dexie-reactive

Shared, SSR-safe Dexie live query state for Vue 3 and Nuxt 3.

dexie-reactive wraps Dexie liveQuery with small Vue composables. One component owns the real Dexie subscription as a producer. Other components can subscribe to the same reactive state by key without creating another Dexie subscription.

Live Demo

See how multiple Vue components share the same reactive Dexie liveQuery state without creating duplicate subscriptions.

The demo showcases:

• producer/consumer live query ownership
• shared reactive IndexedDB state
• Vue 3 composables
• automatic cross-component updates

👉 Open the interactive StackBlitz demo

Why dexie-reactive?

Use dexie-reactive when multiple Vue components need to react to the same Dexie query result without each component creating its own IndexedDB subscription.

It provides:

• one producer-owned Dexie liveQuery per key
• shared Vue reactive state for all consumers
• duplicate producer protection
• SSR-safe client-only subscription behavior
• same-origin tab-to-tab updates through Dexie live query propagation
• persistent IndexedDB-backed state for query results without keeping the whole database in memory
• stale result protection during restarts and component cleanup
• explicit loading and error state
• focused unit and browser integration test coverage

This keeps IndexedDB reactivity predictable in Vue and Nuxt apps while leaving Dexie query construction fully under application control.

Decision Guide

| Use this package when | Avoid it when | | ----------------------------------------------------------------------------- | ------------------------------------------------------------- | | multiple components share the same IndexedDB query result | each component owns completely independent queries | | you want explicit producer and consumer ownership | you want implicit global query caching | | you need Nuxt-safe client-only IndexedDB behavior | you need server-side IndexedDB execution | | you want Dexie queries to stay application-owned | you want a query builder or ORM abstraction | | duplicate shared subscription ownership should fail immediately | duplicate subscriptions are acceptable in your design | | you want IndexedDB-backed state that behaves like persistent shared app state | you need a general-purpose Pinia replacement for all UI state | | you need same-origin tab-to-tab updates from Dexie writes | you need cross-device or backend synchronization |

What It Does Not Do

• It does not replace Dexie.
• It does not replace Pinia for transient UI state.
• It does not build or parse queries.
• It does not sync data to a backend.
• It does not sync data across devices, users, or origins.
• It does not provide persistence beyond IndexedDB.
• It does not create server-side data fetching.
• It does not hide duplicate ownership mistakes.

When To Use It

Use this package when a Vue or Nuxt app needs IndexedDB data that updates reactively after Dexie writes.

• Use useLiveQuery in the component or composable that owns the query.
• Use useLiveQuerySubscription in components that only need to display the already shared state.
• Use an explicit key when multiple components should share one subscription.
• Omit the key for local, non-shared live queries.

Installation

npm install dexie-reactive dexie vue

dexie and vue are peer dependencies. Nuxt users can install the package in a Nuxt 3 project and import the composables directly from dexie-reactive.

Quick Start

Define your Dexie database once:

// db.ts
import Dexie, { type EntityTable } from 'dexie'

export interface Friend {
    id?: number
    name: string
    age: number
}

export interface AppDatabase extends Dexie {
    friends: EntityTable<Friend, 'id'>
}

export const db = new Dexie('app-db') as AppDatabase

db.version(1).stores({
    friends: '++id,name,age',
})

Create a producer composable:

// useOlderFriends.ts
import { useLiveQuery } from 'dexie-reactive'
import { db } from './db'

export function useOlderFriends() {
    return useLiveQuery(() => db.friends.where('age').above(75).toArray(), {
        key: 'older-friends',
    })
}

Use it in a producer component:

<script setup lang="ts">
import { useOlderFriends } from './useOlderFriends'

const { data, loading, hasError } = useOlderFriends()
</script>

<template>
    <p v-if="loading">Loading...</p>
    <p v-else-if="hasError">Could not load friends.</p>
    <ul v-else>
        <li v-for="friend in data" :key="friend.id">
            {{ friend.name }}
        </li>
    </ul>
</template>

Use the same state from a consumer component:

<script setup lang="ts">
import { useLiveQuerySubscription } from 'dexie-reactive'
import type { Friend } from './db'

const { data, loading, hasError } =
    useLiveQuerySubscription<Friend>('older-friends')
</script>

<template>
    <p v-if="loading">Loading...</p>
    <p v-else-if="hasError">Could not load friends.</p>
    <ul v-else>
        <li v-for="friend in data" :key="friend.id">
            {{ friend.name }}
        </li>
    </ul>
</template>

Core Model

useLiveQuery is the producer. It owns the real Dexie live query subscription.

useLiveQuerySubscription is the consumer. It attaches to shared state by key and never creates a Dexie subscription.

