MCP Server Authentication for Enterprise Deployments: Identity, Authorization, and the Boundary Question
Model Context Protocol (MCP) servers have moved from developer-tool integrations to production agent backends inside enterprises. The authentication and authorization model for MCP traffic differs from REST-API authentication in two specific ways that matter at enterprise scale: the principal acting on the MCP server can be an agent on behalf of a human, and the tool invocations have to carry the propagation chain. This article walks through the MCP authentication model, the transport-boundary distinction, and the gateway-layer controls that produce a usable audit trail.