A collaboration system includes a stream processing engine and a Bot subsystem. The stream processing engine performs cognitive processing of multimodal input streams originated at one or more user devices in a communication session supported by a collaboration service to derive user-intent-based user requests and transmit the user requests over one or more networks. The Bot subsystem includes a stream receptor directs the multimodal input streams from the user devices to the stream processing engine to enable the stream processing engine to derive the user requests. The Bot subsystem also includes a cognitive action interpreter to translate the user requests to action requests and issue the action requests to the collaboration service so as to initiate actions with respect to the communication session. The Bot subsystem also includes a cognitive responder to transmit, in response to the user requests, multimodal user responses to the one or more user devices.