The consumer receives shared reactive state by key. It does not get a cloned snapshot and it does not create a second Dexie subscription.

Public API

The package exports only the stable composables and public types:

import {
    useLiveQuery,
    useLiveQuerySubscription,
    type LiveQueryState,
    type UseLiveQueryOptions,
} from 'dexie-reactive'

useLiveQuery(queryFn, options?)

Creates and owns a Dexie live query subscription.

function useLiveQuery<T>(
    queryFn?:
        | (() => T[] | Promise<T[]>)
        | Ref<(() => T[] | Promise<T[]>) | null | undefined>
        | null,
    options?: {
        key?: string
    },
): LiveQueryState<T>

• queryFn is a function that returns an array or a promise of an array.
• queryFn may be passed directly or as a reactive function reference.
• options.key is optional. If omitted, a UUID key is generated and returned.
• Only one producer may exist for a key.
• The live query is created only in the browser.

useLiveQuerySubscription(key)

Consumes existing shared state by key.

function useLiveQuerySubscription<T>(key: string): LiveQueryState<T>

• Receives only a key.
• Never receives a query function.
• Never creates a Dexie live query subscription.
• Returns the same reactive refs as the producer once the producer exists.

Returned State

Both composables return:

interface LiveQueryState<T> {
    key: string
    data: Ref<T[]>
    loading: Ref<boolean>
    hasError: Ref<boolean>
    error?: Ref<unknown | undefined>
    stop: () => void
    restart: () => void
}

error is available only in development mode. Production consumers should rely on hasError.

Generated Key Usage

If no key is provided, useLiveQuery generates a UUID key and returns it.

const friends = useLiveQuery(() => db.friends.toArray())

console.log(friends.key)

Generated keys are useful for local, non-shared subscriptions. Use an explicit key when another component needs to subscribe to the same state.

Error Handling

Errors are caught internally and do not throw to components.

const friends = useLiveQuery(() => db.friends.toArray(), {
    key: 'friends',
})

if (friends.hasError.value) {
    // Render fallback UI or trigger app-level reporting.
}

On failure:

• hasError.value becomes true
• loading.value becomes false
• data.value remains an array
• the original error is exposed only through error in development mode

Query Function Behavior

The package passes your function to Dexie liveQuery; it does not parse, build, transform, or interpret Dexie queries.

const query = () => db.friends.where('age').above(75).toArray()

const friends = useLiveQuery(query, { key: 'older-friends' })

Reactive values used inside the query function are not tracked by dexie-reactive. If external dependencies change, recreate the query function reference.

import { computed } from 'vue'

const minimumAge = ref(75)
const query = computed(
    () => () => db.friends.where('age').above(minimumAge.value).toArray(),
)

const friends = useLiveQuery(query, { key: 'filtered-friends' })

When the query function reference changes, the composable stops the current subscription, resets state to data = [], loading = true, hasError = false, and starts a new subscription.

SSR And Nuxt

The same package build works in plain Vue and Nuxt.

During SSR:

• no Dexie live query subscription is created
• shared state is scoped per runtime environment
• browser state is not shared with SSR
• SSR request state is isolated and cannot leak across requests

Use the composables in Nuxt components or composables, but expect live Dexie updates only on the client because IndexedDB is a browser API.

<script setup lang="ts">
import { useLiveQuery } from 'dexie-reactive'

const friends = useLiveQuery(() => db.friends.toArray(), {
    key: 'friends',
})
</script>

Lifecycle Controls

stop() unsubscribes from Dexie, sets loading to false, and keeps current data.

restart() performs a full reset and starts a new subscription using the latest query function.

