The Promptfoo MCP Proxy: Enterprise MCP Security

The Model Context Protocol (MCP) adoption is rapidly increasing, with NPM installations reaching 4.7 million in July 2025, leading to the introduction of the Promptfoo MCP Proxy to manage security risks for enterprises using MCP servers. While MCP servers, which act as wrappers around existing APIs, are not inherently insecure, their use can create vulnerabilities, as seen in scenarios where malicious MCP servers exfiltrate sensitive company data. The security challenges arise from combining multiple tools in operational loops, which can result in unintentional data leaks. To mitigate these risks, developers are advised to use a single tool per loop, thoroughly review MCP servers, and ensure no conflicting actions occur during critical operations. The Promptfoo MCP Proxy addresses these challenges by offering enterprise-grade security controls, including whitelisting MCP servers, providing visibility and control over server combinations, and ensuring data protection, enabling organizations to safely leverage MCP servers for enhancing LLM capabilities without compromising security.