OpenAI API Integration: Completions in PHP

Lately, ChatGPT has become a hot topic among developers and IT enthusiasts. Its ability to duplicate human dialogue is astonishing and attracts the attention of many.

In the heat of the rising popularity of AI such as ChatGPT, it is time for you to take this opportunity and have your own AI in your application.

Today, we will discuss about integrating OpenAI API with Completions models in your website project that uses PHP language inside CloudRaya’s VM. This will allow you to create a Help Center using the latest technology from OpenAI GPT (generative pre-trained transformer).

Register an OpenAI Account

First step you need to take is to register an account in OpenAI.

Access https://platform.openai.com and follow the signup procedure.

After completing a few verifications, your account is now active. Here is what the OpenAI home panel looks like once you are inside.

Create OpenAI API Key

Now, you can start creating the API Key for OpenAI.

Click your account thumbnail at the top-right side of your screen and choose View API keys

On the API Keys page, you can see previous API keys you have made. These API keys will function as authenticators in our PHP project.

If you have not created any, you can click the  + Create new secret key

Enter the name of the key and, in a moment, the API key will be generated. Make sure you save this key because it will not be displayed for a second time.

Balance and Credit Verification

Every request of our API will cost us the credit balance in our OpenAI account. For those who registered for the first time, you will receive a free trial usage credit for a limited time.

At this point, you need to make sure you have an available credit balance in your account.

To check your balance, you can access the Usage page.

In this tutorial account, I will use the free trial credits given by OpenAI with an expiry date of July 1st, 2023.

Please note that, API service for ChatGPT Plus have separate cost.

You can open the following page to know more about OpenAI price model.

ChatGPT plus subscription only covers https://chat.openai.com/ use and cost up to $20/month.

GPT-based Languange Model

According to the documentation reference for OpenAI API, there are a few language models it can use, namely the Completions model and the Chats model.

Completions allow for the model to create an output based on the previously inserted prompt.

Meanwhile, Chat allows users to directly engage with the model. The model will respond to every message and answer it sequentially as if the user is talking to a human. This model is useful if you want to develop a more natural discussion feeling from the AI.

Every model has different API Endpoint.

This tutorial will delve deeper into Completions model.

About Prompt Engineering

Within the Completion model, there is an important parameter called prompt. What does this prompt do?

Prompt is a text or instruction which you give to the AI at the beginning. This instruction will govern the bot on how to create a response.

By creating the appropriate prompt, we can have better responses given by the AI. A good prompt is to have clear and detailed instructions. As an example, we can take a look at multiple scenarios that are possible to do provided by OpenAI in their Example Page.

Let’s use Grammar Correction as our example scenario.

First, we declare the prompt at the beginning, which in this case will correct the grammar of the inputted text to be in accordance with proper English grammar. Thus, the response generated by the AI is in the form of corrected English grammar.

There are many other scenarios you can do other than those displayed on the example page, as long as the given prompt is clear and detailed.

API Integration Request With PHP

Based on the dialogue box above, OpenAI API is currently limited to only Python, Node JS, cURL, and JSON. To use it with PHP, we can utilize cURL syntax so that it can send HTTP requests from cURL to PHP.

We require several cURL functions, such as curl_init(), curl_setopt(), curl_exec(), etc. These functions will allow us to govern the request options, such as URL, header, content, method, and other necessary data.

You can refer to the code below for the result of the conversion and modification::

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

$openaiApiKey = "YOUR_API_KEY";

$data = array(
  "model" => "text-davinci-003",
  "prompt" => "Correct this to standard English:\n\nShe no went to the market.",
  "temperature" => 0,
  "max_tokens" => 60,
  "top_p" => 1,
  "frequency_penalty" => 0.0,
  "presence_penalty" => 0.0
);

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "https://api.openai.com/v1/completions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode($data),
  CURLOPT_HTTPHEADER => array(
    "Authorization: Bearer " . $openaiApiKey,
    "Content-Type: application/json"
  ),
));

$response = curl_exec($curl);
curl_close($curl);

$result = json_decode($response, true);
$content = $result['choices'][0]['text'];

echo $content;

?>

For Completions, we will use the Endpoint https://api.openai.com/v1/completions.

Syntax error_reporting(E_ALL) and ini_set('display_errors', 1) are used to govern the reporting and notification of errors in PHP. These syntaxes will make any PHP error to be displayed in our browser. It is very useful for monitoring error, such as when there is API problems or insufficient credit usage.

The result from the API request syntax will looks like the following in your browser.

She did not go to the market.

Now, you have your very own AI chat. The next step to do is to integrate the chat with a better and more interesting interface suitable for your application.

▶️ Key Parameter

Before the next step, make sure that you understand the following key parameters governing the result generated by the model.

⏭️ YOUR_OPENAI_API_KEY

This parameter is the API key necessary to authenticate and authorize access to the OpenAI API service.

⏭️ model

This parameter governs the model used in generating the conversation.

For Completions, the best model today is “text-davinci-003“. You can find out more on the reference page to see the list of other models based on their endpoint types.

⏭️ prompt

Write the instructions on how the model is used. To generate the best response, make sure to configure the prompt clearly and in detail.

⏭️ temperature

By configuring the temperature, we can influence the level of randomness and variation of the response generated by the model. High temperature creates more variation and creative response, while low temperature creates a conservative and predictable response. The value used to govern the parameter is between 0,1 to 1,0.

⏭️ max_tokens

max_tokens parameter governs the maximum token used in the model response. The higher the limit, the longer the response will be. Please note, that each token generated will consume your credit usage. So, please pay attention to the value of the parameter.

⏭️ top_p

top_p parameter governs how far the highest probability token is considered in generating the result. It will affect the variation and content of the response generated. The lower the parameter is, the more conservative and predictable the response generated will be. The higher the parameter is, the more variation the response will be.

⏭️ frequency_penalty

frequency_penalty governs how far the model repeats words that often appear in a conversation.

This penalty reduces the probability of common words appearing in the response, thus creating a more unique instead.

⏭️ presence_penalty

presence_penalty governs how far the model will generate words already present in the current input.

This penalty reduces the probability of words which present previously in the input text to create better and non-repetitive responses.

Note: Both frequency_penalty and presence_penalty are meant to increase the diversity of the result however, they work in different ways. frequency_penalty avoids word repetition, while presence_penalty avoids generating words already present in the current input.

Access the following documentation to find out more about the parameters.

Or, you can directly simulate the parameters by accessing the playground page.

Please note, that the use of the playground will cost you your balance.

Result of Implementation

Now that we understand the function of the main parameter and the request framework of OpenAI API, it’s time to implement it into an application.

In this tutorial, I have created a simple PHP application in CloudRaya’s VM. It more or less works as a Trip Advisor, which will give the user a suggestion of an interesting spot to visit.

Within the prompt, I have declared the conditions and limitations for the bot to work around.

Conclusion

This conclude our tutorial to integrate OpenAI API with Completions model for website project based on PHP in CloudRaya’s VM.

Applying such artificial intelligence in your website can increase the interaction and experience of the website user.

Find out more about other interesting tutorial in CloudRaya Knowledge Base page or visit us at our YouTube channel to find it in video form.