CrossmintClient class final

Top-level facade for the Crossmint SDK.

CrossmintClient owns every sub-client (auth, wallets, credentials, orders, tokens, users), the shared transport, the auth session store, and the hidden WebView signer bridge. All sub-clients share a closure that reads the live JWT from auth, so token refresh works without rebuilding the dependency graph.

Lifecycle

1. Construct the client with a CrossmintClientConfig.
2. await client.initialize() — validates config and auto-resolves the app ID from platform metadata if not supplied.
3. await client.auth.restoreSession() — restores any persisted JWT.
4. Use sub-clients or factory helpers (createWalletController, createEvmWallet, etc.) for the rest of your session.
5. await client.dispose() when tearing down — shuts down the signer bridges and releases the auth client.

Typical bootstrap

final client = CrossmintClient(
  config: const CrossmintClientConfig(
    apiKey: 'YOUR_STAGING_API_KEY',
    appScheme: 'com.your.app',
  ),
);
await client.initialize();
await client.auth.restoreSession();

final walletController = client.createWalletController(
  const CrossmintWalletControllerConfig(showOtpSignerPrompt: true),
);

Named constructor parameters on the factory (auth, wallets, transport, runtimeOverrides, etc.) are injection points primarily used by tests and advanced integrations. Leave them null in production to get the default HTTP transport, secure-storage-backed auth, and platform-resolved app ID.

Constructors

CrossmintClient({required CrossmintClientConfig config, CrossmintAuthClient? auth, CrossmintWalletsClient? wallets, CrossmintCredentialsClient? credentials, CrossmintOrdersClient? orders, CrossmintTokensClient? tokens, CrossmintUsersClient? users, CrossmintTransport? transport, CrossmintAuthLauncher? authLauncher, CrossmintClientRuntimeOverrides? runtimeOverrides})

Creates a CrossmintClient.

factory

Properties

appId → String?

The effective app ID — explicit CrossmintClientConfig.appId if set, otherwise the value auto-resolved from platform metadata during initialize. May be null until initialize has completed.

no setter

auth → CrossmintAuthClient

Authentication sub-client — email OTP, OAuth, wallet sign-in, session persistence, JWT refresh.

final

authStorage → CrossmintAuthStorage

The auth storage adapter resolved during construction — either the one passed via CrossmintClientConfig.authStorage or the default flutter_secure_storage-backed implementation.

no setter

config → CrossmintClientConfig

The configuration this client was built with.

final

credentials → CrossmintCredentialsClient

Verifiable credentials sub-client — issue, query, and verify credentials.

final

exportSignerBridgeController → CrossmintExportSignerBridgeRuntimeController

The shared export signer bridge controller, lazily constructed on first access. Drives the private-key export flow in a separate WebView.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

hiddenSignerBridgeController → HiddenSignerBridgeRuntimeController

The shared hidden signer bridge controller, lazily constructed on first access. Powers non-custodial email/phone signing inside a hidden WebView.

no setter

isDisposed → bool

Whether dispose has been called. Once disposed, the client cannot be reused — construct a new one.

no setter

isInitialized → bool

Whether initialize has completed successfully.

no setter

orders → CrossmintOrdersClient

Orders sub-client — checkout orders and mint/purchase flows.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

tokens → CrossmintTokensClient

Tokens sub-client — metadata and balances for tokens held by wallets.

final

transport → CrossmintTransport

The HTTP transport resolved during construction. Shared by every sub-client; injects the live JWT via a closure so token refresh works without rebuilding dependencies.

no setter

users → CrossmintUsersClient

Users sub-client — user profile lookups and updates.

final

wallets → CrossmintWalletsClient

Wallet sub-client — create, list, and read Crossmint-hosted wallets (EVM, Solana, Stellar) and their signers.

final

Methods

createDeviceWalletSigner({required String signerLocator, required String address, DeviceSignerKeyStorage? storage}) → CrossmintDeviceWalletSigner

Builds a hardware-backed device signer for an existing server signer.

createEvmExternalWalletSigner({required String address, String? signerLocator, required CrossmintExternalWalletSignCallback onSign}) → CrossmintEvmExternalWalletSigner

Builds an external-wallet EVM signer that delegates to a user-supplied CrossmintExternalWalletSignCallback. Use for wallets owned by the user (e.g. MetaMask, Rainbow) where the SDK only needs to request signatures.

createEvmNonCustodialSigner({required HiddenSignerBridge bridge, required String signerType, required String signerLocator, String? address, CrossmintSignerAuthRequiredCallback? onAuthRequired, CrossmintOtpDeliveryChannel? channel}) → CrossmintEvmNonCustodialSigner

