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Show HN: Git Auto Commit (GAC) – LLM-powered Git commit command line tool
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 https://github.com/cellwebb/gac
- acoliver 11mo agoOh 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...
- merge-conflict 11mo agoI'm considering making it optionally work as an MCP server!
- deleted 11mo ago[deleted]
- seba_dos1 11mo agoThis misses the point of what a good commit message is so much that it could be a delightful satire.
- jacobsenscott 11mo agoYeah - if these are better than your current commit messages, just don't write commit messages. Anyone can read the code.
- acoliver 11mo agoside-eye "anyone can read the code" -- usually the first words of someone who writes unreadable code. perl -e'$_=q/dk|jk`%fdk%w`da%qm`%fja`/;s/./chr(ord($&)^5)/seg;print'
- jacobsenscott 11mo agoWell, my point is AI won't produce a better commit message than just reading the code. So either write a good commit message or don't write a message at all. AI just produces step by step descriptions that are easily gleaned by skimming the code. In your case it would say * "Add perl to print the string anyone gan zea tne gode" (I'm impressed gemini got that close tbh) A human would write: "Wrote obfuscated perl to see if anyone actually reads the PRs. If they don't my next PR will include an obfuscated shell injection script."
- acoliver 11mo agopfth as if I'd use Gemini.
- alwillis 11mo agoHate writing commit messages. Just installed gac; they nailed the UI/UX. And so far, it works quite well.
- merge-conflict 11mo agoThank you! I used a combination of the questionary and click python libraries for the ui/ux.
- avinash-iitb 11mo agoI 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 11mo agoVery neat little project, I look forward to trying this
- Steeeve 11mo agoYour scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
- dang 11mo agoOmit internet tropes. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- nicksergeant 11mo agoNeat project. If you're looking for something simpler just to use w/ Claude Code, a simple call to "claude -p" can work: https://github.com/nicksergeant/dotfiles/blob/master/zshrc#L335-L394 https://github.com/nicksergeant/dotfiles/blob/master/zshrc#L...
- merge-conflict 11mo agoThanks! Can definitely do that, but GAC is faster than calling claude or another agent as they will take multiple api calls to look at git status, git diffs, etc. vs a single api call with GAC. Plus, GAC won't eat up your weekly limits! ;)
- nicksergeant 11mo agoOh I just pipe the diff into the Claude prompt, so it's only the one call.
- bigwheels 11mo agoaicommit2 works great: https://github.com/tak-bro/aicommit2 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 11mo agoI 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.
- nvartolomei 11mo agoI do often ask Claude Code or Gemini CLI to write commits. I agree with you on why being important. Majority of these being bug fixes accompanied tests where the why is easily inferred from the change/newly added tests and their comments.
- derwiki 11mo agoI often start a change by having Cursor read the Slack thread (via MCP) that is motivating the change. In the same Cursor thread, after making the change, it has fairly good context on the _why_ and writes a helpful commit message.
- therein 11mo agoVery nice, the fewer neurons you use the better. In biology they call it use it and lose it if my memory serves me correctly. Neurons that fire together, fry together.
- pbh101 11mo agoWhile I’m deeply skeptical of any attempt to define a commit message from the diff, if the context and motivation is truly captured in the Slack thread or other prior documents and available for summarization, then how many neurons are you really using on rewording what you already hashed out? Especially if someone would otherwise perhaps skip a message or write a poor one, this sounds like a great approach to get at least a first pass to further modify.
- Ferret7446 11mo agoThere are plenty of commits that don't need an explanation like mechanical cleanups or refactoring. If your code is appropriately documented then an LLM can often extract the explanation too.
- rwdf 11mo ago"gac" is giving me PTSD flashbacks from having to deal with the "Global Assembly Cache" aeons ago.
- ah27182 11mo agoI'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 11mo agoThere'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 11mo agoHey 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 11mo agoChiming 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.
- 0x008 11mo agoI like the lazycommit+lazygit combo. https://github.com/m7medVision/lazycommit https://github.com/m7medVision/lazycommit
- bangaladore 11mo ago> 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
- merge-conflict 11mo agoThe scanning is done on-device. I should've worded it better and said that it scans before any API calls. Too late to edit the post, unfortunately.
- ClimaxGravely 11mo agoMaybe 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 11mo agoThat'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
- torqu3e 11mo agoHere's the 20 line bash version I whipped up a while back cuz yes lazy about writing good commit messages. Supports claude and gemini with model selection and goes into the githook such that when you type `git commit` it invokes and generates the message. https://gist.github.com/torqu3e/c08f4aa4e80fba66dce6c35d63dd0816 https://gist.github.com/torqu3e/c08f4aa4e80fba66dce6c35d63dd...
- sherinjosephroy 11mo ago[flagged]