This skill builds on db-core. Read it first for collection setup and query builder.

TanStack DB — Meta-Framework Integration

Setup

TanStack DB collections are client-side only. SSR is not implemented. Routes using TanStack DB must disable SSR. The setup pattern is:

1. Set ssr: false on the route
2. Preload the eager collection, or preload the live query for an on-demand source
3. Use useLiveQuery in the component

TanStack Start

Global SSR disable

// start.tsx
import { createStart } from '@tanstack/react-start'

export const startInstance = createStart(() => {
  return {
    defaultSsr: false,
  }
})

Per-route SSR disable + preload

import { createFileRoute } from '@tanstack/react-router'
import { useLiveQuery } from '@tanstack/react-db'

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => {
    await todoCollection.preload()
    return null
  },
  component: TodoPage,
})

function TodoPage() {
  const { data: todos } = useLiveQuery({
    query: (q) => q.from({ todo: todoCollection }),
  })
  return (
    <ul>
      {todos.map((t) => (
        <li key={t.id}>{t.text}</li>
      ))}
    </ul>
  )
}

On-demand Query Collection preload

Calling preload() on an on-demand source collection is a no-op. Define the live query once, preload it in the loader, and pass that same collection to the framework hook:

import { createLiveQueryCollection, eq } from '@tanstack/db'
import { useLiveQuery } from '@tanstack/react-db'

const activeTodos = createLiveQueryCollection((q) =>
  q
    .from({ todo: todoCollection })
    .where(({ todo }) => eq(todo.completed, false)),
)

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => {
    await activeTodos.preload()
    return null
  },
  component: () => {
    const { data } = useLiveQuery(activeTodos)
    // ...
  },
})

Multiple collection preloading

export const Route = createFileRoute('/electric')({
  ssr: false,
  loader: async () => {
    await Promise.all([todoCollection.preload(), configCollection.preload()])
    return null
  },
  component: ElectricPage,
})

Next.js (App Router)

Client component with preloading

// app/todos/page.tsx
'use client'

import { useEffect, useState } from 'react'
import { useLiveQuery } from '@tanstack/react-db'

export default function TodoPage() {
  const { data: todos, isLoading } = useLiveQuery({
    query: (q) => q.from({ todo: todoCollection }),
  })

  if (isLoading) return <div>Loading...</div>
  return (
    <ul>
      {todos.map((t) => (
        <li key={t.id}>{t.text}</li>
      ))}
    </ul>
  )
}

Next.js App Router components using TanStack DB must be client components ('use client'). There is no server-side preloading — collections sync on mount.

With route-level preloading (experimental)

// app/todos/page.tsx
'use client'

import { useEffect } from 'react'
import { useLiveQuery } from '@tanstack/react-db'

// Trigger preload immediately when module is loaded
const preloadPromise = todoCollection.preload()

export default function TodoPage() {
  const { data: todos } = useLiveQuery({
    query: (q) => q.from({ todo: todoCollection }),
  })
  return (
    <ul>
      {todos.map((t) => (
        <li key={t.id}>{t.text}</li>
      ))}
    </ul>
  )
}

Remix

Client loader pattern

// app/routes/todos.tsx
import { useLiveQuery } from '@tanstack/react-db'
import type { ClientLoaderFunctionArgs } from '@remix-run/react'

export const clientLoader = async ({ request }: ClientLoaderFunctionArgs) => {
  await todoCollection.preload()
  return null
}

// Prevent server loader from running
export const loader = () => null

export default function TodoPage() {
  const { data: todos } = useLiveQuery({
    query: (q) => q.from({ todo: todoCollection }),
  })
  return (
    <ul>
      {todos.map((t) => (
        <li key={t.id}>{t.text}</li>
      ))}
    </ul>
  )
}

Nuxt

Client-only component

<!-- pages/todos.vue -->
<script setup lang="ts">
import { useLiveQuery } from '@tanstack/vue-db'

const { data: todos, isLoading } = useLiveQuery((q) =>
  q.from({ todo: todoCollection }),
)
</script>

<template>
  <ClientOnly>
    <div v-if="isLoading">Loading...</div>
    <ul v-else>
      <li v-for="todo in todos" :key="todo.id">{{ todo.text }}</li>
    </ul>
  </ClientOnly>
</template>

Wrap TanStack DB components in <ClientOnly> to prevent SSR.

