GitSage

A self-hosted Git interface with AI-powered commit messages and error diagnosis

Quick Start · Configuration · Security · Report Bug

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Warning

This project is currently work in progress. The AI Commit Writer feature contains known bugs and may not work as expected. Use with caution.

What is GitSage?

GitSage is a locally-hosted web UI for Git, built on FastAPI and HTMX. It gives you a clean browser-based dashboard for your daily Git workflow, staging files, committing, branching, and syncing with remotes, without memorising terminal commands.

The standout feature is its deep integration with Google Gemini AI:

• AI Commit Writer — analyses your staged diff and writes a Conventional Commits-style message in one click.
• AI Error Medic — when a Git operation fails, it captures the error, explains the root cause in plain language, and (where safe) offers an auto-fix button.

Everything runs on your machine. No data leaves your environment except the calls you explicitly make to the Gemini API.

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Features

Category	Feature
Status	Visual file status with staged / unstaged / untracked grouping
Staging	Stage or unstage individual files, or stage all at once
Commits	Write and commit with a single click; view history with author and date
AI	Generate commit messages from staged diff (Gemini)
AI	Diagnose Git errors with step-by-step remediation
Branches	List, create, switch, and delete local branches
Remotes	Fetch, pull, and push to configured remotes
Security	All subprocess calls use list arguments — no shell injection surface

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Quick Start

Requirements: Python 3.11+, Git

Option 1: Using Setup Script

# Clone
git clone [https://github.com/yourname/gitsage.git](https://github.com/yourname/gitsage.git)
cd gitsage

# Install and start
./scripts/setup.sh

Option 2: Manual Run

If you prefer running the server directly via Uvicorn:

# Install dependencies
pip install -r requirements.txt

# Run the application
uvicorn main:app --host 127.0.0.1 --port 8000

Open http://localhost:8000 in your browser.

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Configuration

Copy .env.example to .env and edit:

cp .env.example .env

Variable	Default	Description
GEMINI_API_KEY	(empty)	Google Gemini API key. Get one at aistudio.google.com. AI features are disabled when not set.
GEMINI_MODEL	gemini-1.5-flash	Gemini model name
DEFAULT_REPO_PATH	.	Absolute path of the repository to manage
PORT	8000	Server port
DEBUG	false	Enable auto-reload and API docs
MAX_DIFF_BYTES	50000	Max bytes of diff forwarded to AI

Checking Available Models

To see which Gemini models are available for your API Key, run the included utility script:

python list_model_check.py

This will display a list of valid model IDs you can use in your .env file.

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Running Tests

./scripts/run_tests.sh              # full suite with coverage report
./scripts/run_tests.sh --fast       # fast run, no coverage

Or directly:

pytest tests/ -v

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Project Structure

gitsage/
├── main.py                        # Application entry point
├── list_model_check.py            # Utility to check available Gemini models
├── .env.example                   # Configuration template
├── requirements.txt
├── pyproject.toml                 # Pytest and coverage config
│
├── app/
│   ├── api/                       # FastAPI route handlers
│   │   ├── status.py              # Staging and repo status
│   │   ├── commits.py             # Commit and log
│   │   ├── branches.py            # Branch management
│   │   ├── remotes.py             # Remote operations
│   │   └── ai.py                  # AI endpoints
│   ├── core/
│   │   ├── config.py              # Settings (pydantic-settings)
│   │   ├── exceptions.py          # Custom exception types
│   │   └── git_runner.py          # Git subprocess executor
│   └── services/
│       ├── status_service.py
│       ├── commit_service.py
│       ├── branch_service.py
│       ├── remote_service.py
│       └── ai_service.py          # Gemini integration
│
├── frontend/
│   ├── templates/index.html       # Main page (HTMX + Tailwind)
│   └── static/
│       ├── css/app.css
│       ├── js/app.js
│       └── favicon.svg
│
├── tests/
│   ├── conftest.py                # Shared fixtures (temp git repo)
│   ├── unit/
│   │   └── test_validation.py     # Validation and sanitisation logic
│   └── integration/
│       └── test_api.py            # API endpoint tests
│
└── scripts/
    ├── setup.sh                   # Install and run
    └── run_tests.sh               # Test runner

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Security

GitSage is designed for local use only. Key decisions:

• TrustedHostMiddleware restricts access to localhost / 127.0.0.1 only.
• Git commands are executed with a list of arguments (shell=False) — no shell injection is possible.
• The repository path is validated and canonicalised on every request; .. traversal is rejected.
• Credential prompts are disabled via GIT_TERMINAL_PROMPT=0. Git credentials come from your system's credential store, never from GitSage.
• AI-suggested auto-fix commands are validated against a whitelist of known-safe patterns before being presented to the user.
• Commit messages are sanitised to strip control characters before being passed to git.
• The Gemini API key is read from the environment and never logged or surfaced in API responses.

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Stack

Layer	Technology
Backend	FastAPI, Uvicorn
AI	Google Gemini API (via httpx)
Frontend	HTMX, Tailwind CSS
Config	pydantic-settings
Testing	pytest, pytest-asyncio, pytest-cov

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Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feat/your-feature
3. Write tests for new behaviour
4. Open a pull request

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License

MIT — see LICENSE.