Call MCP Server(stdio) directly in the shell

stdio is one of the transport mechanisms MCP(Model Context Protocol) natively supports. Actually stdio is the only transport mechanism Claude Desktop supports currently(as in May, 2025). This article will show you how to call a MCP server in the shell, without mcp dev or any third party tools, only with echo > or copying/pasting JSONRPC message directly. First, let's write a very simple MCP…