Svelte 4 support

svelte-adapter-uws supports both Svelte 4 and Svelte 5. All examples in the docs use Svelte 5 syntax ($props(), runes). If you’re on Svelte 4, here’s how to translate.

Side by side

Svelte 5

<script>
  import { crud } from 'svelte-adapter-uws/client';

  let { data } = $props();
  const todos = crud('todos', data.todos);
</script>

Svelte 4

<script>
  import { crud } from 'svelte-adapter-uws/client';

  export let data;
  const todos = crud('todos', data.todos);
</script>

The only difference is how you receive props: let { data } = $props() in Svelte 5 → export let data in Svelte 4.

Client store API - identical in both versions

The entire client store API uses svelte/store under the hood, which hasn’t changed between Svelte 4 and Svelte 5. Every function works identically in both versions:

• on - subscribe to a topic
• crud - managed CRUD list
• lookup - key-value lookup map
• latest - latest message on a topic
• count - reactive counter
• once - single-fire listener
• status - connection status store
• connect - configure the WebSocket connection

You import them the same way, call them the same way, and subscribe with $store the same way. The only thing that changes is how your component receives its page data from SvelteKit.