add web demo

apps/web/app/api/generate/route.ts

@@ -0,0 +1,81 @@
+import OpenAI from "openai";
+import { OpenAIStream, StreamingTextResponse } from "ai";
+import { kv } from "@vercel/kv";
+import { Ratelimit } from "@upstash/ratelimit";
+
+// Create an OpenAI API client (that's edge friendly!)
+const openai = new OpenAI({
+  apiKey: process.env.OPENAI_API_KEY || "",
+});
+
+// IMPORTANT! Set the runtime to edge: https://vercel.com/docs/functions/edge-functions/edge-runtime
+export const runtime = "edge";
+
+export async function POST(req: Request): Promise<Response> {
+  // Check if the OPENAI_API_KEY is set, if not return 400
+  if (!process.env.OPENAI_API_KEY || process.env.OPENAI_API_KEY === "") {
+    return new Response(
+      "Missing OPENAI_API_KEY – make sure to add it to your .env file.",
+      {
+        status: 400,
+      },
+    );
+  }
+  if (
+    process.env.NODE_ENV != "development" &&
+    process.env.KV_REST_API_URL &&
+    process.env.KV_REST_API_TOKEN
+  ) {
+    const ip = req.headers.get("x-forwarded-for");
+    const ratelimit = new Ratelimit({
+      redis: kv,
+      limiter: Ratelimit.slidingWindow(50, "1 d"),
+    });
+
+    const { success, limit, reset, remaining } = await ratelimit.limit(
+      `novel_ratelimit_${ip}`,
+    );
+
+    if (!success) {
+      return new Response("You have reached your request limit for the day.", {
+        status: 429,
+        headers: {
+          "X-RateLimit-Limit": limit.toString(),
+          "X-RateLimit-Remaining": remaining.toString(),
+          "X-RateLimit-Reset": reset.toString(),
+        },
+      });
+    }
+  }
+
+  let { prompt } = await req.json();
+
+  const response = await openai.chat.completions.create({
+    model: "gpt-3.5-turbo",
+    messages: [
+      {
+        role: "system",
+        content:
+          "You are an AI writing assistant that continues existing text based on context from prior text. " +
+          "Give more weight/priority to the later characters than the beginning ones. " +
+          "Limit your response to no more than 200 characters, but make sure to construct complete sentences.",
+      },
+      {
+        role: "user",
+        content: prompt,
+      },
+    ],
+    temperature: 0.7,
+    top_p: 1,
+    frequency_penalty: 0,
+    presence_penalty: 0,
+    stream: true,
+    n: 1,
+  });
+
+  // Convert the response into a friendly text-stream
+  const stream = OpenAIStream(response);
+
+  // Respond with the stream
+  return new StreamingTextResponse(stream);
+}