# CFPlugIn ``` class CFPlugIn ``` ## Overview `CFPlugIn` provides a standard architecture for application extensions. With `CFPlugIn`, you can design your application as a host framework that uses a set of executable code modules called plug-ins to provide certain well-defined areas of functionality. This approach allows third-party developers to add features to your application without requiring access to your source code. You can also bundle together plug-ins for multiple platforms and let `CFPlugIn` transparently load the appropriate plug-in at runtime. You can use `CFPlugIn` to add plug-in capability to, or write a plug-in for, your application. ## Topics ### Creating Plug-ins [`CFPlugInCreate(_:_:)`](/documentation/CoreFoundation/CFPlugInCreate(_:_:)) Creates a CFPlugIn given its URL. [`CFPlugInInstanceCreate(_:_:_:)`](/documentation/CoreFoundation/CFPlugInInstanceCreate(_:_:_:)) Creates a `CFPlugIn` instance of a given type using a given factory. ### Registration [`CFPlugInRegisterFactoryFunction(_:_:)`](/documentation/CoreFoundation/CFPlugInRegisterFactoryFunction(_:_:)) Registers a factory function and its UUID with a `CFPlugIn` object. [`CFPlugInRegisterFactoryFunctionByName(_:_:_:)`](/documentation/CoreFoundation/CFPlugInRegisterFactoryFunctionByName(_:_:_:)) Registers a factory function with a `CFPlugIn` object using the function’s name instead of its UUID. [`CFPlugInRegisterPlugInType(_:_:)`](/documentation/CoreFoundation/CFPlugInRegisterPlugInType(_:_:)) Registers a type and its corresponding factory function with a `CFPlugIn` object. [`CFPlugInUnregisterFactory(_:)`](/documentation/CoreFoundation/CFPlugInUnregisterFactory(_:)) Removes the given function from a plug-in’s list of registered factory functions. [`CFPlugInUnregisterPlugInType(_:_:)`](/documentation/CoreFoundation/CFPlugInUnregisterPlugInType(_:_:)) Removes the given type from a plug-in’s list of registered types. ### CFPlugIn Miscellaneous Functions [`CFPlugInAddInstanceForFactory(_:)`](/documentation/CoreFoundation/CFPlugInAddInstanceForFactory(_:)) Registers a new instance of a type with `CFPlugIn`. [`CFPlugInFindFactoriesForPlugInType(_:)`](/documentation/CoreFoundation/CFPlugInFindFactoriesForPlugInType(_:)) Searches all registered plug-ins for factory functions capable of creating an instance of the given type. [`CFPlugInFindFactoriesForPlugInTypeInPlugIn(_:_:)`](/documentation/CoreFoundation/CFPlugInFindFactoriesForPlugInTypeInPlugIn(_:_:)) Searches the given plug-in for factory functions capable of creating an instance of the given type. [`CFPlugInGetBundle(_:)`](/documentation/CoreFoundation/CFPlugInGetBundle(_:)) Returns a plug-in’s bundle. [`CFPlugInGetTypeID()`](/documentation/CoreFoundation/CFPlugInGetTypeID()) Returns the type identifier for the `CFPlugIn` opaque type. [`CFPlugInIsLoadOnDemand(_:)`](/documentation/CoreFoundation/CFPlugInIsLoadOnDemand(_:)) Determines whether or not a plug-in is loaded on demand. [`CFPlugInRemoveInstanceForFactory(_:)`](/documentation/CoreFoundation/CFPlugInRemoveInstanceForFactory(_:)) Unregisters an instance of a type with `CFPlugIn`. [`CFPlugInSetLoadOnDemand(_:_:)`](/documentation/CoreFoundation/CFPlugInSetLoadOnDemand(_:_:)) Enables or disables load on demand for plug-ins that do dynamic registration (only when a client requests an instance of a supported type). ### Callbacks [`CFPlugInDynamicRegisterFunction`](/documentation/CoreFoundation/CFPlugInDynamicRegisterFunction) A callback which provides a plug-in the opportunity to dynamically register its types with a host. [`CFPlugInFactoryFunction`](/documentation/CoreFoundation/CFPlugInFactoryFunction) Callback function that a plug-in author must implement to create a plug-in instance. [`CFPlugInUnloadFunction`](/documentation/CoreFoundation/CFPlugInUnloadFunction) Callback function that is called, if present, just before a plug-in’s code is unloaded. ### Constants [Information Property List Keys](/documentation/CoreFoundation/cfplugin-information-property-list-keys) A plug-in’s information property list can contain these keys used for registering types, factories, and interfaces. --- 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)