Message synchronization in networked data communications services callable by applications

A data processing method providing message synchronization, the method comprising:

• maintaining, by a server computer implementing a communications service, a stream of events comprising a plurality of members, the stream of events representing a thread of communication between the plurality of members, wherein each event in the stream comprises a sequence number;
• receiving, by the server computer, a request to synchronize a local state of a client computer, wherein the client computer is associated with a member of the plurality of members;
• sending, by the server computer, a plurality of new events to the client computer using sequence numbers of the stream of events, wherein the client computer represents the thread of communication as conversations;
• receiving, by the server computer, a conversation object comprising a temporary identifier from the client computer;
• assigning, by the server computer, a globally unique identifier to the conversation object;
• notifying, by the server computer, the plurality of members of the conversation object.