How to install a skill: your first one, step by step

If you've never installed a skill, it might sound like something only developers do. It isn't. Give it five minutes and you'll have your first one installed, and you'll use it by just asking your agent, the way you'd ask a teammate.

What a skill is

Quick note. A skill is a folder with a SKILL.md file in it: plain Markdown with instructions for your AI agent. It's not an app and nothing runs. It's a recipe the agent reads when that job comes up.

The SKILL.md starts with a name and a description. The agent uses the description to decide when the skill applies, and the rest of the file tells it how to do the work. Some skills ship scripts or examples in the same folder, but that one file is always the heart of it.

Claude Code follows the open Agent Skills standard, so a lot of skills work the same way in Codex, Cursor, opencode and other agents.

Without a skill, and with one

Take humanizer, the skill we use so the writing on this site doesn't sound like a machine wrote it (this post went through it too).

Without it. You ask your agent for a product description. You get "in today's fast-paced world", three adjectives per sentence and an inspirational sign-off. You fix it by hand. Next week, same thing.

With it. The agent loads humanizer, which carries a list of the usual tells in generated text (inflated vocabulary, everything in threes, dashes everywhere, filler) and strips them out before you see anything. You ask for the text and it comes back already cleaned up.

Two ways to use one

Paste it. Open the SKILL.md on GitHub, copy it and paste it into the chat before your request. Nothing to install, and it's fine for a quick try. The catch is you have to paste it every single time.

Install it. Save it once in your agent's skills folder. From then on it's there in every session: you call it by name, or the agent picks it up on its own when it fits.

If you'll use it more than once, install it.

Where skills live in Claude Code

• ~/.claude/skills/<name>/SKILL.md: your personal skills, available in every project.
• .claude/skills/<name>/SKILL.md inside a repository: that project only. Commit it and the whole team gets it.
• Plugins: a plugin can bundle several skills. You install it from a marketplace, and its skills get the plugin name in front (/plugin:skill).

Quick note. Claude Code watches those folders. Add or edit a skill mid-session and it picks it up without a restart. One exception: if the skills folder didn't exist when you started the session, run /reload-skills.

Install your first skill

We'll use humanizer by Siqi Chen, MIT licensed. The same steps work for any other skill: swap in its repository and name.

1. Read what you're about to install. A skill is a set of instructions your agent will follow to the letter, so open the repository and skim the SKILL.md first, the same way you'd look at a script before running it.

2. Install it with the skills CLI. You'll need Node.js. In your terminal:

npx skills add blader/humanizer --global --agent claude-code

--global puts it in your personal folder (~/.claude/skills/) instead of the current project, and --agent claude-code says which agent it's for. Leave them out and the command asks you.

3. Or do it by hand with git, if you'd rather skip the CLI:

git clone https://github.com/blader/humanizer.git ~/.claude/skills/humanizer

4. Check it's there. In Claude Code, type / and look for humanizer in the list. If it's missing and ~/.claude/skills is a brand-new folder, run /reload-skills. From the terminal, npx skills ls -g lists what you installed with the CLI.

5. Use it. By name:

/humanizer

Or just ask: "run this paragraph through humanizer, it reads like AI".

When it comes as a plugin

Some skills are shipped as Claude Code plugins. Inside Claude Code:

/plugin marketplace add blader/humanizer
/plugin install humanizer@humanizer

The first line adds the marketplace (the repository), the second installs the plugin. Installed this way, the skill gets the prefix: /humanizer:humanizer. The humanizer README asks for Claude Code 2.1.142 or newer for this route.

Superpowers, for example, lives in Anthropic's official marketplace and installs in one line:

/plugin install superpowers@claude-plugins-official

Quick note. There's nothing to compile and no dependencies to break halfway through. Installing a skill means putting a folder with a text file where your agent looks for it. That's the whole trick.

Finding more

The ones we use every day are in our skills catalog, each with its author, its license and the install command. To search on your own, npx skills find takes a keyword:

npx skills find remotion

The short version

• A skill is a folder with a SKILL.md: instructions for your agent, not a program.
• Paste it to try it, install it to keep it.
• In Claude Code they live in ~/.claude/skills/ (every project) or .claude/skills/ (one project).
• npx skills add <user>/<repo> installs one, /name uses it.
• Read the SKILL.md before you install.