Best MCP Gateways, Runtimes, and Registries for engineering and DevOps AI agents (2026)

The Model Context Protocol (MCP) ecosystem is categorized into Registries, Gateways, and Runtimes, each serving distinct purposes for tool discovery, request routing, and secure execution in enterprise environments. Registries focus on cataloging tools without handling authorization or execution, while Gateways serve as routing layers that can connect models to tools but often lack comprehensive per-user authorization, leading to potential security risks. Runtimes provide a secure execution environment with per-user authorization, vaulted credentials, and detailed audit logs, essential for enterprise applications handling sensitive code and data. As enterprises integrate AI agents with tools like GitHub and Jira, they must choose between these infrastructure types based on data sensitivity and security needs. The document warns against using gateways for high-risk environments due to vulnerabilities such as prompt injection attacks, suggesting Runtimes as the preferred choice for maintaining security and compliance.