public protocol FeatureManager: AnyObject {
    func verify(
        viewController: UIViewController,
        request: FeatureRequest,
        credentialReceiver: CredentialReceiver,
        callback: AnyFeatureCallback<VerifyResult>
    ) throws

    func login(
        viewController: UIViewController,
        request: FeatureRequest,
        credentialReceiver: CredentialReceiver,
        callback: AnyFeatureCallback<LoginResult>
    ) throws
}

public protocol FeatureCallback: AnyObject {
    associatedtype Result
    func onComplete(result: Result, data: [String: Any])
    func onError(error: GoPayEnterpriseError)
}

Terminology	Description
requestId	Request identifier generated by the client before initiating any flow via Enterprise SDK.
userCorrelationId	Identifier linking the client user to GoPay, obtained from the credential exchange.
token	The linking token for the user — short-term when an exchange is required, long-term when it is not.

verify

Launches the GoPay verify flow inside the provided UIViewController. Validates the request internally and calls callback.onError (code GPE-2206) if required fields are missing rather than throwing.

Parameter	Type	Description
viewController	UIViewController	The view controller from which the SDK UI will be presented.
request	FeatureRequest	Built via `FeatureRequest.Builder`. Contains `requestId`, `userCorrelationId`, and `token`.
credentialReceiver	CredentialReceiver	Controls how the SDK handles the auth-code handshake. Use `.exchange` for a short-term linking token or `.none` for a long-term token.
callback	AnyFeatureCallback<VerifyResult>	Receives `onComplete(result:data:)` with a `VerifyResult` on success, or `onError(error:)` on failure.

For a detailed usage guide, see Verify with GoPay.

login

Status: Not yet implemented. This method is reserved for the Login with GoPay flow and will be available in a future release. Calling it currently triggers a fatalError.

FeatureCallback

FeatureCallback is a protocol with an associated Result type. Because Swift protocols with associated types cannot be stored directly, the SDK provides a type-erased wrapper AnyFeatureCallback<R> for passing callbacks through the API.

public protocol FeatureCallback: AnyObject {
    associatedtype Result
    func onComplete(result: Result, data: [String: Any])
    func onError(error: GoPayEnterpriseError)
}

public final class AnyFeatureCallback<R> {
    public init<C: FeatureCallback>(wrapping callback: C) where C.Result == R
    public func onComplete(result: R, data: [String: Any] = [:])
    public func onError(error: GoPayEnterpriseError)
}

Create a concrete class conforming to FeatureCallback, then wrap it with AnyFeatureCallback(wrapping:) when passing to SDK methods.

final class VerifyFeatureCallback: FeatureCallback {
    typealias Result = VerifyResult

    func onComplete(result: VerifyResult, data: [String: Any]) {
        print("Submission ID: \(result.submissionId)")
    }

    func onError(error: GoPayEnterpriseError) {
        print("Error [\(error.code)]: \(error.message)")
    }
}

let callback = VerifyFeatureCallback()

try sdk.getFeatureManager().verify(
    viewController: self,
    request: request,
    credentialReceiver: credentialReceiver,
    callback: AnyFeatureCallback(wrapping: callback)
)

Important: Keep a strong reference to your FeatureCallback instance for the duration of the flow. AnyFeatureCallback holds only a weak reference to the wrapped callback.