A digital assistant operating on a device is configured to be engaged as an active participant in communications between local and remote parties by listening to voice and video calls and participating in messaging sessions. The digital assistant typically can be initiated by voice using a key word or phrase and then be requested to perform tasks, provide information and services, etc. using voice or gestures. The digital assistant can respond to the request and take appropriate actions. In voice and video calls, the interactions with the digital assistant (i.e., the request, response, and actions) can be heard by both parties to the call as if the digital assistant was a third party on the call. In a messaging session, messages are generated and displayed to each participant so that they can see the interactions with the digital assistant as if it was a participant.