Cai – Local AI Action Layer for macOS (Free, MIT, MLX)
FreeFreeFree tier
Inputs: text, imageOutputs: text
About Cai – Local AI Action Layer for macOS (Free, MIT, MLX)
Cai is a free, open-source AI action layer for macOS that lets you act on selected text or images instantly. Select any content in any app, press ⌥C, and run custom actions—AI prompts, terminal scripts, URL shortcuts, summaries, translations, OCR, GitHub issues, Linear tickets, and more. You can chain multiple actions together into pipelines, piping a selection through AI, scripts, and destinations (Slack, webhook, AppleScript, Apple Shortcut) with one keystroke. Cai ships with a built-in local AI model (Ministral 3B via MLX), no API key or account required. It also supports Apple Intelligence, LM Studio, Ollama, and cloud APIs like OpenRouter. All processing stays local by default; cloud is optional. MIT licensed.
Key Features
Built-in local AI model (Ministral 3B via MLX) – no API key or account required
Custom actions: AI prompts, terminal scripts, URL shortcuts, summaries, translations, OCR
Action chains: pipe selection through AI, scripts, and destinations in any order
Zero app switching – works inline from any text field or app
Supports multiple models: built-in, Hugging Face MLX, LM Studio, Ollama, OpenRouter, Apple Intelligence
Clipboard history with search, pin, and reuse of last 100 items
Route results anywhere: Slack, GitHub, Linear, Notion, Mail, webhooks, AppleScript, Apple Shortcuts
Keyboard-first interface with per-app context awareness
100% local by default with optional cloud model usage
Free and open source (MIT license)
Pros & Cons
Pros
- Completely free and open source (MIT license)
- 100% local processing by default – no data leaves your machine
- Works in any app without switching context
- Built-in local AI model ready out of the box
- Highly customizable with custom actions, scripts, and chains
- Supports a wide variety of AI backends (local and cloud)
- Keyboard-first design keeps you in flow
- Clipboard history and per-app context enhance productivity
Cons
- macOS only – no Windows or Linux support
- Requires learning the ⌥C shortcut and action chain system
- Built-in local model may be less capable than larger cloud models for complex tasks
- Relatively new tool with a smaller community and fewer extensions
Best For
Summarize selected text or articles inlineTranslate text to another language and replace selectionCreate GitHub issues or Linear tickets from selected text or screenshotsExtract text from images via OCR and then act on itChain actions: fetch a URL, summarize, and send to SlackFix grammar or rewrite selected content with AIRun custom terminal scripts on selected textCreate calendar events from selected meeting information
FAQ
Is Cai really free?
Yes. Cai is free and open source — no subscription, no trial, no account required. If you choose to use a cloud model (like OpenAI or OpenRouter), you will need your own API key and may incur costs from that provider.