# What changed in @storybook/addon-svelte-csf

> 34 changes in @storybook/addon-svelte-csf 5 from its official release notes, upgrade guides and advisories: 7 breaking, 2 new APIs and options. Each one cited. Sources checked 2026-11-13. HTML: https://unstale.sh/npm/@storybook/addon-svelte-csf/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## @storybook/addon-svelte-csf 5

### Breaking changes

- Static stories now require asChild. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The children prop is renamed to template. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- meta can no longer be destructured from a defineMeta() call. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- defineMeta now supports render, replacing the setTemplate function. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The save from UI feature is temporarily disabled. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The addon requires Storybook 8.2.0 or later and supports Storybook 9 prereleases. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The addon now requires Svelte 5. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)

### New APIs and options

- The legacy API flag lets teams migrate stories gradually to the new syntax. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- Stories can use the new snippet-based Svelte CSF syntax. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)

### Performance

- Loads the Svelte config once in the story indexer instead of once per stories file. (5.1.4) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.4)
- The bundle size is smaller. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)

### Behavior and default changes

- All Svelte CSF stories receive the svelte-csf tag. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)

### Tooling

- Peer dependency ranges now include Storybook 11.0 canaries. (5.1.3) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.3)
- The peer dependency range now includes Storybook 10.5 and 10.6 prereleases. (5.1.3) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.3)
- npm releases now include provenance, giving developers release provenance information when evaluating the package. (5.1.2) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.2)
- Adds support for Vite 8. (5.1.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.0)
- The addon supports @sveltejs/vite-plugin-svelte v5. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- Stories and meta definitions are type-safe. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The addon supports Vite 6. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)

### Fixes and other changes

- Fixes code snippet generation crashing when a story references a null arg directly. (5.1.6) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.6)
- Fixes an error with Vite 7 and older when defineMeta or a story gets an empty object or array. (5.1.5) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.5)
- Fixes the last character of a legacy stories file being added to the story again. (5.1.5) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.5)
- Fixes a compile error in the legacy Template and Story components when runes is true. (5.1.4) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.4)
- Preserves the primary component's story args type when defineMeta includes subcomponents. (5.1.4) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.4)
- Generated code snippets now keep the newlines between elements. (5.1.4) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.4)
- Fixes duplicated children, unnecessary {"..."} wrappers, and the <undefined> wrapper in generated code snippets. (5.1.4) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.1.4)
- Peer dependencies for Storybook were updated, affecting which Storybook versions are declared compatible with the addon. (5.0.11) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.11)
- Story children now override args.children as expected. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The addon now works with getAbsolutePath. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- Invalid identifiers are now transformed properly. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The legacy API template hook now runs before Svelte in Vitest. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- Badly formatted ESM that broke on Node 22 and 23 is fixed. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- The parameters attribute on legacy <Story> is no longer removed. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)
- Story-level tags now take effect in the Vitest integration. (5.0.0) — [release notes](https://github.com/storybookjs/addon-svelte-csf/releases/tag/v5.0.0)