Proposal: skills.json format for Agent Skills registry

[JAORMX]

Pre-submission Checklist

• I have verified this would not be more appropriate as a feature request in a specific repository
• I have searched existing discussions to avoid duplicates

Your Idea

The MCP registry does a great job enabling discovery and distribution of MCP servers via server.json. I'd like to propose extending this to cover Agent Skills - the open format for extending AI agents with specialized capabilities.

Agent Skills have seen rapid adoption across tools (Claude Code, Cursor, VS Code/Copilot, Codex, etc.), but there's no standardized way to discover and distribute them through a registry. Skills are currently shared via git repos or manual copying.

Proposal: skills.json

A registry entry format for skills, inspired by server.json but adapted for the Agent Skills spec. Here's a minimal example:

{
  "namespace": "io.github.bob",
  "name": "hello-world",
  "description": "A simple example skill that greets users.",
  "version": "0.1.0",
  "packages": [
    {
      "registryType": "git",
      "url": "https://github.com/bob/hello-world-skill.git",
      "ref": "main"
    }
  ]
}

Design notes

The format borrows heavily from what the MCP registry already does well:

• Uses namespace/name identity with reverse-DNS (so existing auth/ownership verification works)
• Supports both git and OCI distribution (git is easier to start, OCI adds supply chain guarantees)
• Keeps required fields minimal - just the basics to find and fetch a skill

Why extend the registry?

• Skills and MCP servers are complementary (skills often use MCP tools)
• Shared authentication/namespace infrastructure
• Single place for agentic tool discovery
• Could leverage the registry extension API initially

I have a more complete spec with JSON Schema, but wanted to gauge interest first. Happy to share details or iterate based on feedback.

Scope

• Protocol Specification
• SDK Features
• Documentation
• Developer Experience
• Other

[thoorp]

Like the idea but this may belong to a different project unless I'm missing something.

[JAORMX]

The registry supports a servers.json for MCP servers. The idea is to start bringing skills into the registry, and thus, this would be an equivalent concept.

[evan-rash]

What about extending the MCP protocol itself so that the sever can expose skills natively? Similar to how a server can expose resources.

Your concept of a skills.json could then pull in skills for remote repos, but also from the MCP server itself.

I'm able to hack this now by creating a local MCP server that installs the relevant skills in the project at startup, but it would be much more elegant if the protocol supported this natively

[JAORMX]

@evan-rash that's also a valid approach that several pf us have been trying with mixed results. We did do a PoC of expressing skills via MCP Resources. And the base of the approach is not too hard to implement. The tricky thing has been to get clients to pick that up. I know another team member had some ways to work around this.

Regardless, while this solves delivery and usage of skills. Adding skills to the registry and thus the skills.json format aims to standardize packaging + distribution which is a different issue.