Transportation — entry 038 of 69
Transport for Chicago, US
CTA's Developer Center offers two separate real-time services, each requiring its own free API key application: Train Tracker (lapi.transitchicago.com) for rail arrival predictions and Bus Tracker/BusTime (ctabustracker.com) for bus locations and predictions, both returning XML by default with an optional JSON output mode. Static GTFS schedule data is also published for both bus and rail.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSDisabledBrowser calls need a server-side proxy.
PricingFreeNo paid tier — free for the documented use case.
FormatsXML, JSON, GTFSResponses can be requested as XML or JSON or GTFS.
GreatAPIs Score
Score84
Authentication15/25API key required
Pricing20/20Free to use
Docs14/20Documentation URL provided
Formats15/15Supports 3 response formats
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/transport-for-chicago-us/"><img src="https://greatapis.com/badge/transport-for-chicago-us.svg" alt="Scored 84 on greatapis.com"></a>Auth quickstart
- Sign up with the provider to get an API key.
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.