Open World Studio

A web app that wraps the Open World 3D game with an AI-powered chat interface. Users describe changes in natural language, and Claude modifies the game code in real time.

Live: https://open-world-studio-production.up.railway.app

Features

• AI Game Editor — Describe changes in chat, Claude modifies the game code via SEARCH/REPLACE patches
• Instant Preview — See your modified game version immediately in the iframe
• Version History — Browse and switch between all versions created in a session
• Save & Share — Sign in to save versions and generate public share links
• Auth System — Email/username signup and login with JWT
• Bring Your Own Key — Users provide their own Anthropic API key

Tech Stack

• Frontend: Vanilla JS SPA with dark theme UI
• Backend: Python / FastAPI
• AI Agent: Anthropic Claude API (claude-sonnet-4-20250514)
• Database: SQLite (persistent volume on Railway)
• Auth: JWT + bcrypt
• Hosting: Railway

Project Structure

open-world/
├── index.html              # Original game (Three.js, ~4800 lines)
├── zones/                  # Game zone modules
├── app/
│   ├── backend/
│   │   ├── main.py         # FastAPI routes
│   │   ├── agent.py        # Claude API agent
│   │   ├── auth.py         # JWT auth
│   │   ├── models.py       # SQLAlchemy models
│   │   └── database.py     # SQLite setup
│   ├── static/
│   │   ├── index.html      # SPA entry point
│   │   ├── css/styles.css  # UI styles
│   │   └── js/             # auth.js, chat.js, app.js
│   ├── requirements.txt    # Python dependencies
│   └── run.py              # Local dev startup
├── railway.toml            # Railway deploy config
├── nixpacks.toml           # Build config
└── Procfile                # Process definition

Local Development

# Create venv and install deps
python3 -m venv app/venv
app/venv/bin/pip install -r app/requirements.txt

# Optionally copy and edit .env
cp app/.env.example app/.env

# Run the server
app/venv/bin/python app/run.py

Open http://localhost:8000

Deploy to Railway

Prerequisites

• Railway CLI installed (brew install railway)
• Railway account — sign up at https://railway.com

Steps

1. Login to Railway

   railway login

2. Create a new project

   railway init --name open-world-studio

3. Link the project and create a service

   railway link --project <PROJECT_ID>
   railway up --detach

   The first railway up creates the service and triggers the initial build.

4. Link the service

   railway service link open-world-studio

5. Set environment variables

   railway variables set \
     JWT_SECRET=$(openssl rand -hex 32) \
     DATA_DIR=/data/db \
     VERSIONS_DIR=/data/versions

6. Add a persistent volume (for SQLite DB + game version files)

   railway volume add --mount-path /data

7. Generate a public domain

   railway domain

8. Redeploy (picks up the new env vars and volume)

   railway up --detach

Your app will be live at the domain Railway generated.

Subsequent deploys

After pushing changes to GitHub:

railway up --detach

Or connect your GitHub repo in the Railway dashboard for automatic deploys on push.

Environment Variables

Variable	Required	Description
JWT_SECRET	Yes	Secret key for JWT tokens. Generate with openssl rand -hex 32
DATA_DIR	No	Directory for SQLite database. Default: app/data/
VERSIONS_DIR	No	Directory for saved game versions. Default: app/versions/
PORT	No	Server port. Railway sets this automatically