diff --git a/apps/desktop/src/main/electron-env.d.ts b/apps/desktop/src/main/electron-env.d.ts
index 58860c2b..da3774b4 100644
--- a/apps/desktop/src/main/electron-env.d.ts
+++ b/apps/desktop/src/main/electron-env.d.ts
@@ -5,6 +5,7 @@
 interface ImportMetaEnv {
   readonly MAIN_VITE_GATEWAY_URL: string
   readonly MAIN_VITE_WEB_URL: string
+  readonly MAIN_VITE_API_URL?: string
 }
 
 interface ImportMeta {
diff --git a/apps/desktop/src/main/index.ts b/apps/desktop/src/main/index.ts
index f0780a5f..07e362a1 100644
--- a/apps/desktop/src/main/index.ts
+++ b/apps/desktop/src/main/index.ts
@@ -44,6 +44,13 @@ process.stderr?.on?.('error', (err: NodeJS.ErrnoException) => {
   throw err
 })
 
+// Bridge Vite build-time env to process.env for externalized @multica/core
+// In dev mode, electron-vite already loads .env into process.env;
+// In packaged builds, only import.meta.env has the value (injected at build time).
+if (import.meta.env.MAIN_VITE_API_URL) {
+  process.env.MULTICA_API_URL ??= import.meta.env.MAIN_VITE_API_URL
+}
+
 import { app, BrowserWindow, shell, ipcMain } from 'electron'
 import { fileURLToPath } from 'node:url'
 import path from 'node:path'