Guides / Python API

Host a Python API with FastAPI

About 10 minutes. For Debian and Ubuntu. Uses port 10002 as an example, so use one of your own forwarded ports.

1. Install Python tools

apt update
apt install -y python3-venv
mkdir -p /opt/api
cd /opt/api
python3 -m venv venv
venv/bin/pip install fastapi uvicorn

2. Create your app

Save as /opt/api/main.py:

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def home():
    return {"message": "Hello from natbox"}

3. Keep it running

Save as /etc/systemd/system/api.service, using your own port:

[Unit]
Description=My FastAPI app
After=network.target

[Service]
WorkingDirectory=/opt/api
ExecStart=/opt/api/venv/bin/uvicorn main:app --host 0.0.0.0 --port 10002
Restart=always
User=www-data

[Install]
WantedBy=multi-user.target

systemctl daemon-reload
systemctl enable --now api
systemctl status api

4. Test it

From your own computer, using your own port:

curl http://natbox.io:10002/

You should see {"message":"Hello from natbox"}. If you use a firewall, allow the port first with ufw allow 10002/tcp.

5. Add your domain and HTTPS

For a public API, link a domain and put a web server in front. Caddy gets HTTPS certificates for you, and nginx works too. Proxy to your app on 127.0.0.1:10002.

A small API fits on Nano. Choose Box if it also runs a database.