How to stop Cursor from overengineering solutions

1---
2description: State management decision guide
3globs: "src/**/*.tsx,src/**/*.ts"
4alwaysApply: true
5---
6
7## State Management Decision Tree
8| State Type | Solution | Example |
9|-----------|---------|--------|
10| Form input, toggle, local UI | useState | Modal open/close, input value |
11| Shared UI state (2-3 components) | useState + prop drilling | Active tab shared by siblings |
12| Theme, locale, auth | React Context | ThemeProvider, AuthProvider |
13| Server data (read-heavy) | SWR or React Query | User list, product catalog |
14| Complex client state (10+ actions) | Zustand | Shopping cart, editor state |
15| Enterprise (middleware, devtools) | Redux Toolkit | Large team, complex workflows |
16
17## Rules
18- NEVER use Redux for state shared by fewer than 5 components
19- NEVER use Redux for server-cached data (use SWR/React Query)
20- NEVER use Redux for form state (use react-hook-form or useState)
21- Default to the SIMPLEST solution that works
22- If unsure, ask the user which approach they prefer

1// Instead of: "Add state management for this modal"
2// Say:
3
4// Cursor Chat prompt (Cmd+L):
5// Add an open/close toggle for this modal using useState.
6// Do NOT use Redux, Context, or any state library.
7// The state only needs to live in this component.
8
9// Cursor generates:
10const [isOpen, setIsOpen] = useState(false);
11const openModal = () => setIsOpen(true);
12const closeModal = () => setIsOpen(false);

1// If Cursor suggests Redux for fetching users:
2// "Create a Redux slice for user data with fetchUsers thunk"
3
4// Redirect with:
5// Do NOT use Redux for this. User data is server state.
6// Use SWR to fetch from /api/users with automatic caching
7// and revalidation. Create a useUsers() hook in src/hooks/.
8
9import useSWR from 'swr';
10import { fetcher } from '@/lib/fetcher';
11
12export function useUsers() {
13  const { data, error, isLoading } = useSWR('/api/users', fetcher);
14  return { users: data ?? [], isLoading, isError: !!error };
15}

1// Cursor Chat prompt (Cmd+L):
2// Create a shopping cart store using Zustand (NOT Redux).
3// State: items array, total, item count.
4// Actions: addItem, removeItem, clearCart, updateQuantity.
5// Use Zustand's create() function.
6
7import { create } from 'zustand';
8
9interface CartStore {
10  items: CartItem[];
11  addItem: (item: CartItem) => void;
12  removeItem: (id: string) => void;
13  clearCart: () => void;
14  total: () => number;
15}
16
17export const useCartStore = create<CartStore>((set, get) => ({
18  items: [],
19  addItem: (item) => set((s) => ({ items: [...s.items, item] })),
20  removeItem: (id) => set((s) => ({ items: s.items.filter((i) => i.id !== id) })),
21  clearCart: () => set({ items: [] }),
22  total: () => get().items.reduce((sum, i) => sum + i.price * i.qty, 0),
23}));

1// Signs you actually need Redux:
2// 1. More than 10 state slices with cross-slice dependencies
3// 2. Complex middleware (logging, analytics, optimistic updates)
4// 3. Large team needing enforced patterns and devtools
5// 4. Need time-travel debugging for complex workflows
6// 5. Existing Redux codebase that works well
7//
8// If none of these apply, use a simpler solution.