T3 Code is a minimal web GUI for coding agents like Codex, built to give agents a better place to work than a terminal. It is free, open source, fast, and designed so you can install it, plug in the harness you already pay for, and let your agents get to work. It provides a clean, modern interface for interacting with AI coding assistants through both web and desktop applications, with session management, persistent state, thread management, and real-time collaboration. Developers can interact with coding agents through an intuitive chat-based interface, manage coding sessions across projects, track changes with built-in git integration and checkpointing, and control access through Full Access and Supervised runtime modes. T3 Code is built to be modifiable, customizable, and forkable, with an MIT license, commercial-friendly use, TypeScript, strict end-to-end typing, and a monorepo that includes desktop, web, server, and harnesses.