Tutorials Featured

Building Your Own ChatGPT with OpenAI API: A Step-by-Step Guide

shakiroslann

Feb 13, 2023 • 46 min read

About This Tutorial

Welcome to this tutorial on building your ChatGPT app with OpenAI. This step-by-step guide will walk you through the process of creating your own personalized/customized ChatGPT application using the OpenAI API. You will learn to utilize the pre-trained models and integrate them into a functioning app.

Whether you're a developer looking to add AI capabilities to your project or just someone interested in exploring the possibilities of AI, this tutorial will guide you through how to start building your ChatGPT app with OpenAI API and Next.js!

💡

This tutorial assumes basic knowledge of JavaScript and Next.js/React.js. If you’ve never written Next.js code, you should first go through the official Next.js tutorial.

What is OpenAI API

OpenAI API is a cloud-based platform that allows developers to build artificial intelligence models and applications. It provides access to the state-of-the-art language processing capabilities of OpenAI, which can be used to develop chatbots, language translation models, and more.

With OpenAI API, developers can quickly and easily build AI models without needing to have extensive knowledge or expertise in the field. The platform is user-friendly and accessible, making it a great choice for both seasoned AI developers and those who are just starting out.

Preview on what we're going to build

This is just a super simple web app project we can build with Next.js and OpenAI API where you can interact and have a conversation with OpenAI pre-trained models. For this tutorial, we're going to create 3 prompt templates each one has its way of how we want the AI to behave (AI assistant, English to other languages, and image generator). Since these are pre-trained models, we have to give them proper instructions on what we expect them to do.

English to other languages AI translator.

Template Starter Kit

Before we begin, I found awesome starter kit templates to build your app with OpenAI API by Adrian Twarog on Youtube, where you can get some apps idea on what you want to build with OpenAI API and get started quickly and easily, without having to spend hours building the basic functionality from scratch.

💡

Note: These templates are not the same as the app we want to build in this tutorial, But are worth checking out. But for the app we're going to build, the full code is provided at the end of this tutorial.

They are designed to save you time and effort when building your ChatGPT app with React.js and OpenAI.

Fully customizable and configurable so that you can tailor it to your specific needs. Whether you want to change the design, add new features, or tweak the functionality, this template allows you to do it all.

You'll have access to a pre-built UI, a sample codebase, and instructions to guide you through the process. It also includes all the necessary features which will save you time and make your app more robust.

Perfect for developers, researchers, or anyone looking to build a ChatGPT app without having to start from scratch. It is a great tool to quickly prototype your idea and improve it as you go. With this template, you'll be able to focus on the fun part - experimenting with the OpenAI API and building a unique and powerful AI assistant.

Set up a new Next.js project

Let's get started, First, let’s make sure that your development environment is ready.

If you don’t have Node.js installed, install it from here. You’ll need Node.js version 10.13 or later.
You’ll be using your text editor and terminal app for this tutorial or you can use Visual Studio Code which is recommended.
If you use Visual Studio Code hit cmd/ctrl + J to open the terminal

Create a Next.js app

To create a Next.js app, open your terminal, cd into the directory you’d like to create the app in, and run the following command:

npx create-next-app@latest chatgpt

this is my next.js setup for this project:

TypeScript: No
ESLint: Yes
src/ directory: No
experimental app/ directory: No
import alias: @/*

cd chatgpt

Then, run the following command:

npm run dev

This starts your Next.js app’s "development server" (more on this later) on port 3000.

Let’s check to see if it’s working. Open http://localhost:3000 from your browser.

Install Tailwindcss

To quickly style our app we're going to use Tailwindcss which is a CSS framework. Tailwindcss is a CSS framework that emphasizes flexibility and utility. It provides you with modular, customizable classes that can be used to quickly build responsive layouts for the web.

let's Install Tailwindcss and its peer dependencies via npm, and then run the init command to generate both tailwind.config.js and postcss.config.js.

open a new terminal tab and type these commands in your terminal:

npm install -D tailwindcss postcss autoprefixer
npx tailwindcss init -p

Add the paths to all of your template files in your tailwind.config.js file.

/** @type {import('tailwindcss').Config} */
module.exports = {
  content: [
    "./pages/**/*.{js,ts,jsx,tsx}",
    "./components/**/*.{js,ts,jsx,tsx}",
  ],
  theme: {
    extend: {
      
    },
  },
  plugins: [],
}

tailwind.confiq.js

Add the @tailwind directives for each Tailwind’s layers to your styles/globals.css file. Replace everything with this code:

@tailwind base;
@tailwind components;
@tailwind utilities;

global.css

Then go to pages/index.js . Replace everything with this code:

export default function Home() {
  return (
    <h1 className="text-3xl font-bold underline">
      Hello world!
    </h1>
  )
}

index.js

Once everything is done. Restart the server by typing cmd/ctrl + C in the terminal to stop it and then npm run dev to run the server again and you should see this page on http://localhost:3000

Let’s build this page next!

Build the frontend

Let’s edit pages/index.js.

Make sure the Next.js development server is still running.
Open pages/index.js with your text editor.

Adding `Head` to `index.js`

Open the pages/index.js file and add an import for Head from next/head at the beginning of the file:

import Head from 'next/head';

Then, update the exported Home component to include the Head component:

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
    </>   
  )
}

pages/index.js

You can use this image for the title icon. Put it in the public folder

The browser tab should now say “ChatGPT”.

Building the UI

Now, update the pages/index.js to separate the sidebar and the main part of the page.

import Head from "next/head";

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={"w-full min-h-full"}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

You should now see they have been separated

Adding custom background

Create a new file style/bg.module.css and put this custom background CSS code.

.customBg{
    background-color: #1f2937;
    background-image: url("data:image/svg+xml,%3Csvg width='20' height='20' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%239C92AC' fill-opacity='0.52' fill-rule='evenodd'%3E%3Ccircle cx='3' cy='3' r='3'/%3E%3Ccircle cx='13' cy='13' r='3'/%3E%3C/g%3E%3C/svg%3E");
}

bg.module.css

You can make your background in Hero Patterns and paste the code in bg.module.css.

Update the main div from this:

<div className={"w-full min-h-full"}>

to this:

<div className={`w-full min-h-full ${custombg.customBg}`}>

Don't forget to import it into pages/index.js as custombg . Finally, your index.js should look like this:

import Head from "next/head";
import custombg from "/styles/bg.module.css";

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

Here is the result:

First, let's build the new chat button and prompt options select button. These are the only two buttons we need in the sidebar.

Adding a new chat and prompt select button

Now, copy the following code and replace everything in the index.js file:

import Head from "next/head";
import custombg from "/styles/bg.module.css";

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick="">
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange="" className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
          </div> 
        </div> 
      </div>
      
    </>
  )
}

index.js.

You should now see the new buttons have been added if you access http://localhost:3000.

A new chat and select button have been added.

💡

For the time being, the prompt options button is not working, we're going to work on it later in this tutorial.

