CRITICAL DATA-LOSS BUG: Cursor Agent Changes in Jupyter Notebooks Cannot Be Undone or Reverted

[yanxiang_meng]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When using Cursor Agent inside a Jupyter Notebook, accepting an agent-generated code modification permanently changes the notebook with no way to undo or revert the edits.

After accepting the agent’s changes:
• Ctrl+Z does not undo the modification
• Reverting to a previous agent conversation checkpoint does not restore the previous code state

This behavior only occurs in Jupyter Notebooks.
In regular .py files, Cursor Agent edits can be successfully undone using Ctrl+Z or by reverting to a previous agent checkpoint.

This creates a silent data-loss scenario, as users reasonably expect agent edits to be reversible, consistent with .py file behavior.

Steps to Reproduce

Steps to reproduce

1. Open any Jupyter Notebook (.ipynb) in Cursor
2. Select a code cell
3. Invoke Cursor Agent to modify the code
4. Accept the agent’s suggested changes
5. Attempt to:
   • Undo using Ctrl+Z
   • Revert to a previous checkpoint in the agent conversation

Expected Behavior

• Accepted Cursor Agent edits in Jupyter Notebooks should be fully undoable via Ctrl+Z
  or
• Reverting to a previous agent conversation checkpoint should restore the notebook to its prior state

This should behave consistently with how Cursor Agent edits work in standard .py files.

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 2.4.28 (Universal)
VSCode Version: 1.105.1
Commit: f3f5cec40024283013878b50c4f9be4002e0b580
Date: 2026-02-03T00:56:18.293Z (3 days ago)
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 23.4.0

ms-toolsai.jupyter: Version 2025.4.1

Additional Information

• This issue only affects Jupyter Notebooks
• The lack of undo/revert makes this a high-risk bug, as accepting agent changes can permanently destroy existing code without warning
• Users may not realize the data loss until after multiple edits have been made

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

Hey, thanks for the report. This is a known issue with Jupyter notebooks.

For now, a few workarounds:

• Work in regular .py files if it’s important to keep rollback working
• Manually back up cells before accepting changes from the Agent
• Make a git commit before each Agent session in notebooks

Unfortunately, there’s no ETA for a fix yet. Your report helps us prioritize this. I’ll post an update in this thread if there’s any news.

[Colin]

This bug should be fixed in 2.5!

[Alex_Lenail]

@Colin could you share a little more info? I don’t see any details in the changelog.