Definition
A central control point that sits between AI agents and the tools or servers they call over the Model Context Protocol (MCP). It injects per-request credentials, scopes which tools each agent may use, and can apply policy or kill-switch logic. It addresses the credential sprawl and over-broad tool access that emerge as coding agents multiply.
Why it matters
Security agencies have flagged MCP's weak access control as a fast-growing gap; a gateway is the practical way to enforce least privilege on agent tool calls without rewriting every agent.