# Introduction

> learn.ninja turns anything you give your agent into one short, interactive lesson, published as a link.

learn.ninja is a skill for AI agents. The agent turns a topic, an article, notes, docs, a transcript, or code into one short lesson: 5 to 10 minutes of small interactive screens called **bricks**, with feedback on every answer. It checks the lesson and publishes it to a link like `https://learn.ninja/l/how-compound-interest-works-k3x9a2mq`, which anyone can open in a browser. Free, no account. Links last 24 hours.

## Install

```bash
npx skills add https://learn.ninja -g
```

Works with any agent that supports [skills](https://github.com/vercel-labs/skills): Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, Windsurf, Cline, Roo Code, Kiro, Goose, Amp, OpenCode, Antigravity, Junie, and more. To install for one agent without being asked, name it and skip the prompts:

```bash
npx skills add https://learn.ninja -g -a claude-code -y
```

The agent names are `claude-code`, `codex`, `cursor`, `gemini-cli`, `github-copilot`, `windsurf`, `cline`, `roo`, `kiro-cli`, `goose`, `amp`, `opencode`, `antigravity`, and `junie` (the [full list](https://github.com/vercel-labs/skills#supported-agents)). Leave out `-g` to install only in the current project. Needs Node.js 18 or newer and network access. Update with `npx skills update`.

## If you're an agent

1. Install the skill with the command above.
2. Read its `SKILL.md`, then the guides it points to: the teaching guide, the [lesson format](https://learn.ninja/docs/lessons/lesson-format), and the [subject](https://learn.ninja/docs/subjects) that fits.
3. Write the lesson, run `validate` until it passes, then `publish`, and give the user the link. To change the lesson, edit the same file and publish again: the link stays the same.

## Without a shell

An agent that can't run commands (a chat app, or an agent on a locked-down host) can skip the skill:

1. Read the [lesson format](https://learn.ninja/docs/lessons/lesson-format.md) and the [JSON Schema](https://learn.ninja/schema/lesson.schema.json).
2. Write the lesson as JSON.
3. Publish it with the [API](https://learn.ninja/docs/reference/api): `POST https://learn.ninja/api/lessons`. The API runs the same checks as the skill and lists every issue, so fix them and post again.

## Plain text

Everything here is also plain text. Requests that don't ask for HTML get Markdown back, so `curl https://learn.ninja/docs` returns this page.

| URL                                                                | What it is                                                  |
| ------------------------------------------------------------------ | ----------------------------------------------------------- |
| [`/llms.txt`](https://learn.ninja/llms.txt)                                           | A short guide to learn.ninja, with links to every docs page |
| [`/llms-full.txt`](https://learn.ninja/llms-full.txt)                                 | Every docs page in one file                                 |
| `/docs/{page}.md`                                                  | Any docs page as Markdown                                   |
| [`/.well-known/skills/index.json`](https://learn.ninja/.well-known/skills/index.json) | The skill, for `npx skills add https://learn.ninja`         |
| [`/schema/lesson.schema.json`](https://learn.ninja/schema/lesson.schema.json)         | The lesson JSON Schema                                      |