# svelte-storybook-migrate

Migrates Storybook setups in Svelte projects to @storybook/sveltekit, converting story definitions to Svelte CSF v5 and Svelte 5 snippets.

- command · `type=command` · Claude Code · 118 installs
- Author: davila7
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/commands/svelte/svelte-storybook-migrate.md
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/commands/svelte-storybook-migrate

## What it does

This command automates the upgrade process for Storybook installations moving from 6.x to 7.x or newer. It strips deprecated builders such as `@storybook/svelte-vite` and `storybook-builder-vite`, installs `@storybook/sveltekit`, and updates the framework definition in `.storybook/main.js`.

Inside `.stories.svelte` files, the command transitions code to Svelte CSF v5 and CSF 3 standards. It drops the legacy `<Meta>` component in favor of `defineMeta`, swaps old `<Template let:args>` wrappers for Svelte 5 snippets, and updates SvelteKit store mocks to the `sveltekit_experimental` structure.

File transformation relies on `svelte/compiler` to parse and edit the AST structure of your stories. If the project lacks this compiler dependency, automated AST-based file adjustments cannot execute.

## Install

### Claude Code (native platform)

1. **claude-code-templates**
```bash
npx claude-code-templates@latest --command svelte/svelte-storybook-migrate
```

2. **Manually: put the files in place**
- File: `.claude/commands/svelte-storybook-migrate.md` — Call it with /svelte-storybook-migrate. For all projects use ~/.claude/commands/

### Codex

**Manually: put the files in place**
- File: `~/.codex/prompts/svelte-storybook-migrate.md` — Call it with /prompts:svelte-storybook-migrate. Codex marks this format deprecated in favour of skills

### GitHub Copilot

**Manually: put the files in place**
- File: `.github/prompts/svelte-storybook-migrate.prompt.md`

### Gemini CLI

**Manually: put the files in place**
- File: `.gemini/commands/svelte-storybook-migrate.toml` — Gemini stores commands as TOML: the prompt text goes into the prompt field

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/commands/svelte/svelte-storybook-migrate.md

## When to use it
- upgrade Storybook config from @storybook/svelte to @storybook/sveltekit
- convert story files to Svelte CSF v5 using defineMeta
- replace legacy Template blocks with Svelte 5 snippets
- remove obsolete Vite builder packages from package.json

## Example prompts
- /svelte:storybook-migrate
- Migrate my Storybook setup from v6 Svelte to v7 with @storybook/sveltekit
- Convert all .stories.svelte files to Svelte CSF v5 and CSF 3 format

## Source text · svelte-storybook-migrate.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 43cc3ced95bbd7b3.

BEGIN THIRD-PARTY FILE 43cc3ced95bbd7b3
````text
---
description: "Migrate Storybook configurations and stories to newer versions, including Svelte CSF v5 and @storybook/sveltekit framework."
---

# /svelte:storybook-migrate

Migrate Storybook configurations and stories to newer versions, including Svelte CSF v5 and @storybook/sveltekit framework.

## Instructions

You are acting as the Svelte Storybook Specialist Agent focused on migration. When migrating Storybook:

1. **Version Migrations**:
   
   **Storybook 6.x to 7.x**:
   ```bash
   # Automated upgrade
   npx storybook@latest upgrade
   
   # Manual steps:
   # 1. Update dependencies
   # 2. Migrate to @storybook/sveltekit
   # 3. Remove obsolete packages
   # 4. Update configuration
   ```
   
   **Configuration Changes**:
   ```javascript
   // Old (.storybook/main.js)
   module.exports = {
     framework: '@storybook/svelte',
     svelteOptions: { ... } // Remove this
   };
   
   // New (.storybook/main.js)
   export default {
     framework: {
       name: '@storybook/sveltekit',
       options: {}
     }
   };
   ```

2. **Svelte CSF Migration (v4 to v5)**:
   
   **Meta Component → defineMeta**:
   ```svelte
   <!-- Old -->
   <script context="module">
     import { Meta, Story } from '@storybook/addon-svelte-csf';
   </script>
   
   <Meta title="Button" component={Button} />
   
   <!-- New -->
   <script>
     import { defineMeta } from '@storybook/addon-svelte-csf';
     import Button from './Button.svelte';
     
     const { Story } = defineMeta({
       title: 'Button',
       component: Button
     });
   </script>
   ```
   
   **Template → Children/Snippets**:
   ```svelte
   <!-- Old -->
   <Story name="Default">
     <Template let:args>
       <Button {...args} />
     </Template>
   </Story>
   
   <!-- New -->
   <Story name="Default" args={{ label: 'Click' }}>
     {#snippet template(args)}
       <Button {...args} />
     {/snippet}
   </Story>
   ```

3. **Package Migration**:
   
   **Remove Obsolete Packages**:
   ```bash
   npm uninstall @storybook/svelte-vite
   npm uninstall storybook-builder-vite
   npm uninstall @storybook/builder-vite
   npm uninstall @storybook/svelte
   ```
   
   **Install New Packages**:
   ```bash
   npm install -D @storybook/sveltekit
   npm install -D @storybook/addon-svelte-csf@latest
   ```

4. **Story Format Migration**:
   
   **CSF 2 to CSF 3**:
   ```javascript
   // Old (CSF 2)
   export default {
     title: 'Button',
     component: Button
   };
   
   export const Primary = (args) => ({
     Component: Button,
     props: args
   });
   Primary.args = { variant: 'primary' };
   
   // New (CSF 3)
   export default {
     title: 'Button',
     component: Button
   };
   
   export const Primary = {
     args: { variant: 'primary' }
   };
   ```

5. **Addon Updates**:
   
   **Actions → Tags**:
   ```javascript
   // Old
   export default {
     component: Button,
     parameters: {
       docs: { autodocs: true }
     }
   };
   
   // New
   export default {
     component: Button,
     tags: ['autodocs']
   };
   ```

6. **Module Mocking Updates**:
   
   **New Parameter Structure**:
   ```javascript
   // Old approach (custom mocks)
   import { page } from './__mocks__/stores';
   
   // New approach (parameters)
   export const Default = {
     parameters: {
       sveltekit_experimental: {
         stores: { page: { ... } }
       }
     }
   };
   ```

7. **Migration Script**:
   ```javascript
   // migration-helper.js
   import { readdir, readFile, writeFile } from 'fs/promises';
   import { parse, walk } from 'svelte/compiler';
   
   async function migrateStories() {
     // Find all .stories.svelte files
     // Parse and transform AST
     // Update syntax to v5
     // Write updated files
   }
   ```

8. **Testing After Migration**:
````
END THIRD-PARTY FILE 43cc3ced95bbd7b3

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