# Cai Documentation

Act on anything. Locally.

## Quick Start

1. [Download and install Cai](/content/docs/getting-started/installation/index.html)
2. [Set up a local LLM](/content/docs/getting-started/llm-setup/index.html) (optional, for AI-powered actions)
3. Select any text or image and press **⌥C**

## What is Cai?

Cai is a native macOS menu bar app that turns what you select into action. Select a meeting invite and it creates a calendar event. Select an address and it opens Maps. Select any text and ask AI to summarize or translate, or pipe it to a shell script, all without leaving your keyboard.

- **Simple and fast**: one shortcut, one menu, no launcher or bloat
- **Flexible models**: built-in MLX (default), Apple Intelligence, or any local/cloud provider
- **Context aware**: Reply adapts to email vs Slack, actions adapt to content type
- **Keyboard first**: trigger with ⌥C, navigate with arrows, execute with ⌘1–9
- **Local by default**: no accounts, no forced cloud, no telemetry

## Guides

- **[How It Works](/content/docs/usage/how-it-works/index.html)**: content detection, actions, and settings
- **[Keyboard Shortcuts](/content/docs/usage/keyboard-shortcuts/index.html)**: full shortcut reference
- **[Ask AI](/content/docs/usage/custom-actions/index.html)**: run any AI prompt on your selected text
- **[Custom Actions](/content/docs/usage/saved-actions/index.html)**: save prompt, shell, and URL actions for instant access
- **[Troubleshooting](/content/docs/troubleshooting/common-issues/index.html)**: common issues and fixes