Changes and undo
What the agent changed in a turn and how to take it back: the summary under the answer, the diff, a safe rewind that checks for other edits, the file tree.
Every turn that changed files leaves a summary under the answer: how many files and lines were changed. From it you open the diff and rewind the whole turn — with a check that the rewind does not overwrite your own edits.
The turn summary
“Changed 2 files +23 −1” under the answer expands into a list of files: each shows how many lines were added and removed, new and deleted ones are marked. A click on a file opens the changes panel on it.
The changes panel
On the right a “Files Changed N” tab opens — all uncommitted changes in the project, not only this turn’s.
| Button | What it does |
|---|---|
| ← → | previous and next file |
| “Show all lines” / “Hide non-diff lines” | expand or collapse unchanged sections |
| “Unified diff” / “Split diff” | the diff in one column or “before |
| file tree (top left) | show or hide the file list |
| “Open in …” (top right) | open the project folder in a file manager or an editor |
The panel opens and closes with the “Show or hide changes” button in the session header. The panel watches the disk: a file changed by the agent, by a command or by you in an editor appears in it without a reload.
Rewinding a turn
“Rewind the turn” shows what will come back and warns about danger:
- “The rewind is safe” — nobody changed the files after the turn; they return to their state before the turn.
- “There are edits made after the turn” — after the turn the file was changed by someone other than the agent: you in an editor or a command. Such a file is marked — the rewind will overwrite those edits.
- “Only the conversation” — rewind the conversation and leave the files as they are.
- “Revert” — the conversation and the files.
After the rewind, above the input field there is the line “Turn rewound: 2 files are back to their previous state” and the “Bring it back” button. The text of your message returns to the input field — you can edit it and send it again. A new message makes the rewind final.
“Bring it back” restores both the agent’s files and the person’s edits that the rewind overwrote.
The file tree and file view
Project files open in the right panel: “+” next to the tabs gives an “Open file” tab with the project tree and a filter. The tree updates itself when the agent creates or deletes files; new and changed files are marked.
A file opens in a preview tab:
| File | How it is shown |
|---|---|
| code and text | with highlighting and line numbers |
| Markdown, Mermaid | a “Preview / Source” switch; diagrams are drawn |
| images, SVG, audio, video | as they are |
| in the built-in viewer: pages, zoom, search | |
| binary file | with a message that it cannot be shown |
Add to chat. The “Add to chat” item in a file’s menu (right mouse button in the tree), or the button
above a file when lines are selected in it, puts a mention into the input field: @README.md,
@src/cart.js:12. The agent gets the file or those lines together with the message. The same menu has “Open
in” (a file manager, VS Code, Cursor, Zed, Sublime Text) and “Copy path”.
In the console
- Under the answer — “Changed 1 file +1 −0 · /undo — rewind”.
/undoshows the same preview and asks; if there are edits after the turn — a choice between “Only the conversation” and “The conversation and the files”./redobrings back what was undone.
Session: input field, modes, questions
Talking to the agent: the input field, permission modes, permission requests with an edit preview, the agent’s questions, attachments, background work, usage.
Plan, to-do list and goal
A large task in Buff Code: a plan with approval, the agent’s to-do list and a /goal — the agent takes turns until a check confirms the result.