[BUG] Custom statusline OSC 8 hyperlinks don't render inside tmux

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?

Custom statusline programs that output OSC 8 hyperlinks work correctly outside tmux, but hyperlinks are not clickable when running Claude Code inside tmux.

Verified working:

• printf '\033]8;;https://anthropic.com\033\\Click\033]8;;\033\\\n' renders clickable link in the same tmux session
• Custom statusline hyperlinks work when running Claude Code outside tmux
• Statusline binary outputs correct OSC 8 escape sequences (verified with xxd)

Not working:

• Same statusline hyperlinks are not clickable when Claude Code runs inside tmux

Environment:

• tmux 3.5a with allow-passthrough on
• terminal-features configured with hyperlinks for screen-256color
• Ghostty terminal

Conclusion:
Something in Claude Code's rendering layer inside tmux breaks OSC 8 hyperlink passthrough, even though the sequences are output correctly and the terminal handles
them fine from other sources.

What Should Happen?

Hyperlinks in custom statusline output should be clickable inside tmux, just as they are when running Claude Code outside tmux. OSC 8 escape sequences from
statusline programs should pass through Claude Code's rendering layer unchanged.

Error Messages/Logs

Steps to Reproduce

1. Configure a custom statusline that outputs OSC 8 hyperlinks (e.g., \033]8;;https://example.com\033\\link text\033]8;;\033\\)
2. Start tmux with allow-passthrough on and hyperlinks enabled in terminal-features
3. Run Claude Code inside tmux
4. Observe that statusline hyperlinks are not clickable

Control test:

1. Run printf '\033]8;;https://anthropic.com\033\\Click\033]8;;\033\\\n' in the same tmux pane - this renders as a clickable link
2. Run Claude Code outside tmux - statusline hyperlinks work correctly

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.32

Platform

AWS Bedrock

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_