Abstract: Methods are provided for providing a user with real-time access to supplemental information about named entities that appear within a conversation in a messaging application on a user terminal. Named entities, conversational topics, and sentiments are recognized as the user enters messages into the application. These are provided to a semantic search engine in a server system, that classifies the named entities into one of a variety of domains. Each domain has an associated tool for retrieving detailed supplemental information about the named entity. The server system transmits, to the user terminal, indicia that allow the user terminal to retrieve the supplemental information. Advertising related to a named entity having favorable sentiment also may be transmitted to the user terminal for display. These functions occur without the need for a separate search interface in the messaging application.