# appleboy/CodeGPT: a Go CLI that writes commit messages and review briefs from your staged diff

> CodeGPT is a Go command line tool that sends a git diff to an OpenAI, Azure, Gemini, Anthropic, Groq, Ollama or OpenRouter model and returns a commit message or a short review. It is not the VS Code extension of the same name.

**appleboy/CodeGPT** — A CLI written in Go language that writes git commit messages or do a code review brief for you using ChatGPT AI (gpt-4.1, gpt-4o model) and automatically installs a git prepare-commit-msg hook.

- Repository: https://github.com/appleboy/CodeGPT
- Stars: 1,505 · Forks: 133
- Language: Go
- License: MIT
- Published: 2026-09-14 · Updated: 2026-09-14 · Language: en
- Canonical page: https://hysenlabs.com/projects/appleboy-codegpt

## What appleboy/CodeGPT does that a chat window does not

The gap this fills is narrow and specific. Most engineers can already paste a diff into a chat interface and ask for a commit message. The friction is that the diff has to be assembled first, the output has to be copied back, and the formatting convention the repository enforces has to be re-explained every time. CodeGPT moves that loop into the terminal and into git itself. The README describes it as a CLI written in Go that generates git commit messages or provides code review summaries, and that also installs a git prepare-commit-msg hook.

The audience is therefore people who live in a shell and who care about commit hygiene. The README states that output adheres to the conventional commits specification, which matters if your repository runs commitlint. The repository does contain a commitlint.config.mjs at the top level, so the project holds itself to that rule as well. If your team has no convention and no interest in one, the main value proposition shrinks to saving a copy and paste.

A naming warning belongs here. The project is a Go binary distributed through Homebrew, Chocolatey, a shell installer and the Go toolchain. Several widely searched terms, including CodeGPT extension, codegpt vscode and codegpt intellij, refer to a different product, an editor extension. Nothing in the README describes a VS Code or IntelliJ plugin, and the repository layout shows cmd/, core/, provider/, proxy/, git/, prompt/ and util/ directories with no editor manifest. If you arrived looking for a sidebar panel inside your editor, this is not that.

## The diff goes out, the message comes back: the actual pipeline

The flow is a straight line, and the repository layout makes it legible. The git/ package collects the working diff, with the README noting that the number of context lines is configurable and defaults to 3, and that file exclusion patterns can be applied to the diff operation. That trimmed diff is the payload. The provider/ package holds the backends, and go.mod confirms which ones are compiled in: github.com/sashabaranov/go-openai for OpenAI-compatible endpoints, github.com/liushuangls/go-anthropic/v2 for Anthropic, and google.golang.org/genai for Gemini. The prompt/ directory holds the templates, and the README says prompt templates and variables can be customized, with a documented way to change the default prompt folder. The proxy/ package backs the SOCKS or HTTP proxy support listed in the features.

That separation is the design decision worth noticing. Provider choice, prompt text and diff scope are three independent knobs rather than one hardcoded request. It also means the diff size is under your control in a way it is not when you paste into a chat window: context lines and exclusion patterns are the two levers the README names, and they are the two that decide how much of your source leaves the machine.

The output path splits. In CLI mode the tool prints the message. When the git hook is installed, the generated text is handed to prepare-commit-msg, so it appears in your editor as the starting commit message and you can edit or discard it before the commit is created. The README also lists streaming output for real-time token display, which changes the feel of a long generation from a stall to a visible trickle.

## Installing appleboy/CodeGPT and generating your first message

On macOS the README gives a Homebrew tap. On Windows it gives Chocolatey. Both are single commands and both pull a prebuilt binary, which is the least effort if you do not want a Go toolchain.

```sh
brew tap appleboy/tap
brew install codegpt
```

For Linux and anything else, the README offers an install script that detects your OS and architecture, downloads the latest binary and adds it to your PATH. Two environment variables are documented for it: INSTALL_DIR, which defaults to $HOME/.codegpt/bin, and VERSION, which defaults to the latest release. There is also an INSECURE variable that, when set to any value, skips SSL verification during the download. That last one is a deliberate escape hatch for broken certificate stores, and it is exactly the kind of flag that should not end up in a shared script.

```sh
bash < <(curl -sSL https://raw.githubusercontent.com/appleboy/CodeGPT/main/install.sh)
```

If you prefer the Go toolchain, the README documents a single install command against the module path. The Makefile in the repository also exposes a build target that writes to bin/codegpt and an install target, both injecting version information through ldflags from the version/ package.

```sh
go install github.com/appleboy/CodeGPT/cmd/codegpt@latest
```

After either route, the README's manual install section says to confirm with codegpt version. Configuration comes next: the README's configuration section begins by telling you to create an OpenAI API key, and the repository depends on github.com/joho/godotenv, so a .env file is part of the expected setup. The README also documents an API key helper for dynamic credentials with a configurable refresh interval, and a documented priority order between the helper and other sources. Once a key is in place, the practical first use is to stage a change and let the tool draft the message, either directly or through the hook. The README's Git Hook section has separate Install and Uninstall steps, and the Code Review section covers the review mode separately.

## Where CodeGPT gets in the way

The first limitation is the one the README states most plainly: the tool sends your diff to a third party. Every feature that makes it useful, context lines, exclusion patterns, prompt customization, is also a dial on how much source code leaves your machine. The README documents those controls but does not document a local-only default. Ollama is listed among the supported backends, which is the only route to keeping inference on your own hardware, and choosing it means accepting whatever quality that local model gives you on commit-message formatting.

