Five public registries index MCP servers today. They all overlap, none of them is exhaustive, and each has its own editorial philosophy. Understanding what each one is good at helps you read the provenance signals on every Atlas card.
The official registry
registry.modelcontextprotocol.io is the registry maintained by the MCP project itself. It's intentionally narrow — reference servers, well-known integrations, and a small curated set. If a server is listed here, you can usually trust that it adheres to the spec and is actively maintained.
Marketplaces
Smithery, Glama, and PulseMCP are community marketplaces. They index thousands of servers, accept submissions from anyone, and add their own metadata layers — install counts, screenshots, ratings. Coverage is broad; quality varies.
GitHub topic
Anyone can tag a repo with the mcp topic on GitHub. This is the most permissive index — it includes prototypes, abandoned experiments, and works in progress alongside production-grade servers.
How Atlas reads them
We pull from all five on a daily schedule, normalize the schemas into one shared shape, and surface every source on the card. A server in 4 of 5 sources is a stronger signal than a server in 1 — but we never collapse that into a single score. The provenance trail is the signal.