Technology Tales

Generating Git commit messages automatically using aicommit and OpenAI

25^th October 2025

One of the overheads of using version control systems like Subversion or Git is the need to create descriptive messages for each revision. Now that GitHub has its copilot, it now generates those messages for you. However, that still leaves anyone with a local git repository out in the cold, even if you are uploading to GitHub as your remote repo.

One thing that a Homebrew update does is to highlight other packages that are available, which is how I got to learn of a tool that helps with this, aicommit. Installing is just a simple command away:

brew install aicommit

Once that is complete, you now have a tool that generates messages describing very commit using GPT. For it to work, you do need to get yourself set up with OpenAI's API services and generate a token that you can use. That needs an environment variable to be set to make it available. On Linux (and Mac), this works:

export OPENAI_API_KEY=<Enter the API token here, without the brackets>

Because I use this API for Python scripting, that part was already in place. Thus, I could proceed to the next stage: inserting it into my workflow. For the sake of added automation, this uses shell scripting on my machines. The basis sequence is this:

git add .
git commit -m "<a default message>"
git push

The first line above stages everything while the second commits the files with an associated message (git makes this mandatory, much like Subversion) and the third pushes the files into the GitHub repository. Fitting in aicommit then changes the above to this:

git add .
aicommit
git push

There is now no need to define a message because aicommit does that for you, saving some effort. However, token limitations on the OpenAI side mean that the aicommit command can fail, causing the update operation to abort. Thus, it is safer to catch that situation using the following code:

git add .
if ! aicommit 2>/dev/null; then
    echo "  aicommit failed, using fallback"
    git commit -m "<a default message>"
fi
git push

This now informs me what has happened when the AI option is overloaded and the scripts fallback to a default option that is always available with git. While there is more to my git scripting than this, the snippets included here should get across how things can work. They go well for small push operations, which is what happens most of the time; usually, I do not attempt more than that.