Extend T3 Code with your own panels and workspace tools.
An experimental fork of T3 Code that adds an extension system. Extensions can add panels to the conversation sidebar, use T3 Code's UI controls, run commands on the connected server, and respond to conversation lifecycle events.
This fork is a place to experiment and test the idea before proposing it for inclusion in T3 Code. The intention is to contribute the extension system upstream once it is ready, rather than maintain a separate fork long term. Upstream acceptance is not yet agreed.
The aim is to keep the changes to T3 Code small and maintainable, with additional tools built as separate extensions.
- Extension management: install from a local folder, enable, disable, reload, and uninstall through Settings.
- Sidebar panels: each extension appears directly in the panel chooser and opens in its own named tab.
- Shared UI: extensions use the host's React runtime and a small set of its existing controls: buttons, inputs, and badges.
- Workspace context: panels and commands can access the current project, conversation, branch, and worktree context.
- Backend commands and state: extensions run on the selected environment and can persist their own JSON data.
- Lifecycle hooks: respond when conversations are created, settled, restored from settlement, archived, unarchived, or deleted—even when the panel is closed.
See the extension guide and SDK for the package format and API.
Use Node.js 24.13.1 or later within the Node 24 series, and pnpm 11.10.0.
git clone https://github.com/EthanBarlo/t3code-extensions.git
cd t3code-extensions
pnpm install
pnpm dev --home-dir "$PWD/.t3"Open the pairing URL printed by the development server. This command keeps development sessions and extension data in the checkout's ignored .t3 directory.
To use a coding agent, install and authenticate a provider supported by T3 Code. Existing setup instructions are in the upstream user documentation.
In Settings → Extensions, select an environment and install a built extension using its absolute folder path. The folder must exist on the selected server. Then open the extension from a conversation's right-panel chooser.
The official T3 Code downloads and npx t3 install upstream T3 Code. Use this checkout to try the extension system.
This is a working prototype. The API is versioned, but may change as the extension system develops.
Local web behavior has been tested. The implementation uses T3 Code's existing environment connections; remote Tailscale, official T3 Connect, and signed desktop operation still need live validation. There is no extension UI for the native mobile app yet.
Install only extensions you trust. Their frontend code runs inside the app, and their backend code runs with the server user's permissions. Extensions are not sandboxed.
Preview Lab is a separate reference extension used during development. It saves and opens existing preview URLs and demonstrates backend commands and lifecycle hooks. It is not bundled here and does not provision Docker environments.
A marketplace, published SDK, and managed preview hosting are outside the current experiment.
Built on T3 Code by T3 Tools and its contributors. This is an independent fork.
MIT licensed, with the upstream license and attribution retained.