Building the chat area

In the main area, we wanted to have two sides, the chat area, and the text input area. Let's add the input area first. Add the following code above under the Main area div :

{/* Text input area */}
<div>
    <div className="p-5 absolute bottom-0 right-0 left-0">
        <div className="flex justify-center mb-2">
        {/* ClocLoader */}
        </div>
        <form className="relative" onSubmit="">
        <input 
        type="text"
        placeholder= "Start chatting"
        value=""
        required
        onChange=""
        rows="1" 
        className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
        />  
        <button type="submit" className="right-2 bottom-3 absolute pr-2" >
            <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
            	<path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
            </svg>
        </button>
        </form> 
    </div>
</div>

or replace everything in pages/index.js with the following code:

import Head from "next/head";
import custombg from "/styles/bg.module.css";

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick="">
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange="" className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
            {/* Text input area */}
            <div>
              <div className="p-5 absolute bottom-0 right-0 left-0">
                <div className="flex justify-center mb-2">
                  {/* ClocLoader */}
                </div>
                <form className="relative" onSubmit="">
                  <input 
                    type="text"
                    placeholder= "Start chatting"
                    value=""
                    required
                    onChange=""
                    rows="1" 
                    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
                  />  
                  <button type="submit" className="right-2 bottom-3 absolute pr-2" >
                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
                      <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
                    </svg>
                  </button>
                </form> 
              </div>
            </div>
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

You should now see your page like this:

Building the chat component

For the chat area, we're going to make a new component that shows the chat between you and the OpenAI. Let's create a new folder called components and a new file called chat.js inside the folder. It should be components/chat.js .

Paste the following code:

import Image from "next/image"
import profilePic from "/public/user.png";
import openAIPic from "/public/openai.png";

export default function Chat({user}) {
    return (
        <>
            <div id="chat" className="flex justify-center m-3 pr-28 py-7 rounded-md bg-gray-700 ">
                <div className="w-1/5">
                    <Image
                        src= {profilePic}
                        className="ml-auto mr-auto rounded-sm"
                        alt="picture of you"
                        width={30}
                        height={30}
                    />
                </div>
                <div className="w-4/5 text-gray-100 text-sm" style={{whiteSpace: 'pre-wrap'}}>
                    This is you 
                </div>
            </div>
            <div id="chat" className="flex justify-center m-3 pr-28 py-7 rounded-md bg-gray-600 ">
                <div className="w-1/5">
                    <Image
                        src= {openAIPic}
                        className="ml-auto mr-auto rounded-sm"
                        alt="picture of you"
                        width={30}
                        height={30}
                    />
                </div>
                <div className="w-4/5 text-gray-100 text-sm" style={{whiteSpace: 'pre-wrap'}}>
                    This is OpenAI 
                </div>
            </div>
        </>   
    )
}

component/chat.js

You can use this image for the profilePic. Put it in the public folder.

Now we've finished the UI of our app. For the moment it's just the mockup of how we wanted it to be when the real conversation is happening.

Preparing OpenAI API key

We need the API key to connect to the OpenAI API. Let's go to the OpenAI website, you need an account to get the API key. Create one if you don't have an account. Click on your profile picture and "view API key". Create a new secret key.

Once you're done, create a new file called .env in the root folder and paste this code:

OPENAI_API_KEY=

.env

paste your secret key after the = sign.

Create a prompt list

When requesting from the API we have to provide them with some parameters including the prompt we want to send, model, temperature, max_tokens, and more.

request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }

Request queries example.

To understand more about this check them out on the OpenAI website. This is basically how you can control which model completes your request by changing the model.

OpenAI has provided a Playground where you can test and play with these settings before you want to put them in your app.

Now, we wanted to have 3 different setups for 3 different purposes, AI assistant, English to other languages, and image generator. Lets's create an array where we can save all these setups.

Put the following code in your pages/index.js file:

const promptList = [
  {
      name: "AI assistant",
      request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }
  },
  {
      name: "English to other languages",
      request: {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.1,
        max_tokens: 200,
        top_p: 1.0,
        frequency_penalty: 0.0,
        presence_penalty: 0.0,
      }
  },
  {
      name: "Image generator",
      request: {
        prompt: "",
        n: 1,
        size: "512x512",
      }
  }
] 
export {promptList};

Now your pages/index.js should look like this:

import Chat from "@/components/chat";
import Head from "next/head";
import custombg from "/styles/bg.module.css";

const promptList = [
  {
      name: "AI assistant",
      request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }
  },
  {
      name: "English to other languages",
      request: {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.1,
        max_tokens: 200,
        top_p: 1.0,
        frequency_penalty: 0.0,
        presence_penalty: 0.0,
      }
  },
  {
      name: "Image generator",
      request: {
        prompt: "",
        n: 1,
        size: "512x512",
      }
  }
] 

export default function Home() {
  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick="">
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange="" className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
            {/* Chat area */}
            <div id="chat" className="h-[90vh] overflow-auto scrollbar">
                <Chat/>
            </div>
            {/* Text input area */}
            <div>
              <div className="p-5 absolute bottom-0 right-0 left-0">
                <div className="flex justify-center mb-2">
                  {/* ClocLoader */}
                </div>
                <form className="relative" onSubmit="">
                  <input 
                    type="text"
                    placeholder= "Start chatting"
                    value=""
                    required
                    onChange=""
                    rows="1" 
                    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
                  />  
                  <button type="submit" className="right-2 bottom-3 absolute pr-2" >
                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
                      <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
                    </svg>
                  </button>
                </form> 
              </div>
            </div>
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

Build the prompt component

Once we have the prompt list, let's create a component where we can select one prompt at a time. Create a new file components/prompts.js and paste the following code:

import { promptList} from "@/pages"
export default function Prompts() {
    return (
            <>
                {promptList.map((prompt) => (
                    <option key={prompt.name} value={prompt.name}>{prompt.name}</option>
                ))}
            </>
    )
}

components/prompts.js

What happens in this code is it exports a functional component "Prompts" which returns a list of options in the form of a drop-down menu.

The code starts with an import statement that imports the "promptList" variable from the file "@/pages" which is from our index.js. The "@" symbol in the file path represents the root directory of the project.
The "promptList" is an array of objects, where each object represents a prompt. The ".map" function iterates through each item in the array, creating a new "option" element for each prompt. The "key" and "value" attributes are set to the "name" property of the prompt, and the text content of the "option" element is also set to the "name" property of the prompt.

The result of this code will be a drop-down menu that displays a list of prompts, with each prompt as an option in the menu.

In pages/index.js, we can now add the Prompts component:

import the component at the top of pages/index.js then add the component:

import Prompts from "@/components/prompts";

<div className="p-1 flex justify-center">
    <select onChange="" className="form-select appearance-none
    block
    w-full
    px-3
    py-1.5
    text-gray-100
    bg-gray-900 bg-clip-padding bg-no-repeat
    border border-slate-600
    rounded
    transition
    ease-in-out
    m-0
    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
    {/* Prompts select button  */} 
    <Prompts/> //<--- Where you add the component
    </select>
</div>

Now you can use the select button.

