> ## Documentation Index
> Fetch the complete documentation index at: https://docs.yambr.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Skills user guide

> What each built-in skill does, how they show up to the model, and how to add your own.

## How skills work

1. **System prompt injection** — the server builds an `<available_skills>` XML block listing every enabled skill with its name, description, and file path.
2. **Model reads `SKILL.md`** — before starting a task the AI opens the relevant skill's instructions via the `view` tool.
3. **Scripts and references** — skills can bundle Python/bash helpers and reference docs that the AI invokes with `bash_tool`.

Skills are mounted read-only into every sandbox at `/mnt/skills/`.

## Built-in skills (13 public)

Always available, baked into the Docker image:

| Skill                       | What it does                                               |
| --------------------------- | ---------------------------------------------------------- |
| **docx**                    | Word — create, edit, tracked changes, comments             |
| **pdf**                     | PDF — extract text/tables, create, merge/split, fill forms |
| **pptx**                    | PowerPoint — create with html2pptx, edit via OOXML         |
| **xlsx**                    | Excel — formulas, formatting, analysis, visualization      |
| **sub-agent**               | Delegate to autonomous Claude Code                         |
| **playwright-cli**          | Browser automation — navigate, fill forms, screenshot      |
| **describe-image**          | Image analysis via Vision AI                               |
| **frontend-design**         | Production-grade UI / web components                       |
| **webapp-testing**          | Test web apps with Playwright                              |
| **doc-coauthoring**         | Structured document co-authoring workflow                  |
| **test-driven-development** | TDD workflow enforcement                                   |
| **skill-creator**           | Guide for creating new skills                              |
| **gitlab-explorer**         | GitLab repo operations via `glab`                          |

## Example skills (14)

Optional, in the image at `/mnt/skills/examples/`:

`web-artifacts-builder`, `copy-editing`, `social-content`, `canvas-design`, `algorithmic-art`, `theme-factory`, `mcp-builder`, `product-marketing-context`, `writing-skills`, `internal-comms`, `single-cell-rna-qc`, `slack-gif-creator`, `skill-creator` (example variant).

## Creating a skill

A skill is a folder with `SKILL.md` at the root:

```
my-skill/
├── SKILL.md          # Required — instructions for the AI
├── scripts/          # Optional — helper scripts
│   └── process.py
└── references/       # Optional — reference docs
    └── guide.md
```

### `SKILL.md` format

```markdown theme={null}
---
name: my-skill-name
description: Brief description (this is what the AI sees in the skills list)
---

# My Skill Name

Instructions for the AI. Be specific about:
- When to use this skill
- Step-by-step workflow
- Which scripts to run and how
- Expected output format
```

See `skills/public/` in [the repo](https://github.com/Yambr/open-computer-use/tree/main/skills/public) for real examples.

## Per-user skill management

In the production Yambr setup we built a **skill registry** (settings-wrapper):

* The AI manages skills through a dedicated `settings-manager` skill.
* Users enable/disable skills per account.
* Custom skills are uploaded as ZIPs and cached on the server.

For community use, a [mock settings-wrapper](https://github.com/Yambr/open-computer-use/tree/main/settings-wrapper) ships with the API contract. All 13 public skills work out of the box without it.

## Related

* [Skills reference](/skills/reference) — deeper per-skill details
* [Dynamic skills](/skills/dynamic) — under-the-hood injection
* [Creating skills](/skills/creating) — publishing your own