32.30.2 Process-based JSONRPC connections

For convenience, the jsonrpc library comes with a built-in jsonrpc-process-connection transport implementation that can talk to local subprocesses (using the standard input and standard output); or TCP hosts (using sockets); or any other remote endpoint that Emacs’s process object can represent (see Processes).

Using this transport, the JSONRPC messages are encoded on the wire as plain text and prefaced by some basic HTTP-style enveloping headers, such as “Content-Length".

For an example of an application using this transport scheme on top of JSONRPC, see the Language Server Protocol.

Along with the mandatory :request-dispatcher and :notification-dispatcher initargs, users of the jsonrpc-process-connection class should pass the following initargs as keyword-value pairs to make-instance:

:process

Value must be a live process object or a function of no arguments producing one such object. If passed a process object, the object is expected to contain a pre-established connection; otherwise, the function is called immediately after the object is made.

:on-shutdown

Value must be a function of a single argument, the jsonrpc-process-connection object. The function is called after the underlying process object has been deleted (either deliberately by jsonrpc-shutdown, or unexpectedly, because of some external cause).