Mathias Agent Toolbox

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Public Claude Code and Codex plugin marketplace for reusable agent workflows, engineering skills, Rust tooling, and UI quality workflows.

Usage

Claude Code

Add this marketplace:

/plugin marketplace add https://github.com/JedimEmO/mathias-agent-toolbox.git

Install a plugin:

/plugin install <plugin-name>@mathias-agent-toolbox

Codex

Add this marketplace:

codex plugin marketplace add JedimEmO/mathias-agent-toolbox

Then open /plugins in Codex, choose Mathias Agent Toolbox, and install the plugins you want.

Adding a plugin

Create a plugin directory under plugins/:

plugins/my-plugin/
├── .claude-plugin/
│   └── plugin.json
├── .codex-plugin/
│   └── plugin.json
└── skills/            # and/or commands/, agents/, hooks/, output-styles/, .mcp.json
    └── my-skill/
        └── SKILL.md

Then add entries to both marketplace registries.

Claude entry in .claude-plugin/marketplace.json:

{
  "name": "my-plugin",
  "source": "my-plugin",
  "description": "What it does",
  "version": "1.0.0"
}

The source is relative to plugins/ (configured via pluginRoot).

Codex entry in .agents/plugins/marketplace.json:

{
  "name": "my-plugin",
  "source": {
    "source": "local",
    "path": "./plugins/my-plugin"
  },
  "policy": {
    "installation": "AVAILABLE",
    "authentication": "ON_INSTALL"
  },
  "category": "Coding"
}

Codex plugin manifests should point at the shared skill tree:

{
  "skills": "./skills/"
}

If the plugin has .mcp.json, add "mcpServers": "./.mcp.json" to plugins/my-plugin/.codex-plugin/plugin.json.

Quality checks

Run the skill metadata/progressive-disclosure audit:

tools/audit-skills.mjs

Plugin-level trigger and behavior scenarios live in skill-evals/.