chore: update env variables in readme

.env.example

@@ -1,2 +1,3 @@
+# Do not share your OpenAI API key with anyone! It should remain a secret.
 OPENAI_API_KEY=<YOUR_API_KEY>
 OPENAI_API_ENDPOINT=<YOUR_API_ENDPOINT>

README.md

@@ -36,9 +36,15 @@ SQL Chat is built by Next.js, it supports following databases and will add more
 
 ## Local Development
 
-1. Create a `.env` file in the root directory with your `OPENAI_API_KEY`;
+1. Make a copy of the example environment variables file;
 
-2. Install dependencies and start the dev server;
+   ```bash
+   cp .env.example .env
+   ```
+
+2. Add your [API key](https://platform.openai.com/account/api-keys) and OpenAI API Endpoint(optional) to the newly created `.env` file;
+
+3. Install dependencies and start the dev server;
 
    ```bash
    pnpm i && pnpm dev

pages/api/chat.ts

@@ -6,9 +6,11 @@ export const config = {
   runtime: "edge",
 };
 
+const apiEndpoint = new URL(`${openAIApiEndpoint}/v1/chat/completions`);
+
 const handler = async (req: NextRequest) => {
   const reqBody = await req.json();
-  const rawRes = await fetch(`${openAIApiEndpoint}/v1/chat/completions`, {
+  const res = await fetch(apiEndpoint, {
     headers: {
       "Content-Type": "application/json",
       Authorization: `Bearer ${openAIApiKey}`,
@@ -23,10 +25,10 @@ const handler = async (req: NextRequest) => {
       stream: true,
     }),
   });
-  if (!rawRes.ok) {
-    return new Response(rawRes.body, {
-      status: rawRes.status,
-      statusText: rawRes.statusText,
+  if (!res.ok) {
+    return new Response(res.body, {
+      status: res.status,
+      statusText: res.statusText,
     });
   }
 
@@ -52,7 +54,7 @@ const handler = async (req: NextRequest) => {
         }
       };
       const parser = createParser(streamParser);
-      for await (const chunk of rawRes.body as any) {
+      for await (const chunk of res.body as any) {
         parser.feed(decoder.decode(chunk));
       }
     },