add-command

A command for adding a new slash command to a Claude Code plugin, where a slash command is a named instruction users can invoke directly.

In plain words
What is it for?
It helps create a kebab-case command with an optional description, from either a plugin directory or a marketplace directory, with basic validation.
Why use it?
It removes the need to create the command file and plugin structure manually, reducing setup mistakes.

Command

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 commands/kossakovsky/cc-plugins/add-command
Clone the repo
git clone --depth 1 https://github.com/kossakovsky/cc-plugins
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,686 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 94% 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 $0.00009 $0.02686
Opus 5 $0.00005 $0.01343
Sonnet 5 $0.00002 $0.00537
Haiku 4.5 $0.00001 $0.00269

Measured yesterday against content hash 69b5dc7aa58f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-command 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

94% identical to add-command — 13 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.

plugins/plugin-development/commands/add-command.md · 382 lines

How it starts

The opening of the file, as written. The whole thing — 382 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add Command

Create a new slash command file with proper frontmatter and structure.

Arguments

  • $1 (required): Command name in kebab-case (e.g., my-command)
  • $2 (optional): Description in quotes (e.g., "Format code according to standards")
  • --plugin=<plugin-name> (optional): Specify which plugin to add the command to

Usage:

# From within a plugin directory, with description
/plugin-development:add-command format-code "Format code according to project standards"

# Without description (uses default)
/plugin-development:add-command format-code

# From marketplace root, specifying plugin
/plugin-development:add-command format-code "Format code" --plugin=plugin-development

Prerequisites

  • Must be run from either:
    • A plugin root directory (containing .claude-plugin/plugin.json), OR
    • A marketplace root directory (containing .claude-plugin/marketplace.json)
  • commands/ directory will be created if needed

Instructions

Validation

IMPORTANT: When running test commands for validation (checking directories, files, etc.), use require_user_approval: false since these are read-only checks.

  1. Detect context and target plugin (output thoughts during this process):

    a. Check if we're in a plugin directory:

    • Look for .claude-plugin/plugin.json in current directory
    • Output: "Checking for plugin directory..."
    • If found:
      • Output: "Found plugin.json - using current directory as target plugin"
      • Use current directory as target plugin
    • If not found:
      • Output: "Not in a plugin directory, checking for marketplace..."

    b. If not in plugin directory, check if we're in marketplace root:

    • Look for .claude-plugin/marketplace.json in current directory
    • If found:
      • Output: "Found marketplace.json - this is a marketplace root"
      • This is a marketplace root
    • If not found:
      • Output: "Error: Neither plugin.json nor marketplace.json found"
      • Show error and exit

Read the full file on GitHub · 382 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 · 382 lines · 0 tokens per session scan A 69b5dc7aa58f

Subscribe to this mod's changes

add-command is a command published in the GitHub repository kossakovsky/cc-plugins (3 stars, last pushed 5mo ago), licensed MIT. It adds 9 tokens to every session and 2,686 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. It is 94% identical to add-command, differing in 13 lines, and is treated as a copy.