HOW TO

How to install Claude skills

Three routes, all ending in a folder with a SKILL.md in it: the npx installer for libraries published in the Agent Skills format, the plugin marketplace for packaged plugins, and copying the folder by hand. Then one line to check it loaded.

Written by Additionupdated 11 September 2026

Route 1: npx skills add

The skills CLI from Vercel Labs installs from any GitHub repository laid out in the Agent Skills format. It detects which agents you have (Claude Code, Cursor, Codex, Windsurf and others) and asks where to install; for Claude Code that is .claude/skills/, and universal agents share .agents/skills/. Twenty of the skills on this site live in one repository, github.com/addition-labs/skills, each folder with its original author’s licence and a note naming the source commit.

See what is on the shelf

npx skills add addition-labs/skills --list

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

Named skills

npx skills add addition-labs/skills --skill schema ai-seo

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

The whole shelf, for every project

npx skills add addition-labs/skills --all --global

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

The same command works on any repository in the format, so the upstream libraries named on each item page install the same way. Each item page carries the exact line.

Route 2: the plugin marketplace

Plugins bundle skills with agents, hooks and scripts and install from inside Claude Code. Add the marketplace once, then install the plugin. The five claude-seo skills on this site and the claude-ads toolkit install this way.

Example

/plugin marketplace add AgriciDaniel/claude-seo
/plugin install claude-seo@agricidaniel-claude-seo

Type this inside Claude Code; it is a slash command, not a shell command.

claude-seo is the exception: its README installs from a clone with bash install.sh, pinned to a release tag so the skill does not change under you, and creates an isolated Python runtime for its 56 scripts on first use.

To remove a plugin’s skills, uninstall the plugin: /plugin uninstall name@marketplace. Claude Code unloads them when the change applies or when you restart.

Route 3: copy the folder

Every route ends in the same folder, so the manual one works for any skill that is instructions only. Clone the repository, copy the skill folder into your personal or project skills directory, restart Claude Code. A skill that calls plugin scripts (claude-seo, claude-ads) needs its plugin and that plugin’s runtime; copying the folder alone leaves the scripts behind.

Personal, every project

mkdir -p ~/.claude/skills
cp -r skills/editorial-qa ~/.claude/skills/

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

This project only

mkdir -p .claude/skills
cp -r skills/editorial-qa .claude/skills/

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

For Claude.ai and the desktop app, plans that support custom skills take the folder as a zip under Settings, Capabilities, Skills; the skill can then sync to Claude Code.

Check it loaded

In Claude Code, type a slash and the skill name; if it autocompletes, it is installed. In any agent, say the trigger phrase from its description and watch whether the skill loads; the item pages on this site list those phrases. If nothing happens, check the folder name matches the name field in the frontmatter exactly, because the specification requires it and a mismatch is the most common reason a skill is invisible.

Write one of your own in ten minutes

Two required fields and instructions. The description is what decides whether the skill is ever chosen, so write it the way the specification’s good example does: what it does, then when to use it, with the words a request would contain.

~/.claude/skills/weekly-search-report/SKILL.md

---
name: weekly-search-report
description: Summarise last week’s Search Console export into what moved and why. Use when the user says weekly search report, GSC summary, or what changed in search.
---

# Weekly search report

1. Ask for the export or read the file the user names.
2. Compare the week with the previous week: clicks, impressions, average position.
3. Name the three queries and three pages that moved most, with the numbers.
4. Say what you could not verify.

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

Validate the frontmatter

skills-ref validate ./weekly-search-report

Run this in a terminal inside your project folder. Claude Code, Cursor and Codex then read the skill from where it lands.

Keep the body under 500 lines and move long material into a references folder the instructions point to; agents load those files only when told, which keeps the context small.

What the format is, and how it differs from a prompt or an MCP server

Questions

Questions people ask before installing

Do I need Node for npx?

Yes, Node.js for the npx route. The plugin and copy routes need Claude Code, plus whatever runtime a plugin’s scripts declare: claude-seo sets up its own Python environment; claude-ads needs Python, Playwright, WeasyPrint and Pango.

Can a skill update itself?

No. Re-run the installer or pull the repository to update. claude-seo pins a release tag for exactly that reason.

Where do Cursor skills go?

The npx installer places them for Cursor when it detects it; the shared location for agents that follow the standard is .agents/skills/.