migrate-stitches

name	migrate-stitches
description	This skill should be used when the user asks to "migrate from Stitches", "convert Stitches to RSC", "upgrade to Seams", "replace @stitches/react", or mentions migrating existing Stitches.js code to Seams.

Migrate from Stitches.js to Seams

Guide migration from the original @stitches/react or @stitches/core packages to @artmsilva/seams-react or @artmsilva/seams-core.

Migration Overview

Seams is a 1:1 API-compatible replacement. Most code works without changes. The key differences are:

1. Package names: @stitches/react → @artmsilva/seams-react
2. Build plugin required: Add Next.js or Vite plugin for CSS extraction
3. No runtime CSS: CSS is extracted at build time, not generated at runtime

Migration Steps

Step 1: Analyze Current Usage

Search the codebase for Stitches imports and usage patterns:

# Find all Stitches imports
grep -r "from '@stitches" --include="*.ts" --include="*.tsx"
grep -r "from \"@stitches" --include="*.ts" --include="*.tsx"

# Find stitches.config files
find . -name "stitches.config.*" -type f

Step 2: Update Package Dependencies

Replace Stitches packages in package.json:

Before:

{
  "dependencies": {
    "@stitches/react": "^1.2.8"
  }
}

After:

{
  "dependencies": {
    "@artmsilva/seams-react": "^0.1.0"
  }
}

For core-only usage:

{
  "dependencies": {
    "@artmsilva/seams-core": "^0.1.0"
  }
}

Step 3: Update Imports

Replace import paths throughout the codebase:

// Before
import { styled, css, globalCss, keyframes, createTheme } from "@stitches/react";
import { createStitches } from "@stitches/react";

// After
import { styled, css, globalCss, keyframes, createTheme } from "@artmsilva/seams-react";
import { createStitches } from "@artmsilva/seams-react";

Use sed for bulk replacement:

# macOS
find . -type f \( -name "*.ts" -o -name "*.tsx" \) -exec sed -i '' "s/@stitches\/react/@artmsilva\/seams-react/g" {} +
find . -type f \( -name "*.ts" -o -name "*.tsx" \) -exec sed -i '' "s/@stitches\/core/@artmsilva\/seams-core/g" {} +

# Linux
find . -type f \( -name "*.ts" -o -name "*.tsx" \) -exec sed -i "s/@stitches\/react/@artmsilva\/seams-react/g" {} +

Step 4: Add Build Plugin

For Next.js - Install and configure:

pnpm add @artmsilva/seams-next-plugin

Update next.config.js:

const withSeams = require("@artmsilva/seams-next-plugin");

module.exports = withSeams({
  useScope: true,
  useLayers: true,
})({
  // existing Next.js config
});

For Vite - Install and configure:

pnpm add @artmsilva/seams-vite-plugin

Update vite.config.ts:

import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";
import seams from "@artmsilva/seams-vite-plugin";

export default defineConfig({
  plugins: [
    react(),
    seams({
      useScope: true,
      useLayers: true,
    }),
  ],
});

Step 5: Handle Breaking Patterns

getCssText() Usage

The getCssText() function still works but is primarily for SSR. With build plugins, CSS is extracted automatically.

Before (SSR hydration):

// _document.tsx
<style id="stitches" dangerouslySetInnerHTML={{ __html: getCssText() }} />

After: Remove this - the build plugin handles CSS injection.

Dynamic css prop with Non-Serializable Values

Functions in css prop won't work at build time:

// Won't work - function can't be extracted
<Box css={{ color: () => getColor() }} />

// Works - static value or variable
<Box css={{ color: dynamicColor }} />

The build plugin converts dynamic values to CSS variables automatically.

Step 6: Verify Migration

1. Run the build to check for errors:

   pnpm build
   

2. Check generated CSS for proper layer structure:

   # Look for @layer declarations in output
   grep -r "@layer stitches" dist/
   

3. Test in browser - styles should apply without runtime JS

Common Migration Issues

Issue: Styles not applying

Cause: Build plugin not processing files Fix: Check include/exclude patterns in plugin config

Issue: TypeScript errors

Cause: Type definitions slightly different Fix: Update type imports if needed - most types are compatible

Issue: Theme tokens not resolving

Cause: Token syntax difference Fix: Ensure $token syntax is used (same as original Stitches)

Additional Resources

See references/api-differences.md for detailed API comparison. See examples/ for before/after migration examples.