Catch stdout pollution and handshake failures in MCP stdio servers before clients do.
mcp-stdio-guard is a tool that validates MCP stdio servers by catching stdout pollution and handshake failures before they affect clients. It starts the server, performs a real MCP initialize handshake, optionally sends a post-initialize request like tools/list, validates every stdout frame, and scans source for risky stdout calls. It helps ensure MCP servers conform to the stdio transport protocol.
