What Free API Surprised You The Most?

#discuss #webdev #python #api

I've been building Python toolkits for free APIs for the past few months. Some of them blew my mind — I had no idea these existed.

My top 3 surprises:

1. Crossref — Every DOI Ever Assigned

I didn't know there was a free API that holds metadata for 150 million scholarly articles. No API key. No signup. Just send a GET request.

import requests
article = requests.get("https://api.crossref.org/works/10.1038/nature12373").json()["message"]
print(f"{article['title'][0]} — cited {article['is-referenced-by-count']} times")

Every DOI you've ever seen? The metadata lives in Crossref.

2. USGS Earthquake API — Every Earthquake in Real Time

Every earthquake on Earth, updated every minute. Free. No key.

resp = requests.get("https://earthquake.usgs.gov/fdsnws/event/1/query",
    params={"format": "geojson", "minmagnitude": 5, "limit": 3}).json()
for eq in resp['features']:
    print(f"M{eq['properties']['mag']} — {eq['properties']['place']}")

3. Open-Meteo — Weather Without API Key

Most weather APIs charge money or require OAuth. Open-Meteo? Just send a request. Done.

resp = requests.get("https://api.open-meteo.com/v1/forecast",
    params={"latitude": 51.5, "longitude": -0.12, "current_weather": True}).json()
print(f"London: {resp['current_weather']['temperature']}°C")