---
name: swift-sharing
description: A library for sharing state across your app with persistence and observation support
---

# Sharing

Instantly share state among your app's features and external persistence layers, including user

## Documentation Structure

### Essentials

- **Persistence strategies** ([Articles/PersistenceStrategies.md](Articles/PersistenceStrategies.md)): Learn about the various persistence strategies that ship with the library, as well as how to create
- **Mutating shared state** ([Articles/MutatingSharedState.md](Articles/MutatingSharedState.md)): Learn how to mutate shared state in a safe manner in order to prevent race conditions and data loss.
- **Observing changes to shared state** ([Articles/ObservingChanges.md](Articles/ObservingChanges.md)): Learn how to observe changes to shared state in order to update your UI or react to changes.
- **Dynamic Keys** ([Articles/DynamicKeys.md](Articles/DynamicKeys.md)): Learn how to dynamically change the key that powers your shared state.
- **Deriving shared state** ([Articles/DerivingSharedState.md](Articles/DerivingSharedState.md)): Learn how to derive shared state to sub-parts of a larger piece of shared state.
- **Reusable, type-safe keys** ([Articles/TypeSafeKeys.md](Articles/TypeSafeKeys.md)): Learn how to define keys for your shared state that allow you to reference your data in a statically
- **Initialization rules** ([Articles/InitializationRules.md](Articles/InitializationRules.md)): Learn the various ways to initialize shared state, both when using a persistence strategy and
- **Testing** ([Articles/Testing.md](Articles/Testing.md)): Learn how to test features that use shared state, even when persistence strategies are involved.
- **Gotchas of @Shared** ([Articles/Gotchas.md](Articles/Gotchas.md)): Learn about a few gotchas to be aware of when using shared state in your application.

### Persistence


### Custom persistence


### Migration guides

- **Migration guides** ([Articles/MigrationGuides.md](Articles/MigrationGuides.md)): Learn how to upgrade your application to the newest version of Sharing.

## Usage Notes

- Documentation is organized progressively from getting started to advanced topics
- Start with the Introduction or Getting Started section
- Consult specific guides for detailed information

## License & Attribution

This skill contains content converted from DocC documentation format.