Skip to main content

​
Reference

​
useStore

function useStore<TState, TSelected = NoInfer<TState>>(
  store: Atom<TState> | ReadonlyAtom<TState>,
  selector?: (state: NoInfer<TState>) => TSelected,
  options?: UseStoreOptions<TSelected>
): { readonly current: TSelected }
A Svelte 5 function that subscribes to a TanStack Store atom using runes and returns a reactive object with a current property. The value will update when the selected state changes according to the equality function.
​
store
Atom<TState> | ReadonlyAtom<TState>
The store atom to subscribe to.
​
selector
(state: TState) => TSelected
default:"(d) => d"
Optional function that selects a slice of state from the atom. Defaults to returning the entire state.
​
options
UseStoreOptions<TSelected>
Optional configuration object.

​
Returns

​
{ readonly current: TSelected }
{ readonly current: TSelected }
A reactive object with a readonly current property containing the selected state value.

​
Usage

​
Basic Usage

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const count = useStore(store, (state) => state.count)
</script>

<div>Count: {count.current}</div>

​
Selecting Multiple Values

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const user = useStore(store, (state) => ({
  name: state.user.name,
  email: state.user.email,
  avatar: state.user.avatar
}))
</script>

<div>
  <h2>{user.current.name}</h2>
  <p>{user.current.email}</p>
  <img src={user.current.avatar} alt="Avatar" />
</div>

​
Custom Equality Function

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

// Custom deep equality
const deepEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b)

const settings = useStore(
  store,
  (state) => state.settings,
  { equal: deepEqual }
)
</script>

<div>{JSON.stringify(settings.current)}</div>

​
Using Entire State

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const state = useStore(store)
</script>

<div>
  <p>Count: {state.current.count}</p>
  <p>Name: {state.current.name}</p>
  <p>Active: {state.current.isActive}</p>
</div>

​
With Conditional Rendering

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const isLoggedIn = useStore(store, (state) => state.isLoggedIn)
const user = useStore(store, (state) => state.user)
</script>

{#if isLoggedIn.current}
  <div>Welcome, {user.current.name}!</div>
{:else}
  <div>Please log in</div>
{/if}

​
With Each Blocks

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const todos = useStore(store, (state) => state.todos)
</script>

<ul>
  {#each todos.current as todo (todo.id)}
    <li>{todo.text}</li>
  {/each}
</ul>

​
Derived Values

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const todos = useStore(store, (state) => state.todos)

// Use $derived rune for computed values
const stats = $derived({
  total: todos.current.length,
  completed: todos.current.filter(t => t.done).length,
  pending: todos.current.filter(t => !t.done).length
})
</script>

<div>
  <p>Total: {stats.total}</p>
  <p>Completed: {stats.completed}</p>
  <p>Pending: {stats.pending}</p>
</div>

​
Selecting Array Slices

<script>
import { useStore } from '@tanstack/svelte-store'
import { store } from './store'

const activeItems = useStore(
  store,
  (state) => state.items.filter(item => item.active)
)
</script>

<div>
  <p>Active items: {activeItems.current.length}</p>
  <ul>
    {#each activeItems.current as item (item.id)}
      <li>{item.name}</li>
    {/each}
  </ul>
</div>

​
Notes

  • Built for Svelte 5 using the new runes system ($state, $effect)
  • Returns an object with a readonly current property
  • Uses $state rune internally for reactivity
  • Automatically cleans up subscriptions using $effect cleanup
  • Defaults to shallow equality comparison
  • Access the value via .current property
  • Compatible with Svelte’s reactive declarations and derived values
  • Works seamlessly with {#if}, {#each}, and other Svelte control flow