Here should be some extensive documentation on how to use the API.
All communication within a DDS network happens through domains. A domain is a combination of an integer identifier and a set of config parameters. The concept of a domain is what allows you to run multiple DDS systems on a single network without interference. As in any other DDS API, this connection to a domain is represented with a DomainParticipant . Your connection to the DDS network is started with the creation of the participant and ended with its destruction.
1from cyclonedds.domain import Participant
3dp = Participant(0)