LCU now gives JetBrains Junie computer use, and the Windows candidate installs with the current ChatGPT app

LCU gives your coding agent the original computer-use runtime from the ChatGPT desktop app, with no Codex sign-in. Your harness talks to LCU, and LCU runs the runtime that is already installed on your machine. Version 0.13 adds an experimental harness, JetBrains Junie. It also lets the Windows candidate finish a full install with the current Store app.

To try it, run LCU setup for the Junie agent, then restart Junie. Setup adds the LCU server to Junie's MCP config and its turn hooks to Junie's config file. With approval mode set to auto, it also allows exactly LCU's two tools in Junie's allowlist. Setup supports macOS and Linux, at user scope only, and keeps everything else in those files.

A plain MCP registration would fall short here. Junie's MCP client can't show approvals, doesn't send request metadata, and drops server instructions. So LCU registers a relay as Junie's MCP server, and adds Junie hooks. The hooks end LCU's turns, and add the original instructions to the session.

Windows is still a candidate platform for LCU. With the current ChatGPT Store app, the Windows installer refused the app on any drive. And LCU setup for the Codex agent then could not trust its hooks.

This release fixes each step that failed. LCU now recognises that app's host layout, and matches short Windows temp paths and the hook command Codex reports on Windows. A Store app installed on another drive is now accepted and copied. A full Codex install and LCU doctor were checked on Windows Server 2025, with the app on C and on D. Windows still has no archive in this release.

Junie can't show LCU's per-app approval prompt, so approvals work differently there. For an app that isn't allowed yet, Junie is told to run LCU apps allow itself. You approve with Touch ID or your password, and that app then stays allowed for every agent until you run LCU apps revoke. Setup warns you about this and asks before it registers Junie.

Setup with agent all now includes Junie. In 0.12.1 it selected six harnesses. Now it selects seven. Junie registers through its config files, without its CLI, so it is registered even when Junie isn't installed yet. Setup shows the approval warning for it too.

Junie support is experimental. It was verified with the Junie CLI on Linux x64, against a scripted model. Desktop control on macOS, a live model, and the JetBrains IDE plugin are not verified yet.

To upgrade, run LCU update, then restart your agents. To add Junie, run setup for the Junie agent and restart Junie, knowing that its app approvals last until you revoke them. To go back, reinstall 0.12.1. LCU 0.13 brings computer use to Junie, and the Windows candidate now installs with the current Store app.