Migrating from RTK Query

Quantum Query is designed to be simpler and lighter than RTK Query. Here is how concepts map.

Core Concepts

RTK Query	Quantum Query
createApi	Not needed. Just use queryCache or hooks directly.
endpoints	Just async functions.
useGetXQuery	useQuery({ queryKey: ['x'], queryFn: ... })
tagTypes / providesTags	queryKey (arrays)
invalidatesTags	queryCache.invalidate(['key'])

Example Refactor

RTK Query:

const api = createApi({
    baseQuery: fetchBaseQuery({ baseUrl: '/api' }),
    endpoints: (builder) => ({
        getTodo: builder.query({
            query: (id) => `todo/${id}`,
        }),
    }),
});

Quantum Query:

// Define a fetcher
const fetchTodo = (id) => fetch(`/api/todo/${id}`).then(r => r.json());

// Use it
const { data } = useQuery({
    queryKey: ['todo', id],
    queryFn: () => fetchTodo(id)
});

Why Switch?

• Bundle Size: Save ~50KB (No Redux required).
• Flexibility: Use any fetcher (fetch, axios, ky).
• Simplicity: No boilerplate "slice" setup.