# How to Invoke a HumanLayer Skill: A Complete Guide to Using the NPX Skills CLI

> Learn how to invoke a HumanLayer skill using the NPX Skills CLI. Follow our guide to easily add and run skills for your projects.

- Repository: [HumanLayer/skills](https://github.com/humanlayer/skills)
- Tags: how-to-guide
- Published: 2026-09-07

---

**Invoke a HumanLayer skill by installing it with `npx skills add humanlayer/skills --skill <name>` and then running it as a slash command like `/show-me`.**

HumanLayer skills are self-contained CLI plugins that extend your development workflow with specialized capabilities. Each skill exposes both a command-line interface through the `npx skills` helper and a runtime slash command. This guide covers the complete workflow for discovering, installing, and invoking skills from the `humanlayer/skills` repository.

---

## Adding a HumanLayer Skill to Your Project

The first step to invoke any HumanLayer skill is local installation. The `skills` CLI pulls the skill definition directly from the repository and registers it for your project.

Run this command once per repository:

```bash
npx skills add humanlayer/skills --skill <SKILL_NAME>

```

The CLI fetches the skill's [`SKILL.md`](https://github.com/humanlayer/skills/blob/main/SKILL.md) and metadata from the repository's `plugins/<skill>` directory. For example, to install the `show-me` skill:

```bash
npx skills add humanlayer/skills --skill show-me

```

---

## Invoking an Installed Skill

After installation, invoke a HumanLayer skill using its **root path** as a slash command. The pattern is consistent across all skills:

```bash
/<skill-root-path>

```

The [`README.md`](https://github.com/humanlayer/skills/blob/main/README.md) in `humanlayer/skills` documents this pattern with the generic example: ` /show-me ` at lines 77-81.

### Practical Examples

```bash

# Install and invoke the design-control-loop skill

npx skills add humanlayer/skills --skill design-control-loop
/design-control-loop

```

```bash

# Install and invoke the narrow-react-prop-types skill

npx skills add humanlayer/skills --skill narrow-react-prop-types
/narrow-react-prop-types

```

---

## How Skill Invocation Works Under the Hood

The `skills` CLI follows a predictable pipeline when you invoke a HumanLayer skill:

1. **Reads [`plugin.json`](https://github.com/humanlayer/skills/blob/main/plugin.json)** — Located at `plugins/<skill>/.claude-plugin/plugin.json`, this file contains metadata including the `source` path pointing to the skill's folder (e.g., `./plugins/show-me`).

2. **Bundles skill assets** — The CLI collects the [`SKILL.md`](https://github.com/humanlayer/skills/blob/main/SKILL.md) file (the declarative skill description) plus any reference files like [`response-template.md`](https://github.com/humanlayer/skills/blob/main/response-template.md) or [`memory-template.md`](https://github.com/humanlayer/skills/blob/main/memory-template.md).

3. **Executes via Claude Code backend** — When you run the slash command, the CLI transmits the request to the Claude Code backend, which parses [`SKILL.md`](https://github.com/humanlayer/skills/blob/main/SKILL.md) and executes the defined skill logic.

---

## Finding Available HumanLayer Skills

The repository's **Marketplace manifest** at [`.claude-plugin/marketplace.json`](https://github.com/humanlayer/skills/blob/main/.claude-plugin/marketplace.json) contains the canonical list of all built-in skills. Each entry specifies the skill name, description, and source directory:

```json
"plugins": [
  {
    "name": "show-me",
    "description": "Explain the current topic with concise diagrams, code-shape sketches, and focused HTML artifacts",
    "source": "./plugins/show-me"
  }
]

```

Browse this file to discover which HumanLayer skills you can invoke in your projects.

---

## The `show-me` Skill: A Complete Example

The `show-me` skill demonstrates the full invocation pattern. Its definition lives at [`plugins/show-me/skills/show-me/SKILL.md`](https://github.com/humanlayer/skills/blob/main/plugins/show-me/skills/show-me/SKILL.md) and specifies visual output formats including pseudocode, call trees, Mermaid diagrams, and diff snippets.

To invoke this HumanLayer skill:

```bash

# One-time installation

npx skills add humanlayer/skills --skill show-me

# Run the skill

/show-me

```

---

## Key Files for Understanding Skill Invocation

| File | Purpose |
|------|---------|
| [`README.md`](https://github.com/humanlayer/skills/blob/main/README.md) | General usage instructions and the "Then invoke" example |
| [`.claude-plugin/marketplace.json`](https://github.com/humanlayer/skills/blob/main/.claude-plugin/marketplace.json) | Master list of all shipped skills with descriptions and source paths |
| `plugins/<skill>/skills/<skill>/SKILL.md` | Declarative description defining skill behavior |
| `plugins/<skill>/.claude-plugin/plugin.json` | CLI metadata for locating skill sources |

---

## Summary

- **HumanLayer skills** are installed via `npx skills add humanlayer/skills --skill <name>` and invoked as `/<skill>` slash commands.
- The `skills` CLI reads [`plugin.json`](https://github.com/humanlayer/skills/blob/main/plugin.json) metadata and bundles [`SKILL.md`](https://github.com/humanlayer/skills/blob/main/SKILL.md) with reference files before execution.
- Available skills are cataloged in [`.claude-plugin/marketplace.json`](https://github.com/humanlayer/skills/blob/main/.claude-plugin/marketplace.json) with full descriptions and source paths.
- Installation is per-repository; invocation is repeatable and consistent across all skills.

---

## Frequently Asked Questions

### What is the exact command to invoke a HumanLayer skill after installation?

Run the skill's root path as a slash command: `/<skill-name>`. For example, after installing the `show-me` skill, type `/show-me` in your terminal.

### Where does the `skills` CLI find skill definitions?

The CLI retrieves metadata from `plugins/<skill>/.claude-plugin/plugin.json` and the skill description from `plugins/<skill>/skills/<skill>/SKILL.md` within the `humanlayer/skills` repository.

### Can I invoke a HumanLayer skill without installing it first?

No. You must run `npx skills add humanlayer/skills --skill <name>` once per repository to register the skill locally before any slash command invocation will work.

### How do I discover which HumanLayer skills are available?

Examine [`.claude-plugin/marketplace.json`](https://github.com/humanlayer/skills/blob/main/.claude-plugin/marketplace.json) in the repository root. This JSON file lists every built-in skill with its name, description, and source directory path.