Command Development

A guide for creating Claude Code slash commands, which are reusable Markdown instructions invoked with a command such as /command-name.

In plain words
What is it for?
Use it to add a slash command, define its arguments and frontmatter, organize commands, or include project files in the instructions.
Why use it?
It helps turn repeated prompts into consistent, shareable workflows with arguments, configuration, file references, and optional interaction.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/xyruscode/ai-sync/command-development
Any agent
npx skills add XyrusCode/ai-sync --skill command-development
Clone the repo
git clone --depth 1 https://github.com/XyrusCode/ai-sync

Made for: Claude Code, Codex.

Per session 99 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,284 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00099 $0.04284
Opus 5 $0.00049 $0.02142
Sonnet 5 $0.00020 $0.00857
Haiku 4.5 $0.00010 $0.00428

Measured yesterday against content hash cf4372aa8f5e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Command Development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to command-development — 11 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/command-development/SKILL.md · 835 lines

How it starts

The opening of the file, as written. The whole thing — 835 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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.

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):

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 (shared with team):

  • Location: .claude/commands/
  • Scope: Available in specific project
  • Label: Shown as "(project)" in /help
  • Use for: Team workflows, project-specific tasks

Personal commands (available everywhere):

  • Location: ~/.claude/commands/
  • Scope: Available in all projects
  • Label: Shown as "(user)" in /help
  • Use for: Personal workflows, cross-project utilities

Read the full file on GitHub · 835 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 835 lines · 99 tokens per session scan A cf4372aa8f5e

Subscribe to this mod's changes

Command Development is a skill published in the GitHub repository XyrusCode/ai-sync (2 stars, last pushed yesterday), licensed MIT. It adds 99 tokens to every session and 4,284 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to command-development, differing in 11 lines, and is treated as a copy.

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