Skill: skill-installer

Install Claude Code skills from various sources.

user-invocable: false description: Handles skill installation from skills.sh, GitHub, or direct SKILL.md download. Always confirms with user before installing. allowed-tools: [Read, Write, Bash, WebFetch, Glob, AskUserQuestion]

Instructions

When called with a skill to install, determine the source type and follow the appropriate flow.

Pre-installation Checks

1. Conflict detection: Check if a skill with the same name already exists:

   Glob: ~/.claude/skills/{skill-name}/SKILL.md

2. If already installed, inform the user and ask if they want to update/overwrite.
3. Always confirm with the user before proceeding with installation.

Installation by Source Type

Type: installed

The skill is already installed locally. Inform the user:

"This skill is already available on your system. You can use it right away."

Type: skills-add

The skill is listed on skills.sh and can be installed via npx. Run:

npx skills add -y -g {owner/repo}

• -y: skip confirmation prompts
• -g: install globally to ~/.claude/skills/
• Format: {owner/repo} (e.g., vercel-labs/agent-skills)
• To install a specific skill from a multi-skill repo: {owner/repo}/{skill-name}

IMPORTANT: The old npx skillsadd package is deprecated and no longer works. Always use npx skills add.

If npx skills add fails (e.g., "No valid skills found"), fall back to direct GitHub download:

1. Find the SKILL.md path via: https://api.github.com/repos/{owner}/{repo}/git/trees/main?recursive=1
2. Download: curl -sL https://raw.githubusercontent.com/{owner}/{repo}/refs/heads/main/{path-to-SKILL.md}
3. Save to ~/.claude/skills/{skill-name}/SKILL.md

Type: github-plugin

The skill is part of a GitHub-hosted plugin. Guide the user:

"This skill is available as a GitHub plugin. To install, run:

/plugin install {github-url}
```"

Type: skill-md

A standalone SKILL.md file that can be downloaded directly:

1. Confirm with the user.
2. Create the skill directory:

   mkdir -p ~/.claude/skills/{skill-name}

3. Download the SKILL.md:

   WebFetch: {raw-url}

4. Write the content:

   Write: ~/.claude/skills/{skill-name}/SKILL.md

5. If the skill has associated scripts, download those too.

Post-installation Verification

After installation, verify:

1. The SKILL.md file exists at the expected path
2. The file is valid (non-empty, contains expected headers)
3. Report success or failure to the user

Output

Provide a clear summary:

• What was installed
• Where it was installed
• How to use it (if applicable)