feat: add support for Vertex AI

.env

@@ -1,2 +1,6 @@
 # create your own API KEY at https://aistudio.google.com/apikey
-#REACT_APP_GEMINI_API_KEY=''
+REACT_APP_GEMINI_API_KEY=your_api_key_here
+# Vertex AI (for WIP (Workload Identity Federation))
+REACT_APP_USE_VERTEX_AI=false  # set to true to use Vertex AI
+REACT_APP_GOOGLE_CLOUD_PROJECT=your-project-id
+REACT_APP_GOOGLE_CLOUD_LOCATION=us-central1

src/App.tsx

@@ -24,13 +24,37 @@ import cn from "classnames";
 import { LiveClientOptions } from "./types";
 
 const API_KEY = process.env.REACT_APP_GEMINI_API_KEY as string;
-if (typeof API_KEY !== "string") {
-  throw new Error("set REACT_APP_GEMINI_API_KEY in .env");
+const USE_VERTEX_AI = process.env.REACT_APP_USE_VERTEX_AI === 'true';
+const PROJECT_ID = process.env.REACT_APP_GOOGLE_CLOUD_PROJECT as string;
+const LOCATION = process.env.REACT_APP_GOOGLE_CLOUD_LOCATION as string;
+
+
+function createApiOptions(): LiveClientOptions {
+  if (USE_VERTEX_AI) {
+    // Vertex AI configuration (supports WIF)
+    if (!PROJECT_ID || !LOCATION) {
+      throw new Error(
+        "When using Vertex AI, set REACT_APP_GOOGLE_CLOUD_PROJECT and REACT_APP_GOOGLE_CLOUD_LOCATION in .env"
+      );
+    }
+
+    return {
+      vertexai: true,
+      project: PROJECT_ID,
+      location: LOCATION,
+    };
+  } else {
+    if (!API_KEY) {
+      throw new Error("set REACT_APP_GEMINI_API_KEY in .env");
+    }
+
+    return {
+      apiKey: API_KEY,
+    };
+  }
 }
 
-const apiOptions: LiveClientOptions = {
-  apiKey: API_KEY,
-};
+const apiOptions: LiveClientOptions = createApiOptions();
 
 function App() {
   // this video reference is used for displaying the active stream, whether that is the webcam or screen capture

src/types.ts

@@ -22,9 +22,9 @@ import {
 } from "@google/genai";
 
 /**
- * the options to initiate the client, ensure apiKey is required
+ * The options to initiate the client, supporting either API key or Vertex AI.
  */
-export type LiveClientOptions = GoogleGenAIOptions & { apiKey: string };
+export type LiveClientOptions = GoogleGenAIOptions;
 
 /** log types */
 export type StreamingLog = {