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

# ERC-4337 Account Abstraction

> Send a UserOp through an ERC-4337 bundler using viem and permissionless.

# ERC-4337 Account Abstraction

Send a UserOp through an ERC-4337 bundler using viem and permissionless.

Send a UserOp through an ERC-4337 bundler using viem and permissionless.

## Explanation

ERC-4337 enables account abstraction without protocol changes. Users submit UserOperations to a bundler, which batches them and submits to an EntryPoint contract. This enables gasless transactions, social recovery, and custom validation logic.

## Code

```typescript theme={null}
import { createBundlerClient, toSmartContractAccount } from "permissionless";
import { pimlicoBundlerActions } from "permissionless/actions/pimlico";
import { http, createClient } from "viem";
import { mainnet } from "viem/chains";

const bundlerClient = createBundlerClient({
  chain: mainnet,
  transport: http("https://api.pimlico.io/v1/mainnet/rpc?apikey=YOUR_KEY"),
}).extend(pimlicoBundlerActions());

// Build a UserOperation
const userOp = {
  sender: smartAccountAddress,
  nonce: await bundlerClient.getAccountNonce({ address: smartAccountAddress }),
  initCode: "0x",
  callData: encodeFunctionData({
    abi: smartAccountAbi,
    functionName: "execute",
    args: [targetAddress, value, callData],
  }),
  callGasLimit: 100_000n,
  verificationGasLimit: 100_000n,
  preVerificationGas: 50_000n,
  maxFeePerGas: parseGwei("2"),
  maxPriorityFeePerGas: parseGwei("1"),
  signature: "0x",
};

const userOpHash = await bundlerClient.sendUserOperation({
  userOperation: userOp,
  entryPoint: entryPointAddress,
});
console.log("UserOp hash:", userOpHash);
```

***

**Canonical knowledge ID:** `code-example:erc-4337-account-abstraction`