prepare-commit-msg

An AI-powered Git commit message generator.

This tool automatically generates commit messages based on the staged changes in your Git repository.

If a message is passed to the git-commit command with the -m or -F flags, the tool will perform a spelling and grammar check, fixing any issues found and making minor improvements for clarity.

It is designed to be used as a Git hook but can also function as a command-line program. When used from the command line, it can either output the generated message to standard output or save it to a file if an argument is provided.

AI Support

Currently, this tool supports the Anthropic (Claude 3.5) and OpenAI (GPT-4) models.

Installation

Requirements: Go 1.16+.

To install, run:

go install github.com/julianolf/prepare-commit-msg@latest

Configuration

To access the AI models, you need an API key, which can be generated on the providers' pages:

• Anthropic: console
• OpenAI: dashboard

After obtaining your API key, export it as an environment variable:

export ANTHROPIC_API_KEY='xyzabc123'

or

export OPENAI_API_KEY='xyzabc123'

You can add this to your .rc file so it is automatically exported when you start a new shell.

Configuration File

Configurations can be defined using a JSON file. The following configurations are supported:

• AI: Specifies the AI model to use (anthropic or openai).
• APIKey: Specifies the API key to use when accessing the AI model.
• System: Specifies the system prompts to provide instructions to the AI. There are two different prompts that can be defined:
  • GenMsg: Used when generating commit messages from staged changes.
  • FixMsg: Used when improving a message provided as input.

{
  "AI": "openai",
  "APIKey": "xyzabc123",
  "System": {
    "GenMsg": "Detailed instructions on how to generate the message",
    "FixMsg": "Detailed instructions on how to improve the message"
  }
}

Notes:

1. The keys are case-sensitive.
2. All configurations are optional; if a configuration is missing, default values are assumed.

The default location for the configuration file is different depending on the operating system.

On Unix systems, the default location is $XDG_CONFIG_HOME/prepare-commit-msg/config.json if the environment variable XDG_CONFIG_HOME is defined, or $HOME/.config/prepare-commit-msg/config.json otherwise.

On macOS, it's located at $HOME/Library/Application Support/prepare-commit-msg/config.json.

On Windows, it's %AppData%\prepare-commit-msg\config.json.

You can explicitly pass a configuration file when running the program by using an argument flag:

prepare-commit-msg -config=my-config.json

Git Hook

For details on how to configure it as a Git hook, refer to the documentation:

• Git hooks: prepare-commit-msg
• Git config: core.hooksPath

Usage

For usage, run:

prepare-commit-msg -h