MATLAB app and class to access ChatGPT API from OpenAI


Updated Thu, 20 Jul 2023 20:19:00 +0000

From GitHub

View License on GitHub

MatGPT - MATLAB® app and class to access ChatGPT API from OpenAI™

View MatGPT on File Exchange Open in MATLAB Online

MatGPT Logo

MatGPT is a MATLAB app powered by chatGPT class that allows you to easily access the ChatGPT API provided by OpenAI. With the app, you can load a list of prompts for specific use cases and engage in conversations with ease. If you're new to ChatGPT and prompt engineering, MatGPT is a great way to learn. If you're already familiar with ChatGPT, you can directly use the class.

The app and class simply serve as an interface to the ChatGPT API. You should be familiar with the limitations and risks associated with using this technology as well as with OpenAI terms and policies. You are responsible for any fees OpenAI may charge for the use of their API.

What's New



  1. Download the content of this repository into a MATLAB path.
  2. Launch MATLAB
  3. Before using, set an environment variable with your OpenAI API key named OPENAI_API_KEY. You can also set an environmental variable using the Settings in the app.
setenv("OPENAI_API_KEY","your key here")
  1. Open MatGPT.mlapp in App Designer and click 'Run'

How to use: MatGPT app

MatGPT Chat Tab

  1. Click on "+ New Chat" in the left nav to add a new chat. This opens the Settings tab.
  2. In the Settings tab, either choose a preset to populate the settings or customize on your own. Once you have completed the settings, click "Start New Chat" to initiate a chat. This will take you back to the Main tab.
  • Presets are loaded from Presets.csv - feel free to customize your prompts.
  1. In the Main tab, a sample prompt is already provided based on the preset you selected, but feel free to replace it with your own. When you click Send button, the response will be shown in the 'Chat' tab.
  • The Send button is disabled until a chat is configured in the Settings tab.
  • If you want suggestion for follow-up questions in the reponse, check Suggest follow-up questions checkbox.
  • If your prompt is intended to generate MATLAB code, check Test Generated MATLAB Code checkbox to test the returned code.
  • The Usage tab shows number of tokens used and the cost incurred in the current chat session.
  • Add stop sequences in Advanced tab to specify the sequences where the API will stop generating further tokens
  1. Continue the conversation by keep adding more prompts and clicking Send.
  2. You can right-click or double-click a chat in the left nav to rename, delete, or save the chat to a text file.
  3. When you close the app, the chat will be saved and will be reloaded into the left nav when you relaunch the app.

How to use: chatGPT class

chatGPT class creates an instance to access OpenAI API using your own API key, and optionally max_tokens that determine the length of the response. Once you create an instance, then you can use its chat method to post prompt via OpenAPI ChatGPT API updated on June 13, 2023. Please note that this class doesn't support function calling.

Where to find it

chatGPT class is located in helpers folder.

Set up the bot

First, make sure you set your OpenAI API key in the environment variable as shown above. Create an instance using the default parameters. Your API key will be loaded from the OS environment variable.

myBot = chatGPT();

You can also set max_tokens parameter, which determines the length of the response. If you don't specify max_tokens, the response will be limited to up to 1000 tokens. The max_tokens must be less than 4096.

myBot = chatGPT(max_tokens=50);

You can also specify other parameters, such as model and temperature.

  • models: gpt-3.5-turbo (default - stable release), gpt-4 (requires paid subsription to the API)
  • temperature: 0 = more strict, 1 = balanced, 2 = more creative

You can pass a role to prime the chatbot for a specific use case. By default the chatbot is primed to act as an AI assistant, using the prompt "You are a helpful assistant." You can customize this for specific use cases.

role = "You define the role the chatbot should play.";
myBot = chatGPT(model="gpt-3.5-turbo", max_tokens=1000, temperature=0.9,role=role);

Chat with the bot

Use the instance you created to send your prompt to the API.

answer = chat(myBot,"your prompt")

You will get an error if the API didn't return response successfully.

Check the token usage

Use usage method to obtain the number of tokens used in the current session. It returns the completion tokens used, prompt tokens used, and total tokens used. Different API rate applies depending on the model and type of tokens. Please consult OpenAI pricing page for details.

[completion_tokens,prompt_tokens,total_tokens] = usage(myBot)

Save the chat history

Use saveChat method to save the chat history to a file. The supported format includes .mat, .xlsx, and .json.


chatGPT class example

role = "You are a MATLAB expert who only answers with code with no explanation.";

myBot = chatGPT(model="gpt-3.5-turbo", max_tokens=1000, temperature=0.9, role=role);

answer = chat(myBot, "Generate 10x10 matrix using integers from 0 to 9.")


This code is adapted from this MATLAB Answers comment by Hans Scharler and uses Brian Buechel's CodeChecker and other great contributions.


The license for MatGPT is available in the LICENSE.txt file in this GitHub repository.

Cite As

Toshiaki Takeuchi (2023). MatGPT (, GitHub. Retrieved .

MATLAB Release Compatibility
Created with R2022b
Compatible with R2021a and later releases
Platform Compatibility
Windows macOS Linux

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!
Version Published Release Notes

See release notes for this release on GitHub:

See release notes for this release on GitHub:

See release notes for this release on GitHub:

See release notes for this release on GitHub:

See release notes for this release on GitHub:

See release notes for this release on GitHub:


To view or report issues in this GitHub add-on, visit the GitHub Repository.
To view or report issues in this GitHub add-on, visit the GitHub Repository.