command-development

Command Development for Antigravity

Note: The .gemini/commands/ directory is a legacy format. For new skills, use the .gemini/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 Gemini 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 Gemini 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 Gemini

Commands are written for agent consumption, not human consumption.

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

Correct approach (instructions for Gemini):

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

Command Locations

Project commands (shared with team):