JSON-RPC
JSON-RPC is a lightweight remote procedure call protocol that encodes a method name, parameters, and an identifier as a JSON object, letting one system ask another to run a named operation and return a result or error in a matching JSON reply. Version 2.0, the version in current use, is the wire format the Model Context Protocol (MCP) builds on: an MCP client sends JSON-RPC requests like initialize or tools/list to a server, which responds with a JSON-RPC result carrying its capabilities or exposed tools. Because JSON-RPC itself defines only the message shape, not authentication or transport security, an MCP server's actual protection against unauthorized calls depends entirely on what the server (or a gateway in front of it) adds on top.
By AdminKit team, Netbase JSC · Updated