Svelte

October brought the stable release of SvelteKit 3, with TypeScript 6 and Node 22 as new minimums and a full adapter refresh.

Adapters move to Rolldown for edge builds. The Vercel and Netlify adapters (v7) now use Rolldown — bundled in Vite 8 — for edge function packaging, targeting es2022. The adapter-node adapter (v6) makes the same migration and replaces the ORIGIN environment variable with a kit.paths.origin config option. Adapter-static v4 completes the suite, requiring SvelteKit 3.

Remote function types have a new home. Remote function types move to $app/server. The experimental.handleRenderingErrors flag is removed, and getRequest/setResponse are now synchronous. Clicking a link to the current URL refreshes all load functions and queries.

Migration to SvelteKit 3 is mostly automated. Running npx sv migrate sveltekit-3 --tasks all --confirm handles most of the upgrade path. The sv CLI itself hit 1.0 on the same day, making the community add-on API official. The @sveltejs/package tooling gained import-alias rewriting and a warning when .server. files are used without importing a server-only module.

The Netlify adapter conforms to the stable Frameworks API. Netlify CLI v17.31.0 or later is required for deploys and previews. Static files are now written based on the publish adapter option, not the netlify.toml file.

Reactive tracking is more precise in the compiler. Svelte 5.57.2 corrects cases where async deriveds would persist after a component is destroyed mid-await, prevents disconnected dependencies from lingering in untracked reads, and fixes event handlers assigned after a top-level await in production.