Handle Submit function

It's time to take the input and handle them when we enter the prompt. Replace the code the <form> tag with this code:

<form className="relative" onSubmit="">
    <input 
    type="text"
    placeholder= {generatePlaceholder(currentPrompt)}
    value={userInput} 
    required
    onChange={(e)=>setUserInput(e.target.value)} 
    rows="1" 
    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
    />  
    <button type="submit" className="right-2 bottom-3 absolute pr-2" >
    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
    <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
    </svg>
    </button>
</form>

New form tag.

We've updated the form properties to make it do something when we submit some text.

placeholder is set to the result of calling the generatePlaceholder function and passing in the currentPrompt.
value is set to the "userInput" state.
required is a boolean attribute that specifies the input must be filled out before the form can be submitted.
onChange is an event handler that sets the userInput state when the input value changes. The setUserInput function is called and passed the event target's value.

Now, let's declare all the states and functions needed to make it work.

Create `clearChat` function for the New chat button

Import and declare the mesages useState Hook under the export default function Home() function and create a clearChat function.

💡

If you're confused about where to put this code, Don't worry I will show the whole code what your code should look like when everything is working.

import { useState } from "react";

//...code

export default function Home() {
  // Save and set conversation
  const [messages, setMessages] = useState([]);
  
  // Set a new chat
  function clearChat() {
    setMessages([]);
  }
}

The useState is a hook, that is used to save and set a conversation between two users. The hook is invoked with an initial value of an empty array, which is used to store the messages in the conversation. The hook returns an array with two elements, the first is the current state value (in this case, messages), and the second is a setter function that updates the state value (in this case, setMessages).
We also include a function called clearChat which sets a new chat. This function is called by setting the state value messages to an empty array using the setMessages setter function. This will clear any existing messages and start a new chat.

Call the clearChat function in the New chat button onClick event handler.

{/* New chat */}
<div>
    <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick={clearChat}>
    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
    <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
    </svg>
    <h2 className="text-sm px-1">
    New chat
    </h2>
    </div>
</div>

But nothing will happen when you hit the new Chat button, simply because we don't have any chat yet. You will see it in action when later in this tutorial.

Create `setPrompt` function for the prompt select button

Let's declare the currentPrompt useState Hook under the export default function Home() and create a SetPrompt and generatePlaceholderfunction.

// To generate placeholder
function generatePlaceholder(currentPrompt) { 
  switch(currentPrompt) {
    case promptList[0].name:
      return "Start chatting"
    case promptList[1].name:
      return "Insert any text you want to translate into French,Spanish,Japanese and Malay: "
    case promptList[2].name:
      return "Insert your prompt to generate image:"
    default:
      return "Start chatting."
  }
}

export default function Home() {
  // .....code
  
  // Save and set current prompt
  const [currentPrompt, setCurrentPrompt] = useState(`AI assistant`);
  
  // .... code
  
  // Set prompt
  function setPrompt(event) {
    event.preventDefault();
    clearChat();
    setCurrentPrompt(event.target.value);
  }
}

We start with a function called generatePlaceholder which generates a placeholder string based on the current prompt. This function takes the currentPrompt as an argument and returns a different placeholder string based on the value of currentPrompt.
The generatePlaceholder function uses a switch statement to determine the correct placeholder string based on the current prompt. If the current prompt is equal to the first element in the "promptList" array, the function returns the string "Start chatting". If the current prompt is equal to the second element in the "promptList" array, the function returns the string "Insert any text you want to translate into French, Spanish, Japanese, and Malay:". If the current prompt is equal to the third element in the "promptList" array, the function returns the string "Insert your prompt to generate image:". If the current prompt does not match any of these cases, the function returns the string "Start chatting."
Then we declare useState hook to save and set the current prompt. The hook is invoked with an initial value of "AI assistant", which is used to store the current prompt. The hook returns an array with two elements, the first is the current state value (in this case, currentPrompt), and the second is a setter function that updates the state value (in this case, setCurrentPrompt).
The component also includes a function called setPrompt which sets the current prompt. This function is called when we set the prompt through the prompt select button, and it's triggered by an event. The function starts by calling "event.preventDefault()", which prevents the default behavior of the event (e.g., a form submission reloading the page).
Next, the function calls the clearChat function to clear any existing chat messages so that we can have a fresh conversation when we want to change the prompt. Then, the function calls setCurrentPrompt and passes in the value of the event target to set the current prompt.
The setPrompt function is used to update the current prompt whenever you select a new prompt from a select button. The new prompt will be displayed as the placeholder text in an input field, and you can start typing your response based on the placeholder.

Call the setPrompt function in the select button onchange event handler.

<select onChange={setPrompt} className="form-select appearance-none
    block
    w-full
    px-3
    py-1.5
    text-gray-100
    bg-gray-900 bg-clip-padding bg-no-repeat
    border border-slate-600
    rounded
    transition
    ease-in-out
    m-0
    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
    {/* Prompts select button  */}
    <Prompts/>
</select>

Now when you select a different prompt option, you will see the placeholder is changing according to the selected prompt.

The placeholder is changing based on the `currentPrompt`.

If it’s still not working, your current pages/index.js should look like this:

import Chat from "@/components/chat";
import Prompts from "@/components/prompts";
import Head from "next/head";
import custombg from "/styles/bg.module.css";
import { useState } from "react";

const promptList = [
  {
      name: "AI assistant",
      request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }
  },
  {
      name: "English to other languages",
      request: {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.1,
        max_tokens: 200,
        top_p: 1.0,
        frequency_penalty: 0.0,
        presence_penalty: 0.0,
      }
  },
  {
      name: "Image generator",
      request: {
        prompt: "",
        n: 1,
        size: "512x512",
      }
  }
]
export {promptList}; 

// To generate placeholder
function generatePlaceholder(currentPrompt) { 
  switch(currentPrompt) {
    case promptList[0].name:
      return "Start chatting"
    case promptList[1].name:
      return "Insert any text you want to translate into French,Spanish,Japanese and Malay: "
    case promptList[2].name:
      return "Insert your prompt to generate image:"
    default:
      return "Start chatting."
  }
}

export default function Home() {
  // Save and set conversation
  const [messages, setMessages] = useState([]);
  // Save and set current prompt
  const [currentPrompt, setCurrentPrompt] = useState(`AI assistant`);
  // Save and set userinput
  const [userInput,setUserInput] = useState("");

  // Set a new chat
  function clearChat() {
    setMessages([]);
  }

  // Set prompt
  function setPrompt(event) {
    event.preventDefault();
    clearChat();
    setCurrentPrompt(event.target.value);
  }

  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick={clearChat}>
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange={setPrompt} className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    <Prompts/>
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
            {/* Chat area */}
            <div id="chat" className="h-[90vh] overflow-auto scrollbar">
                <Chat/>
            </div>
            {/* Text input area */}
            <div>
              <div className="p-5 absolute bottom-0 right-0 left-0">
                <div className="flex justify-center mb-2">
                  {/* ClocLoader */}
                </div>
                <form className="relative" onSubmit="">
                  <input 
                    type="text"
                    placeholder= {generatePlaceholder(currentPrompt)}
                    value={userInput} 
                    required
                    onChange={(e)=>setUserInput(e.target.value)} 
                    rows="1" 
                    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
                  />  
                  <button type="submit" className="right-2 bottom-3 absolute pr-2" >
                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
                      <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
                    </svg>
                  </button>
                </form> 
              </div>
            </div>
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

Create `submit` function to handle the input

This function is going to be an async function. Since we're going to fetch the API from here, it allows our application to continue processing other tasks while it waits for the result of this asynchronous function.