For shared keys, these controls affect all consumers because they point to the producer-owned state.

Flow Diagrams

Producer Flow

flowchart TD
    A["useLiveQuery(queryFn, options)"] --> B["Resolve or generate key"]
    B --> C{"Key already exists?"}
    C -->|Yes| D["Throw duplicate producer error"]
    C -->|No| E["Create shared reactive state"]
    E --> F["Store state in subscription map"]
    F --> G["Emit registration message"]
    G --> H{"Browser runtime?"}
    H -->|No| I["Do not create Dexie subscription"]
    H -->|Yes| J["Start Dexie liveQuery"]
    J --> K["Apply latest result to shared refs"]

Consumer Flow

flowchart TD
    A["useLiveQuerySubscription(key)"] --> B{"Key exists in subscription map?"}
    B -->|Yes| C["Return existing shared reactive state"]
    B -->|No| D["Create waiting reactive state"]
    D --> E["Register waiting consumer by key"]
    E --> F["Return waiting state"]

Waiting Consumer Flow

flowchart TD
    A["Consumer subscribes before producer"] --> B["Waiting consumer is stored by key"]
    B --> C["Producer later registers same key"]
    C --> D["Registration message is emitted synchronously"]
    D --> E["Waiting consumer attaches to producer refs"]
    E --> F["Waiting entry is removed"]

Duplicate Producer Error Flow

flowchart TD
    A["First useLiveQuery registers key"] --> B["subscriptionMap has key"]
    B --> C["Second useLiveQuery uses same key"]
    C --> D["No second Dexie subscription is created"]
    D --> E["Error is thrown immediately"]

Limitations

• Dexie queries must return arrays.
• Consumers cannot create subscriptions.
• Keys are identifiers for shared state, not a security boundary.
• Live queries run only in the browser.
• The package uses vanilla Dexie liveQuery semantics through the composables.
• It does not use framework-specific Dexie bindings such as React hooks.

Anti-Patterns

Do not create duplicate producers for the same key:

useLiveQuery(() => db.friends.toArray(), { key: 'friends' })
useLiveQuery(() => db.friends.toArray(), { key: 'friends' }) // throws

Do not pass query functions to consumers:

useLiveQuerySubscription('friends') // correct
useLiveQuerySubscription(() => db.friends.toArray()) // incorrect

Do not rely on reactive values inside a stable query function reference:

const minimumAge = ref(75)

useLiveQuery(() => db.friends.where('age').above(minimumAge.value).toArray(), {
    key: 'friends',
})

Recreate the query function when dependencies change instead.

Demo And Browser Integration Test

The browser test app doubles as a small local demo:

npm run test:browser:server

Open the printed local URL and inspect IndexedDB under that same origin. The demo database is named dexie-reactive-browser and uses a friends object store.

Testing Strategy

The unit test suite focuses on the shared live query contract:

• public API exports and returned reactive state shape
• browser singleton and SSR-isolated subscription scopes
• producer lifecycle for start, stop, restart, unsubscribe, and cleanup
• duplicate producer rejection without creating a second Dexie subscription
• consumer coordination for producer-first and waiting-consumer flows
• shared reactive state references instead of cloned consumer state
• stale result protection across stop, restart, scope disposal, and rapid query changes
• missing, invalid, and changing query function handling
• error, loading, and development-only error exposure behavior
• generated UUID key uniqueness
• Dexie liveQuery usage through the provided query callback

The browser integration suite mounts a minimal Vue app in Chromium with a real Dexie IndexedDB database. It verifies producer and consumer components sharing one key, database updates propagating to all mounted components, consumer unmount/remount behavior, and duplicate producer errors in the browser runtime.

Scripts

• npm run lint checks the code with ESLint.
• npm run format:check verifies Prettier formatting.
• npm run typecheck runs TypeScript without emitting files.
• npm run test runs Vitest tests from tests/*.
• npm run test:browser runs Playwright browser integration tests.
• npm run build builds the package with unbuild.
• npm run check runs linting, formatting, type checking, tests, and build.

Git Hooks

Husky runs staged linting before commits and commitlint for commit messages.