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npm / @storybook/addon-svelte-csf

@storybook/addon-svelte-csf

What changed in @storybook/addon-svelte-csf 5, from its official release notes, upgrade guides and advisories. Sources checked 2026-11-13.

7 breaking2 new APIs and options2 performance1 behavior and defaults7 tooling15 fixes and other

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@storybook/addon-svelte-csf 534 changes

Breaking changes 7

  • Static stories now require asChild.

    5.0.0release notes

  • The children prop is renamed to template.

    5.0.0release notes

  • meta can no longer be destructured from a defineMeta() call.

    5.0.0release notes

  • defineMeta now supports render, replacing the setTemplate function.

    5.0.0release notes

  • The save from UI feature is temporarily disabled.

    5.0.0release notes

  • The addon requires Storybook 8.2.0 or later and supports Storybook 9 prereleases.

    5.0.0release notes

  • The addon now requires Svelte 5.

    5.0.0release notes

New APIs and options 2

  • The legacy API flag lets teams migrate stories gradually to the new syntax.

    5.0.0release notes

  • Stories can use the new snippet-based Svelte CSF syntax.

    5.0.0release notes

Performance 2

  • Loads the Svelte config once in the story indexer instead of once per stories file.

    5.1.4release notes

  • The bundle size is smaller.

    5.0.0release notes

Behavior and default changes 1

  • All Svelte CSF stories receive the svelte-csf tag.

    5.0.0release notes

Tooling 7

  • Peer dependency ranges now include Storybook 11.0 canaries.

    5.1.3release notes

  • The peer dependency range now includes Storybook 10.5 and 10.6 prereleases.

    5.1.3release notes

  • npm releases now include provenance, giving developers release provenance information when evaluating the package.

    5.1.2release notes

  • Adds support for Vite 8.

    5.1.0release notes

  • The addon supports @sveltejs/vite-plugin-svelte v5.

    5.0.0release notes

  • Stories and meta definitions are type-safe.

    5.0.0release notes

  • The addon supports Vite 6.

    5.0.0release notes

Fixes and other changes 15

  • Fixes code snippet generation crashing when a story references a null arg directly.

    5.1.6release notes

  • Fixes an error with Vite 7 and older when defineMeta or a story gets an empty object or array.

    5.1.5release notes

  • Fixes the last character of a legacy stories file being added to the story again.

    5.1.5release notes

  • Fixes a compile error in the legacy Template and Story components when runes is true.

    5.1.4release notes

  • Preserves the primary component's story args type when defineMeta includes subcomponents.

    5.1.4release notes

  • Generated code snippets now keep the newlines between elements.

    5.1.4release notes

  • Fixes duplicated children, unnecessary {"..."} wrappers, and the <undefined> wrapper in generated code snippets.

    5.1.4release notes

  • Peer dependencies for Storybook were updated, affecting which Storybook versions are declared compatible with the addon.

    5.0.11release notes

  • Story children now override args.children as expected.

    5.0.0release notes

  • The addon now works with getAbsolutePath.

    5.0.0release notes

  • Invalid identifiers are now transformed properly.

    5.0.0release notes

  • The legacy API template hook now runs before Svelte in Vitest.

    5.0.0release notes

  • Badly formatted ESM that broke on Node 22 and 23 is fixed.

    5.0.0release notes

  • The parameters attribute on legacy <Story> is no longer removed.

    5.0.0release notes

  • Story-level tags now take effect in the Vitest integration.

    5.0.0release notes