How To Use GPT-4 API?

Last updated: October 1, 2026

Many companies have started integrating AI models into their apps and services. Companies can train their custom AI using existing pre-trained fine-tuned models or datasets. If you are a developer and want to know how to use GPT-4, we have prepared a beginner’s guide.

Quick answer: If you are a developer and want to know how to use GPT-4, we have prepared a beginner's guide.

With the latest release of OpenAI, companies can enable developers to create more powerful apps and services. Models like the company’s chat completions account for 97% of API GPT usage. GPT stands for Generative Pre-trained Transformer model. It is trained on vast data with natural language processing and can conversationally generate content in human-like text. With the introduction of GPT-4, it is way more accurate and performs better than the previous generation of GPT.

Capabilities of GPT-4

OpenAI has recently made the GPT-4 model generally available to everyone, making its DALL-E and Whisper available to everyone who has successfully paid by the end of this month. If you have yet to receive the GPT-4, you can get it by signing up for GPT-4.

We all know how capable GPT-3.5 AI models are. Now, advanced AI models are being developed with more sophisticated training techniques and the same data. GPT-4 has been trained on around 100T parameters and can generate up to 25,000 words compared to the previous model, which could only generate 8,000 words simultaneously.

It can now generate text faster than previous generations, making it more suitable for writing content, stories, essays, and code.
It has better text summarization. Lengthy articles or documents can be more easily summarised, making them more accessible.
GPT-4 also brings more language support and is skilled at translating text between languages, facilitating communication and breaking down language barriers.
Sentiment analysis is another feature that comes with GPT-4. You can do better marketing, market research, and customer feedback analysis.
Now, with the prompt, it can gain insights and information based on the provided content. Previously, it needed help understanding the question.

OpenAI has been focusing on making it more conversational AI since the beginning. That is why Microsoft has used the GPT model on their Bing ChatBot, which brings three different parameters to set the creative levels: Balance, Creative, and Precise. Along with these capabilities, it is also useful for individuals, developers, enterprises, and businesses. For repetitive tasks, you can do automation to unlock the potential of the OpenAI GPT-4 model, enabling chatbots and virtual assistance, and for repetitive tasks, automate via Zapier. You should use the GPT-4 API for several reasons: It can fine-tune or train your dataset. Alternatively, you can get your hands on GPT-4 via OpenAI Playgrounds.

Get your OpenAI API

To get started with GPT-4 API, you need an OpenAI Account. For this, you can visit the OpenAI Platform. Then, with your emails or authentication like Google, or Microsoft, you can verify your emails, and it then asks for Mobile verification. After doing this now, you can have access to the OpenAI key.

You can get the API from your OpenAI account; from there, you can create an API Key, and to use this API, you do need to get Tokens.

Open the OpenAI platform, then click on your profile in the upper-right corner.
From the context menu, You will find the View API keys.
Click on it to redirect you to the API keys page. From there, create your OpenAI Key by giving it a name and then Copy the Key because you will not be able to retrieve it later.
That is it!

Setup Developer Environments

After gettings your OpenAI API key, You need to set up your Developer Environments. For this, there are several programming languages that you can use that support HTTPS like Python, JavaScript, or Ruby. For this, we are continuing with Python, and for this, here is the guide you can follow.

First thing first, download and install Python on your machine.
After that, you need to Create a New Directory and then Navigate to Terminal or CMD to execute the command to download the Dependencies.
- $ python -m venv my_gpt4_project
After that, Enable Virtual Environments by executing these commands.
- Windows: $ my_gpt4_project\Scripts\activate
- Linux/macOS: source my_gpt4_project/bin/activate
Then install the HTTP Request Library with “$ pip install requests”, which will install the OpenAI GPT-4 API Libraries to interact with the API

So we have installed some of the important defences and have set up the Developer Environments for them. Now it comes to API endpoints and the interaction method with the GPT-4 Model.

To get the GPT-4 API endpoint as primary, we will be executing the https://api.openai.com/v1/chat/completions, which will be used to send a chat message to the GPT-4 model and will receive the response in the context of the prompt.
After this, you need to customise the API Called with parameters you can test with the OpenAI Playgrounds.
- Several adjustments can be made, like customisation of the Models, Message, Temperature, Top_p, n, Steam, Stop, max_token, Presence penalty, frequency penalty, Logit_bias, and users.

After customising the parameters, you need to ensure the fine-tuning of the models and explore your GPT-4 Based AI-model apps or service. Now let’s make an API Call.

Now import the necessary library; this includes the HTTPS request for making API calls and json for data handling.
- import requests
- import json
Now, Define your API key and Endpoint; here, you need to remember that you have to place your API KEY.
- API_KEY = “<YOUR_API_KEY>”
- API_ENDPOINT = “https://api.openai.com/v1/chat/completions“
Now, Create a function that will allow interaction with the GPT-4 API; with the message list, adjust the optional parameter as input and returns that will generate chat competitions.
- def generate_chat_completion(messages, model=”gpt-4″, temperature=1, max_tokens=None):
- headers = {
- “Content-Type”: “application/json”,
- “Authorisation”: f “Bearer {API_KEY}”,
- }
- data = {
- “model”: model,
- “messages”: messages,
- “temperature”: temperature,
- }
- if max_tokens is None:
- data[“max_tokens”] = max_tokens
- response = requests.post(API_ENDPOINT, headers=headers, data=json.dumps(data))
- if response.status_code == 200:
- return response.json()[“choices”][0][“message”][“content”]
- else:
- raise Exception(f”Error {response.status_code}: {response.text}”)
With the list of messages in the chat format, Each message will have a role that includes the system, users, or assistance and content, but it can help set the behaviour of the assistance
- messages = [
- {“role”: “system”, “content”: “You are a helpful assistant.” },
- {“role”: “user”, “content”: “Translate the following English text to French: ‘Hello, how are you?'”}
- ]
- response_text = generate_chat_completion(messages)
- print(response_text)

The generate_chat_completion function will send you a message to GPT-4 API and get you an assistance response.

We recommend testing your app or service on OpenAI playgrounds before deploying it to your local machine or service. This is because it requires you to set up a developer environment, which OpenAI playgrounds do by default.

The company offers free credit worth $5, and if you’re unsure how many tokens you need, head over to the OpenAI token calculator to get your pricing and usage information. You can start using OpenAI to build your AI-powered apps or services. For example, we have embedded a video for the same.

To learn more about the project, you can also refer to Datacamp, or OpenAI documents.

OpenAI’s GPT-4 Access

This is how you can get access and use the GPT-4 model to integrate it into your apps or services. However, the company is currently processing 8K requests and will soon make a 32K engine available for everyone. In addition to generating text content, you can also use images since it can now understand them.

It allows you to receive natural language, code, instructions, or artificial intelligence responses to photos, which means that users can upload unique images alongside a clear set of instructions, questions, or opinions. However, this functionality is only available via API and not on ChatGPT. Also, GPT-4 isn’t an alternative, but if you want to use it for free, you can try free services like Writesonic, Perplexity, Microsoft BingChat, or any other service you prefer.