MCP app is hidden by default

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

MCP app gets invoked but the iframe is rolled into trace and is not visible to users right away.

Steps to Reproduce

Use MCP tool with MCP app attached to it.

Screenshots / Screen Recordings

image.jpg
image.jpg1664×1512 156 KB

Operating System

MacOS

Version Information

Version: 3.12.30
VS Code Extension API: 1.128.0
Commit: 63a2996a10d9e476b6c28e951dd7691d9c0cf480
Date: 2026-07-21T22:50:03.568Z
Layout: Agent Window
Build Type: Stable
Release Track: Default
Electron: 40.10.3
Chromium: 144.0.7559.236
Node.js: 24.15.0
V8: 14.4.258.32-electron.0
xterm.js: 6.1.0-beta.256
OS: Darwin arm64 24.6.0

For AI issues: which model did you use?

Composer 2.5

Additional Information

We are observing this behavior on internal build of AWS MCP server.

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

5

Hey Maxim, thanks for moving this to a separate thread, it’s easier to track. And thanks for the detailed report with the version and a screenshot, that really helps.

This is a known bug. The widget itself renders fine (it’s already fixed in 3.12), but after the turn ends, the transcript collapses all tool-call activity into a “Worked for Ns” group, and the MCP App widget gets hidden inside it. While the agent is running you can see the widget, but on the next turn or after reopening the chat it collapses, which is what you’re seeing.

Workaround: expand the “Worked for Ns” group (click it) and the widget will show up again.

I’ll post an update here once it’s available.

7

Hi Dean,

Do we have a timeline for fixing this? This tremendously hurts customer-facing MCPs.

Thanks.

8

Hey Dolev, I don’t have a specific timeline for the fix yet. We’re tracking the issue, but I can’t share an ETA. As soon as I have an update, I’ll reply here in the thread.

For now, the workaround is the same. Expand the “Worked for Ns” group by clicking it, and the widget will show up again. The widget renders correctly, it only gets hidden in the collapsed transcript after the turn ends.