Sound in Theory — Claude Code Plugin Marketplace

A shared collection of Claude Code plugins for the Sound in Theory development team.

Installation

Add this marketplace to Claude Code

Run the following slash command in Claude Code:

/plugin marketplace add soundintheory/claude-plugins

This registers the marketplace under the name soundintheory. You only need to do this once.

Install a plugin

Browse available plugins:

/plugin

Or install directly by name:

/plugin install <plugin-name>@soundintheory

For example:

/plugin install example-plugin@soundintheory

Update plugins

/plugin update

---

Contributing a Plugin

1. Create a new directory under plugins/<your-plugin-name>/
2. Follow the structure below
3. Open a pull request — plugins are available to the team once merged to main

Plugin Structure

plugins/
└── your-plugin-name/
    ├── .claude-plugin/
    │   └── plugin.json          # Required metadata
    ├── README.md                # Plugin documentation
    ├── skills/
    │   ├── your-skill/
    │   │   └── SKILL.md         # Model-invoked skill (context-aware guidance)
    │   └── your-command/
    │       └── SKILL.md         # User-invoked slash command (/your-command)
    └── .mcp.json                # Optional MCP server configuration

plugin.json

{
  "name": "your-plugin-name",
  "description": "What this plugin does",
  "author": {
    "name": "Your Name",
    "email": "you@soundintheory.co.uk"
  }
}

Skill types

Model-invoked — Claude activates the skill automatically based on task context. The description field controls when it triggers:

---
name: your-skill
description: This skill should be used when the user mentions "X", asks about "Y", or is working on Z.
version: 1.0.0
---

User-invoked — Creates a /your-command slash command the user can call explicitly:

---
name: your-command
description: Short description shown in /help
argument-hint: <required> [optional]
allowed-tools: [Read, Glob, Grep, Bash]
version: 1.0.0
---

See example-plugin for a working reference implementation.