The techniques discussed herein allow an agent that provides dialog-based services to converse with a user via any mode. A central service programmed to be able to communicate via any mode collects information from agents necessary to act on the agents' behalf. In order to ensure that an agent has a maximal presence across modes, the central service provides auxiliary services such as language translation, fidelity upgrading and/or downgrading, modal constraint conformation, etc. Moreover, the central service provides session tracking via user profiles stored at the intercom so that if a user changes a mode by which the user is conversing with an agent, the central service can keep the context of the conversation across the new mode. Furthermore, agents can communicate with other agents via the central service, allowing other agents to provide services to agents or to add their services to an ongoing dialog with a user.