Guide
Install a mod in two commands, then check what it can touch
Mods are on by default from Claude Code 2.1.287. Installing one takes two commands. The part most guides skip is the check in between — a mod is not sandboxed, so it is worth thirty seconds to see what it reaches for before you let it run.
What you need
Claude Code 2.1.287 or later. Check with claude --version and update if yours is
older. There is nothing to switch on.
A terminal that reports the mouse, if the mod draws boards or buttons.
1Add the marketplace and install
Most mods publish their own repository as a plugin marketplace. Add it once, then install the mod from it. Each mod page shows its documented commands, including local-clone installation where no marketplace is available.
claude plugin marketplace add <owner>/<repo>
claude plugin install <mod>@<marketplace>
The name after @ comes from the repository's
.claude-plugin/marketplace.json. It is often the same as the mod name, and
sometimes not. Inside a session, /plugin install <mod>@<marketplace>
does the same as the second command.
2Check it before it runs
A mod runs inside Claude Code with your permissions. It can read and write your files, start programs, make network requests, read environment variables, and see every prompt and tool call. Only install mods from authors you trust — and know what this one asks for.
Clone the repository and validate it without running it:
git clone https://github.com/<owner>/<repo>
claude plugin validate ./<repo>The output has two lines worth reading:
hooks:
The events the mod handles. If you see tool.call or
prompt.submit, it sees — and can change — every tool call or every prompt.
calls:
What it asks Claude Code to do. $.fs.read and $.fs.write touch
files. $.process.run starts programs. $.http.fetch goes to the
network. $.env.get and $.settings.read read values that can hold
API keys. $.model.complete spends your usage.
3Load it and confirm
Start claude. If a session was already open when you installed from the shell,
run /reload-plugins in it. Then run /plugin: a dim line under the
tabs names every mod the session loaded.
/reload-plugins
/plugin
If your mod is missing from that line, it did not load — check the marketplace name after
@ first, that is the usual cause.
Where a mod actually shows up
Hooks run everywhere the plugin loads. What it draws does not.
| Where you run it | Hooks | Drawing |
|---|---|---|
| claude in a terminal (including editor terminals) | Yes | Yes |
| Code tab in the Claude Desktop app | Yes | Yes, but not terminal-only elements |
| VS Code extension chat panel | Yes | No |
| claude -p and the Agent SDK | Yes | No |
| A cloud session | Yes, if the plugin reaches it | No |
Update or remove
claude plugin update <mod>@<marketplace>
claude plugin uninstall <mod>@<marketplace>If it does not load
- Version too old. Anything below 2.1.287 will not see mods at all.
- Wrong marketplace name. The part after
@comes from the repo'smarketplace.json, not from the repo name. - Session was already open.
/reload-pluginsbefore you look for it. - Nothing draws. Hooks can run in a VS Code chat panel, but nothing is drawn there. Open a terminal.