https://diffusion.sandr.in

A block-based AI canvas for rapid creative exploration. Compose ideas as networks of text and image blocks, connect them into directed acyclic graphs (DAGs), and use AI tools to branch, remix, and evolve those ideas.

Check out the demo below:

Local Development

# Backend
cd backend
pip install -r requirements.txt
export DATABASE_URL="postgresql://username:password@localhost:5432/diffusiongarden"
export IMAGES_DIR="./images"
export OPENAI_API_KEY="your-key"
export GOOGLE_API_KEY="your-key"
uvicorn app.main:app --reload --port 8000

# Frontend (in another terminal)
cd frontend
npm install
npm run dev

Deployment

Frontend (GitHub Pages)

The frontend is automatically deployed to GitHub Pages via a GitHub Actions workflow on every push to master that modifies files in frontend/.

Setup:

1. In your repo settings, enable GitHub Pages with Source set to GitHub Actions
2. Add a repository secret VITE_API_HOST with the backend API URL (e.g., https://your-backend-domain.railway.app/api)
3. If using a custom domain, configure it in the Pages settings

The workflow (.github/workflows/deploy-frontend.yml) builds the Vite app and copies index.html to 404.html for SPA routing.

Backend (Railway)

1. Go to railway.app and create a new empty project
2. Add a PostgreSQL database: New → Database → PostgreSQL
3. New → GitHub Repo → Select this repo
4. Set Root Directory to backend
5. Add environment variables:
   • OPENAI_API_KEY - Your OpenAI API key
   • GOOGLE_API_KEY - Your Google AI API key
   • IMAGES_DIR - /app/images
   • FRONTEND_URL - Your GitHub Pages URL (for CORS)
   • DEBUG - false
6. Link the PostgreSQL service (auto-injects DATABASE_URL)
7. Add a Volume mounted at /app/images for image storage
8. Generate a domain

Environment Variables Reference

Variable	Service	Description
DATABASE_URL	Backend	PostgreSQL connection string (auto from Railway)
OPENAI_API_KEY	Backend	OpenAI API key
GOOGLE_API_KEY	Backend	Google AI API key
IMAGES_DIR	Backend	Path to image storage directory
FRONTEND_URL	Backend	GitHub Pages URL for CORS
DEBUG	Backend	Set to false for production
VITE_API_HOST	Frontend	Backend API URL (set as GitHub repo secret)