Agent skills and plugin marketplaces
Two open standards dominate in 2026: MCP for tool connections and the Agent Skills SKILL.md format. Directory counts are inflated: a full walk of the official MCP registry in August 2026 found 22,636 active entries, of which only 12,077 had a reachable endpoint. No directory publishes a safety grade next to its listings.
Catalog only, not yet measureddev.to count; mcpindex.ai; registry walk (GitHub discussion #1547) · Aug 19, 2026 to Nov 2, 2026
Official MCP registry, by the numbers
54,988
entries, Nov 2, 2026
22,636
active, Aug 19, 2026 walk
12,077
with a reachable endpoint
53%
of active entries reachable
Tools
Alphabetical. Links go to each vendor's own site.
| Tool | What it does | Evidence | Price or terms |
|---|---|---|---|
| Agent Skills (SKILL.md) | open format; implemented by 27+ platforms | 27.0k GitHub stars | open standard (Apache-2.0) |
| anthropics/skills | Anthropic's official repo of example and production skills | 188.8k GitHub stars | free, open source |
| Claude plugin marketplace | official plugin directory | official repo 46.4k stars; top plugin 1.13M installs | free to browse |
| Glama | MCP server directory with letter grades for license, quality, maintenance | 117k+ servers listed | free |
| MCP registry | canonical; no ranking, no trust check | none yet | free |
| OpenAI plugins | skills + MCP for ChatGPT and Codex | none yet | free to browse |
| skills.sh | skills install CLI and directory | ~280M installs in 7 months (Vercel report) | free, open-source CLI |
| Smithery | MCP install CLI and hosted runtime | none yet | Hobby free |
Caveats
- Install and listing counts are self-reported by each directory.
- Security scanners exist (Invariant MCP-Scan, Snyk Agent Scan, OWASP MCP Top 10) but no directory shows their results.