> For the complete documentation index, see [llms.txt](/llms.txt).

# Ed25519 private key

To retrieve the ed25519 private key of the user, use the `getEd25519PrivateKey` method. This private key can be used to sign transactions on Solana, Near, Algorand, and other chains that use the ed25519 curve.

The method throws if the user isn't authenticated: Android returns a `PlatformException`, and iOS returns `null`, which surfaces in Dart as a type error. To check for an existing session, use [getPrivateKey](/embedded-wallets/sdk/flutter/usage/get-private-key/), which returns an empty string instead.

## Usage

```dart
try {
  final String privateKey = await Web3AuthFlutter.getEd25519PrivateKey();
} catch (e) {
  // No active session.
  log(e.toString());
}

```

note

Web3Auth supports two widely used cryptographic curves, Secp256k1 and Ed25519, making it chain-agnostic and compatible with multiple blockchain networks. [Learn more about how to connect different blockchains](/embedded-wallets/connect-blockchain/).