Hey, this isn’t a Cursor bug. It’s a limitation on the ACP client side, in your case Zed.
How it works: to show a thinking level or variant picker like Fast vs non-Fast, the ACP client has to declare the parameterizedModelPicker capability during initialization. If the client doesn’t declare it, the backend falls back to variants mode and returns only one default variant per model:
- Composer 2.5: Fast only
- Opus 4.7: medium thinking only
- etc.
Right now, Zed’s ACP integration doesn’t declare this capability, so the selector doesn’t show up. The same thing happened with IntelliJ ACP, confirmed here: IntelliJ Cursor ACP Reasoning Levels, and in a couple of similar reports:
So the fix is likely on Zed’s side. They need their ACP client to support the parameterized model picker, or there needs to be an upstream change in the ACP spec. On our side, we’re tracking this because of side effects like unexpected quota usage, but we can’t add this as a Zed in-app feature without client support.
Current workaround: use Cursor CLI directly outside ACP. The thinking level and variants selector works there as expected.