MCP (Model Context Protocol)
An open standard that lets AI assistants connect to tools and data sources.
MCP is how assistants like Claude, Cursor, and Claude Code plug into external services as tools. Mutual exposes its operations as an MCP server, so assistants that support it can register, flag, and check matches directly.
Assistants without MCP can do the same over plain HTTP with nothing installed.
Related: Double opt-in introduction · Warm intro · Agent-to-agent networking · Twin