Claude Code Plugins Directory is a marketplace containing plugins for Claude Code, including tools, commands, skills, agents, hooks, and model context servers. Claude Code users browse it to install Anthropic-maintained or approved third-party extensions.
Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add anthropics/claude-plugins-official/plugin install plugin-devWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/anthropics/claude-plugins-official/command-development)<a href="https://agentmods.dev/skills/anthropics/claude-plugins-official/command-development"><img src="https://agentmods.dev/badge/skills/anthropics/claude-plugins-official/command-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/anthropics/claude-plugins-official/command-development"><img src="https://agentmods.dev/badge/skills/anthropics/claude-plugins-official/command-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket warn
- Snyk pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00099 | $0.04335 |
| Opus 5.5 | $0.00040 | $0.01734 |
| Sonnet 5.5 | $0.00020 | $0.00867 |
| Haiku 4.5 | $0.00010 | $0.00434 |
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 1mo ago.
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.
Copies of this mod
8 near-identical copies found in the catalogue:
- command-development — 100% identical, 0 lines differ
- command-development — 100% identical, 8 lines differ
- command-development — 100% identical, 0 lines differ
- command-development — 100% identical, 0 lines differ
- command-development — 100% identical, 0 lines differ
- command-development — 100% identical, 0 lines differ
- command-development — 100% identical, 0 lines differ
- Command Development — 92% identical, 78 lines differ
How it starts
The opening of the file, as written. The whole thing — 885 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Command Development for Claude Code
Note: The
.claude/commands/directory is a legacy format. For new skills, use the.claude/skills/<name>/SKILL.mddirectory format. Both are loaded identically — the only difference is file layout. See theskill-developmentskill 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):
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):
What ships with it
10 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- examples/plugin-commands.md 14 KB
- examples/simple-commands.md 8.5 KB
- README.md 7.5 KB
- references/advanced-workflows.md 13 KB
- references/documentation-patterns.md 15 KB
- references/frontmatter-reference.md 8.9 KB
- references/interactive-commands.md 20 KB
- references/marketplace-considerations.md 16 KB
- references/plugin-features-reference.md 14 KB
- references/testing-strategies.md 14 KB
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.
- 1mo ago First seen · 885 lines · 99 tokens per session scan A c55ad02cfe4c
command-development is a skill published in the GitHub repository anthropics/claude-plugins-official (42,673 stars, last pushed yesterday), licensed Apache-2.0. It adds 99 tokens to every session and 4,335 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
obsidian-bases
Create and edit Obsidian Bases (.base files) with views, filters, formulas, and summaries. Use when working with .base files, creating database-like views of notes, or when the user mentions Bases, table views, card views, filters, or formulas in Obsidian.
file-organizer
Intelligently organizes your files and folders across your computer by understanding context, finding duplicates, suggesting better structures, and automating cleanup tasks. Reduces cognitive load and keeps your digital workspace tidy without manual effort.
stay-within-limits
Use when long-running or parallel agent work must respect 5-hour and weekly usage limits by checking usage between waves, pausing near the cap, and resuming only when the window is clear.
learn
Runs a six-phase research workflow from source bundle to publish-ready output. Use when researching an unfamiliar domain or compiling materials into one reference. Not for quick lookups or single-file reads.
find-journalists
Build a researched, fit-checked journalist list for a specific PR campaign. Prefer Medialyst's asynchronous media-list research workflow when available, with explicit approval before credit spend; otherwise produce a best-effort local list without guessed contacts.
story-origin-check
Recover the first public timestamp and canonical major coverage for a newsjacking signal, then decide whether newer coverage is the same story, a different story, or a materially new development.