1. Treat server state as a separate responsibility
A common mobile architecture problem is storing API data in many local states across screens. That makes refresh, error handling and updates inconsistent. TanStack Query gives the app a shared model for server state.
The first decision is what belongs to the server cache and what is truly local UI state.
- Use query keys that describe resource, filters and identity.
- Keep temporary UI state outside server cache.
- Centralize API clients and response typing.
- Avoid duplicate fetch logic in screens.
- Make empty, loading, error and success states explicit.
2. Cache keys and invalidation are architecture decisions
A cache is only useful when the team knows when data becomes stale. Query keys, stale time and invalidation rules should reflect product behavior, not random defaults.
For example, account data, dashboard totals and editable records may need different refresh strategies.
- Create query key helpers for important resources.
- Use stale time based on how often the data changes.
- Invalidate specific queries after mutations instead of clearing everything.
- Document which screens depend on the same cached data.
- Be careful with cached data after logout or account switching.
3. Mutations need user feedback and recovery paths
Creating, editing or deleting data is not only an API call. The app must show progress, handle validation errors, update the right cache and recover when the request fails.
Optimistic updates can make the app feel faster, but they require rollback behavior and clear user feedback.
- Show submit progress without freezing unrelated screens.
- Map backend validation errors to the related fields when possible.
- Invalidate or update cached records after a successful mutation.
- Use optimistic updates only when rollback is safe.
- Keep destructive actions explicit and reversible when possible.
4. Mobile apps need network, focus and background rules
React Native apps move between foreground, background, unstable networks and offline moments. TanStack Query can support these states, but the team still needs to decide what should refetch and what should wait.
Good API state management reduces surprise: the user knows whether data is fresh, syncing, saved locally or waiting for network recovery.
- Tune refetch behavior when the app regains focus.
- Represent offline states clearly in the UI.
- Avoid infinite retry loops on predictable validation errors.
- Coordinate query behavior with offline queues when they exist.
- Track API failures that affect important business flows.
How to use this article
Treat this page as a decision aid. Use it with the related hub, checklist or service route when the topic affects production, customer experience, deployment, security or business continuity.