# Creating a Core Data model Define your app’s object structure with a data model file. ## Discussion The first step in working with Core Data is to create a data model file to define the structure of your app’s objects, including their object types, properties, and relationships. You can add a Core Data model file to your Xcode project when you create the project, or you can add it to an existing project. ### Add Core Data to a New Xcode Project In the dialog for creating a new project, select the Use Core Data checkbox, and click Next.  The resulting project includes an `.xcdatamodeld` file.  ### Add a Core Data Model to an Existing Project Choose File > New > File and select the iOS platform tab. Scroll down to the Core Data section, select Data Model, and click Next.  Name your model file, select its group and targets, and click Create.  Xcode adds an `.xcdatamodeld` file with the specified name to your project.  ## See Also [Configuring Attributes](/documentation/CoreData/configuring-attributes) Describe the properties that compose an entity. [Configuring Relationships](/documentation/CoreData/configuring-relationships) Specify how entities relate and how change propagates between them. [Generating code](/documentation/CoreData/generating-code) Automatically or manually generate managed object subclasses from entities. --- 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)