API Bridge — Curated Public API Toolkit for AI Agents

AI agents constantly need real-world data. This skill provides a curated, tested collection of the highest-value free public APIs organized by use case. Each entry includes the endpoint pattern, output shape, and curl example.

Philosophy: Curation + examples = the product. These are stable, mostly key-free APIs with good uptime.

Quick Reference

Weather

wttr.in — Minimal Weather (CORS: ✅, No Key)

curl -s "wttr.in/San+Jose,CA?format=j1"

Use: Current conditions, 3-day forecast, moon phase, airport weather.

Output: JSON with current_condition, weather[] (daily), nearest_area.

# Specific location
curl -s "wttr.in/San+Jose,CA?format=3"
# Named locations work well; coordinates less so

Open-Meteo — Open Source Weather API (CORS: ✅, No Key)

Base: https://api.open-meteo.com/v1/forecast

curl -s "https://api.open-meteo.com/v1/forecast?latitude=37.34&longitude=-121.89&current=temperature_2m,relative_humidity_2m,weather_code,wind_speed_10m&temperature_unit=fahrenheit&wind_speed_unit=mph&timezone=America%2FLos_Angeles"

Use: Current conditions + hourly forecast, no key needed, global coverage.

Parameters:

• latitude, longitude — required
• current= — comma-separated variables: temperature_2m, relative_humidity_2m, weather_code, wind_speed_10m, precipitation, cloud_cover
• hourly= — same variables for 48h forecast
• daily= — daily forecast: temperature_2m_max, temperature_2m_min, precipitation_sum, weather_code
• temperature_unit=fahrenheit|celsius
• timezone=America%2FLos_Angeles (or auto)

Weather codes: 0=clear, 1-3=partly cloudy, 45-48=fog, 51-67=rain/drizzle, 71-77=snow, 80-82=rain showers, 95-99=thunderstorm.

Geocoding

ipapi.co — IP Geolocation (CORS: ❌, No Key)

Base: https://ipapi.co/json/ or https://ipapi.co/{IP}/json/

# Your sandbox出口IP
curl -s "https://ipapi.co/json/" | jq '.location, .city, .region, .country_name, .latitude, .longitude'
# Specific IP
curl -s "https://ipapi.co/8.8.8.8/json/" | jq '{city, region, country_name}'

Use: IP → city/region/country/lat-lon. Not CORS-friendly for browser use. Good for server/CLI agents.

Fields: ip, city, region, region_code, country_name, country_code, latitude, longitude, timezone, utc_offset, asn, org.