[BUG] Diff approval clicks in VS Code extension webview don't reach Claude Code (diff opens, Approve/Reject unresponsive)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

What's Wrong?

In the VS Code extension's graphical chat panel, when Claude proposes a file edit, one of two things happens inconsistently:

1. The change shows as an inline snippet in the chat panel instead of opening a diff tab, OR
2. A diff view does open in a new editor tab, but clicking Approve/Reject in it does not register — Claude Code never receives the response and the session doesn't proceed.

This is not the ide_backend_stall_detected issue (checked output panel via Ctrl+Shift+U — that string does not appear in my logs), and not a general webview "Not responding" hang — the panel remains responsive, it's specifically the diff approval action that fails to reach the backend.

Troubleshooting already tried (no effect)

• Reload Window (Developer: Reload Window)
• Full uninstall/reinstall of the extension
• Restarted the machine
• Ran /doctor — found and installed an available update, no change in behavior

Workaround confirmed

Switching to terminal mode (claudeCode.useTerminal setting) restores correct behavior: the diff opens in a tab and keyboard-based (y/n) approval in the integrated terminal works every time. This isolates the bug to the webview panel's approve/reject click handler specifically, not the diff/IDE MCP integration itself.

What Should Happen?

What Should Happen?

Clicking Approve/Reject in the graphical diff view should reliably notify Claude Code, the same as pressing y/n does in terminal mode.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Open the Claude Code graphical panel (not terminal mode) in VS Code
2. Ask Claude to make a file edit
3. When the diff view opens in a new tab, click Approve
4. Observe that Claude Code does not proceed / never receives the approval

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.218

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Claude Code Version

2.1.218 (Claude Code)

Operating System

Windows 11 Pro 25H2 (OS Build 26200.8893)

VS Code Version

1.130.0 (Electron 42.6.0, Chromium 148.0.7778.280, Node.js 24.18.0)

Terminal/Shell

VS Code integrated terminal (issue occurs in graphical panel mode; terminal mode is unaffected)

Is this a regression?

Unclear — first noticed the behavior recently, no specific version pinpointed

Related Issues

• #17333 (WebSocket/bidirectional communication hang)
• #33998 (diff tab no longer opens after VS Code update)
• #39807 (webview "Not responding" on Windows 11, ide_backend_stall_detected)

This report differs from the above: no stall-detected log entry, webview stays responsive, and only the diff approval action fails — narrowing this down to the approve/reject button's message-passing specifically.