Plugins — and choosing the right setup
The best-of-both building block: plugins bundle MCP servers, skills and commands behind proper marketplaces. Install a few, then land the simple rule for when to use MCP, skills or plugins.
Last, and best-of-both: plugins. If MCP and skills felt like a lot to navigate, plugins are the answer — and they lead straight into the simple decision rule that ends the day.
01What a plugin is
A plugin packages features together: one or more MCP servers, skills, slash-commands, and other pieces (like hooks and agents, which we'll meet later). It's the highest-level idea of the three, and the newest — plugins arrived in October 2025.
Plugins solve the discovery jankiness with proper, authoritative marketplaces, and they let the plugin's author make the MCP-vs-skill trade-offs for you. You explicitly trigger their commands by typing them, which removes the "will this fire?" hand-waviness of skills.
Remember the Ralph loop from Class 7? That was a plugin — a bundle including the
/ralph-loop command. You've been a plugin user since yesterday.
Plugins are, for now, Claude Code-only (unlike MCP and skills). They're the least configurable — you install the whole bundle, a broad-brush stroke, rather than mixing and matching. And it's best not to over-install: a pile of plugins complicates your setup.
02Installing plugins from the marketplace
Run /plugin for the in-Claude experience: three tabs — Discover,
Installed, Marketplaces. By default you're linked to the
claude-plugins-official marketplace (an Anthropic GitHub repo with first-party
plugins and third-party external ones — GitHub, GitLab,
Playwright, Slack, Stripe, Supabase…).
# Discover is sorted by most-installed. Space to select, i to install: [x] front-end-design # most popular — distinctive, production-grade UIs [x] context7 # just wraps Upstash's Context7 MCP server [x] code-review # official PR code-review flow [x] code-simplifier # Anthropic's own agent for de-slopping code [ ] ralph-loop # the one from Class 7 # press i → "installed 4 plugins", then restart Claude
You can add other marketplaces you trust — a classic use is your company's or team's own marketplace, given as a GitHub address. That's how you share a curated set of plugins across an organisation. Add third-party marketplaces only with care, and only ones you trust.
After restarting, /context shows them loaded — an MCP plugin (Context7), a
code-simplifier agent, front-end-design and
code-review. Try one with natural language — "please use the code-simplifier agent
to simplify the entire codebase" — and it figures out the real name (code-simplifier:code-simplifier),
runs for ~6 minutes, refactors, and reports tests passing. Note what happened: a plugin just installed an
agent — something we haven't even covered yet — and it worked.
03MCP vs Skills vs Plugins — the decision
Everything comes together here. First, the honest scorecard:
| 🔌 MCP | 📄 Skills | 📦 Plugins | |
|---|---|---|---|
| Pros | Huge ecosystem; flexible; maturing marketplaces & ratings. | Context-efficient; dead simple; great results; loved. | Best of both; simplest to set up; explicit commands. |
| Cons | Context-hungry (better now); complex to build; very granular. | Less flexible; immature discovery/marketplaces. | Claude Code-only; least configurable; easy to over-install. |
| Works beyond Claude Code? | Yes | Yes | No (for now) |
Start with plugins. If a plugin does what you need, use it — you needn't care whether it's MCP or skills underneath. Reach for MCP directly only for specialised tools that demand it (live market data via Massive). Reach for a skill directly when you want a specific one (Agent Browser) or to share expertise across your team via Git. Even then, the simplest path is usually a plugin that contains those skills.
✓ Key takeaways
- A plugin bundles MCP servers + skills + commands (+ hooks/agents), made discoverable via marketplaces.
- Install via
/plugin→ Discover; you already used one (the Ralph loop). - Add trusted team/company marketplaces by GitHub address to share a curated set.
- Trade-offs: plugins are Claude Code-only and least configurable; don't over-install.
- Decision: start with plugins; use MCP for specialised tools; use skills for a specific skill or team sharing.
A giant day, digested: the tools idea, MCP end-to-end, skills and progressive disclosure, and plugins with a clear decision rule. We'll use all three again tomorrow and keep building on them as we move into agents. Take a moment — you're a good deal more of a pro than you were yesterday.