I am planning a protocol where two applications open a socket between them and send and receive legal json objects.
Can a sequence of json objects be unequivocally parsed, or will I need delimiters, or prefixing each object with its lengths or something like that?
Real JSON objects always start and end with matching { and } characters. So you should be able to build a stream parser that correctly determines the boundaries on the fly, without needing to know the lengths in advance.
See json.org for details of the syntax.