You arrange the editor yourself: tabs inside panes, panes split as many ways as you like, and a layout that is still there when you come back tomorrow. This page covers how to open, split, move and resize, and what happens when the assistant needs a pane of its own.
## Tabs
Click a file in the tree and it opens as a **preview** tab. A preview tab is temporary. The next single click replaces it, so you can walk a folder without collecting twenty tabs. Three things pin it permanently:
- Double-click the file in the tree.
- Double-click the tab itself.
- Type into the file. Editing always pins.
Drag tabs sideways to reorder them inside a pane. Two tabs are not files. The **Welcome** tab holds the assistant's full-width view, and the **Graph** tab draws your workspace as a link graph and opens from the command palette.
## Splitting a pane
Drag a file from the tree, or a tab from any pane, and hold it over the pane you want to split. Four target zones light up:
| Drop on | Result |
|---|---|
| Left half | **Split Left**, new pane on the left |
| Right half | **Split Right**, new pane on the right |
| Top half | **Split Top**, new pane above |
| Bottom half | **Split Bottom**, new pane below |
| Centre | No split. The file opens, or the tab moves, into that pane |
Splits nest, so you can split a pane that is already half of a split and get columns inside rows. Drag the divider between two panes to resize them, down to a floor of 10 percent each. Close the last tab in a pane and the pane closes with it, and its space goes back to its neighbour.
> [!NOTE]
> Splitting is a desktop-width feature. On a phone the layout stays a single pane, and drops open the file instead of splitting.
## The same file in two panes
Open one file in two panes and both stay in step as you type, character by character, with no save in between. Only the pane you are typing in is editable; the mirror is read-only while the other pane owns the file. Click into the mirror and ownership moves with your cursor.
## Modes that apply everywhere
Three toggles are global, so they affect every open editor at once:
| Mode | What it does | Where |
|---|---|---|
| Read-only | Locks every pane against edits | Command palette, "Enable read-only mode" |
| Raw markdown | Swaps the rendered view for the source, for markdown, HTML and canvas files | Cmd/Ctrl + Shift + V, or the tab actions menu |
| Compact | Shrinks the rendered document so more of it fits | Command palette, "Enable compact mode" |
## When the assistant takes over a pane
When an agent edits a file, the pane switches to a side-by-side diff with the old content on the left, the new content on the right, and two buttons:
- **Keep** accepts the change and returns the pane to the editor.
- **Revert** writes the previous content back. If the agent created the file, Revert deletes it and closes the tab.
```mermaid
flowchart LR
A[Agent writes a file] --> D[Pane shows a diff]
D -->|Keep| E[Back to the editor]
D -->|Revert| O[Previous content restored]
```
The diff persists. If you close the tab, reload, or come back the next day, an unreviewed change still opens as a diff, rebuilt from the version captured before the run. [[Reviewing Changes]] covers the whole-run view, where you keep or revert everything at once.
## What persists, and what does not
The browser you are using stores your panes, tabs, active tab and split sizes, so a reload or a closed laptop lid restores the exact layout. Another browser or the desktop app starts with its own layout. Switching to a different workspace clears the tabs on purpose, because a path in one workspace means nothing in another. See [[Personal and Team]].
## Next steps
:::cards
- [[Files and Folders]] — Paths, the file tree, renaming, moving, deleting and restoring.
- [[Keyboard Shortcuts]] — Every shortcut in the app, by area.
- [[Reviewing Changes]] — The diff view and the changeset card: keep or revert everything an agent touched.
- [[Backlinks and Graph]] — See what links to a file, and navigate your workspace as a graph.
:::