name: flutter-add-endpoint description: Adds a single new API action to an existing Flutter feature, wiring the full clean architecture stack: params class, datasource method, repository interface update, repository implementation update, new use case, and a new cubit. Use when the user says "add endpoint", or asks to add a new API call to an existing feature without rebuilding the whole feature from scratch.

Flutter Add Endpoint

Adds one new API action to an existing feature. Work through each step in order.

Step 1 — Params (if any input is required)

File: lib/features/{feature}/domain/usecases/params/{Feature}{Action}Params.dart

class {Feature}{Action}Params {
  final String? fieldName;
  const {Feature}{Action}Params({this.fieldName});

  Map<String, dynamic> toJson() => {"field_name": fieldName};

  {Feature}{Action}Params copyWith({String? fieldName}) =>
      {Feature}{Action}Params(
        fieldName: fieldName ?? this.fieldName,
      );
}

Skip this step if the endpoint takes no input.

Step 2 — Datasource Method

File: lib/features/{feature}/data/datasources/{feature}_remote_datasource.dart

• Add the method to the abstract class and its implementation.
• Use the endpoint constant from lib/core/utils/constants.dart. Add it there if missing.
• Return the typed model — never dynamic.

// Abstract
Future<{Name}RespModel> {action}{Name}({Feature}{Action}Params params);

// Implementation
@override
Future<{Name}RespModel> {action}{Name}({Feature}{Action}Params params) async {
  final response = await _dio.post(
    ApiConstants.{endpointConstant},
    data: params.toJson(),
  );
  return {Name}RespModel.fromJson(response.data);
}

Step 3 — Repository Interface

File: lib/features/{feature}/domain/repository/{feature}_repository.dart

Add the abstract method:

Future<Either<Failure, {Name}Entity>> {action}{Name}(
  {Feature}{Action}Params params,
);

Step 4 — Repository Implementation

File: lib/features/{feature}/data/repository/{feature}_repository_impl.dart

@override
Future<Either<Failure, {Name}Entity>> {action}{Name}(
  {Feature}{Action}Params params,
) async {
  try {
    final result = await remoteDataSource.{action}{Name}(params);
    return Right(result.data!);
  } on ServerException catch (e) {
    return Left(ServerFailure(e.message));
  }
}

Step 5 — Use Case

File: lib/features/{feature}/domain/usecases/{action}_{feature}.dart

class {Action}{Feature} {
  final {Feature}Repository repository;
  {Action}{Feature}(this.repository);

  Future<Either<Failure, {Name}Entity>> call(
    {Feature}{Action}Params params,
  ) => repository.{action}{Name}(params);
}

Step 6 — Cubit + State

State: lib/features/{feature}/presentation/cubit/{action}_{feature}_state.dart Cubit: lib/features/{feature}/presentation/cubit/{action}_{feature}_cubit.dart

• States: initial, loading, success({Name}Entity), failure(String).
• Cubit exposes one method only.

Step 7 — Dependency Injection

In lib/features/{feature}/{feature}_injection.dart, register:

ServiceLocator.instance
  ..registerLazySingleton(() => {Action}{Feature}(ServiceLocator.instance()))
  ..registerFactory(() => {Action}{Feature}Cubit(ServiceLocator.instance()));