Python: two Flask projects under the same HTTP Port

You don’t need a “3rd Flask project” to route between the two apps – that’s exactly what a **reverse proxy** like **nginx** is for.

The standard production pattern is:

- Each Flask app runs on its **own internal port** (localhost-only).

- **nginx** listens on the single public HTTP port.

- nginx uses `location` blocks to forward `/url1/...` to app1 and `/url2/...` to app2.

---

## 1. Run your Flask apps on different internal ports

Example:

# App 1

FLASK_APP=main.py flask run --host=127.0.0.1 --port=5001

# App 2

FLASK_APP=main.py flask run --host=127.0.0.1 --port=5002

And then nginx:

server {
    listen 80;
    server_name your.server.ip;  # or domain

    # Route /url1/... to Flask app 1
    location /url1/ {
        proxy_pass http://127.0.0.1:5001/;
        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;
    }

    # Route /url2/... to Flask app 2
    location /url2/ {
        proxy_pass http://127.0.0.1:5002/;
        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;
    }
}

Thank you so much! I've got your point. That was so simple ))

P.S. if you make it as an reply so I can mark it as a solution

I guess put both projects in a docker container but don't open them to any ports on the host to the server, use Nginx Proxy Manager in a third container with open port on the host and use the dockers internal ip of each container in Nginx Proxy Manager.

This is dead simple with Caddy

https://caddyserver.com