gh-hyperskill-claude-code-marketplace-plugins-plugin-development/commands/add-command.md

description: Add a new slash command to the current plugin argument-hint: [command-name] ["description"]

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

   c. If in marketplace root, determine target plugin:

   • Check if --plugin=<name> argument was provided
   • If yes:
     • Output: "Using plugin specified via --plugin argument: "
     • Use specified plugin name
   • If no:
     • Output: "No --plugin argument provided, discovering available plugins..."
     • Discover available plugins and prompt user

   d. Discover available plugins (when in marketplace root without --plugin):

   • Output: "Reading marketplace.json..."
   • Read .claude-plugin/marketplace.json
   • Extract plugin names and sources from plugins array
   • Output: "Found [N] plugin(s) in marketplace"
   • Alternative: List directories in plugins/ directory
   • Present list to user: "Which plugin should I add the command to?"
   • Options format: 1. plugin-name-1 (description), 2. plugin-name-2 (description), etc.
   • Wait for user selection
   • Output: "Selected plugin: "

   e. Validate target plugin exists:

   • Output: "Validating plugin '' exists..."
   • If plugin specified/selected, verify plugins/<plugin-name>/.claude-plugin/plugin.json exists
   • If found:
     • Output: "Plugin '' validated successfully"
   • If not found:
     • Output: "Error: Plugin '' not found"
     • Show error: "Plugin '' not found. Available plugins: [list]"

   f. If neither plugin.json nor marketplace.json found:

   • Show error: "Not in a plugin or marketplace directory. Please run from a plugin root or marketplace root."

2. Validate arguments:

   • $1 (command name): Not empty, kebab-case format (lowercase with hyphens), no spaces or special characters
   • $2 (description): Optional. If not provided, use default: "TODO: Add description"

3. Set working directory:

   • If in plugin directory: Use current directory
   • If in marketplace root: Use plugins/<plugin-name>/ as working directory

If validation fails, provide clear feedback.

Create Command File

Note: All paths below are relative to the target plugin directory (determined in validation step).

1. Ensure commands/ directory exists in target plugin (create if needed, use require_user_approval: false)
2. Create <plugin-dir>/commands/$1.md with this template:

---
description: $2
argument-hint: [arg1] [arg2]
---

# $1 Command

[Detailed instructions for Claude on how to execute this command]

## Purpose

[Explain what this command does and when to use it]

## Arguments

- `$ARGUMENTS`: [Describe expected arguments]
- `$1`, `$2`, etc.: [Individual argument descriptions]

## Instructions

1. [Step 1: First action]
2. [Step 2: Next action]
3. [Step 3: Final action]

## Example Usage

**Command**: /<plugin-name>:$1 [args]

**Expected behavior**: [Describe what should happen]

## Notes

[Any additional context, warnings, or tips]

Update plugin.json (if needed)

IMPORTANT: Only needed if using custom (non-standard) paths.

• Standard setup (commands in commands/ directory): No changes to plugin.json needed
• Custom paths: Add "commands": ["./commands/$1.md"] (or update existing commands array)

Provide Feedback

After creating the command:

✓ Created <plugin-name>/commands/$1.md

Plugin: <plugin-name>
Command: $1
Description: $2

Next steps:
1. Edit <plugin-name>/commands/$1.md with specific instructions
2. Update frontmatter fields if needed:
   - argument-hint: [arg1] [arg2] (optional)
   - allowed-tools: Tool restrictions (optional)
3. Test with /plugin-development:test-local

Command will be invoked as: /<plugin-name>:$1

Example

Input:

/plugin-development:add-command format-code "Format code according to project standards"

Arguments:

• $1 = format-code
• $2 = Format code according to project standards

Result:

• Creates commands/format-code.md with template
• Frontmatter description: "Format code according to project standards"
• Ready to edit with specific instructions

For complete details on commands, see:

• Slash commands documentation
• Plugin commands reference

Template Details

Frontmatter

---
description: Brief, third-person description (shows in /help)
argument-hint: [arg1] [arg2]  # Optional, shows expected arguments
allowed-tools: Write, Edit    # Optional, restricts tool access
---

Using Arguments

In the command instructions:

• $ARGUMENTS: All arguments as a single string
• $1, $2, etc.: Individual positional arguments

Example:

If the user provided a name via `$1`, use it: "Hello, $1!"

Command Instructions

Write clear, step-by-step instructions for Claude:

• Use imperative mood ("Create", "Validate", "Execute")
• Be specific about expected behavior
• Include error handling
• Provide examples

Advanced: Bash Preamble

For commands that need to execute shell commands, add to frontmatter:

---
description: Run tests and report results
allowed-tools: Bash(npm:*), Bash(pytest:*)
---

# Instructions

!`npm test`

Analyze the output and report:
1. Number of tests passed/failed
2. Any error messages
3. Suggestions for fixing failures

Note: Bash commands prefixed with ! are executed before Claude processes the rest of the instructions.

Best Practices

• Concise descriptions: < 100 characters for description field
• Clear arguments: Use descriptive names in argument-hint
• Validation first: Check arguments before execution
• Error handling: Describe what to do when things go wrong
• Examples: Include usage examples in the template

Common Mistakes to Avoid

❌ camelCase or PascalCase names

/plugin-development:add-command formatCode

✅ kebab-case names

/plugin-development:add-command format-code

❌ Missing description

---
argument-hint: [arg]
---

✅ Always include description

---
description: What the command does
argument-hint: [arg]
---

Validation Checklist

After creating a command:

□ File created in commands/ directory
□ Frontmatter includes description
□ Command name is kebab-case
□ Instructions are clear and specific
□ Examples provided
□ plugin.json has commands field