# AEAssessmentSessionDelegate An interface that the session uses to provide information about session state changes to a delegate. ``` protocol AEAssessmentSessionDelegate : NSObjectProtocol ``` ## Overview An assessment session operates asynchronously because it takes time to make the changes associated with starting or stopping a session, and external events might affect the state of the session. Adopt the [`AEAssessmentSessionDelegate`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate) protocol to receive callbacks at key points in the session life cycle. Store your adopter in the session’s [`delegate`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSession/delegate) property before starting a session. By listening for delegate callbacks, you learn when you can safely start an assessment after calling the session’s [`begin()`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSession/begin()) method, when the session has finished after calling the [`end()`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSession/end()) method, or if the session has been interrupted for some reason. You also find out when it’s safe to proceed after changing a session’s configuration. The session calls all delegate methods on the main thread. ## Topics ### Responding to session start and stop [`func assessmentSessionDidBegin(AEAssessmentSession)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSessionDidBegin(_:)) Tells the delegate that the session started. [`func assessmentSession(AEAssessmentSession, failedToBeginWithError: any Error)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSession(_:failedToBeginWithError:)) Tells the delegate that the session failed to start. [`func assessmentSession(AEAssessmentSession, wasInterruptedWithError: any Error)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSession(_:wasInterruptedWithError:)) Tells the delegate that a system failure interrupted the session. [`func assessmentSessionDidEnd(AEAssessmentSession)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSessionDidEnd(_:)) Tells the delegate that the session ended. ### Responding to configuration changes [`func assessmentSessionDidUpdate(AEAssessmentSession)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSessionDidUpdate(_:)) Tells the delegate that a configuration update succeeded. [`func assessmentSession(AEAssessmentSession, failedToUpdateTo: AEAssessmentConfiguration, error: any Error)`](/documentation/AutomaticAssessmentConfiguration/AEAssessmentSessionDelegate/assessmentSession(_:failedToUpdateTo:error:)) Tells the delegate that a configuration update failed. ## Relationships ### Inherits From [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)