SkyGlance 0.2.0 — first release

Ask Claude what's flying above you. 24 tools for live aircraft data, built entirely on free ADS-B feeds. No API keys, no accounts, $0/month.

claude mcp add skyglance -- uvx --from skyglance skyglance

Or with the sky skill bundled, which teaches Claude how to talk about aircraft to someone who's never spotted one:

/plugin marketplace add darshjoshi/skyglance-mcp
/plugin install skyglance@skyglance

What you can ask

"What's flying over me right now?"      → ranked by what you'd actually notice
"What's about to pass overhead?"        → but only 90 seconds ahead, honestly
"What is that plane?"                   → type, operator, route, photograph
"Where has N520JB flown today?"         → ~24h of flight path
"What's departing Heathrow?"            → observed, not a schedule
"How many Emirates flights are up?"     → 47, and what types
"Which airports are busiest right now?" → from one global snapshot
"Have I ever seen this plane before?"   → your own sighting history

Why it's shaped this way

"Over you" is an angle, not a distance. An airliner at 38,000 ft that's 19 km away sits 32° above the horizon — a speck near the treeline. A helicopter at 800 ft at the same distance is at 0.7°, invisible behind buildings. SkyGlance computes elevation, bearing and slant range, so an answer tells you where to point your face.

It won't predict further than it can. Straight-line extrapolation is accurate to ~0.11 km at 30 seconds but misses by a median 6 km at four minutes, because aircraft on approach turn constantly. Countdowns stop at 90 seconds; beyond that it says "inbound" with no number.

It knows when it can't see. Free ADS-B comes from volunteers with rooftop receivers. Dense Europe, US and East Asia get 90–95% of a commercial feed. Oceans, Africa and central Asia get near zero. Thin results are reported as thin coverage, never as an empty sky.

Your coordinates are rounded before they leave. Query centres are coarsened to ~1.1 km so no feed operator gets a rooftop-accurate log of where you are and when you're awake. Bearing and elevation are still computed locally from your exact position. There's a test that fails if an uncoarsened coordinate ever reaches a feed.

What it deliberately can't do

No schedules, delays, gates, or ETAs against a timetable — ADS-B carries positions, not timetables. No history beyond ~24 hours. No oceanic coverage. These are licensed data products, and buying one would end the no-API-keys story. The tools refuse those questions rather than estimating, and the bundled skill tells Claude to do the same.

Local sighting history

Set SKYGLANCE_HOME_LAT / SKYGLANCE_HOME_LON and it polls your sky once a minute, recording every pass to SQLite at ~/.skyglance/sky.db — locally, uploaded nowhere. That's what makes "have I seen this tail before?" answerable. Disable with SKYGLANCE_POLL=0.

Credits

Aircraft data from adsb.lol (ODbL 1.0), airplanes.live, adsb.fi, adsbdb, hexdb.io, planespotters.net, Open-Meteo, and OurAirports. Volunteers pay for the bandwidth this runs on — see NOTICE.md.

Not for operational use.