Comsg — Generate High-Quality Commit Messages from Git Diffs

Comsg is a developer tool that automatically converts Git stagged diffs into clear, consistent, and context-aware commit messages. By analyzing code changes at a semantic level, Comsg helps maintain a clean commit history without requiring developers to manually craft messages for every change.

Features

🔍 Diff Parsing

• Accepts Git staged changes
• Identifies added, removed, and modified lines
• Handles multi-file diffs and complex change sets

🤖 AI-Driven Commit Message Generation

• Interprets the intent behind code changes
• Generates concise commit titles and optional extended descriptions
• Supports multi-scope summaries for large patches

🧱 Commit Standard Support

Comsg supports the full range of Conventional Commit types, including:

• feat — a new feature
• fix — a bug fix
• docs — documentation changes
• style — code style changes (formatting, missing semicolons, etc.)
• refactor — code restructuring without functional changes
• test — adding or updating tests
• build — build system or dependency changes
• ci — CI/CD configuration updates
• perf — performance improvements
• chore — maintenance tasks not affecting source code

These commit types help maintain consistent and meaningful commit history across projects and teams.

Installation

Follow these steps to install Comsg globally:

npm i -g comsg

OR

1. Clone the project

git clone https://github.com/vaibhavjha-dev/comsg
cd comsg

2. Make the CLI executable

chmod +x index.js

3. Install globally using npm

npm link

After installation, the comsg command becomes available system-wide.

Usage

Before running Comsg, you must add your OpenAI API key in the project where you want to use this tool.

1. Create a .env file

In the root of your project:

nano .env

Add the following environment variable:

OPENAI_API_KEY=your_api_key_here

2. Generate a commit message automatically

comsg

Comsg will analyze your current Git stagged diff and generate a commit message based on your changes.

Customization

Comsg allows customization of how commit messages are generated.

🔧 Where to Customize

All customization lives in the index.js file. Inside this file, look for the commit-tool's description, which defines how commit messages should be formatted and structured. Modify the description according to you.

const commitTool = tool({
  name: "commit-tool",
  description: `
    An intelligent tool that transforms raw Git diffs into commit messages...

    Rules:
    - Always generate commit messages in the format: <type>(<scope>): <description>
    - Use types like feat, fix, docs, style, refactor, test, chore
    - Scope is optional but should indicate the affected area
    - Description should be imperative and concise
    - Ensure commit descriptions are 50 characters or less
    ...
  `,

You are ready to use the customized tool.