MCP Registry Architecture: A Technical Overview

Launched in preview in September 2025, the Model Context Protocol (MCP) Registry provides a centralized metadata catalog for MCP servers, aiming to reduce fragmentation within the ecosystem by allowing AI applications and tool clients to discover and connect to servers efficiently. It supports extension and federation, enabling organizations to create custom sub-registries while adhering to a consistent interface. The registry is built as an open catalog with an API backed by an OpenAPI specification, and it focuses on discovery rather than running or auditing the servers. It includes minimal validation to ensure reliability and offers extensibility for additional properties, such as tags and categorization. The registry's architecture promotes federation, allowing both public and private subregistries to augment or mirror the canonical public MCP server metadata provided by the upstream registry. While namespace and ownership verification are proposed features, the registry also emphasizes scalability and evolution, with plans for future enhancements, including integrity verification and package support, though these are not part of the current preview. Moderation is managed through a hybrid model of community oversight and automated systems, ensuring safety while maintaining openness.