Deploy and Host FastAPI WebSocket Chat on Railway

A real-time chat application built with FastAPI and WebSockets. Users pick a username and join a shared chat room with instant messaging, typing indicators, online user counts, and join/leave notifications — all served from a single Python file with a dark-themed embedded UI.

About Hosting FastAPI WebSocket Chat

Hosting a WebSocket chat app requires a platform that supports persistent, long-lived connections — not just standard HTTP request-response cycles. Railway handles this seamlessly. The app is a single app.py file with the HTML/CSS/JS frontend embedded inline, so there's no build step or static file configuration needed. Railway auto-detects the Python runtime, installs dependencies from requirements.txt, and exposes the app on a public URL. The PORT environment variable is read automatically, making deployment zero-config. Push to GitHub and Railway takes care of the rest.

Common Use Cases

• Learning how WebSockets work in a real deployed environment with FastAPI
• Starting point for building multiplayer or collaborative real-time apps
• Teaching students or beginners about full-stack Python web development with minimal setup

Dependencies for FastAPI WebSocket Chat Hosting

• Python 3.10+
• FastAPI — web framework with native WebSocket support
• Uvicorn — ASGI server to run the app
• websockets — underlying WebSocket protocol library

Deployment Dependencies

• Railway — hosting platform
• FastAPI Documentation — WebSocket reference
• Uvicorn — ASGI server docs

Implementation Details

The entire app is a single main.py. The frontend is served as an inline HTML string from the root route, and the WebSocket endpoint handles connections at /ws/{username}:

@app.websocket("/ws/{username}")
async def websocket_endpoint(ws: WebSocket, username: str):
    await manager.connect(ws, username)
    await broadcast_users()
    try:
        while True:
            data = await ws.receive_json()
            if data.get("type") == "typing":
                # relay typing indicator to other clients
                ...
            elif data.get("type") == "message":
                await manager.broadcast(data["text"], username)
    except WebSocketDisconnect:
        manager.disconnect(ws)

A ConnectionManager class tracks active connections and broadcasts messages and user counts to all clients.

Why Deploy FastAPI WebSocket Chat on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying FastAPI WebSocket Chat on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.