Getting Started

Prerequisites

You'll need:

• Python 3.11+ (for the backend)
• Node.js 18+ (for the frontend)
• Git (obviously)

Platform Notes

Platform	Development	Notes
Linux	✅ Primary	Most heavily tested
Windows	⚠️ WSL2 recommended	Native Windows dev tooling is painful
macOS	✅ Should work	Needs testing before v1.0

I develop on Arch Linux. The venv + package-lock approach means everything should work on any platform, but I can only verify what I actually run.

Quick Setup

Prerequisites

• Python 3.11+ with uv package manager
• Node.js 18+ with npm
• Git

Install uv if you don't have it:

curl -LsSf https://astral.sh/uv/install.sh | sh

Linux

# Clone the repository
git clone https://github.com/Sigilweaver/Loom.git
cd Loom

# Backend setup (uses uv, not pip)
cd server
uv sync --all-extras

# Frontend setup
cd ../studio
npm install

Windows (WSL2)

Native Windows development is possible but frustrating. I recommend WSL2:

# In WSL2 (Ubuntu)
sudo apt update && sudo apt install python3 nodejs npm git build-essential
curl -LsSf https://astral.sh/uv/install.sh | sh

# Then follow Linux instructions above

If you must use native Windows:

• Use PowerShell, not cmd
• Watch for CRLF line endings (configure Git: git config --global core.autocrlf input)
• Paths use backslashes. Let Node's path module and Python's pathlib handle it

macOS

# Install dependencies
brew install python node git
curl -LsSf https://astral.sh/uv/install.sh | sh

# Then follow Linux instructions above

Running Development Servers

The recommended approach:

# From repo root - starts both backend and frontend
./scripts/dev.py

Or manually:

# Terminal 1: Backend (using uv)
cd server
uv run uvicorn app.main:app --reload --port 25811
# Runs at http://localhost:25811

# Terminal 2: Frontend
cd studio
npm run dev
# Runs at http://localhost:25810

# Terminal 3: Electron (optional, for desktop app testing)
cd studio
npm run dev:electron

The frontend dev server proxies API calls to the backend, so you need both running.

Hub Development

Hub is the orchestration platform for managing workflows across multiple servers. It lives at the top level in hub/.

Hub Setup

# From hub/ directory

# Start PostgreSQL (required for Hub)
docker compose up -d

# Backend setup
cd backend
uv sync --all-extras
uv run alembic upgrade head  # Run database migrations

# Frontend setup
cd ../frontend
npm install

# Start Hub dev servers
cd ..
./scripts/dev.py

Hub will be available at:

• Frontend: http://localhost:25803
• Backend API: http://localhost:25802
• API Docs: http://localhost:25802/docs

Verifying Your Setup

Backend Health Check

curl http://localhost:25811/api/health/
# Should return: {"status":"healthy","version":"0.0.0-dev","message":"Sigilweaver Loom Backend is running"}

Frontend

Electron should have started, but you can also open http://localhost:25810 in your browser. You should see the Sigilweaver Loom canvas.

Run Tests

# All tests (from repo root)
./scripts/test.py

# Or individually
cd server && uv run pytest tests/
cd studio && npm test

If tests pass, you're ready to contribute.

Daily Workflow

# Start development (from repo root)
./scripts/dev.py

# Run tests before committing
./scripts/test.py

# Build a release (when needed)
./scripts/build.py

Project Structure Overview

loom/
├── server/            # Python (FastAPI + Polars)
│   ├── app/          # Application code
│   │   ├── api/      # REST endpoints
│   │   └── domain/   # Business logic, tools
│   └── tests/        # pytest suite
├── studio/            # TypeScript (React + Electron)
│   ├── src/          # React application
│   ├── electron/     # Electron main process
│   └── tests/        # Vitest suite
├── hub/               # Hub orchestration platform
│   ├── backend/      # FastAPI + PostgreSQL
│   ├── frontend/     # React admin UI
│   └── scripts/      # Hub dev scripts
├── scripts/          # Build and dev utilities
└── docs/             # Project documentation

For deeper understanding, see Architecture Overview.

Troubleshooting

"Module not found" in Server

Make sure you've run uv sync:

cd server && uv sync --all-extras

Studio can't reach Server

Check that the Server is actually running on port 25811. The Vite dev server proxies /api/* requests.

Electron window is blank

The Electron app needs the Vite dev server running first. Start npm run dev, wait for it to be ready, then run npm run dev:electron.

Tests fail on Windows

Check line endings. Run:

git config --global core.autocrlf input
git checkout -- .

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Next: Architecture Overview to understand how the pieces fit together.