---

name: manage-reatom-stores description: Create or update Reatom stores in this repo. Use when adding a new store under src/stores, changing store state shape, adding computed atoms, or creating/updating related store service functions.

Manage Reatom Stores

Follow these steps to create or update stores using the existing appSession patterns.

1) Define or update state types

Create or update the state interface in src/api/* when the store shape is shared or reused.

Example:

Copyexport interface Movie {
  id: string
  title: string
  year: number
  tags?: string[]
}

2) Create or update the store atom

Add a new file in src/stores/* or update the existing atom.

Example:

Copyimport { atom, computed } from '@reatom/core'
import { Movie } from '../api/movie'

export const moviesAtom = atom<Movie[]>([])

export const movieCountAtom = computed(() => moviesAtom().length)

Keep initial state explicit, and prefer small, focused atoms.

3) Add or update service functions (if needed)

If store updates involve side effects or async logic, place functions in src/stores/*.service.ts and mutate state via *.set.

Example:

Copyimport { moviesAtom } from './movies'

export function addMovie(movie: Movie): void {
  moviesAtom.set((movies) => [...movies, movie])
}

4) Update usages

Search for all usages and update them to match the new store shape.

Use:

• rg -n "moviesAtom|movieCountAtom|addMovie" src

5) Keep types strict and clean

Ensure no unused imports or params remain, and that strict TypeScript checks pass.