# Command Development

Should be used when the user asks to "create a slash command", "add a command", "write...

- Repository: https://github.com/anthropics/claude-plugins-official (45706 stars)
- Category: AI and agents
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add anthropics/claude-plugins-official --skill command-development -g -a claude-code -y`
Codex: `npx skills add anthropics/claude-plugins-official --skill command-development -g -a codex -y`
Cursor: `npx skills add anthropics/claude-plugins-official --skill command-development -g -a cursor -y`
Gemini CLI: `npx skills add anthropics/claude-plugins-official --skill command-development -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add anthropics/claude-plugins-official`

## Description

This skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Command Development for Claude Code

> **Note:** The `.claude/commands/` directory is a legacy format. For new skills, use the `.claude/skills/<name>/SKILL.md` directory format. Both are loaded identically, the only difference is file layout. See the `skill-development` skill for the preferred format.

## Overview

Slash commands are frequently-used prompts defined as Markdown files that Claude executes during interactive sessions. Understanding command structure, frontmatter options, and dynamic features enables creating powerful, reusable workflows.

**Key concepts:**

- Markdown file format for commands
- YAML frontmatter for configuration
- Dynamic arguments and file references
- Bash execution for context
- Command organization and namespacing

## Command Basics

### What is a Slash Command?

A slash command is a Markdown file containing a prompt that Claude executes when invoked. Commands provide:

- **Reusability**: Define once, use repeatedly
- **Consistency**: Standardize common workflows
- **Sharing**: Distribute across team or projects
- **Efficiency**: Quick access to complex prompts

### Critical: Commands are Instructions FOR Claude

**Commands are written for agent consumption, not human consumption.**

When a user invokes `/command-name`, the command content becomes Claude's instructions. Write commands as directives TO Claude about what to do, not as messages TO the user.

**Correct approach (instructions for Claude):**

```markdown
Review this code for security vulnerabilities including:

- SQL injection
- XSS attacks
- Authentication issues

Provide specific line numbers and severity ratings.
```

**Incorrect approach (messages to user):**

```markdown
This command will review your code for security issues.
You'll receive a report with vulnerability details.
```

The first example tells Claude what to do. The second tells the user what will happen but doesn't instruct Claude. Always use the first approach.

### Command Locations

The rest: https://github.com/anthropics/claude-plugins-official/blob/HEAD/plugins/plugin-dev/skills/command-development/SKILL.md