Under the Home function, let's create a function called submit .

export default function Home() {
	// .....code
    
    // Handle submit 
  async function submit(event) {
    event.preventDefault();

  }
  
  // .....code
}

Don't forget to call this function for onSubmit event handler in <form> tag

// .....code
<form className="relative" onSubmit={submit}>
// .....code

Currently, we use event.preventDefault to prevent it from doing the default behavior which is to refresh the page and send the form data to the server. Because we wanted to use JavaScript to submit the form, we prevent this behavior.

The next thing we want to do when we receive the input is to show them in the chat area. First, we have to differentiate which one is us and which one is OpenAI. Let's declare an object for that purpose.

export default function Home() {
   // .....code
    
   // message type
  const messageType = {me: "me", openAI: "openAI"};
  
  // .....code
}

Next, we can now save userInput into the messages state.

  // Handle submit 
  async function submit(event) {
    event.preventDefault();
    // temporary 
    let tempMessages = [...messages, {user: `${messageType.me}`, message: `${userInput}`}];
    // put the userInput in the messages
    setMessages(tempMessages);
    // clear user input
    setUserInput("");
  }

The first line of the function calls event.preventDefault() which is used to prevent the default behavior of a submit event, which is to refresh the page.
Then, the function creates a new array tempMessages which contains the current messages array and a new object that represents the user's input message. The new object contains two properties: messageType which is equal to messageType.me and message which is equal to userInput.
The function then sets the messages state to the new tempMessages array using the setMessages function and clear user input by setUserInput to "".

Show the message in the chat area

Open components/chat.js and replace everything with this code:

import Image from "next/image";
import profilePic from "/public/user.png";
import openAIPic from "/public/openai.png";


export default function Chat({user}) {

    return (  
            <div id="chat" className={`flex justify-center m-3 pr-28 py-7 rounded-md ${user.user === "me" ? "bg-gray-700" : "bg-gray-600"} `}>
                <div className="w-1/5">
                    <Image
                        src= {user.user === "me" ? profilePic : openAIPic}
                        className="ml-auto mr-auto rounded-sm"
                        alt="picture of you"
                        width={30}
                        height={30}
                    />
                </div>
                <div className="w-4/5 text-gray-100 text-sm" style={{whiteSpace: 'pre-wrap'}}>
                   {user.image ? <img src={user.image}/> : user.message}  
                </div>
            </div>   
    )
}

chat.js

in index.js we should check if there's at least one message to show them in the chat area. Then we loop through every message and pass user into the chat component as a prop. Replace everything in the {/* Chat area */} with this code:

{/* Chat area */}
<div id="chat" className="h-[90vh] overflow-auto scrollbar">
    {messages.length > 0 && 
    messages.map((user, index)=>(
    	<Chat key={index} user={user}/>
    ))
    }
</div>

If everything is done correctly, you can now type some messages and they will appear in the chat area. Also when you click the New chat, it will reset the chat area for a new conversation.

here is the full pages/index.js code for your reference:

import Chat from "@/components/chat";
import Prompts from "@/components/prompts";
import Head from "next/head";
import custombg from "/styles/bg.module.css";
import { useState } from "react";

const promptList = [
  {
      name: "AI assistant",
      request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }
  },
  {
      name: "English to other languages",
      request: {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.1,
        max_tokens: 200,
        top_p: 1.0,
        frequency_penalty: 0.0,
        presence_penalty: 0.0,
      }
  },
  {
      name: "Image generator",
      request: {
        prompt: "",
        n: 1,
        size: "512x512",
      }
  }
]
export {promptList}; 

// To generate placeholder
function generatePlaceholder(currentPrompt) { 
  switch(currentPrompt) {
    case promptList[0].name:
      return "Start chatting"
    case promptList[1].name:
      return "Insert any text you want to translate into French,Spanish,Japanese and Malay: "
    case promptList[2].name:
      return "Insert your prompt to generate image:"
    default:
      return "Start chatting."
  }
}

export default function Home() {
  // Save and set conversation
  const [messages, setMessages] = useState([]);
  // Save and set current prompt
  const [currentPrompt, setCurrentPrompt] = useState(`AI assistant`);
  // Save and set userinput
  const [userInput,setUserInput] = useState("");
  // message type
  const messageType = {me: "me", openAI: "openAI"};

  // Set a new chat
  function clearChat() {
    setMessages([]);
  }

  // Set prompt
  function setPrompt(event) {
    event.preventDefault();
    clearChat();
    setCurrentPrompt(event.target.value);
  }

  // Handle submit 
  async function submit(event) {
    event.preventDefault();
    // temporary message
    let tempMessages = [...messages, {user: `${messageType.me}`, message: `${userInput}`}];
    // put the userInput in the messages
    setMessages(tempMessages);
    // clear user input
    setUserInput("");
  }

  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick={clearChat}>
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange={setPrompt} className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    <Prompts/>
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
            {/* Chat area */}
            <div id="chat" className="h-[90vh] overflow-auto scrollbar">
              {messages.length > 0 && 
                messages.map((user, index)=>(
                  <Chat key={index} user={user}/>
                ))
              }
            </div>
            {/* Text input area */}
            <div>
              <div className="p-5 absolute bottom-0 right-0 left-0">
                <div className="flex justify-center mb-2">
                  {/* ClocLoader */}
                </div>
                <form className="relative" onSubmit={submit}>
                  <input 
                    type="text"
                    placeholder= {generatePlaceholder(currentPrompt)}
                    value={userInput} 
                    required
                    onChange={(e)=>setUserInput(e.target.value)} 
                    rows="1" 
                    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
                  />  
                  <button type="submit" className="right-2 bottom-3 absolute pr-2" >
                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
                      <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
                    </svg>
                  </button>
                </form> 
              </div>
            </div>
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

Call the API

First, we have to call the API from the server side which we're going to create later. In pages/index.js find this line of code:

// Handle submit
async function submit(event) {
	// .....code
}

Replace them with the following code:

  // Handle submit 
  async function submit(event) {
    event.preventDefault();
    // Get instruction prompt
    const instructionPrompt = generateInstructionPrompt(userInput, currentPrompt)
    // Temporary message
    let tempMessages = [...messages, {user: `${messageType.me}`, message: `${userInput}`}];
    // Put the userInput in the messages
    setMessages(tempMessages);
    // Clear user input
    setUserInput("");

    // Call the API
    try {
      const response = await fetch("api/generate",{
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: generateBody(currentPrompt, messages, userInput, tempMessages, instructionPrompt)
      });
      
      // If we get unsuccessful response
      const data = await response.json();
      if (response.status !== 200) {
        throw data.error || new Error(`Request failed with status ${response.status}`);
      }
      console.log(data.openAI);
      setMessages([...tempMessages, {user: messageType.openAI, message: `${data.openAI && data.openAI.trimStart()}`, image: data.image }]);
    } 
    catch (error) {
      // Consider implementing your own error handling logic here
      console.error(error);
      alert(error.message);
    }
  }

submit function.

