A method is described for supplementing a live broadcast. The method is performed on a server system having one or more processors and memory storing one or more programs for execution by the one or more processors to perform the method. The server system receives first keywords related to the live broadcast. The server system then receives a plurality of input streams, wherein each input stream includes a plurality of events. The server system then extracts second keywords from the plurality of events. The server system then determines the relevance of each event in the plurality of events to the live broadcast by correlating the first and second keywords. The server system then transmits the relevant events to a client device.