T3 Code

free, open-source app for running and managing AI coding agents

T3 Code is a free, open-source app for running and managing AI coding agents. Its makers describe it as an "agent harness control surface":^[1] rather than supplying a model or agent of its own, it gives one interface to the coding agents a developer already has set up, such as Claude Code from Anthropic, Codex from OpenAI, Cursor, Grok Build, OpenCode and Antigravity from Google, using the developer's existing subscriptions.^[1][2] The agents run on the developer's own computer, which T3 Code controls through a desktop app for macOS, Windows and Linux, a web app, or companion apps for iOS and Android.^[1][2] It is published by T3 Tools Inc. under the MIT License,^[3][4] and is one of the products of Ping Labs, the company co-founded by Theo Browne (T3).^[5]

History

Browne created T3 Code with the engineer Julius Marminge.^[2] Its source repository was created on GitHub on 8 February 2026,^[1] and on 7 March 2026 Browne announced that T3 Code was "available for everyone to use", "fully open source" and built on top of OpenAI's Codex CLI, so that users could bring their existing Codex subscriptions.^[6] A Better Stack guide that month described Codex as its main integration, with support for Claude Code awaiting approval and Cursor, OpenCode and Gemini planned;^[7] support for other agents followed.^[1]

In May 2026, when Anthropic changed how Claude subscriptions could be used through third-party tools, Browne warned that Claude subscribers using T3 Code and similar apps had had their usage "cut by 25x",^[8] and argued that T3 Code's users had been hit even though it connected through the officially supported route; he cancelled his own subscription.^[9]

The iOS companion app was released on the App Store on 29 July 2026, and an Android app is available on Google Play, where it had more than 10,000 downloads by October 2026.^[4][10] The mobile apps connect to a computer running T3 Code through pairing codes or the managed T3 Connect service.^[4][11]

The project is developed in public: it passed 20,000 stars on GitHub on 27 August 2026, and its 0.0.34 release included work from 114 contributors,^[2] although its README says that it is "very very early" and mostly not accepting outside contributions.^[1] By mid-October 2026 the repository had about 28,000 stars.^[1] Its website says that more than 500,000 developers use it.^[12] In October 2026 Browne said that Anthropic's newest Claude Opus model had become the first to receive more than half of all prompts sent through T3 Code.^[13]

On 15 October 2026 the project released version 0.1.0, the first stable release of its rebuilt "Orchestrator V2", the part of T3 Code that runs agents. It added a tool with which one agent can start child agents on another provider or model and wait for their results, the ability to fork any thread or switch provider mid-thread, an MCP server through which agents can create and manage threads, support for the Pi, OpenCode 2 and Muse Code agents, and scheduled tasks.^[14]

Features

Each conversation thread can run in its own Git worktree, so that an agent's changes stay apart from the developer's main checkout until they are reviewed. The app includes a diff viewer for reviewing changes turn by turn, built-in terminals, project-specific quick actions, and one-click commits, pushes and pull requests.^[7][2] Permission modes range from "Supervised", which asks for approval before commands and file changes, to "Full access", which needs none.^[15] Better Stack found the Electron-based desktop app "noticeably responsive", with switching between projects and long threads instant even with several agents running.^[7]

T3 Code can be installed from the command line, through Homebrew, winget, Scoop or the Arch User Repository, or as a desktop app from its GitHub releases. It is written in TypeScript using the Effect library.^[1]