Moon Tracker Template

What it does

Up or down

Says plainly whether the moon is above the horizon, and how many degrees.

Any location

Cities to try, any latitude and longitude, or the visitor’s own location.

Which way to look

On paid plans, the compass direction and the moon’s distance in km and miles.

Keeps your key private

The page calls a server route that holds the key, checks the input and limits each visitor to 10 lookups a minute.

A web app and a CLI

python app.py runs the page and its route locally. The same lookups work from the terminal, sharing one small API helper.

How it works

The Flask route: it checks the coordinates and time, then calls Moon Position.

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TIME = re.compile(r'^([01]\d|2[0-3]):[0-5]\d$')


def coordinate(name, limit):
    try:
        value = float(request.args.get(name, ''))
    except ValueError:
        return None
    return value if -limit <= value <= limit else None


@app.get('/api/moon')
def moon():
    """GET /api/moon?lat=40.71&lon=-74.01&time=21:30: where the moon is in the sky (time is UTC, today)."""
    lat, lon = coordinate('lat', 90), coordinate('lon', 180)
    if lat is None or lon is None:
        return fail('Enter a latitude from -90 to 90 and a longitude from -180 to 180.')
    params = {'lat': round(lat, 4), 'lon': round(lon, 4)}
    time = request.args.get('time', '').strip()
    if time:
        if not TIME.match(time):
            return fail('Use a 24-hour time, like 21:30.')
        params['time'] = time
    return jsonify(call_api('moonposition', params))

See the whole file on GitHub →

Deploy it

1. Get a free API key

   The free plan includes 200 credits a month, no card needed. Create your key.

2. Deploy it

   Click Deploy to Vercel. Vercel copies the repo to your GitHub account and asks for APIVERVE_API_KEY: paste your key there.

3. Open your app

   Vercel builds it and gives you a live URL, usually in about a minute. Every push to the repo redeploys it.

Try the Moon Position API — the call this template makes

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{
  "status": "ok",
  "error": null,
  "data": {
    "date": "01-22-2026",
    "time": "14:30",
    "coordinates": {
      "latitude": 37.7749,
      "longitude": -122.4194
    },
    "moon": {
      "altitude": -0.407908976399288,
      "azimuth": 1.4720499058762104,
      "distance": 404332.6834067969
    }
  }
}