[BUG] OSC 52 + MobaXterm issue

[cweng-IAA]

Preflight Checklist

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

What's Wrong?

Terminal: MobaXterm (latest version, WSL local tab — not SSH)
Claude Code: 2.1.146
Symptom: OSC 52 clipboard not supported — "sent N chars via OSC 52" message appears but nothing reaches Windows clipboard; highlight-to-copy and right-click paste both broken inside Claude Code session
Workaround: Shift+Insert works for 'paste'

Copy/Paste was still working last week.

What Should Happen?

highlight to copy and right click to paste should work in MobaXterm

Error Messages/Logs

Steps to Reproduce

In MobaXterm (WSL, Ubuntu 22)
Open Claude Code
Try highlighting text to copy → test paste somewhere >> not working
Try right-click to paste something in >> not working

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

2.1.146

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

MobaXterm (WSL, Ubuntu 22)

[btherl]

I am seeing the same behaviour, only with "/tui fullscreen" enabled in Claude Code.

Holding shift uses MobaXterm's copy behaviour, bypassing Claude Code, this appears to work normally.

This might be an issue with MobaXterm handling of OSC 52, rather than with Claude Code itself. Disabling "copy on select" at least prevents CC from trying to send the sequence, although shift is still required to use MobaXterm copy behaviour.

[chrisastley]

I have the same issue, which seems to have started yesterday. Very annoying.

[kainzhong]

Same on warp terminal. Have to hold shift and then select & copy

[btherl]

Another workaround is to launch Claude Code CLI like this:

CLAUDE_CODE_DISABLE_MOUSE=1 claude

This allows fullscreen TUI but doesn't give Claude the mouse, so all terminal mouse actions work as before. Of course you also can't click to expand, you have to use the old ctrl-O method (which is still available in fullscreen).

And another workaround is to press ctrl + O and then '[', which will put claude's history into your terminal's scrollback buffer, and also bypass Claude's mouse control, until you press esc or q to exit the mode. Bit of a hassle though, and may push data off-screen when it expands things out.

[Shlomo-Galle]

Adding "tui": "default" to ~/.claude/settings.json fixes the issue.

[cebejarano]

Still reproducing this on 2.1.233 (latest, confirmed via claude update), same MobaXterm + nested-WSL pattern, so the fix in this range didn't cover my case (or it's a separate root cause with the same symptom).

Environment: Oracle Linux 9 VM running inside WSL2, accessed via MobaXterm on Windows.

Copy-on-select emits the OSC 52 sequence (toast shows "N chars copied") but the content never reaches the real Windows clipboard — pasting elsewhere (e.g. Notepad) produces nothing.

Isolated the cause: manually running printf '\033]52;c;%s\a' "$(printf 'test' | base64 -w0)" directly in the raw shell (outside Claude Code) does successfully reach the Windows clipboard. So the OSC 52 transport chain (VM → WSL2 → MobaXterm → Windows clipboard) works fine — the problem is specific to how Claude Code's own copy-on-select feature emits the sequence.

Workaround in use: disabled copy-on-select via /config, relying on MobaXterm's native mouse-selection (X11-style) to copy, and Shift+Insert to paste.

[cebejarano]

Update: confirmed the fix works for my setup too — adding "tui": "default" to ~/.claude/settings.json (per Shlomo-Galle's comment above) resolved it. After a full restart of Claude Code, copy-on-select now correctly reaches the real Windows clipboard through MobaXterm + nested WSL2 + Oracle Linux 9 VM.

[cweng-IAA]

confirmed the fix works for my setup too! MobaXterm + WSL2 + Amazon Linux 2023.