CrossmintExternalWalletSignCallback typedef

CrossmintExternalWalletSignCallback = Future<String> Function(String payload)

Callback signature for user-owned external-wallet signers.

Receives the payload to sign (hex-encoded for EVM, base58-encoded for Solana, base64-encoded transaction blob for Stellar) and returns the user-produced signature in the same encoding. Implementations typically delegate to a wallet SDK like WalletConnect, MetaMask Flask, or a platform-native wallet adapter.

Implementation

typedef CrossmintExternalWalletSignCallback =
    Future<String> Function(String payload);