# Index(_:) Specifies the key-paths that SwiftData uses to create one or more binary indices for the associated model. ``` @freestanding(declaration) macro Index(_ indices: [PartialKeyPath]...) where T : PersistentModel ``` --- 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)