---
title: ASWebAuthenticationSession.Callback
framework: authenticationservices
role: symbol
role_heading: Class
path: authenticationservices/aswebauthenticationsession/callback
---

# ASWebAuthenticationSession.Callback

An object for evaluating navigation events in an authentication session.

## Declaration

```swift
class Callback
```

## Overview

Overview When ASWebAuthenticationSession navigates to a matching URL, it passes the URL to the session completion handler. important: Your browser app needs to add CallbackURLMatchingIsSupported with the value YES to the ASWebAuthenticationSessionWebBrowserSupportCapabilities dictionary in your app’s information property list to use this API. If the system doesn’t find this key in the default browser app, it sends the request to Safari instead.

## Topics

### Creating callbacks

- [customScheme(_:)](authenticationservices/aswebauthenticationsession/callback/customscheme(_:).md)
- [https(host:path:)](authenticationservices/aswebauthenticationsession/callback/https(host:path:).md)

### Evaluating URLs

- [matchesURL(_:)](authenticationservices/aswebauthenticationsession/callback/matchesurl(_:).md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Creating a session

- [init(url:callback:completionHandler:)](authenticationservices/aswebauthenticationsession/init(url:callback:completionhandler:)-6nut7.md)
- [ASWebAuthenticationSession.CompletionHandler](authenticationservices/aswebauthenticationsession/completionhandler.md)