chore: use env file.

.env.example

@@ -0,0 +1 @@
+OPENAI_API_KEY="<your-key-here>"

README.md

@@ -4,10 +4,10 @@ This is an example application showing how to use the [OpenAI Realtime API](http
 
 ## Installation and usage
 
-Before you begin, you'll need an OpenAI API key - [create one in the dashboard here](https://platform.openai.com/settings/api-keys). Export it as a system environment variable:
+Before you begin, you'll need an OpenAI API key - [create one in the dashboard here](https://platform.openai.com/settings/api-keys). Create a `.env` file from the example file and set your API key in there:
 
 ```bash
-export OPENAI_API_KEY=<your key here>
+cp .env.example .env
 ```
 
 Running this application locally requires [Node.js](https://nodejs.org/) to be installed. Install dependencies for the application with:
@@ -24,6 +24,8 @@ npm run dev
 
 This should start the console application on [http://localhost:3000](http://localhost:3000).
 
+_Note:_ The `server.js` file uses [@fastify/vite](https://fastify-vite.dev/) to build and serve the Astro frontend contained in the `/client` folder. You can find the configuration in the [`vite.config.js` file](./vite.config.js)
+
 ## Previous WebSockets version
 
 The previous version of this application that used WebSockets on the client (not recommended in client-side browsers) [can be found here](https://github.com/openai/openai-realtime-console/tree/websockets).

package.json

@@ -10,6 +10,7 @@
     "lint": "eslint . --ext .js,.jsx --fix"
   },
   "dependencies": {
+    "@fastify/env": "^4.4.0",
     "@fastify/one-line-logger": "^1.2.0",
     "@fastify/react": "^0.6.0",
     "@fastify/vite": "^6.0.5",

server.js

@@ -1,5 +1,6 @@
 import Fastify from "fastify";
 import FastifyVite from "@fastify/vite";
+import fastifyEnv from "@fastify/env";
 
 // Fastify + React + Vite configuration
 const server = Fastify({
@@ -10,6 +11,18 @@ const server = Fastify({
   },
 });
 
+const schema = {
+  type: "object",
+  required: ["OPENAI_API_KEY"],
+  properties: {
+    OPENAI_API_KEY: {
+      type: "string",
+    },
+  },
+};
+
+await server.register(fastifyEnv, { dotenv: true, schema });
+
 await server.register(FastifyVite, {
   root: import.meta.url,
   renderer: "@fastify/react",