# SvelteKit 3.0.0-next.19

- Product: SvelteKit (https://whatsnew.fyi/product/sveltekit)
- Vendor: Svelte
- Date: 2026-08-11
- Version: 3.0.0-next.19
- Original notes: https://github.com/sveltejs/kit/releases/tag/%40sveltejs/kit%403.0.0-next.19
- Permalink: https://whatsnew.fyi/product/sveltekit/releases/3.0.0-next.19
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **removed** — Move `defineParams` and associated types to `@sveltejs/kit/params`
- **changed** — Run all errors through the `handleError` hook
- **removed** — Move `Page`, `ReadonlyURL` and `ReadonlyURLSearchParams` from `@sveltejs/kit` to `$app/state`
- **removed** — Move `BeforeNavigate`, `OnNavigate`, `AfterNavigate`, `Navigation`, `NavigationTarget`, `NavigationType`, `GotoOptions` and the `Navigation*` variant types from `@sveltejs/kit` to `$app/navigation`
- **removed** — Move `ActionResult` and `SubmitFunction` from `@sveltejs/kit` to `$app/forms`
- **removed** — Remove `handleValidationError` and pass remote function validation errors to `handleError` with `kind: 'validation'`
- **added** — Ignore files with + prefix if they contain test/spec/stories
- **fixed** — Rebuild the dev manifest when route files disappear during an incremental update
- **fixed** — Externalize `@opentelemetry/api` to prevent bundler chunk colocation between `instrumentation.server.js` and application code
- **fixed** — Surface prerender errors during development
- **fixed** — Adjust error overload for optional `App.Error` parameters

###### Major Changes

- breaking: move `defineParams` and associated types to `@sveltejs/kit/params` ([#16716](https://github.com/sveltejs/kit/pull/16716))

- breaking: run all errors through the `handleError` hook ([#16664](https://github.com/sveltejs/kit/pull/16664))

- breaking: move `Page`, `ReadonlyURL` and `ReadonlyURLSearchParams` from `@sveltejs/kit` to `$app/state` ([#16694](https://github.com/sveltejs/kit/pull/16694))

- breaking: move `BeforeNavigate`, `OnNavigate`, `AfterNavigate`, `Navigation`, `NavigationTarget`, `NavigationType`, `GotoOptions` and the `Navigation*` variant types from `@sveltejs/kit` to `$app/navigation` ([#16694](https://github.com/sveltejs/kit/pull/16694))

- breaking: move `ActionResult` and `SubmitFunction` from `@sveltejs/kit` to `$app/forms` ([#16694](https://github.com/sveltejs/kit/pull/16694))

- breaking: remove `handleValidationError` and pass remote function validation errors to `handleError` with `kind: 'validation'` ([#16672](https://github.com/sveltejs/kit/pull/16672))

###### Minor Changes

- feat: ignore files with + prefix if they contain test/spec/stories ([#16715](https://github.com/sveltejs/kit/pull/16715))

###### Patch Changes

- fix: rebuild the dev manifest when route files disappear during an incremental update ([#16643](https://github.com/sveltejs/kit/pull/16643))

- fix: externalize `@opentelemetry/api` to prevent bundler chunk colocation between `instrumentation.server.js` and application code ([#16302](https://github.com/sveltejs/kit/pull/16302))

- fix: surface prerender errors during development ([#16507](https://github.com/sveltejs/kit/pull/16507))

- fix: adjust error overload for optional `App.Error` parameters ([#16725](https://github.com/sveltejs/kit/pull/16725))