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client/vite.config.ts

@@ -2,16 +2,54 @@ import { defineConfig, loadEnv } from 'vite'
 import react from '@vitejs/plugin-react'
 import tailwindcss from '@tailwindcss/vite'
 import path from 'path'
+import fs from 'fs'
+
+/** Same default as server when `server/.env` has no PORT (see repo root `mailflow.dev.port.json`). */
+function readMailflowDevPort(): string {
+  const f = path.resolve(__dirname, '../mailflow.dev.port.json')
+  try {
+    const j = JSON.parse(fs.readFileSync(f, 'utf8')) as { port?: number }
+    if (j.port != null && Number.isFinite(Number(j.port))) return String(j.port)
+  } catch {
+    /* missing or invalid */
+  }
+  return '3030'
+}
+
+/** Align Vite proxy with server/.env PORT (client/.env does not load server PORT). */
+function readBackendPortFromServerEnv(): string {
+  const envFile = path.resolve(__dirname, '../server/.env')
+  try {
+    let text = fs.readFileSync(envFile, 'utf8')
+    if (text.charCodeAt(0) === 0xfeff) text = text.slice(1)
+    for (const line of text.split(/\r?\n/)) {
+      if (/^\s*#/.test(line)) continue
+      const noComment = line.split('#')[0]?.trim() || ''
+      const m = /^\s*PORT\s*=\s*"?(\d+)"?/i.exec(noComment)
+      if (m) return m[1]
+    }
+  } catch {
+    /* no server/.env */
+  }
+  return readMailflowDevPort()
+}
+
+/** Origin only (no trailing /api) — matches client api.ts / VITE_DEV_BACKEND_ORIGIN contract. */
+function stripTrailingApiFromOrigin(o: string): string {
+  let s = o.replace(/\/$/, '')
+  while (s.endsWith('/api')) {
+    s = s.slice(0, -4).replace(/\/+$/, '')
+  }
+  return s
+}
 
 // https://vite.dev/config/
 export default defineConfig(({ mode }) => {
   const env = loadEnv(mode, __dirname, '')
   const appwriteDevOrigin = (env.APPWRITE_DEV_ORIGIN || '').replace(/\/$/, '')
+  const defaultApiOrigin = `http://127.0.0.1:${readBackendPortFromServerEnv()}`
   // 127.0.0.1 avoids Windows localhost → IPv6 (::1) vs backend listening on IPv4-only
-  const apiDevTarget = (env.VITE_DEV_API_ORIGIN || 'http://127.0.0.1:3000').replace(
-    /\/$/,
-    ''
-  )
+  const apiDevTarget = stripTrailingApiFromOrigin(env.VITE_DEV_API_ORIGIN || defaultApiOrigin)
 
   const proxy: Record<
     string,
@@ -37,6 +75,13 @@ export default defineConfig(({ mode }) => {
   }
 
   return {
+    // Browser ruft Express direkt an (CORS) — vermeidet 404, wenn der Vite-/api-Proxy nicht greift
+    define:
+      mode === 'development'
+        ? {
+            'import.meta.env.VITE_DEV_BACKEND_ORIGIN': JSON.stringify(apiDevTarget),
+          }
+        : {},
     plugins: [react(), tailwindcss()],
     resolve: {
       alias: {
@@ -44,10 +89,13 @@ export default defineConfig(({ mode }) => {
       },
     },
     server: {
+      host: true,
       port: 5173,
       // Wenn 5173 schon belegt ist, nicht still auf einen anderen Port wechseln — sonst öffnet man oft noch die alte URL und bekommt für /api 404.
       strictPort: true,
       proxy,
     },
+    // `vite preview` hat standardmäßig keinen Dev-Proxy — sonst wäre /api ein 404.
+    preview: { proxy },
   }
 })