ChatTab is a native macOS application that provides a streamlined interface for interacting with OpenAI's ChatGPT and other language models. It allows users to access advanced AI models—including GPT-3.5, GPT-4, GPT-4 Vision, and Claude 2—using their own API key or a built-in key. The app focuses on speed, privacy, and productivity with features like multiple conversation tabs, smooth markdown rendering, global shortcut keys for instant access, and iCloud sync for prompts. The Assistant API support enables code interpretation and document analysis (PDF, XML, JSON, CSV, MD). All sensitive data, including API keys, stays in Apple's Keychain, and conversations are stored locally. ChatTab is suitable for anyone looking for a fast, distraction-free AI assistant on the Mac.