Extensions spec

[domdomegg]

Is your feature request related to a problem? Please describe. We receive lots of suggestions to improve the MCP registry. Like:

• free-text / "smart" search ( https://github.com/modelcontextprotocol/registry/issues/389, https://github.com/modelcontextprotocol/registry/issues/135 )
• MCP server ( https://github.com/modelcontextprotocol/registry/issues/24 )
• skills ( https://github.com/modelcontextprotocol/registry/issues/721 )
• client MCP documentation
• clients registry

This puts us in the unfortunate position of having to choose between:

• Implementing something that might not get broad usage, and then it being very hard to unship because to do so would cause a breaking registry API spec change. Then we're stuck with this maintenance burden forever.
• Not implementing things that might be useful. Then we lose out on registry being better.

Describe the solution you'd like Develop some convention around common extensions, ideally so that:

• there are conventions around common extensions, so that people may start to adopt them / AI agents know how to use them
• there are conventions around how to build extensions, so that things are generally standardised ish & easy to adopt
• anyone can build custom extensions if they like, and be unlikely to clash with others

Ideally we also try to build things out such that it's easy to compose things together.

[domdomegg]

Draft spec available in #777