Add Vite plugin to download Python wheels from PyPI during build

Remove pystitch wheel from source control and implement automatic downloading via custom Vite plugin. The plugin fetches wheels from PyPI API and serves them in both dev and production builds.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

vite.config.ts

@@ -4,6 +4,9 @@ import tailwindcss from '@tailwindcss/vite'
 import { viteStaticCopy } from 'vite-plugin-static-copy'
 import { dirname, join } from 'path'
 import { fileURLToPath } from 'url'
+import { writeFile, mkdir } from 'fs/promises'
+import { existsSync } from 'fs'
+import type { Plugin } from 'vite'
 
 const PYODIDE_EXCLUDE = [
   '!**/*.{md,html}',
@@ -23,9 +26,117 @@ function viteStaticCopyPyodide() {
   })
 }
 
+interface PyPIPackage {
+  package: string
+  version: string
+}
+
+interface WheelData {
+  filename: string
+  buffer: Buffer
+}
+
+async function getPyPIWheelUrl(packageName: string, version: string): Promise<{ url: string; filename: string }> {
+  const pypiUrl = `https://pypi.org/pypi/${packageName}/${version}/json`
+
+  const response = await fetch(pypiUrl)
+  if (!response.ok) {
+    throw new Error(`Failed to fetch PyPI metadata: ${response.statusText}`)
+  }
+
+  const data = await response.json()
+
+  // Find the wheel file (.whl) for py3-none-any
+  const wheelFile = data.urls.find((file: any) =>
+    file.packagetype === 'bdist_wheel' &&
+    file.filename.endsWith('-py3-none-any.whl')
+  )
+
+  if (!wheelFile) {
+    throw new Error(`No py3-none-any wheel found for ${packageName} ${version}`)
+  }
+
+  return {
+    url: wheelFile.url,
+    filename: wheelFile.filename,
+  }
+}
+
+function downloadPyPIWheels(packages: PyPIPackage[]): Plugin {
+  const wheels: WheelData[] = []
+
+  return {
+    name: 'download-pypi-wheels',
+    async buildStart() {
+      try {
+        // Download all wheels in parallel
+        const downloadPromises = packages.map(async ({ package: packageName, version }) => {
+          console.log(`[download-pypi-wheels] Downloading ${packageName}@${version} from PyPI...`)
+
+          // Get wheel info from PyPI
+          const { url, filename } = await getPyPIWheelUrl(packageName, version)
+
+          // Download the wheel file
+          const response = await fetch(url)
+          if (!response.ok) {
+            throw new Error(`Failed to download ${filename}: ${response.statusText}`)
+          }
+
+          const arrayBuffer = await response.arrayBuffer()
+          const buffer = Buffer.from(arrayBuffer)
+
+          console.log(`[download-pypi-wheels] Successfully downloaded ${filename}`)
+
+          return { filename, buffer }
+        })
+
+        const downloadedWheels = await Promise.all(downloadPromises)
+        wheels.push(...downloadedWheels)
+      } catch (error) {
+        console.error(`[download-pypi-wheels] Error downloading wheels:`, error)
+        throw error
+      }
+    },
+    configureServer(server) {
+      // Serve wheel files during dev mode
+      server.middlewares.use((req, res, next) => {
+        const wheel = wheels.find((w) => req.url === `/${w.filename}`)
+        if (wheel) {
+          res.setHeader('Content-Type', 'application/octet-stream')
+          res.setHeader('Content-Length', wheel.buffer.length)
+          res.end(wheel.buffer)
+          return
+        }
+        next()
+      })
+    },
+    async generateBundle() {
+      if (wheels.length === 0) {
+        throw new Error('No wheel files were downloaded')
+      }
+
+      // Add all wheel files as assets to the bundle
+      for (const wheel of wheels) {
+        this.emitFile({
+          type: 'asset',
+          fileName: wheel.filename,
+          source: wheel.buffer,
+        })
+      }
+    },
+  }
+}
+
 // https://vite.dev/config/
 export default defineConfig({
-  plugins: [react(), tailwindcss(), viteStaticCopyPyodide()],
+  plugins: [
+    react(),
+    tailwindcss(),
+    downloadPyPIWheels([
+      { package: 'pystitch', version: '1.0.0' },
+    ]),
+    viteStaticCopyPyodide(),
+  ],
   optimizeDeps: {
     exclude: ['pyodide'],
   },