diff --git a/README.md b/README.md
index c399b6a..ed19cfd 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,6 @@ View your app in AI Studio: https://ai.studio/apps/drive/1a8wkyYOUvPDWvUXbrtN2dz
 
 1. Install dependencies:
    `npm install`
-2. Set the `GEMINI_API_KEY` in [.env.local](.env.local) to your Gemini API key
+2. Set the `VITE_API_KEY` in [.env.local](.env.local) to your Gemini API key (e.g., `VITE_API_KEY=your_key_here`)
 3. Run the app:
    `npm run dev`
diff --git a/services/geminiService.ts b/services/geminiService.ts
index 607cd52..a5191db 100644
--- a/services/geminiService.ts
+++ b/services/geminiService.ts
@@ -3,10 +3,14 @@ import { VoiceName } from '../types';
 import { normalizeUrl } from '../utils/url';
 
 const getAiClient = () => {
-  const apiKey = process.env.API_KEY;
+  const apiKey = import.meta.env.VITE_API_KEY;
+
   if (!apiKey) {
-    throw new Error("API Key is missing");
+    throw new Error(
+      "Gemini API key is missing. Set VITE_API_KEY in your .env.local file (e.g., VITE_API_KEY=your_key_here)."
+    );
   }
+
   return new GoogleGenAI({ apiKey });
 };
 
diff --git a/tsconfig.json b/tsconfig.json
index 0f950d7..5bcf8cd 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -16,6 +16,6 @@
     "noUnusedParameters": false,
     "noFallthroughCasesInSwitch": true
   },
-  "include": ["**/*.ts", "**/*.tsx"],
+  "include": ["**/*.ts", "**/*.tsx", "**/*.d.ts"],
   "exclude": ["node_modules"]
 }
\ No newline at end of file
diff --git a/vite-env.d.ts b/vite-env.d.ts
new file mode 100644
index 0000000..11f02fe
--- /dev/null
+++ b/vite-env.d.ts
@@ -0,0 +1 @@
+/// <reference types="vite/client" />
diff --git a/vite.config.ts b/vite.config.ts
index 15cd120..f43fbe9 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,16 +1,6 @@
-import { defineConfig, loadEnv } from 'vite';
+import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
 
-export default defineConfig(({ mode }) => {
-  // Load env file based on `mode` in the current working directory.
-  const env = loadEnv(mode, (process as any).cwd(), '');
-  
-  return {
-    plugins: [react()],
-    define: {
-      // This allows the app code to continue using process.env.API_KEY
-      // even though it is running in the browser.
-      'process.env.API_KEY': JSON.stringify(env.API_KEY)
-    }
-  };
+export default defineConfig({
+  plugins: [react()]
 });
\ No newline at end of file