What are best practices for structuring RTK Query API slices in large apps?

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As applications scale, organizing RTK Query API slices effectively becomes crucial for maintainability, performance, and team collaboration. Following a modular and consistent structure helps ensure that each feature remains isolated yet reusable. **1. Use Feature-Based Slices:** Create separate API slices for distinct features or domains (e.g., `userApi`, `postsApi`, `productsApi`). This keeps concerns isolated and makes maintenance easier. **2. Define Shared Base Queries:** Use a shared `baseQuery` for common configuration like base URLs, headers, or authentication logic, and extend it across feature APIs. **3. Use `injectEndpoints` for Modularity:** Start with a root API and dynamically inject endpoints in different modules to prevent circular dependencies and allow lazy loading. **4. Keep Tag Types Organized:** Define meaningful and unique `tagTypes` to manage cache invalidation clearly between slices. **5. Co-locate API Logic with Features:** Place each API slice in the same directory as its feature’s components, Redux slice, or hooks for better discoverability. **6. Export Only Hooks and Utilities:** Re-export generated hooks (like `useGetPostsQuery`) and keep internal configuration private to maintain clean module boundaries. **7. Use TypeScript for Safety:** Leverage RTK Query’s strong typing for request and response data to ensure reliable refactoring and fewer runtime errors. import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react';

// Root API
export const api = createApi({
  reducerPath: 'api',
  baseQuery: fetchBaseQuery({ baseUrl: '/api' }),
  tagTypes: ['User', 'Post'],
  endpoints: () => ({}),
});

// postsApi.js
export const postsApi = api.injectEndpoints({
  endpoints: (build) => ({
    getPosts: build.query({
      query: () => '/posts',
      providesTags: ['Post'],
    }),
  }),
});

export const { useGetPostsQuery } = postsApi; In this example, the `api` slice serves as a root configuration, while the `postsApi` slice injects feature-specific endpoints. This modular approach simplifies code splitting and scaling. **- Scalability:** Easily add new features without refactoring existing logic. **- Maintainability:** Clear separation of concerns improves readability and debugging. **- Reusability:** Shared `baseQuery` and consistent tagging simplify endpoint reuse. **- Performance:** Smaller, modular slices allow selective loading and cache management. By organizing your RTK Query API slices around features, reusing a shared base configuration, and leveraging `injectEndpoints`, large-scale apps remain efficient, modular, and easy to evolve.

What are best practices for structuring RTK Query API slices in large apps?

What are best practices for structuring RTK Query API slices in large apps?

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