The function uses the fetch API to make a POST request to the API endpoint /api/generate with a request body generated by the generateBody function. The request body contains information such as the current prompt, messages, user input, temporary messages, and the instruction prompt.
If the API returns a successful response, the function logs the response data and adds the response from OpenAI to the list of messages using the setMessages function.
If the API returns an unsuccessful response or if an error occurs, the error message is logged to the console and an alert with the error message is displayed to the user.

Generate instruction prompt

OpenAI models can do everything from generating original stories to performing complex text analysis. Because they can do so many things, you have to be explicit in describing what you want. Showing, not just telling, is often the secret to a good prompt. These models can be used as a starting point for your own models, or you can fine-tune them to meet your specific needs.

So we have to show them what we wanted the model to do for us. These are some examples of how to explicitly give them the instructions.

Add the following code in index.js you can put them under the prompList array:

function generateInstructionPrompt(userInput, currentPrompt) {
  let instructionPrompt = ``;
  switch (currentPrompt) {
    case promptList[0].name:
         instructionPrompt = `The following is a conversation with an AI assistant. The assistant is helpful, creative, clever, and very friendly.
         \nHuman: Hello, who are you?
         \nAI: I am an AI created by OpenAI. How can I help you today?
         \nHuman: ${userInput}
         \nAI:`
         break;
    case promptList[1].name:
        instructionPrompt = `Translate this into four languages 1. French, 2. Spanish, 3. Japanese and 4. Malay:\n\n${userInput}\n\n`
        break;
    case promptList[2].name:
        instructionPrompt = `${userInput}`
        break;
    default: 
    instructionPrompt = `The following is a conversation with an AI assistant. The assistant is helpful, creative, clever, and very friendly.
    \n\nHuman: Hello, who are you?
    \nAI: I am an AI created by OpenAI. How can I help you today?
    \nHuman: ${userInput}`
  }
  return instructionPrompt;
}

generateInstructionPrompt function.

This code defines a function generateInstructionPrompt that generates an instruction prompt based on the current prompt selected by the user and the user input. The function takes two parameters: userInput and currentPrompt.

The function starts with an empty string instructionPrompt and then uses a switch statement to set the value of instructionPrompt based on the value of currentPrompt. The switch statement compares the value of currentPrompt with the names of the prompts in an array promptList.

If the value of currentPrompt matches the name of the first prompt in promptList, the instructionPrompt is set to a string that contains the instructions for a conversation with an AI assistant. The userInput is included in the instructions.
If the value of currentPrompt matches the name of the second prompt in promptList, the instructionPrompt is set to a string that contains the instructions for translating a text into four languages: French, Spanish, Japanese, and Malay. The userInput is included in the instructions.
If the value of currentPrompt matches the name of the third prompt in promptList, the instructionPrompt is set to the userInput.
If the value of currentPrompt doesn't match any of the names in promptList, the instructionPrompt is set to a string that contains the default instructions for a conversation with an AI assistant. The userInput is included in the instructions.

Finally, the function returns the instructionPrompt.

Create a function to generate the body

Different prompt needs different body when we send the request to the API. So we have to create a function to generate a specific body for each prompt.

Add the following code in index.js you can put them under the generateInstructionPrompt function:

function generateBody(currentPrompt, messages, userInput, tempMessages, instructionPrompt) { 
  let body = "";
  switch(currentPrompt) {
    case promptList[0].name:
      body = JSON.stringify({input: `${messages.length === 0 ? instructionPrompt : tempMessages.map(m => m.message).join(" ")}`, prompt: currentPrompt})
      break;
    case promptList[1].name:
      body = JSON.stringify({input: instructionPrompt, prompt: currentPrompt})
    case promptList[2].name:
      body = JSON.stringify({input: instructionPrompt, prompt: currentPrompt})
      break;
    default:
      body = JSON.stringify({input: `${messages.length === 0 ? instructionPrompt : tempMessages.map(m => m.message).join(" ")}`, prompt: currentPrompt})
  }
  return body
}

generateBody function.

The function generates a request body to be used in a fetch API call. The body is generated based on the value of currentPrompt which is used to determine the type of prompt for the API call.

It uses a switch statement to determine the type of prompt. If currentPrompt is equal to promptList[0].name, the body is set to a JSON string with the following properties:

input: This is either the value of instructionPrompt if messages.length is equal to 0, or a string concatenated from the message properties of objects in the tempMessages array.
prompt: This is equal to the value of currentPrompt.

If currentPrompt is equal to promptList[1].name or promptList[2].name, the body is set to a JSON string with the following properties:

input: This is equal to the value of instructionPrompt.
prompt: This is equal to the value of currentPrompt.

If currentPrompt does not match any of the cases, the body is set to a JSON string with the following properties:

input: This is either the value of instructionPrompt if messages.length is equal to 0, or a string concatenated from the message properties of objects in the tempMessages array.
prompt: This is equal to the value of currentPrompt.

Finally, the function returns the generated body.

Create the `pages/api/generate` endpoint

First., we need to install OpenAI official Node.js library to interact with the API through HTTP requests. Run this command in the terminal:

npm install openai

If you don't know, any file inside the folder pages/api is mapped to /api/* and will be treated as an API endpoint instead of a page. They are server-side-only bundles and won't increase your client-side bundle size.

This is where we're going to make the request to OpenAI API. Let's create a new file pages/api/generate.js and populate it with the following contents:

import { Configuration, OpenAIApi } from "openai";
import { promptList} from "@/pages"
const configuration = new Configuration({
    apiKey: process.env.OPENAI_API_KEY,
});

// using the secret key for authentication
const openai = new OpenAIApi(configuration);

// the function is called from index.js when it fetch(api/generate)
export default async function(req, res) {
    if (!configuration.apiKey) {
        res.status(500).json({
          error: {
            message: "OpenAI API key not configured, please follow instructions in README.md",
          }
        });
        return;
    }

    // Get input and currentPrompt
    const { input, prompt }  = req.body;

    const APIrequest = generateAPIrequest(prompt,input);

    // If current prompt is Image generator
    if(prompt === "Image generator") {
        // Request OpenAI API
        try {

            const response = await openai.createImage(APIrequest);
            res.status(200).json({image:response.data.data[0].url})
        } catch(error) {
            // Consider adjusting the error handling logic for your use case
            if(error.response){
                console.error(error.response.data, error.response.status);
                res.status(error.response.status).json(error.response.data);
            } else {
                console.log(`Error with OpenAI API request: ${error.message}`);
                res.status(500).json({
                    error: {
                        message: 'An error occurred during your request.',
                    }
                });
            }
        }

        return;
    }

    // Request OpenAI API if current prompt is not Image generator
    try {
        const response = await openai.createCompletion(APIrequest); 
        res.status(200).json({openAI:response.data.choices[0].text})
    } catch(error) {
        // Consider adjusting the error handling logic for your use case
        if(error.response){
            console.error(error.response.data, error.response.status);
            res.status(error.response.status).json(error.response.data);
        } else {
            console.log(`Error with OpenAI API request: ${error.message}`);
            res.status(500).json({
                error: {
                    message: 'An error occurred during your request.',
                }
            });
        }
    }
}

