whenTrain?

Real-time NYC subway arrival times for all stations within a 15-minute walk of your location. Live at whentrain.lushchik.com.

What it does

• Requires your location to find nearby stations — share it when prompted
• Finds every subway station within a 15-minute walk (~1,260 m)
• Shows the next northbound and southbound trains at each station
• Refreshes every 30 seconds, silently re-checking your position each time
• Installable as a PWA on iOS and Android

Stack

Layer	Tech
Frontend	Lit 3 web components, Vite, vite-plugin-pwa
Backend	Node.js + Express, TypeScript
Data	MTA GTFS static (stops, trips) + GTFS-RT protobuf feeds
Cache	Redis — raw feed bytes cached 30 s per feed endpoint
Infra	Docker Compose, nginx (reverse proxy + static files)
Deploy	Coolify on DigitalOcean, HTTPS via Let's Encrypt

Running locally

docker compose up --build

Open http://localhost. The backend downloads the MTA GTFS static zip on first start (~10 s), then serves arrivals at /api/arrivals?lat=&lng=.

Project layout

packages/
  backend/   Express API — GTFS parsing, feed fetching, Redis cache
  frontend/  Lit PWA — station cards, geolocation, auto-refresh

API

GET /api/arrivals?lat={lat}&lng={lng}

Returns all stations within 15 minutes walking distance, each with northbound and southbound arrival times.

GET /health

Returns {"ok":true} once the GTFS data is loaded.