Git Context "Diff With Main Branch" does not send to model for large diffs

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When adding the “Diff With Main Branch” Git context item to a chat request, if the diff is sufficiently large (not sure what the exact cutoff is, but it is not difficult to reproduce with a medium sized pull request), then the model does not receive the diff. It appears to work correctly for small diffs, but not for larger ones.

Steps to Reproduce

  • Ask Cursor to review a branch
  • Attach the “Diff With Main Branch” context item
  • Send the chat

Expected Behavior

The model should always receive the diff when I attach this context item.

Operating System

Windows 10/11
MacOS
Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.54 (Universal)
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z
Electron: 34.5.8
Chromium: 132.0.68.34.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

For AI issues: which model did you use?

Occurs with multiple models

Does this stop you from using Cursor

No - Cursor works, but with this issue