// Selecting which request to send based on current prompt and injecting user input into the request
function generateAPIrequest(currentPrompt, input) {
    let request = {};
    for(let i = 0; i < promptList.length; i ++) {
        if(currentPrompt === promptList[i].name)
        {
            promptList[i].request.prompt = input;
            request = promptList[i].request;
        }
    }
    return request;
}

pages/api/generate.js

The code starts by importing the necessary libraries: Configuration and OpenAIApi from the openai library, and promptList from the @/pages file. The configuration object is then instantiated with the API key, which is taken from the environment variables or .env which we created earlier.
The function then uses the openai object to make an API request to the OpenAI API. The request type (image generation or completion generation) is determined by the value of the prompt field in the request body.
If the prompt is "Image generator", the code makes a call to openai.createImage with the request details. If the request is successful, the URL of the generated image is returned in the response. If the request fails, the code logs the error message and returns an error status.
Otherwise, if the prompt is not an "Image generator", the code makes a call to openai.createCompletion to generate a text completion. The response from the API is then returned in the HTTP response.
The code also includes error-handling logic to handle errors that may occur during the API request. If an error occurs, the code logs the error and returns an error status in the HTTP response.
The generateAPIrequest function is called to determine the API request to be made, based on the currentPrompt and the user's input. The function loops through the elements of the promptList array and sets the request object to the correct request, based on the value of currentPrompt. The request object is then returned by the function.

Now everything is working! go and try to use the app.

Final touch

For this final touch, we're going to add auto-scrolling and loading animation to make this app a bit more lively.

Add auto-scrolling

To make everything quick, let's install react-scroll using the terminal:

npm install react-scroll

and add the following code in pages/index.js :

import { useEffect } from "react";
import { animateScroll as scroll } from 'react-scroll';

//....code

export default function Home() {
//.....code
	useEffect(() => {
    scroll.scrollToBottom({
        containerId: "chat",
        duration: 250,
      });
    }, [messages])
//.....code
}

This code uses the useEffect hook in React to perform a side effect whenever the messages state updates.
The effect is to scroll the chat container to the bottom when the messages state updates. This is to ensure that the user is always viewing the latest message in the chat log.
The scroll.scrollToBottom function is from the scroll-behavior library and it is used to scroll the chat container to the bottom. The containerId property is set to "chat", meaning that the chat container element should have an ID of "chat". The duration property is set to 250 milliseconds, meaning that the scrolling animation should last for 250 milliseconds.
The useEffect hook takes two arguments: the first is a function that performs the side effect, and the second is an array of dependencies. In this case, the dependency is [messages], meaning that the effect will only run when the messages state changes.

Style the scrollbar

This is optional, just to make the scrollbar consistent with the design.

Open styles/globals.css and this following code:

@tailwind base;
@tailwind components;
@tailwind utilities;

@layer utilities {
    .scrollbar::-webkit-scrollbar {
      width: 10px;
      height: 10px;
    }
  
    .scrollbar::-webkit-scrollbar-track {
      background: #1F2937;
    }
  
    .scrollbar::-webkit-scrollbar-thumb {
      background: #374151;
      border-radius: 100vh;
    }
  
    .scrollbar::-webkit-scrollbar-thumb:hover {
      background: #4B5563;
    }
}

Add loading animation

The next and last thing is the loading animation. We're going to use React Spinners by David Hu. Go check his page for more loading animation. For this tutorial, we're going to use CloakLoader animation.

Use this command to install React Spinners:

npm install --save react-spinners

Then we declare loading useState Hook:

export default function Home() {
  // loading useState
  const [loading, setLoading] = useState(false);
  
  //.....code
}

We wanted the loading animation to be true when the request is happening. So we set it to true when submitting and then set it back to false when we get the response (success or error).

In pages/index.js find the following line and set the loading animation according to this code:

// Handle submit 
async function submit(event) {
    event.preventDefault();
    // Set loading animation to true
    setLoading(true);
    
    //.....code
    
    try {
      //....code
      // Set loading animation to false
      setLoading(false);
    }
    catch (error) {
      // Set loading animation to false
      setLoading(false);
      //.....code
    }
}

The last step is to add the loading component. Find this {/* ClocLoader */} line and add the component.

import { ClockLoader } from 'react-spinners';

//....code

//....code

//....code

<div className="flex justify-center mb-2">
	{/* ClocLoader */}
	<ClockLoader size={20} color={"#F3F4F6"} loading={loading} />
</div>

You can try it now, to make sure it's working.

There you go! We've finally finished the app. If you're still here, thank you for taking the time to read this tutorial. I hope you have gained a deeper understanding of the code and its functionality. If you have any questions or concerns, feel free to reach out to me. I am always happy to help. I hope this tutorial has been a valuable resource for you and that you can put your newfound knowledge to good use. Cheers!

Full code

Something Wrong?

If it’s still not working. This is the whole code for your reference. (Next js file structure)

`pages/index.js`

import Chat from "@/components/chat";
import Prompts from "@/components/prompts";
import Head from "next/head";
import custombg from "/styles/bg.module.css";
import { useState } from "react";
import { useEffect } from "react";
import { animateScroll as scroll } from 'react-scroll';
import { ClockLoader } from 'react-spinners';

const promptList = [
  {
      name: "AI assistant",
      request : {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.9,
        max_tokens: 150,
        top_p: 1,
        frequency_penalty: 0,
        presence_penalty: 0.6,
        stop: [" Human:", " AI:"],
      }
  },
  {
      name: "English to other languages",
      request: {
        model: "text-davinci-003",
        prompt: "",
        temperature: 0.1,
        max_tokens: 200,
        top_p: 1.0,
        frequency_penalty: 0.0,
        presence_penalty: 0.0,
      }
  },
  {
      name: "Image generator",
      request: {
        prompt: "",
        n: 1,
        size: "512x512",
      }
  }
]
export {promptList}; 

// Generate instruction prompt
function generateInstructionPrompt(userInput, currentPrompt) {
  let instructionPrompt = ``;
  switch (currentPrompt) {
    case promptList[0].name:
         instructionPrompt = `The following is a conversation with an AI assistant. The assistant is helpful, creative, clever, and very friendly.
         \nHuman: Hello, who are you?
         \nAI: I am an AI created by OpenAI. How can I help you today?
         \nHuman: ${userInput}
         \nAI:`
         break;
    case promptList[1].name:
        instructionPrompt = `Translate this into four languages 1. French, 2. Spanish, 3. Japanese and 4. Malay:\n\n${userInput}\n\n`
        break;
    case promptList[2].name:
        instructionPrompt = `${userInput}`
        break;
    default: 
    instructionPrompt = `The following is a conversation with an AI assistant. The assistant is helpful, creative, clever, and very friendly.
    \n\nHuman: Hello, who are you?
    \nAI: I am an AI created by OpenAI. How can I help you today?
    \nHuman: ${userInput}`
  }
  return instructionPrompt;
}

