Act on anything. Locally.
Create and run custom AI actions and scripts with ⌥C. Send results to GitHub, Linear, or anywhere.
100% Local
Built-in AI
No Account
"You did in a very short time what Apple Intelligence failed to deliver." @nemuro87 on r/LocalLLM
Download for Free
v1.4.0 | Install via Homebrew
Install via Homebrew
To install Cai, run the following command in your terminal:
$ brew tap cai-layer/cai && brew install --cask cai
Cai is a free, open-source AI action layer for macOS. Select any text or image, press ⌥C, and instantly run custom actions: AI prompts, terminal scripts, URL shortcuts, summaries, translations, OCR, GitHub issues via MCP, Linear tickets. Unlike clipboard managers, Cai acts on your selection, not just stores it. Unlike AI chat apps, it works inline without app switching. Ships with a built-in local AI model (Ministral 3B via MLX). No API key, no account, no setup. Also supports Apple Intelligence on macOS 26+, LM Studio, Ollama, and cloud APIs. Local by default. Cloud optional. MIT licensed.
How it works
Three steps. One shortcut. Zero app switching.
01
Select
Highlight text in any app. An error in terminal, a Slack message, a screenshot, a draft email...
02
Summon
Press ⌥C. See your list of actions. No tabs, no distractions.
03
Act
Pick an action, done. Summarize, create a ticket, run a script or route it anywhere.
Smart actions, ready-to-use.
Cai reads what you selected (meetings, addresses, code, images) and surfaces the right actions automatically.
- Ask AI
- Reply
- Image to Text (OCR)
- Create GitHub Issue
- Create Linear Ticket
- Create Calendar Event
- Summarize
- Fix Grammar
- Translate
Make it yours
Build your own actions with custom prompts, shell scripts, URL searches. Route results anywhere.
- Custom Prompts
- URL Actions
- Custom Scripts
- Custom Destinations
- Community Extensions
- Keyboard-First
Your own action library
Type it once. Run it forever.
Save any AI prompt, shell script, or URL shortcut as a one-keystroke action. Your library grows with you.
cai — shell action$ lsof -ti :{{selected text}} | xargs kill -9$ gh pr list --search "{{selected text}}"
cai — prompt action✦ Translate to a git command: {{selected text}}→ "undo last 2 commits" → git reset --soft HEAD~2
If it runs in Terminal or as a prompt, it runs in Cai.
Designed to disappear
Stay in flow. Stay private. Make it yours.
GitHub & Linear
Create issues and tickets with AI from any selected text or screenshot.
Zero App Switching
Results appear right where you are. No tabs, no copy-paste loops.
Image to Text
Select a screenshot or error image. Cai extracts the text, then runs any action on it.
Local & Private by Default
All processing stays on your machine. Want a cloud provider? Your choice.
Clipboard History
Search, pin, and reuse your last 100 clipboard items.
Route Anywhere
Replace your selection inline, or send results to Slack, Notion, or any app via custom destinations.
Bring Your Own Brain
Use our built-in model, load any model from the HuggingFace MLX community, connect to a local server, or use a cloud provider like OpenRouter.
Ministral 3B (MLX)built-inApple Intelligence built-in
LlamaMistralQwenGemmaPhiDeepSeekLFM2...
Works in any text field, any app
Select some text, let Cai do the rest.
Use AI without switching apps.
- VS Code
- Terminal
- Browser
- GitHub
- Linear
- Jira
- Slack
- Notion
- Figma
Power tip: teach Cai per-app context →
Frequently Asked Questions
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'll need their API key, but the app itself is free.
How is Cai different from other tools?
Clipboard managers store and organize what you copy; Cai acts on it. And unlike ChatGPT or other AI tools that need you to switch to a separate app, Cai runs directly on your selected text in any app, without breaking your flow. Connect GitHub or Linear, then create issues or tickets without leaving what you're doing. It's a custom-action layer that runs locally on your Mac by default.
Detailed comparisons: vs Maccy, vs ChatGPT, vs Raycast, vs Bolt AI, vs Alter.
Does Cai work offline?
Yes. The built-in models, Apple Intelligence, and local LLM providers all run on-device — everything works without internet. Cloud providers need internet, but that's optional.
Is Cai secure?
Yes. By default, Cai runs locally on your Mac and nothing leaves the device. If you connect a cloud model, your selected text is sent only to that provider. The choice is yours.
What models does Cai support?
Cai ships with Ministral 3B, Qwen 2.5 7B, Apple Intelligence on macOS 26+, local servers (LM Studio, Ollama) and cloud APIs like OpenRouter. You can also load any MLX model from the HuggingFace MLX community. More info in our docs.
How do I create custom actions?
You can create custom actions and destinations using AI prompts, URL templates, shell scripts, webhooks, deeplinks, and more. Open Cai's settings → Custom Actions to start. Full guide in the docs.
Browse community-shared actions at cai-extensions.
How do I connect GitHub or Linear?
Open Cai's settings → Connectors, paste a GitHub personal access token or Linear API key, and test the connection. "Create GitHub Issue" and "Create Linear Ticket" then appear in your action list. Step-by-step guide in the docs.
Why ⌥C?
Because your hand is already there. ⌘C to copy, ⌥C to act on it. Same finger position, new capability. One modifier key away from muscle memory you already have.
If ⌥C conflicts with something you use, you can change it in Settings → General → Hotkey.
Why does Cai need Accessibility permissions?
Cai uses the system hotkey ⌥C to copy your selected text via a simulated ⌘C. macOS requires Accessibility access for apps that interact with system-level keyboard commands. This is what lets Cai work in every app, from Safari to Slack to Terminal.
To enable it, open System Settings → Privacy & Security → Accessibility and toggle Cai on.