MCP Client Roots
definition
Roots are a mechanism through which MCP clients inform servers about which parts of the filesystem or data they have access to, helping servers scope their operations to relevant directories or resources. When a client connects to an MCP server, it can declare roots — typically filesystem paths like project directories — that tell the server "here's where my code lives.
Roots are a mechanism through which MCP clients inform servers about which parts of the filesystem or data they have access to, helping servers scope their operations to relevant directories or resources. When a client connects to an MCP server, it can declare roots — typically filesystem paths like project directories — that tell the server "here's where my code lives." This scoping mechanism is important for security because it allows servers to limit operations to declared boundaries rather than having unbounded access, and for relevance because it helps servers focus their analysis and tool operations on the right subset of the user's system. Understanding roots is most relevant for developers building MCP clients or customizing MCP server integrations. This concept connects to MCP overview for the protocol fundamentals, MCP security for the broader security model, and least privilege for the underlying security principle.