Addition of Twistd Proxy to Existing Python Twistd Server Implementation

I've got an existing python twistd server that accepts connections via a LineOnlyReceiver to handle jsonrpc calls that get passed to another process. I'm looking to add a proxy in front of this server, that accepts incoming connections, reads the json looking for a specific field, and if found, searches for values in some sort of cache (redis, memcached), based on those cached values it must then forward the entire original payload to a specific port (that has the original twistd server listening)