The Composable Architecture is a library for building applications with state management, composition, side effects, and testing in mind. It can be used with SwiftUI, UIKit, and more.

Enhances Swift code testing with expressive APIs, custom behaviors, flexible organization, scalable execution, and cross-platform support. Compatible with XCTest for easy migration.

Defaults is a type-safe wrapper around UserDefaults and supports Codable, NSSecureCoding, change observation, and SwiftUI integration. It offers iCloud synchronization and custom serialization.

A dependency management library for controlling and overriding dependencies in Swift applications. Helps with testing, SwiftUI previews, and compile-time performance.

CasePaths extends the functionality of key paths to enum cases, allowing for the extraction, modification, and testing of associated values in enums.

Offers observation tools for earlier versions of Swift, mimicking @Observable and providing compatibility with newer Swift observation features.