The APIs have no rate limiting, but you should avoid doing more than 10 requests per second. If you need to make large amount of requests, you might want to host the API locally.
If you want to improve or modify the APIs in some way, you can either contribute to the projects through https://gitlab.com/opentransport or host your own APIs based on those sources.
|Routing API||Routing API (OpenTripPlanner) provides a way to plan itineraries and query public transport related information about routes, stops and timetables.|
|Geocoding API||Geocoding API provides a way to perform address searches and address lookups (also known as geocoding and reverse geocoding).|
|Map API||Provides raster map images (background map tiles) as well as vector map tiles for stops and other points of interests like ticket sales positions, city bike stations and park and ride areas.|
|Real-time API - Service alerts||Provides HSL's disruption information in the GTFS-RT Service Alerts format and cancelled trips as Trip Updates.|
|Real-time API - Trip updates||Provides realtime trip progress and schedule deviations (predictions) in the GTFS-RT Trip Updates format.|
|Real-time API - High frequency positioning||Provides realtime vehicle locations in a JSON format over MQTT.|