

<CodeGroup>
  ```javascript Testnet theme={null}
  import { createPublicClient, createWalletClient, custom, http } from 'viem'
  import { abstractTestnet } from 'viem/chains'
  import { eip712WalletActions } from 'viem/zksync'

  // Create a client from a wallet
  const walletClient = createWalletClient({
    chain: abstractTestnet,
    transport: custom(window.ethereum!),
  }).extend(eip712WalletActions()) ;

  // Create a client without a wallet
  const publicClient = createPublicClient({
    chain: abstractTestnet,
    transport: http()
  }).extend(eip712WalletActions());
  ```

  ```javascript Mainnet theme={null}
  import { createPublicClient, createWalletClient, custom, http } from 'viem'
  import { abstract } from 'viem/chains'
  import { eip712WalletActions } from 'viem/zksync'

  // Create a client from a wallet
  const walletClient = createWalletClient({
    chain: abstract,
    transport: custom(window.ethereum!),
  }).extend(eip712WalletActions()) ;

  // Create a client without a wallet
  const publicClient = createPublicClient({
    chain: abstract,
    transport: http()
  }).extend(eip712WalletActions());
  ```
</CodeGroup>

Learn more on the official [viem documentation](https://viem.sh/zksync).

### Reading Blockchain Data

Use a [public client](https://viem.sh/docs/clients/public)
to fetch data from the blockchain via an [RPC](/connect-to-abstract).

```javascript theme={null}
const balance = await publicClient.getBalance({
  address: "0x8e729E23CDc8bC21c37a73DA4bA9ebdddA3C8B6d",
});
```

### Sending Transactions

Use a [wallet client](https://viem.sh/docs/clients/wallet)
to send transactions to the blockchain.

```javascript theme={null}
const transactionHash = await walletClient.sendTransaction({
  to: "0x8e729E23CDc8bC21c37a73DA4bA9ebdddA3C8B6d",
  data: "0x69",
});
```

#### Paymasters

Viem has native support for Abstract [paymasters](/how-abstract-works/native-account-abstraction/paymasters).

Provide the `paymaster` and `paymasterInput` fields when sending a transaction.

[View Viem documentation](https://viem.sh/zksync#2-use-actions).

```javascript theme={null}
const hash = await walletClient.sendTransaction({
  to: "0x8e729E23CDc8bC21c37a73DA4bA9ebdddA3C8B6d",
  paymaster: "0x5407B5040dec3D339A9247f3654E59EEccbb6391", // Your paymaster contract address
  paymasterInput: "0x", // Any additional data to be sent to the paymaster
});
```

#### Smart Contract Wallets

Viem also has native support for using [smart contract wallets](/how-abstract-works/native-account-abstraction/smart-contract-wallets).
This means you can submit transactions `from` a smart contract wallet by providing
a smart wallet account as the `account` field to the [client](#client-configuration).

[View Viem documentation](https://viem.sh/zksync/accounts/toSmartAccount).

<CodeGroup>
  ```javascript Testnet theme={null}
  import { toSmartAccount, eip712WalletActions } from "viem/zksync";
  import { createWalletClient, http } from "viem";
  import { abstractTestnet } from "viem/chains";

  const account = toSmartAccount({
    address: CONTRACT_ADDRESS,
    async sign({ hash }) {
      // ... signing logic here for your smart contract account
    },
  });

  // Create a client from a smart contract wallet
  const walletClient = createWalletClient({
    chain: abstractTestnet,
    transport: http(),
    account: account, // <-- Provide the smart contract wallet account
  }).extend(eip712WalletActions());

  // ... Continue using the wallet client as usual (will send transactions from the smart contract wallet)
  ```

  ```javascript Mainnet theme={null}
  import { toSmartAccount, eip712WalletActions } from "viem/zksync";
  import { createWalletClient, http } from "viem";
  import { abstract } from "viem/chains";

  const account = toSmartAccount({
    address: CONTRACT_ADDRESS,
    async sign({ hash }) {
      // ... signing logic here for your smart contract account
    },
  });

  // Create a client from a smart contract wallet
  const walletClient = createWalletClient({
    chain: abstract,
    transport: http(),
    account: account, // <-- Provide the smart contract wallet account
  }).extend(eip712WalletActions());

  // ... Continue using the wallet client as usual (will send transactions from the smart contract wallet)
  ```
</CodeGroup>