> ## Documentation Index
> Fetch the complete documentation index at: https://docs.opus-host.de/llms.txt
> Use this file to discover all available pages before exploring further.

# Reverse Proxy Multiple Apps With Nginx on One VPS

> Use Nginx as a reverse proxy on your Opus Host VPS to serve multiple apps on different domains from a single VPS, all on ports 80 and 443.

Only one process can listen on port 80 at a time. A reverse proxy solves that: Nginx sits on ports 80 and 443, and forwards each request to the right backend app based on the domain. Run a Node.js app, a Python API, and a static site side by side on one Opus Host VPS.

## Install Nginx

```bash theme={null}
sudo apt update
sudo apt install -y nginx
```

See [Web Server](/guides/install-web-server) if you want a fuller intro.

## Example: proxy a Node.js app on port 3000

Suppose your app runs on `localhost:3000` (see [Node.js & PM2](/guides/nodejs-pm2)). Create `/etc/nginx/sites-available/app.example.com`:

```nginx theme={null}
server {
    listen 80;
    server_name app.example.com;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # WebSocket support
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}
```

Enable and reload:

```bash theme={null}
sudo ln -s /etc/nginx/sites-available/app.example.com /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl reload nginx
```

## Add a second app on another subdomain

Repeat the pattern with a new file and a different `server_name` and `proxy_pass` port:

```nginx theme={null}
server {
    listen 80;
    server_name api.example.com;

    location / {
        proxy_pass http://127.0.0.1:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}
```

Each app listens on its own local port. Nginx handles the public entry point.

## Serve static files alongside proxied apps

```nginx theme={null}
server {
    listen 80;
    server_name example.com;
    root /var/www/example.com;
    index index.html;

    location / {
        try_files $uri $uri/ =404;
    }

    location /api/ {
        proxy_pass http://127.0.0.1:8000/;
        proxy_set_header Host $host;
    }
}
```

## Add HTTPS

Run Certbot to add HTTPS to each domain. See [Let's Encrypt SSL](/guides/lets-encrypt-ssl).

```bash theme={null}
sudo certbot --nginx -d app.example.com -d api.example.com
```

<Tip>
  Bind your backend apps to `127.0.0.1` instead of `0.0.0.0` so they are not reachable from outside. Nginx is the only public entry point.
</Tip>

## Test and reload safely

Always test the config before reloading. Nginx will refuse to reload a broken config, but catching mistakes early saves headaches:

```bash theme={null}
sudo nginx -t
sudo systemctl reload nginx
```