Riverpod Family

Riverpod — Family

Instructions

Family lets a single provider have multiple independent states, one per parameter combination (like a Map from parameter to state). Use it for API calls that depend on an ID, query, or page number.

Creating a family (functional)

Add .family and an extra type parameter for the argument. The provider function receives (ref, param):

final userProvider = FutureProvider.autoDispose.family((ref, id) async {
  final dio = Dio();
  final response = await dio.get('https://api.example.com/users/$id');
  return User.fromJson(response.data);
});

With code generation, add parameters to the function; the generated provider accepts arguments: userProvider(id).

Creating a family (Notifier)

Use NotifierProvider.family / AsyncNotifierProvider.family (and .autoDispose.family). The Notifier must have a constructor that stores the parameter:

final userProvider = AsyncNotifierProvider.autoDispose.family(
  UserNotifier.new,
);

class UserNotifier extends AsyncNotifier {
  UserNotifier(this.id);
  final String id;

  @override
  Future build() async {
    final dio = Dio();
    final response = await dio.get('https://api.example.com/users/$id');
    return User.fromJson(response.data);
  }
}

Using a family

Pass the parameter when watching or reading:

final user = ref.watch(userProvider('123'));
final other = ref.watch(userProvider('456'));  // independent state

Parameters must have consistent == and hashCode. Do not use mutable or list/map literals as parameters (e.g. ref.watch(myProvider([1,2,3])) is wrong because [1,2,3] != [1,2,3]). Prefer primitives or custom classes with ==/hashCode. Enable riverpodlint providerparameters rule to catch mistakes.

Auto-dispose with family

Enable auto-dispose when using family so that when the parameter goes out of use (e.g. user navigates away), that parameter's state can be disposed and you avoid unbounded cache growth.

Overriding in tests

• Override a single parameter: pass the same parameter to the override.
• Override all parameters: override with a provider that ignores the parameter or returns a fixed value. See riverpod-overrides and the docs for exact syntax.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: serverpod
• Source: serverpod/skills-registry
• License: BSD-3-Clause

Install and usage instructions live in the source repository linked above.