// Generate body
function generateBody(currentPrompt, messages, userInput, tempMessages, instructionPrompt) { 
  let body = "";
  switch(currentPrompt) {
    case promptList[0].name:
      body = JSON.stringify({input: `${messages.length === 0 ? instructionPrompt : tempMessages.map(m => m.message).join(" ")}`, prompt: currentPrompt})
      break;
    case promptList[1].name:
      body = JSON.stringify({input: instructionPrompt, prompt: currentPrompt})
    case promptList[2].name:
      body = JSON.stringify({input: instructionPrompt, prompt: currentPrompt})
      break;
    default:
      body = JSON.stringify({input: `${messages.length === 0 ? instructionPrompt : tempMessages.map(m => m.message).join(" ")}`, prompt: currentPrompt})
  }
  return body
}

// To generate placeholder
function generatePlaceholder(currentPrompt) { 
  switch(currentPrompt) {
    case promptList[0].name:
      return "Start chatting"
    case promptList[1].name:
      return "Insert any text you want to translate into French,Spanish,Japanese and Malay: "
    case promptList[2].name:
      return "Insert your prompt to generate image:"
    default:
      return "Start chatting."
  }
}

export default function Home() {
  // loading useState
  const [loading, setLoading] = useState(false);
  // Save and set conversation
  const [messages, setMessages] = useState([]);
  // Save and set current prompt
  const [currentPrompt, setCurrentPrompt] = useState(`AI assistant`);
  // Save and set userinput
  const [userInput,setUserInput] = useState("");
  // Message type
  const messageType = {me: "me", openAI: "openAI"};

  // Scroll the chat container to the bottom
  useEffect(() => {
    scroll.scrollToBottom({
        containerId: "chat",
        duration: 250,
      });
  }, [messages])

  // Set a new chat
  function clearChat() {
    setMessages([]);
  }

  // Set prompt
  function setPrompt(event) {
    event.preventDefault();
    clearChat();
    setCurrentPrompt(event.target.value);
  }

  // Handle submit 
  async function submit(event) {
    event.preventDefault();
    // Set loading animation to true
    setLoading(true);
    // Get instruction prompt
    const instructionPrompt = generateInstructionPrompt(userInput, currentPrompt)
    // Temporary message
    let tempMessages = [...messages, {user: `${messageType.me}`, message: `${userInput}`}];
    // Put the userInput in the messages
    setMessages(tempMessages);
    // Clear user input
    setUserInput("");

    // Call the API
    try {
      const response = await fetch("api/generate",{
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: generateBody(currentPrompt, messages, userInput, tempMessages, instructionPrompt)
      });
      
      // If we get unsuccessful response
      const data = await response.json();
      if (response.status !== 200) {
        throw data.error || new Error(`Request failed with status ${response.status}`);
      }
      setMessages([...tempMessages, {user: messageType.openAI, message: `${data.openAI && data.openAI.trimStart()}`, image: data.image }]);
      // Set loading animation to false
      setLoading(false);
    } 
    catch (error) {
      // Set loading animation to false
      setLoading(false);
      // Consider implementing your own error handling logic here
      console.error(error);
      alert(error.message);
    }
  }

  return (
    <>
      {/* Head */} 
      <Head>
          <title>ChatGPT</title>
          <link rel="icon" href="/openai.png"/>
      </Head>
      {/* Main */}
      <div className={`w-full min-h-full ${custombg.customBg}`}>
        <div className="flex">
          {/* Sidebar */}
          <div className="bg-gray-800 h-screen w-1/5 p-2">
            <div>
              {/* New chat */}
              <div>
                <div className="text-gray-100 flex items-center text-xl p-3  bg-gray-900 rounded-md border border-slate-600 shadow-md m-1 hover:bg-gray-700" onClick={clearChat}>
                    <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" strokeWidth={1.5} stroke="currentColor" className="w-6 h-6">
                      <path strokeLinecap="round" strokeLinejoin="round" d="M12 6v12m6-6H6" />
                    </svg>
                    <h2 className="text-sm px-1">
                        New chat
                    </h2>
                </div>
              </div>
              {/* Prompts */}
              <div>
                  <h2 className="text-sm px-2 py-1 text-gray-100">
                        Prompt options:
                  </h2>
                  <div className="p-1 flex justify-center">
                    <select onChange={setPrompt} className="form-select appearance-none
                    block
                    w-full
                    px-3
                    py-1.5
                    text-gray-100
                    bg-gray-900 bg-clip-padding bg-no-repeat
                    border border-slate-600
                    rounded
                    transition
                    ease-in-out
                    m-0
                    focus:text-gray-100 focus:bg-gray-900 focus:border-slate-600 focus:outline-none">
                    {/* Prompts select button  */}
                    <Prompts/>
                    </select>
                  </div>
              </div>
            </div>
          </div> 
          {/* Main area */}
          <div className="w-4/5 relative">
            {/* Chat area */}
            <div id="chat" className="h-[90vh] overflow-auto scrollbar">
              {messages.length > 0 && 
                messages.map((user, index)=>(
                  <Chat key={index} user={user}/>
                ))
              }
            </div>
            {/* Text input area */}
            <div>
              <div className="p-5 absolute bottom-0 right-0 left-0">
                <div className="flex justify-center mb-2">
                  {/* ClocLoader */}
                  <ClockLoader size={20} color={"#F3F4F6"} loading={loading} />
                </div>
                <form className="relative" onSubmit={submit}>
                  <input 
                    type="text"
                    placeholder= {generatePlaceholder(currentPrompt)}
                    value={userInput} 
                    required
                    onChange={(e)=>setUserInput(e.target.value)} 
                    rows="1" 
                    className="block p-2.5 w-full text-sm text-gray-50 bg-gray-700 rounded-lg focus:outline-none ring-gray-500 focus:border-gray-500 shadow-md"
                  />  
                  <button type="submit" className="right-2 bottom-3 absolute pr-2" >
                    <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="gray" className="w-5 h-5">
                      <path d="M3.105 2.289a.75.75 0 00-.826.95l1.414 4.925A1.5 1.5 0 005.135 9.25h6.115a.75.75 0 010 1.5H5.135a1.5 1.5 0 00-1.442 1.086l-1.414 4.926a.75.75 0 00.826.95 28.896 28.896 0 0015.293-7.154.75.75 0 000-1.115A28.897 28.897 0 003.105 2.289z" />
                    </svg>
                  </button>
                </form> 
              </div>
            </div>
          </div> 
        </div> 
      </div>
      
    </>
  )
}

pages/index.js

API

`api/generate.js`

import { Configuration, OpenAIApi } from "openai";
import { promptList} from "@/pages"
const configuration = new Configuration({
    apiKey: process.env.OPENAI_API_KEY,
});

// using the secret key for authentication
const openai = new OpenAIApi(configuration);

// the function is called from index.js when it fetch(api/generate)
export default async function(req, res) {
    if (!configuration.apiKey) {
        res.status(500).json({
          error: {
            message: "OpenAI API key not configured, please follow instructions in README.md",
          }
        });
        return;
    }

