Backend code

[pelguetat]

Hey, thanks for sharing this, it's amazing. I'm trying to adapt it for a similar use case but I'm having issues with Vercel when calling OpenAI. Would you mind sharing your backend code? Thanks.

[enesakar]

oops sorry I missed this.

import { NextRequest, NextResponse } from "next/server";
import { Ratelimit } from "@upstash/ratelimit"; // for deno: see above
import { Redis } from "@upstash/redis";
import { ipAddress } from "@vercel/edge";

const redis = new Redis({
  url: process.env.UPSTASH_REDIS_REST_URL!,
  token: process.env.UPSTASH_REDIS_REST_TOKEN!,
});

// Create a new ratelimiter, that allows 10 requests per 10 seconds
const ratelimit = new Ratelimit({
  redis: redis,
  limiter: Ratelimit.slidingWindow(10, "1 h"),
  analytics: true,
});

export const config = {
  runtime: "edge",
};

export default async (req: NextRequest) => {
  const data = await req.json();
  const prompt = data.prompt;
  const tone = data.tone;
  const ip = ipAddress(req) || "unknown";
  let response;

  if (!prompt) {
    return new Response("No prompt in the request", { status: 400 });
  }

  const { success } = await ratelimit.limit(ip);

  if (!success) {
    response = new NextResponse(
      "During the beta phase, you may only make 10 requests per hour. We apologize for any inconvenience this may cause."
    );
  } else if (prompt.length > 1000) {
    response = new NextResponse(
      "During the beta phase, input exceeding the limit of 1000 characters will not be permitted. We apologize for any inconvenience this may cause."
    );
  } else {
    let content = "";

    if (!tone || tone === "") {
      content = `Improve: ${prompt}`;
    } else if (tone === "fix") {
      content = `Fix the grammar: ${prompt}`;
    } else {
      content = `Improve writing in a ${tone} way: ${prompt}`;
    }

    console.log(content);

    const payload = {
      model: "gpt-3.5-turbo",
      messages: [{ role: "user", content: content }],
    };

    const res = await fetch("https://api.openai.com/v1/chat/completions", {
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${
          process.env.OPENAI_API_KEY ??
          "sk-rzThfddsdsffnj4WGI1"
        }`,
      },
      method: "POST",
      body: JSON.stringify(payload),
    });
    const msg = await res.json();
    response = new NextResponse(msg.choices[0].message.content);
  }

  // Set custom header
  response.headers.set("Access-Control-Allow-Credentials", "true");
  response.headers.set("Access-Control-Allow-Origin", "*");
  response.headers.set(
    "Access-Control-Allow-Methods",
    "GET,OPTIONS,PATCH,DELETE,POST,PUT"
  );
  response.headers.set(
    "Access-Control-Allow-Headers",
    "X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version"
  );
  return response;
};