What Are Claude Code Plugins?

Overview

A plugin packages Claude Code extensions: skills, agents, legacy commands, hooks, MCP configuration, and supporting resources. Some plugins are mostly instructions; others execute scripts or start servers. There is no supported fixed percentage that makes instruction plugins inherently non-executable or harmless.

Browse the current public catalog at Explore. Catalog entries, public search results, and discovered skills are different cohorts; the site’s displayed counts describe its generated public snapshot rather than a universal inventory.

Layout and manifest

A typical repository submission looks like this:

example-plugin/
├── .claude-plugin/
│   └── plugin.json
├── skills/
│   └── review-diff/
│       └── SKILL.md
├── README.md
└── LICENSE

Native Claude can discover components from the standard layout without a manifest. If a native manifest is present, name is required. That permissive platform floor is not this marketplace’s submission contract.

The current local manifest overlay requires name, version, description, author, homepage, license, keywords, and commands. A plugin with no legacy command files can use an empty commands array. This complete metadata example uses an illustrative project identity:

{
  "name": "example-plugin",
  "version": "1.0.0",
  "description": "Review supplied diffs with documented local instructions.",
  "author": { "name": "Example Team" },
  "homepage": "https://example.com/example-plugin",
  "license": "MIT",
  "keywords": ["review", "testing"],
  "commands": []
}

Replace the example homepage and author with truthful project metadata. author is an object, not a string. Additional supported manifest fields exist, including component paths and other native metadata; this example is not an exhaustive allowlist. Consult the plugin reference, the pinned authoring kernel, and the repository validator for the applicable contract.

Install and load

The canonical marketplace repository is jeremylongshore/tons-of-skills-marketplace; the marketplace slug is claude-code-plugins-plus.

claude plugin marketplace add jeremylongshore/tons-of-skills-marketplace
claude plugin install api-test-automation@claude-code-plugins-plus --scope project

Native scopes are user, project, and local. Project and local settings have different sharing boundaries. Inspect the install summary; reload plugins or start a new session when required. Copying a directory into a cache path is not equivalent to registering and enabling a plugin.

For a local development directory, load it explicitly:

claude --plugin-dir /absolute/path/to/example-plugin

Use only reviewed local code. Hooks, dynamic skill preprocessing, scripts, and MCP servers can execute commands under the applicable permission model.

Skills, agents, commands, hooks, and MCP

Plugin skill and command invocations are namespaced. A plugin named example-plugin with a skill named review-diff exposes /example-plugin:review-diff when user invocation is allowed.

Validation and quality evidence

The Python validator defaults to standard outside CI and auto-selects marketplace in CI unless a tier is explicit. Select the intended tier explicitly:

python3 scripts/validate-skills-schema.py --standard /absolute/path/to/example-plugin
python3 scripts/validate-skills-schema.py --marketplace --verbose /absolute/path/to/example-plugin

Marketplace skills require all eight fields: name, description, allowed-tools, version, author, license, compatibility, and tags. Missing required fields are errors. The public schema, static production gate, and optional behavioral evidence answer different questions; a static grade or badge is not a runtime, security, or provider certification.

When contributing here, use the repository’s current validation and generation instructions. Do not hand-edit generated catalogs. Commit legitimate generated changes produced by the canonical commands.

Updates and removal

Claude Code provides native plugin update and uninstall operations; consult the current plugin management reference. Do not assume uninstall/reinstall is required for updates or that it preserves all plugin-specific data.

The tracked ccpi helper has upgrade, not update, and that command currently prints guidance rather than applying a complete plugin upgrade transaction. Its legacy installation guidance is not the authority for native scope flags. See the CLI reference for the delivered commands and limitations.