    // Get input and currentPrompt
    const { input, prompt }  = req.body;

    const APIrequest = generateAPIrequest(prompt,input);

    // If current prompt is Image generator
    if(prompt === "Image generator") {
        // Request OpenAI API
        try {

            const response = await openai.createImage(APIrequest);
            res.status(200).json({image:response.data.data[0].url})
        } catch(error) {
            // Consider adjusting the error handling logic for your use case
            if(error.response){
                console.error(error.response.data, error.response.status);
                res.status(error.response.status).json(error.response.data);
            } else {
                console.log(`Error with OpenAI API request: ${error.message}`);
                res.status(500).json({
                    error: {
                        message: 'An error occurred during your request.',
                    }
                });
            }
        }

        return;
    }

    // Request OpenAI API if current prompt is not Image generator
    try {
        const response = await openai.createCompletion(APIrequest); 
        res.status(200).json({openAI:response.data.choices[0].text})
    } catch(error) {
        // Consider adjusting the error handling logic for your use case
        if(error.response){
            console.error(error.response.data, error.response.status);
            res.status(error.response.status).json(error.response.data);
        } else {
            console.log(`Error with OpenAI API request: ${error.message}`);
            res.status(500).json({
                error: {
                    message: 'An error occurred during your request.',
                }
            });
        }
    }
}

// Selecting which request to send based on current prompt and injecting user input into the request
function generateAPIrequest(currentPrompt, input) {
    let request = {};
    for(let i = 0; i < promptList.length; i ++) {
        if(currentPrompt === promptList[i].name)
        {
            promptList[i].request.prompt = input;
            request = promptList[i].request;
        }
    }
    return request;
}

api/generate.js

Components

`components/chat.js`

import Image from "next/image";
import profilePic from "/public/user.png";
import openAIPic from "/public/openai.png";


export default function Chat({user}) {

    return (  
            <div id="chat" className={`flex justify-center m-3 pr-28 py-7 rounded-md ${user.user === "me" ? "bg-gray-700" : "bg-gray-600"} `}>
                <div className="w-1/5">
                    <Image
                        src= {user.user === "me" ? profilePic : openAIPic}
                        className="ml-auto mr-auto rounded-sm"
                        alt="picture of you"
                        width={30}
                        height={30}
                    />
                </div>
                <div className="w-4/5 text-gray-100 text-sm" style={{whiteSpace: 'pre-wrap'}}>
                   {user.image ? <img src={user.image}/> : user.message}  
                </div>
            </div>   
    )
}

components/chat.js

`components/prompt.js`

import { promptList} from "@/pages"
export default function Prompts() {
    return (
            <>
                {promptList.map((prompt) => (
                    <option key={prompt.name} value={prompt.name}>{prompt.name}</option>
                ))}
            </>
    )
}

components/prompt.js

Styles

`styles/bg.module.css`

.customBg{
    background-color: #1f2937;
    background-image: url("data:image/svg+xml,%3Csvg width='20' height='20' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%239C92AC' fill-opacity='0.52' fill-rule='evenodd'%3E%3Ccircle cx='3' cy='3' r='3'/%3E%3Ccircle cx='13' cy='13' r='3'/%3E%3C/g%3E%3C/svg%3E");
  }

styles/bg.module.css

`styles/globals.css`

@tailwind base;
@tailwind components;
@tailwind utilities;

@layer utilities {
    .scrollbar::-webkit-scrollbar {
      width: 10px;
      height: 10px;
    }
  
    .scrollbar::-webkit-scrollbar-track {
      background: #1F2937;
    }
  
    .scrollbar::-webkit-scrollbar-thumb {
      background: #374151;
      border-radius: 100vh;
    }
  
    .scrollbar::-webkit-scrollbar-thumb:hover {
      background: #4B5563;
    }
}

styles/globals.css

Environment

`.env`

OPENAI_API_KEY=Your OpenAI secret key

FAQs:

How do I get started with OpenAI API?

Getting started with OpenAI API is simple and straightforward. Here are the steps you can follow to get up and running:

Sign up for an OpenAI account: You can sign up for an OpenAI account on their website. You'll need to provide some basic information, including your name and email address.
Obtain an API key: Once you've signed up, you'll be able to obtain an API key. This key will be used to access the OpenAI API and is required to make API calls.
Choose a use case: Before you start using OpenAI API, you'll need to choose a use case. This could be anything from building a chatbot to developing a language translation model.
Test the API: Once you have your API key, you can test the API by making a sample API call. OpenAI provides detailed documentation and tutorials to help you get started.
Start building: Now that you have your API key and a clear use case in mind, you can start building your AI model using OpenAI API. You can use the API to develop and train your model, and then deploy it for use in your applications.

By following these steps, you can quickly and easily get started with OpenAI API and start building your own AI models and applications!

What are the key components of OpenAI API?

OpenAI API has several key components that make it a powerful and flexible platform for building AI models and applications. These include:

Pre-trained models: OpenAI API provides access to a range of pre-trained models that have been developed using the latest AI techniques. These models can be used as a starting point for your own models, or you can fine-tune them to meet your specific needs.
Model training and deployment: OpenAI API provides tools for training and deploying AI models, making it easy to build and deploy AI models in a variety of settings.
API documentation and tutorials: OpenAI provides extensive documentation and tutorials to help you get started with the API, and to guide you as you build and deploy your AI models.
Scalability: OpenAI API is designed to scale to meet the demands of your applications. You can train your models on large datasets and then deploy them at scale, making it a great choice for large-scale AI projects.
Access to cutting-edge AI technology: OpenAI is a leader in AI research and development, and OpenAI API provides access to the latest AI technologies and techniques. This means you'll be able to build cutting-edge AI models that can deliver high performance and accuracy.

These are the key components of OpenAI API, and they make it a powerful and accessible platform for building AI models and applications.

About This Tutorial

What is OpenAI API

Preview on what we're going to build

Template Starter Kit

Set up a new Next.js project

Create a Next.js app

Install Tailwindcss

Build the frontend

Adding Head to index.js

Building the UI

Adding custom background

Building the sidebar

Adding a new chat and prompt select button

Building the chat area

Building the chat component

Preparing OpenAI API key

Create a prompt list

Build the prompt component

Handle Submit function

Create clearChat function for the New chat button

Create setPrompt function for the prompt select button

Create submit function to handle the input

Show the message in the chat area

Call the API

Generate instruction prompt

Create a function to generate the body

Create the pages/api/generate endpoint

Final touch

Add auto-scrolling

Style the scrollbar

Add loading animation

Full code

Something Wrong?

pages/index.js

API

api/generate.js

Components

components/chat.js

components/prompt.js

Styles

styles/bg.module.css

styles/globals.css

Environment

.env

FAQs:

How do I get started with OpenAI API?

What are the key components of OpenAI API?

Adding `Head` to `index.js`

Create `clearChat` function for the New chat button

Create `setPrompt` function for the prompt select button

Create `submit` function to handle the input

Create the `pages/api/generate` endpoint

`pages/index.js`

`api/generate.js`

`components/chat.js`

`components/prompt.js`

`styles/bg.module.css`

`styles/globals.css`

`.env`