Svelte 5 Runes: First Impressions

Overview

Svelte 5 swaps the implicit reactivity model for explicit runes. The change feels invasive at first, but a few hours into a migration the new APIs read more like the rest of the language and less like compiler magic.

Highlights

• $state() and $derived() make reactive boundaries explicit without ceremony
• $props() plays nicely with TypeScript, finally
• Module-level rune state is a clean replacement for ad-hoc stores