Large Prompt Causes Background Agent to Load Forever

Bug Reports
1

Where does the bug appear (feature/product)?

Background Agent (GitHub, Slack, Web, Linear)

Describe the Bug

When launching a background agent with a very large prompt, the agent remains in the “starting” state for over 1 hour without progress. Here is the agent link: Agents | Cursor - The AI Code Editor

Steps to Reproduce

  1. Create a background agent with a very large prompt.
  2. Start the agent.
  3. Observe that the agent stays in the “starting” state for more than an hour.

Expected Behavior

The background agent should start normally and process the prompt in a reasonable amount of time instead of getting stuck in the starting state.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.0.43
VSCode Version: 1.99.3
Commit: 8e4da76ad196925accaa169efcae28c45454cce0
Date: 2025-10-30T18:49:27.589Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 23.3.0

For AI issues: which model did you use?

GPT5-High

For AI issues: add Request ID with privacy disabled

bc-5e7f4d3b-790e-458a-92a0-1dd34bccb4fd

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

2

hi @joeo and thank you for the detailed bug report.

Just to confirm:

  • Does this occur only for long prompts and then works well with short prompts?

Usually slow start would indicate issue with Cursor Cloud environment setup for that Background Agent.

3

Hi @condor, it used to just occur for long prompts but Cloud Agents spawned from the API have not been working at all for almost two weeks now. Please see my other topic on the matter Background Agent stuck on loading with small prompt. We’d really appreciate being able to use Cloud Agents again.

4

Yes agreed, team is already working on the issue.