command-development

Command Development for Claude Code

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.

Command Basics

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):

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):

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

• Project commands (.claude/commands/): Shared with team, shown as "(project)" in /help
• Personal commands (~/.claude/commands/): Available in all projects, shown as "(user)" in /help
• Plugin commands (plugin-name/commands/): Available when plugin installed, shown as "(plugin-name)" in /help

File Format

Commands are Markdown files with .md extension. No frontmatter needed for basic commands:

Review this code for security vulnerabilities including:

- SQL injection
- XSS attacks
- Authentication bypass

With YAML frontmatter for configuration:

---
description: Review code for security issues
allowed-tools: Read, Grep, Bash(git:*)
model: sonnet
---

Review this code for security vulnerabilities...

YAML Frontmatter Fields

description