Cursor 3 UX for unsupported cloud models is cluncky

Ideas Feedback
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1

Where does the bug appear (feature/product)?

Background Agent (GitHub, Slack, Web, Linear)

Describe the Bug

When kicking off a background agent from the Cursor 3 UI I can select across all models I can use locally. However, only a limited set of models are supported by Background Agents.

Currently, if I select an unsupported model and try to send off a prompt nothing happens. This is a bit clunky because the lack of feedback makes you think something is broken until you learn that the problem is that you chose a wrong/unsupported model.

Steps to Reproduce

Open Cursor 3 (Cloud Agents need to be enabled for the project).
Select “New Agent”.
Select “Cloud” in the environment dropdown.
Select “Composer 2 Fast” as the model.
Type an arbitrary prompt.
Click send.

Expected Behavior

I would expect that incompatible models are disabled, I get a warning in the UI when I select an incompatible model, or that I get an error/feedback when I send off a prompt.

Something to indicate that I am on the wrong path.

Operating System

MacOS

Version Information

Version: 3.0.12 (Universal)
VSCode Version: 1.105.1
Commit: a80ff7dfcaa45d7750f6e30be457261379c29b00
Date: 2026-04-04T00:13:18.452Z
Layout: glass
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0

For AI issues: which model did you use?

Composer 2 Fast

Does this stop you from using Cursor

No - Cursor works, but with this issue

3

I stand corrected. The bug isn’t that I can’t use some models in background agents; I just managed to kick off a Background Agent with “Composer 2 Fast”. Instead, what it looks like is that I can’t start a new Background Agent until I switch the model at least once.

5

Hey, thanks for the report. I saw the extra detail in your second message. The issue is that the new Cloud Agent won’t start until you switch the model at least once.

This is a known bug. It was fixed before, but it looks like it’s back in 3.0.12. I’ve passed it to the team to take a look. For now, the temporary workaround is to switch the model there and back before sending your prompt.

Also about your original UX feedback on unsupported models, I agree it would be better to show a warning or disable incompatible models in the dropdown for Cloud Agents.

Let me know if you run into anything else.