CTA (Chicago Transit Authority)
CTA provides real-time departures for Chicago 'L' trains and buses via the official CTA Train Tracker and Bus Tracker APIs.
Coverage Area
- All 'L' lines: Red, Blue, Brown, Green, Orange, Purple, Pink, Yellow
- All CTA bus routes
- Not included: Metra and Pace (use Transitous for those)
API Details
| Property | Value |
|---|---|
| Base URL | https://lapi.transitchicago.com/api/1.0/ · https://www.ctabustracker.com/bustime/api/v3/ |
| API Key | Required (free) — one key for buses, one for 'L' trains |
| Timezone | America/Chicago |
| Data Format | CTA Train Tracker / Bus Tracker JSON |
Getting the API Keys
CTA issues two separate free keys. You need the one for the stops you want to monitor, or both:
- Bus Tracker key — create an account at ctabustracker.com, sign in, open My Account → Developer API and apply.
- Train Tracker key — fill in the application form at transitchicago.com/developers.
Enter the Bus Tracker key in the first field and the Train Tracker key in the second field of the config flow.
Configuration
Setup Steps
- Select CTA — USA (Chicago, API Key) as provider
- Enter your Bus Tracker and/or Train Tracker key
- Search for your stop (e.g. "Clark/Lake")
- Select the stop and configure departures and filters
Stop search works without a key and finds both 'L' stations and bus stops.
Example Stops
- Clark/Lake
- Howard
- Michigan & Washington
- Belmont
Features
- Real-time 'L' arrivals (live predictions; scheduled ones are marked as not real-time)
- Real-time bus predictions with delay and cancellation notices
- Line colours for the 'L'
- Free API keys
New provider
This provider was built from the official API documentation and could not yet be tested with real keys. Please report any problems on GitHub (#101).