Convex with TanStack Start

Loaders and Prefetching

TanStack Start routes can have isomorphic loader functions that run on the server for the initial pageload and on the client for subsequent client-side navigations.

These three links navigate to subpages that show chat messages from different channels. Notice how client navigations between these pages work differently.

Awaiting ensureQueryData will block rendering of the page until that data is available and calling prefetchQuery will start the request but not block. Loaders also run during prefetching, triggered by the cursor mousing onto a link in TanStack Start by default.

When to use a loader

Loading a query in a loader ejects from the convenience of component-local reasoning through useSuspenseQuery where a component fetching its own data to the cold reality of fast page loads when you need it.

2
User 27062/4/26, 3:29 PM

Hi Emma! how was your weekend?

2
User 27062/4/26, 3:29 PM

hello Jamie- I'll be late to make the meeting tomorrow morning

2
User 27062/4/26, 3:29 PM

Hi Jamie; how's the weather in SF?

2
User 23571/27/26, 9:42 PM

hi Nipunn, what's your favorite ice cream place?

2
User 23571/27/26, 9:42 PM

Hi Jamie! Could you let the customer know we've fixed their issue?

9
User 90101/15/26, 5:01 PM

hello Jamie... how's the weather in SF?

9
User 90101/15/26, 5:01 PM

hey Emma; how was your weekend?

8
User 80801/15/26, 2:06 AM

hi Jamie, Could you let the customer know we've fixed their issue?

5
User 57381/15/26, 2:04 AM

hi James- how's the weather in SF?

5
User 59071/13/26, 3:52 PM

hello James; what's your favorite ice cream place?

5
User 59071/13/26, 3:51 PM

hi James... what's your favorite ice cream place?

2
User 23941/10/26, 11:09 PM

hi Nipunn... how was your weekend?

2
User 23941/10/26, 11:09 PM

hi Emma- how was your weekend?

4
User 44281/10/26, 3:41 AM

hi Emma... I'll be late to make the meeting tomorrow morning

4
User 44281/10/26, 3:41 AM

hi Jamie... what's your favorite ice cream place?

4
User 44281/10/26, 3:41 AM

Hi James; what's your favorite ice cream place?

4
User 44281/10/26, 3:41 AM

Hi James... Could you let the customer know we've fixed their issue?

4
User 44281/10/26, 3:41 AM

hey Nipunn, how's the weather in SF?

4
User 44281/10/26, 3:41 AM

hello Jamie- Could you let the customer know we've fixed their issue?

4
User 44281/10/26, 3:41 AM

Hi Emma- how's the weather in SF?

1export const Route = createFileRoute('/loaders/ensure')({
2  loader: async (opts) => {
3    await opts.context.queryClient.ensureQueryData(
4      convexQuery(api.messages.list, {}),
5    );
6  },
7  component: () => {
8    const { data } = useQuery(
9      convexQuery(api.messages.list, {})
10    );
11  },
12})

Learn More

Tanner's An Early Glimpse of TanStack Start video

TanStack Router Preloading Guide