Riverpod — Providers

Instructions

Providers are the central feature of Riverpod: memoized functions that cache their result and let multiple widgets (or other providers) access the same value. They are declared as top-level final variables. State lives in a ProviderContainer (or ProviderScope in Flutter), not in the provider itself.

Provider variants

• Sync vs Future vs Stream: Match the return type of your function (int, Future<T>, Stream<T>).
• Unmodifiable: Widgets only read the value. Use for computed or fetched data.
• Modifiable: Expose a Notifier with a build() method and custom methods; widgets call ref.read(provider.notifier).someMethod(). Use when the UI must update state.

Pick the type based on what you want to return; the provider type follows naturally. FutureProvider / AsyncNotifierProvider are the most common.