SvelteKit

Client-side only page

<!-- src/routes/todos/+page.svelte -->
<script lang="ts">
  import { browser } from '$app/environment'
  import { useLiveQuery } from '@tanstack/svelte-db'

  const todosQuery = browser
    ? useLiveQuery((q) => q.from({ todo: todoCollection }))
    : null
</script>

{#if todosQuery}
  {#each todosQuery.data as todo (todo.id)}
    <li>{todo.text}</li>
  {/each}
{/if}

Or disable SSR for the route:

// src/routes/todos/+page.ts
export const ssr = false

Core Patterns

What preload() does

For eager collections, collection.preload() starts the sync process and returns a promise that resolves when the collection reaches "ready" status. This means:

1. The sync function connects to the backend
2. Initial data is fetched and written to the collection
3. markReady() is called by the adapter
4. The promise resolves

Subsequent calls to preload() on an already-ready collection return immediately.

For on-demand collections, source collection.preload() warns and does nothing because no subset has been requested. Create the required live query and await liveQuery.preload().

Stable collection ownership

For one global QueryClient and one global server resource, define the collection in a shared module and import it in loaders and components:

// lib/collections.ts
import { createCollection, queryCollectionOptions } from '@tanstack/react-db'

export const todoCollection = createCollection(
  queryCollectionOptions({ ... })
)

// routes/todos.tsx — loader uses the same collection instance
import { todoCollection } from '../lib/collections'

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => {
    await todoCollection.preload()
    return null
  },
  component: () => {
    const { data } = useLiveQuery({
      query: (q) => q.from({ todo: todoCollection }),
    })
    // ...
  },
})

When the QueryClient, tenant, project, account, or route parameter defines the resource, create one stable collection per QueryClient and business scope. Memoize it and put it in router/request context rather than using a process-global collection. Remove unused entries and call collection.cleanup() in long-lived scope maps.

See the Query adapter runtime and business-scope pattern.

Server-Side Integration

This skill covers the client-side read path only (preloading, live queries). For server-side concerns:

• Electric proxy route (forwarding shape requests to Electric) — see the Electric adapter reference
• Mutation endpoints (createServerFn in TanStack Start, API routes in Next.js/Remix) — implement using your framework's server function pattern. See the Electric adapter reference for the txid handshake that mutations must return.

Common Mistakes

CRITICAL Enabling SSR with TanStack DB

Wrong:

export const Route = createFileRoute('/todos')({
  loader: async () => {
    await todoCollection.preload()
    return null
  },
})

Correct:

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => {
    await todoCollection.preload()
    return null
  },
})

TanStack DB collections are client-side only. Without ssr: false, the route loader runs on the server where collections cannot sync, causing hangs or errors.

Source: examples/react/todo/src/start.tsx

HIGH Forgetting to preload in route loader

Wrong:

export const Route = createFileRoute('/todos')({
  ssr: false,
  component: TodoPage,
})

Correct:

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => {
    await todoCollection.preload()
    return null
  },
  component: TodoPage,
})

Without preloading, the collection starts syncing when the component first renders, causing a loading flash. Preloading in the route loader starts sync during navigation, so the data is already there on that first render.

MEDIUM Creating separate collection instances in one scope

Wrong:

// routes/todos.tsx
const todoCollection = createCollection(queryCollectionOptions({ ... }))

export const Route = createFileRoute('/todos')({
  ssr: false,
  loader: async () => { await todoCollection.preload() },
  component: () => {
    const { data } = useLiveQuery({
      query: (q) => q.from({ todo: todoCollection }),
    })
  },
})

Correct:

// lib/collections.ts — shared for a global QueryClient and global resource
export const todoCollection = createCollection(queryCollectionOptions({ ... }))

Collections are stable within a QueryClient and business scope; they are not universal singletons. Creating several instances in one scope causes duplicate syncs and split state. A request-, router-, tenant-, or route-scoped client needs a scoped factory instead of the global module pattern.

See also: react-db/SKILL.md, vue-db/SKILL.md, svelte-db/SKILL.md, solid-db/SKILL.md, angular-db/SKILL.md — for framework-specific hook usage.

See also: db-core/collection-setup/SKILL.md — for collection creation and adapter selection.