Switch to auto option leads to invalid model option "auto"

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When a model’s rate limit or quota is exceeded, Cursor displays a “Switch to Auto” option. Upon accepting it, the model is changed to the raw string value “auto” (lowercase). However, when sending a new message afterwards, the request fails with: “Invalid model option: auto”. The workaround is to manually open the model picker dropdown and click “Auto”, which properly sets the model to the correct internal identifier.

Steps to Reproduce

  1. Use a specific model (e.g., GPT-4.1) until its quota/rate limit is reached
  2. When the “Switch to Auto” suggestion appears, accept it
  3. Observe the model picker now shows “auto” (set programmatically)
  4. Try sending a new message
  5. Error appears: “Invalid model option: auto”
  6. Manually click the model picker and select “Auto” — this works correctly

Expected Behavior

Accepting “Switch to Auto” should set the model to the same valid identifier as manually selecting “Auto” from the model picker dropdown, allowing requests to proceed without errors.

Operating System

Linux

Version Information

IDE: Cursor 2.6.20
Build: b29eb4ee5f9f6d1cb2afbc09070198d3ea6ad760
Arch: x64

For AI issues: which model did you use?

Opus 4.6

For AI issues: add Request ID with privacy disabled

Any model that hits its rate limit (e.g., GPT-4.1). The issue is with the “Switch to Auto” fallback mechanism.

Additional Information

The root cause appears to be that the programmatic “Switch to Auto” sets the model to the string “auto” instead of the proper model identifier (e.g., “copilot/auto” with vendor metadata). Manually selecting “Auto” from the picker works because it uses the full model object with correct identifier and metadata.

Does this stop you from using Cursor

No - Cursor works, but with this issue

Hey, this is a known bug. There’s already a similar report here: Bug when switching to auto if other models are not avilable.

The Switch to Auto button sends the string auto instead of the correct internal identifier. A workaround is to manually select Auto from the model dropdown, instead of using the button.

The team is aware of the issue. Let me know if there’s anything else.

A post was merged into an existing topic: Bug when switching to auto if other models are not avilable