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

# CrossmintEvmWallet

> Flutter Final Class

**Final Class**

Runtime wallet for EVM chains (Base, Ethereum, Polygon, Optimism, etc.).

```dart theme={null}
final class CrossmintEvmWallet extends CrossmintRuntimeWalletBase
```

Adds EVM-specific entry points on top of `CrossmintRuntimeWalletBase`:
create + sign transactions, sign arbitrary messages, and sign EIP-712
typed data. Every entry point calls `preAuthIfNeeded()` first, so
recovery flows and pending device-signer registrations are handled
automatically before the request hits the Crossmint API.

The default chain is `base-sepolia` on staging environments and `base`
on production — override per-call via `CrossmintEvmTransactionRequest.chain`.

## Constructors

### CrossmintEvmWallet

```dart theme={null}
CrossmintEvmWallet({
  required super.client,
  required super.wallet,
  super.recoverySigner,
  super.signer,
  super.additionalSigners,
  super.deviceSignerKeyStorage,
  super.onAuthRequired,
})
```

Creates a runtime EVM wallet. Use `CrossmintClient.createEvmWallet` or the wallet controller instead of constructing this directly.

## Properties

### defaultChain

```dart theme={null}
String get defaultChain
```

## Methods

### createTransaction

```dart theme={null}
Future<CrossmintTransactionDetails> createTransaction(
  CrossmintEvmTransactionRequest request,
)
```

Submits a transaction request to the Crossmint API without waiting for approval or confirmation. Use this when you want to inspect the created record before approving — most callers should use `sendTransaction`.

### sendTransaction

```dart theme={null}
Future<CrossmintTransactionDetails> sendTransaction(
  CrossmintEvmTransactionRequest request,
)
```

End-to-end: creates the transaction, approves it with the active signer, polls for confirmation (exponential backoff 1s → 8s, up to 60 attempts, with jitter), and returns the final `CrossmintTransactionDetails`.

### signMessage

```dart theme={null}
Future<String> signMessage(String message)
```

Signs an arbitrary UTF-8 string as a personal message (EIP-191). Returns the hex-encoded signature. Calls `preAuthIfNeeded()` first.

### signTypedData

```dart theme={null}
Future<String> signTypedData(CrossmintTypedData typedData)
```

Signs an EIP-712 typed data payload. Requires `domain.name`, `domain.version`, `domain.chainId`, `domain.verifyingContract`, `primaryType`, `types`, and `message`. Throws `CrossmintWalletException` on malformed input.