1---
2category: '@Firebase'
3---
4 
5# useRTDB
6 
7Reactive [Firebase Realtime Database](https://firebase.google.com/docs/database) binding. Making it straightforward to **always keep your local data in sync** with remotes databases.
8 
9## Usage
10 
11```ts
12import { useRTDB } from '@vueuse/firebase/useRTDB'
13import { initializeApp } from 'firebase/app'
14import { getDatabase } from 'firebase/database'
15 
16const app = initializeApp({ /* config */ })
17const db = getDatabase(app)
18 
19// in setup()
20const todos = useRTDB(db.ref('todos'))
21```
22 
23## Options
24 
25| Option         | Type                   | Default         | Description                                               |
26| -------------- | ---------------------- | --------------- | --------------------------------------------------------- |
27| `autoDispose`  | `boolean`              | `true`          | Automatically unsubscribe when the component is unmounted |
28| `errorHandler` | `(err: Error) => void` | `console.error` | Custom error handler for database errors                  |
29 
30## Return Value
31 
32Returns a `Ref<T | undefined>` that is automatically updated when the database value changes.
33 
34## Reusing Database References
35 
36You can reuse the db reference by passing `autoDispose: false`
37 
38```ts
39const todos = useRTDB(db.ref('todos'), { autoDispose: false })
40```
41 
42or use `createGlobalState` from the core package
43 
44```ts twoslash include store
45// @filename: store.ts
46// ---cut---
47// store.ts
48import { createGlobalState } from '@vueuse/core'
49import { useRTDB } from '@vueuse/firebase/useRTDB'
50 
51export const useTodos = createGlobalState(
52  () => useRTDB(db.ref('todos')),
53)
54```
55 
56```vue
57<!-- app.vue -->
58<script setup lang="ts">
59// @include: store
60// ---cut---
61import { useTodos } from './store'
62 
63const todos = useTodos()
64</script>
65```
66 
67## Type Declarations
68 
69```ts
70export interface UseRTDBOptions {
71  errorHandler?: (err: Error) => void
72  autoDispose?: boolean
73}
74/**
75 * Reactive Firebase Realtime Database binding.
76 *
77 * @see https://vueuse.org/useRTDB
78 */
79export declare function useRTDB<T = any>(
80  docRef: DatabaseReference,
81  options?: UseRTDBOptions,
82): Ref<T | undefined, T | undefined>
83```
84