OTP Interfaces (APIs) and Data Sources
At the core of OpenTripPlanner is a library of Java code that finds efficient paths through multi-modal transportation networks built from OpenStreetMap and GTFS data. It can also receive GTFS-RT (realtime) data...
In addition to GTFS, OTP2 can also load data in the Nordic Profile of Netex, the EU-standard transit data interchange format. The upcoming EU-wide profile was heavily influenced by the Nordic Profile and uses the same schema, so eventual support for the full the EU profile is a possibility.
GTFS and Netex data are converted into OTP's own internal model which is a superset of both. It is therefore possible to mix Netex and GTFS data, and potentially even data from other sources.
Interfaces to Services (APIs)
Several different services are built upon this routing library, and expose APIs:
The OTP Transit Index API is another RESTful web service that provides information derived from the input GTFS feed(s). Examples include routes serving a particular stop, upcoming vehicles at a particular stop, upcoming stops on a given trip, etc. More complex transit data requests can be formulated using a GraphQL API.
Additional experimental APIs are provided by sandbox extensions:
The Actuator API provides endpoints for checking the health status of the OTP instance. It can be useful when running OTP in a container.
The Transmodel GraphQL API is the Transmodel API (version 3) used at Entur in production(Sep, 2020).
The HSL Legacy GraphQL API is the HSL's GraphQL API used by the Digitransit project.