Stella

A self-hosted, open-source AI software engineer.

Stella listens to GitHub webhooks, reads your issues, plans a solution, writes the code, runs tests, and opens a Pull Request—entirely autonomously.

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Setup

1. Clone the Repository

git clone https://github.com/sohamsangole/stella.git
cd stella

2. Create a Virtual Environment

python3 -m venv venv
source venv/bin/activate

3. Install Dependencies

pip install -r requirements.txt

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Create a GitHub App

1. Go to GitHub → Settings → Developer settings → GitHub Apps.
2. Click New GitHub App.
3. Set:

Setting Value

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Homepage URL http://localhost:8000 Webhook URL Your Smee URL Webhook Secret Any secure random string

Repository Permissions

Grant Read & Write access to:

• Contents
• Issues
• Pull Requests

Subscribe to Events

Enable:

• Issue comments

Generate Credentials

• Generate a Private Key (.pem)
• Download it
• Install the GitHub App on your test repository

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Configure Environment Variables

Create a .env file:

GITHUB_WEBHOOK_SECRET="your-webhook-secret"

REDIS_URL="redis://localhost:6379/0"

GITHUB_APP_ID="your-app-id"

GITHUB_PRIVATE_KEY_PATH="/absolute/path/to/private-key.pem"

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Running Stella

Open four terminals.

Terminal 1 --- Start Redis

docker run -p 6379:6379 -d redis

Terminal 2 --- Start Smee

Replace with your own Smee URL.

npx smee-client \
  --url https://smee.io/your-channel \
  --target http://localhost:8000/webhook/github

Terminal 3 --- Start FastAPI

uvicorn main:app --reload --port 8000

Terminal 4 --- Start Celery

celery -A worker.app worker --loglevel=info

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Usage

1. Open an issue in your repository.
2. Mention Stella in a comment:

@coding-agent-stella fix the login bug

3. Stella will:

• Receive the GitHub webhook
• Queue the task in Redis
• Celery picks up the task
• Clone the repository
• Generate a solution using the configured LLM
• Commit the changes
• Open a Pull Request

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License

MIT License