CLAUDE_CODE_COWORK_PLUGIN_SKILL

Updated November 6, 2026 by Alex Sorokoletov

CLAUDE_CODE_COWORK_PLUGIN_SKILL is a Claude Code environment variable: Enables the built-in plugin-building skill when set, provided another check does not already disable it. Added in v2.1.319 and still present in v2.1.319. It is not in the official reference.

How to set it

For one session, export it in the shell that starts Claude Code:

export CLAUDE_CODE_COWORK_PLUGIN_SKILL=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "CLAUDE_CODE_COWORK_PLUGIN_SKILL": "<value>"
  }
}

Related variables

• CLAUDE_API_SKILL_DESCRIPTION: Registration hook for the built-in "claude-api" skill that bundles Anthropic SDK docs (Python, TypeScript, Java, Go, Ruby, PHP, C#, curl) plus shared references on models, prompt caching, managed agents, and tool use.
• CLAUDE_CODE_DESKTOP_SKILLS_PLUGIN_DIR: Holds a directory path the desktop app passes for its skills plugin; the client reads it into the desktop-skills plugin directory, then clears it from the environment.
• CLAUDE_CODE_DISABLE_CLAUDE_API_SKILL: Disables the built-in Claude API skill.
• CLAUDE_CODE_DISABLE_CLAUDE_CODE_SKILL: When set to true, registers the built-in Claude Code skill as disabled so it is not available.
• CLAUDE_CODE_DISABLE_PLUGIN_FORWARDING: When set, disables forwarding this machine's enabled plugins to cloud and remote sessions and hides the cloud-plugins setting.
• CLAUDE_CODE_ENABLE_BACKGROUND_PLUGIN_REFRESH: Enables automatic background plugin refresh when the runtime detects updates are needed.
• CLAUDE_CODE_HOST_SKILL_CATALOG: A JSON object ({"skills": [...]}) of 1 to 64 folder names that scopes which synced claude.ai skills a remote session loads.
• CLAUDE_CODE_PLUGIN_ATTRIBUTION: Provides per-plugin attribution metadata as JSON (fields such as marketplace name, server plugin id, installation preference and marketplace kind), looked up by plugin and used before the default source; capped at 65536 bytes.

Frequently asked questions

All variables, searchable: Claude Code environment variables.