Build your first plugin

This is your workspace for the Unit 9, Lesson 3 task: assemble a couple of components into a working Claude Code plugin and test it locally.

What's in here

Two ready-made components live in building-blocks/:

• summarize-changes.md — a slash command that summarises what changed on a branch
• code-reviewer.md — a subagent that reviews recent changes Your job is to organise them into a proper plugin. (Made your own command or subagent earlier in the course? Use those instead — the steps are the same.)

Target structure

.
├── .claude-plugin/
│   └── plugin.json            # name + version (the manifest)
├── commands/
│   └── summarize-changes.md
├── agents/
│   └── code-reviewer.md
└── README.md                  # what your plugin does

Remember the one rule that trips people up: only plugin.json goes inside .claude-plugin/ — the component folders sit at the root.

Steps

1. Create .claude-plugin/plugin.json with a name and a version. A minimal one looks like:

   { "name": "qa-kit", "version": "0.1.0" }

2. Make the component folders and move the pieces into place: building-blocks/summarize-changes.md → commands/, and building-blocks/code-reviewer.md → agents/. Delete the empty building-blocks/ folder afterwards.
3. If a component runs a bundled script, reference it through ${CLAUDE_PLUGIN_ROOT} — never a hardcoded path.
4. Replace this README with one that describes your plugin: what it does, the commands it adds, how to use them.
5. From the repo root, load it with claude --plugin-dir .. Run the command as /your-plugin:summarize-changes, and trigger the subagent by asking Claude to review your recent changes (it should reach for code-reviewer). Use /reload-plugins after edits.
6. Commit and push.

How you'll know it's done

This repo has an automated check — Validate plugin — that runs every time you push. It's red right now, because there's no plugin yet. As you build, commit and push your work; the check turns green once the plugin is structured correctly:

• .claude-plugin/plugin.json exists, is valid JSON, and has a name
• the component folders sit at the root, not inside .claude-plugin/
• at least one component is present A green check means the structure is right. To confirm it actually works, load the plugin locally with claude --plugin-dir . and run each piece — the command by its namespaced name, the subagent by asking for a review.