Cai

Cai is a free, open-source AI action layer designed for macOS that enables users to perform a range of AI-powered and scripted actions directly on selected text or images in any application. By pressing a keyboard shortcut (⌥C), users can instantly run custom actions such as AI prompts, terminal scripts, URL shortcuts, summaries, translations, OCR, and the creation of GitHub issues or Linear tickets, all without switching between apps. Cai distinguishes itself from clipboard managers by acting on the user's current selection rather than merely storing it, and from traditional AI chat applications by operating inline within the workflow.

The platform allows users to create, chain, and save custom pipelines that route selected content through multiple actions—such as AI processing, scripting, and sending results to destinations like Slack, webhooks, AppleScript, or Apple Shortcuts—with a single keystroke. Built-in smart actions can automatically suggest relevant tasks based on the nature of the selected content, including meetings, addresses, code, or images. Cai also supports extracting text from images (OCR) and can replace selected content inline or send outputs to various external apps, such as Notion or Slack, via custom destinations.

Cai operates locally by default, shipping with a built-in AI model (Ministral 3B via MLX) and supporting on-device processing through Apple Intelligence on macOS 26+ and other local LLM providers like LM Studio and Ollama. Users have the option to connect to cloud AI APIs, such as OpenRouter, or load additional models from the HuggingFace MLX community. All local processing is private, with no data leaving the device unless a cloud provider is chosen. The tool also includes features like clipboard history for searching and reusing recent clipboard items.

Installation is available through direct download or via Homebrew, and no account or API key is required for local use. Cai is released under the MIT license and does not require a subscription or trial. Its extensibility is further enhanced by support for community extensions and custom action creation, making it adaptable to a wide range of workflows on macOS.