Embodiments relate to providing remote procedure calls (RPC) with call-by-reference semantics using remote direct memory access (RDMA). An aspect includes establishing a session between a client and a server. A client session heap memory and a server session heap memory are initialized with a RDMA provider. A parameter is then stored in the session heap memory. A handle for the parameter is passed to the server which permits access to the parameter responsive to an on-demand request from the server.