add-command

A command that creates a new slash command file inside a plugin, using the expected metadata and structure.

In plain words
What is it for?
Use it to add a named command to the current plugin or to a selected plugin in a marketplace.
Why use it?
It avoids setting up command files by hand and helps keep their names and layout consistent.

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/arcblock/agent-skills/add-command
Clone the repo
git clone --depth 1 https://github.com/ArcBlock/agent-skills
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 2,710 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 $0.02710
Opus 5 $0.00005 $0.01355
Sonnet 5 $0.00002 $0.00542
Haiku 4.5 $0.00001 $0.00271

Measured 2d ago against content hash ccfce43d7698, 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 2d 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.

Origin

This is a copy

94% identical to add-command — 10 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 · 385 lines

How it starts

The opening of the file, as written. The whole thing — 385 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 · 385 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. 2d ago First seen · 385 lines · 0 tokens per session scan A ccfce43d7698

Subscribe to this mod's changes

add-command is a command published in the GitHub repository ArcBlock/agent-skills (5 stars, last pushed 2d ago), licensed MIT. It adds 9 tokens to every session and 2,710 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 10 lines, and is treated as a copy.