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Show HN: Git Auto Commit (GAC) – LLM-powered Git commit command line tool (github.com)

56 points by merge-conflict ↗ HN
GAC is a tool I built to help users spend less time summing up what was done and more time building. It uses LLMs to generate contextual git commit messages from your code changes. And it can be a drop-in replacement for `git commit -m "..."`.

Example:

  feat(auth): add OAuth2 integration with GitHub and Google

  - Implement OAuth2 authentication flow

  - Add provider configuration for GitHub and Google

  - Create callback handler for token exchange

  - Update login UI with social auth buttons
Don't like it? Reroll with 'r', or type `r "focus on xyz"` and it rerolls the commit with your feedback.

You can try it out with uvx (no install):

  uvx gac init  # config wizard

  uvx gac
Note: `gac init` creates a .gac.env file in your home directory with your chosen provider, model, and API key.

Tech details:

14 providers - Supports local (Ollama & LM Studio) and cloud (OpenAI, Anthropic, Gemini, OpenRouter, Groq, Cerebras, Chutes, Fireworks, StreamLake, Synthetic, Together AI, & Z.ai (including their extremely cheap coding plans!)).

Three verbosity modes - Standard with bullets (default), one-liners (`-o`), or verbose (`-v`) with detailed Motivation/Architecture/Impact sections.

Secret detection - Scans for API keys, tokens, and credentials before committing. Has caught my API keys on a new project when I hadn't yet gitignored .env.

Flags - Automate common workflows:

  `gac -h "bug fix"` - pass hints to guide intent

  `gac -yo` - auto-accept the commit message in one-liner mode

  `gac -ayp` - stage all files, auto-accept the commit message, and push (yolo mode)
Would love to hear your feedback! Give it a try and let me know what you think! <3

GitHub: https://github.com/cellwebb/gac

22 comments

[ 3.1 ms ] story [ 56.2 ms ] thread
acoliver
Oh nice. Man I hate filling out all that stuff. And getting the LLM to do it without freestyling and hallucinating is a pain. Kinda wish it were an MCP so I can shove it in my CLI or maybe the hooks for git...
[deleted]
(comment deleted)
seba_dos1
This misses the point of what a good commit message is so much that it could be a delightful satire.
alwillis
Hate writing commit messages.

Just installed gac; they nailed the UI/UX.

And so far, it works quite well.

avinash-iitb
I like that you’ve added secret detection and multi-provider support — that’s something most LLM commit tools miss. Have you benchmarked latency differences between local models (like Ollama) and OpenAI/Anthropic? Would be interesting to see a speed comparison.
adrianbooth17
Very neat little project, I look forward to trying this
Steeeve
Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
bigwheels
aicommit2 works great: https://github.com/tak-bro/aicommit2

Getting started is as easy as installing claude/codex/gemini: npm install -g aicommit2

I'm excited to give gac a try and see how it stacks up! The steering hints with gac might give it an edge.

martinohansen
I don’t get these kind of tools. A commit should be the why of a change, not a summary of what it is, anyone can either get that themselves or just read the code if they desire. What you can not get from the code is the _why_ which only you as the author can put.
nsonha
That's a PR description. Commit messages describing why is pretty annoying and useless.
rwdf
"gac" is giving me PTSD flashbacks from having to deal with the "Global Assembly Cache" aeons ago.
ah27182
I've been using LMStudio to run a local LLM (Qwen3-4B) to generate commit messages using this command:

```

git diff --staged --diff-filter=ACMRTUXB | jq -Rs --arg prompt 'You are an assistant that writes concise, conventional commit messages. Always start with one of these verbs: feat, fix, chore, docs, style, refactor, test, perf. Write a short!! message describing the following diff:' '{model:"qwen/qwen3-4b-2507", input:($prompt + "\n\n" + .)}' | curl -s http://localhost:1234/v1/responses -H "Content-Type: application/json" -d @- | jq -r ".output[0].content[0].text"

```

cypriss9
There's three types of people: those who already write excellent commit messages explaining the why, those who write decent ones explaining the what, and those who write garbage commit messages. Empirically, the first set is small. This tool will help the middle type be more efficient, and help the last type drastically.

Well done OP.

glitch253
Hey all - disclaimer I'm one of Cell's friends and encouraged them to release their utility on Pypi for others. It quickly became one of my favorite tools that I use every day.

`git commit` is gone, `uvx gac` is in!

paulirish
Chiming in with my alternative, like others' but uses simonw's `llm`:

    git upstream-diff | llm --system-fragment cl-description.md
However, in practice, I notice the generated messages focus more on the what than the why. So it's rare I use them verbatim.
bangaladore
> Automatic secret detection: Scans for API keys, passwords, and tokens before committing

Surely this is done on-device right? Or is the prompt asking the LLM if there are secrets in the changes.

Arguably I trust Github / Gitlab / etc more than OpenAI / Anthropic / etc

ClimaxGravely
Maybe it's because these days I use perforce more than git but I tend to find myself writing 80% of my commit message before I write any code and touch it up a little at the end.
AnicetN
That's very cool! I actually built a Claude Code Web alternative* over the last few months and made my own auto-commit solution for it. I reckon though having the prompt is what helps me and the agent generate relevant prompt messages that can explain the why. Anyway even a average commit message is way better than none

*ariana.dev