The second is credential management. The API key helper exists because static keys expire, and the README documents a refresh interval and a priority order for resolving which credential wins. That is a real mechanism, but it is also a moving part. A misconfigured helper that silently falls back to a stale key produces authentication errors that look like provider outages.

The third is the hook itself. A prepare-commit-msg hook runs on every commit in that repository, including merges, amends and rebases. The README documents installing and uninstalling the hook but does not document how it behaves when the diff is empty or when the network is unavailable, so the failure mode you should test for is a commit that hangs waiting on an HTTP request. The README also does not document rollback beyond the uninstall step, and it says nothing about how the hook interacts with an existing commit template.

Finally, scope. This is a commit-message and review-brief tool. It does not review a pull request in a browser, it does not annotate lines in a diff view, and it does not run in CI unless you wire it there yourself. If what you want is a reviewer that comments on a pull request, you are looking at the wrong category of tool.

## How CodeGPT differs from editor-integrated assistants

The obvious alternative is an editor-integrated assistant, the kind that sits in a sidebar and answers questions about the file you have open. The difference is where the context comes from. An editor assistant sees the buffer and whatever files it decides to pull in. CodeGPT sees a git diff, filtered by the context-line count and the exclusion patterns you configured, and it produces one of two artifacts: a commit message or a review brief. That is a narrower input and a narrower output, and the narrowness is the point. There is no chat history to manage and no ambiguity about what was sent.

A second alternative is writing the commit message yourself. That sounds like a non-answer, but it is the honest baseline, and it is worth measuring against. The tool earns its place only if the generated message is good enough that editing it is faster than writing it, and only if the conventional-commits formatting is something you would otherwise have to remember.

Within the same category, the meaningful choice is the backend rather than a competing binary. The README lists Azure OpenAI Service, OpenAI API, Gemini, Anthropic, Ollama, Groq and OpenRouter, and go.mod shows the client libraries for OpenAI, Anthropic and Gemini compiled into the binary. That means provider selection is a configuration change, not a different tool. Ollama is the interesting one because it is the only listed backend that can run without sending the diff to a hosted service, at the cost of running a model yourself.

## Maintenance, licence and what upgrading costs you

The repository is not archived and the last push was on 2026-08-30, which is recent. Releases are tagged rather than continuous: v1.7.0 on 2026-03-12, v1.7.1 on 2026-03-22 and v1.7.2 on 2026-06-28. The gap between minor releases is measured in months, so you should not expect a fix for a provider API change to land the same week.

Upgrade cost is low if you installed through a package manager, since Homebrew and Chocolatey handle the binary swap. It is slightly higher if you pinned a version through the install script's VERSION variable or built from source with the Makefile, because version metadata is injected at build time through ldflags from the version/ package and you will want to rebuild rather than reuse an old binary. The dependency list is the thing to watch on a source build: go.mod targets Go 1.25.11 and pulls in the Charmbracelet TUI stack along with three separate provider SDKs, so a from-source upgrade is a real compile, not a script.

The licence is MIT, which is permissive and places few obligations on how you redistribute or embed the binary. That is a statement about the licence text, not legal advice; if you are shipping this inside a commercial product, read the LICENSE file in the repository and talk to whoever handles licensing on your side. Note also that the MIT licence covers this CLI, not the model providers you point it at, and those have their own terms and their own per-token billing.

## Conclusion

Adopt it if you already pay for one of the supported providers and want commit messages generated locally from your staged diff rather than from an editor extension. Skip it if your team needs a hosted review dashboard, a GUI, or a provider that is not on the list. Before rolling it out, verify two things on your own repository: that the prepare-commit-msg hook leaves your existing commit template intact, and that codegpt config writes the provider block you expect under your home directory.

## FAQ

### What is appleboy/CodeGPT?

It is a CLI written in Go that generates git commit messages or provides code review summaries using AI models, and that can install a git prepare-commit-msg hook. It is distributed as a binary, not as an editor extension.

### How do I install CodeGPT?

The README gives Homebrew for macOS, Chocolatey for Windows, an install script that detects your OS and architecture, and go install against github.com/appleboy/CodeGPT/cmd/codegpt@latest. The manual install path ends with codegpt version to confirm the binary works.

### Is CodeGPT free?

The source is MIT licensed, so the CLI itself costs nothing. The model backends it calls are separate services with their own terms and billing, and the README's configuration section starts by telling you to create an OpenAI API key.

### Is CodeGPT safe to use?

The README does not make a safety claim. What it does document is that your diff is sent to a model provider, with context lines and file exclusion patterns as the two controls over how much is sent. Ollama is the only listed backend that can keep inference local.

### How do I use CodeGPT in VS Code?

There is no VS Code integration in this project. The README describes a Go CLI and a git prepare-commit-msg hook, and the repository layout shows no editor manifest. Searches for a CodeGPT VS Code extension refer to a different product.

## Sources

- [appleboy/CodeGPT on GitHub](https://github.com/appleboy/CodeGPT)
- [Issues](https://github.com/appleboy/CodeGPT/issues)
- [License: MIT](https://github.com/appleboy/CodeGPT/blob/main/LICENSE)
- [README](https://github.com/appleboy/CodeGPT/blob/main/README.md)
- [Releases](https://github.com/appleboy/CodeGPT/releases)

---

Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/appleboy-codegpt