Working with APIs in React Native: fetch, loading, errors, and cache

Why the API layer breaks UX first

Users never see your fetch call directly, but they immediately notice an empty screen, a flashing loader, an endless retry loop, or an unclear error. That is why the API layer in a mobile product should be designed as part of the UI.

What the first reliable layer should include

Even in a simple app, define these early:

• one consistent API client;
• explicit loading, error, and empty states;
• clear retry actions;
• normalized responses and errors.

When React Query becomes useful

React Query gives you cache, refetching, invalidation, and calmer data flow. Its value becomes much higher once the basics are already stable: endpoint naming, status handling, and predictable response shape.

What to check on every screen

Before shipping a screen, ask:

• what the user sees before the server responds;
• what happens on a slow connection;
• what the empty state looks like;
• what the recovery path is after an error;
• how data refreshes after user actions.

If those answers already exist in the UI, the API layer is supporting the product instead of fighting it.