diffscribe

AI-powered commit message generator for Conventional Commits.

Features

• ✅ Conventional Commits compliance
• ✅ Concise and detailed modes
• ✅ Preview before committing
• ✅ Automatic clipboard copy
• ✅ Regeneration loop
• ✅ Smart model selection (free draft + paid refinement for long diffs)
• ✅ Mock mode for testing
• ✅ Error handling with clear messages

How It Works

1. Reads your staged Git diffs
2. Generates a Conventional Commit message using AI
3. Preview and accept/reject
4. Copies to clipboard on accept
5. Run git commit and paste message

Installation

Global Installation (Recommended)

npm install -g diffscribe

After installation, you can run the dcs command from anywhere:

dcs        # If installed globally

Zero-install via npx

npx diffscribe

Setup

1. Get OpenRouter API Key

Visit https://openrouter.ai/keys to get your API key.

2. Set Environment Variable

export OPENROUTER_API_KEY=your-api-key-here

For permanent setup, add to your shell profile:

echo 'export OPENROUTER_API_KEY=your-api-key-here' >> ~/.bashrc  # or ~/.zshrc
source ~/.bashrc

3. Verify Setup

echo $OPENROUTER_API_KEY

Usage

Basic Usage

# Stage your changes
git add .

# Generate commit message (if installed globally)
dcs

# Or using npx
npx diffscribe

Mock Mode (Testing)

For testing without API calls:

dcs --mock          # If installed globally
npx diffscribe --mock  # Using npx

Model Strategy

The tool uses a smart two-stage approach for optimal cost and quality:

Draft Stage (Free Models)

• Primary: mistralai/devstral-2512:free — Fast free model for initial commit message
• Backup: qwen/qwen3-coder:free — Falls back if primary hits rate limits

Refinement Stage (Paid Model)

• Refinement: google/gemini-2.5-flash-lite — Polishes messages for large diffs (300+ lines or 12KB+)

When Does Refinement Run?

Only for larger changes to improve clarity and structure. Smaller diffs skip refinement to save cost.

Options

### dcs

Generate AI-powered commit messages for your staged changes.

```bash
dcs [options]

Options: -V, --version output the version number --mock Use mock generation instead of LLM (for testing) -h, --help display help for command

Examples

# Generate commit message with AI
dcs

# Test without API calls
dcs --mock

# Using npx (no installation needed)
npx diffscribe
npx diffscribe --mock

## Requirements

- Node.js >= 20
- Git repository
- OpenRouter API key (unless using --mock mode)

## Development

```bash
# Install dependencies
npm install

# Build
npm run build

# Watch mode
npm run dev

# Type check
npm run typecheck

License

MIT