In the lab · Built and working, but only in the direct download of mChatAI+, behind the Show Experimental switch on the home screen.

Code Editor

Open any folder, browse and edit its files in tabs, with an AI panel docked underneath.

In the lab · Experimental, in the direct download only — switch on Show Experimental on the home screen to see it

What it does

Opens a folder you pick — or one of your past AI build workspaces — as a collapsible file tree, skipping the usual noise directories: .git, node_modules, .build, .swiftpm, Pods, DerivedData, pycache, .venv, venv, xcuserdata and a few more
Opens files in closable tabs; what you type is written straight back to disk on every keystroke, so there is no separate save step
Markdown files get a rendered-preview toggle in the editor toolbar and open in preview by default
The bottom third of the window is a resizable, collapsible panel that switches between two tabs: 'AI Harness' (the app's full build-an-automation surface, embedded whole) and 'Code Chat', a plain chat with a senior-engineer system prompt and its own model picker
The sidebar's empty state lists your past AI dev runs — the goal text, the working folder, which backend ran it and an outcome icon — and clicking one opens the folder that run produced
Panel height and collapsed state are remembered between sessions

On the home screen turn on the 'Show Experimental' toggle, then open the Code Editor tile.
In the left sidebar press 'Open Folder…' and choose a project — or click one of the 'Recent Workspaces' pills, or a row under 'Dev Agent Runs'.
Click a file in the tree to open it in a tab and edit it; the change lands on disk as you type.
At the bottom, switch between the 'AI Harness' and 'Code Chat' tabs, and drag the divider above them to resize the panel.

AI Harness (the same AIHarnessView is embedded as one of the two bottom-panel tabs)
The app's dev-session history (AIAutomationViewModel.devSessionSummaries supplies both the Recent Workspaces pills and the Dev Agent Runs list)
Workbench (AICodeEditorAppletView accepts an initialDirectory, so a hosted session's working folder opens directly)

Code Editor ships with mChatAI+. Native macOS app. Your own API keys, or fully on-device. Get mChatAI+