Builds a non-custodial EVM signer bound to an existing HiddenSignerBridge. Produces secp256k1 signatures inside the WebView without exposing keys to Dart.

createEvmWallet({required CrossmintWallet wallet, CrossmintSignerConfig? recoverySigner, CrossmintWalletApprovalSigner? signer, List<CrossmintWalletApprovalSigner> additionalSigners = const <CrossmintWalletApprovalSigner>[], DeviceSignerKeyStorage? deviceSignerKeyStorage, CrossmintSignerAuthRequiredCallback? onAuthRequired}) → CrossmintEvmWallet

Wraps a server-issued CrossmintWallet in a runtime CrossmintEvmWallet.

createExportSignerBridge({HiddenSignerBridgeConfig? config}) → CrossmintExportSignerBridgeRuntimeController

Builds a new CrossmintExportSignerBridgeRuntimeController instance. Used internally by exportSignerBridgeController.

createHiddenSignerBridge({HiddenSignerBridgeConfig? config}) → HiddenSignerBridgeRuntimeController

Builds a new HiddenSignerBridgeRuntimeController instance — used internally by hiddenSignerBridgeController. Override the bridge config to point at a custom signer URL (e.g. for testing).

createPasskeyApprovalSigner({required String credentialId, required String signerLocator, required Future<CrossmintPasskeySignResult> onSign(String message)}) → CrossmintPasskeyApprovalSigner

Builds a passkey approval signer. The caller provides onSign — a callback that performs the WebAuthn / platform-native passkey assertion and returns a CrossmintPasskeySignResult. Native platform passkey support is pending (Stage 2); today every passkey signer requires an explicit callback or CrossmintSignerException(code: passkeyCallbackMissing) is thrown during signing.

createSolanaExternalWalletSigner({required String address, String? signerLocator, required CrossmintExternalWalletSignCallback onSign}) → CrossmintSolanaExternalWalletSigner

Builds an external-wallet Solana signer that delegates to a user-supplied CrossmintExternalWalletSignCallback.

createSolanaNonCustodialSigner({required HiddenSignerBridge bridge, required String signerType, required String signerLocator, String? address, CrossmintSignerAuthRequiredCallback? onAuthRequired, CrossmintOtpDeliveryChannel? channel}) → CrossmintSolanaNonCustodialSigner

Builds a non-custodial Solana signer bound to an existing HiddenSignerBridge. Produces ed25519 signatures inside the WebView.

createSolanaWallet({required CrossmintWallet wallet, CrossmintSignerConfig? recoverySigner, CrossmintWalletApprovalSigner? signer, List<CrossmintWalletApprovalSigner> additionalSigners = const <CrossmintWalletApprovalSigner>[], DeviceSignerKeyStorage? deviceSignerKeyStorage, CrossmintSignerAuthRequiredCallback? onAuthRequired}) → CrossmintSolanaWallet

Wraps a server-issued CrossmintWallet in a runtime CrossmintSolanaWallet.

createStellarExternalWalletSigner({required String address, String? signerLocator, required CrossmintExternalWalletSignCallback onSign}) → CrossmintStellarExternalWalletSigner

Builds an external-wallet Stellar signer that delegates to a user-supplied CrossmintExternalWalletSignCallback.

createStellarNonCustodialSigner({required HiddenSignerBridge bridge, required String signerType, required String signerLocator, String? address, CrossmintSignerAuthRequiredCallback? onAuthRequired, CrossmintOtpDeliveryChannel? channel}) → CrossmintStellarNonCustodialSigner

Builds a non-custodial Stellar signer bound to an existing HiddenSignerBridge. Produces ed25519 signatures inside the WebView.

createStellarWallet({required CrossmintWallet wallet, CrossmintSignerConfig? recoverySigner, CrossmintWalletApprovalSigner? signer, List<CrossmintWalletApprovalSigner> additionalSigners = const <CrossmintWalletApprovalSigner>[], DeviceSignerKeyStorage? deviceSignerKeyStorage, CrossmintSignerAuthRequiredCallback? onAuthRequired}) → CrossmintStellarWallet

Wraps a server-issued CrossmintWallet in a runtime CrossmintStellarWallet.

createWalletController(CrossmintWalletControllerConfig config) → CrossmintWalletController

Creates a CrossmintWalletController bound to this client.

dispose() → Future<void>

Releases the signer bridges and auth client, then marks the client as disposed. Safe to call multiple times. After disposal, construct a new CrossmintClient rather than reusing this one.

initialize() → Future<void>

Validates configuration and prepares the client for use.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited