Hey, thanks for the detailed report and the video.
I took a look at your Activity Monitor screenshot. The top process is extension-host (user) apiv3.wask.co, using several GB, and there are a few more extension-host processes tied to wask-backend-services taking a few hundred MB each. This is a third-party AI extension, and it’s very likely the main cause of the memory issue.
We recently had an almost identical case. A user had multiple AI extensions running alongside Cursor’s built-in AI. Memory usage was over 30 GB, and after disabling them it dropped to about 1,5 GB: Cursor causing extremely high CPU and memory usage (extension-host processes)
Try this first:
- Disable the wask.co extension (and any other third-party AI extensions), restart Cursor, and check Activity Monitor again.
- If you want to confirm it’s the cause, run
cursor --disable-extensionsfrom Terminal and compare memory usage.
Also, there’s a known macOS issue where closing the window with the red button doesn’t always fully shut down child processes. So even after fixing the extension issue, I’d recommend using Cmd+Q to fully quit Cursor between repo sessions instead of just closing windows.
A couple questions:
- What other extensions do you have installed? (in Terminal:
cursor --list-extensions) - Are you using MCP servers? (check for
.cursor/mcp.jsonin your projects)
Running Cursor’s built-in AI together with third-party AI extensions often causes this kind of resource spike. Cursor already includes built-in AI features, so extra layers can conflict and eat memory.
Let me know how it goes after disabling the wask.co extension.strong text