Markdown links with vscode:// (and other custom URL schemes) don't open when clicked in Claude Code Desktop

Summary

When Claude outputs a markdown link whose href is a custom URL scheme — e.g. vscode://file/<abs-path> — clicking it in the Claude Code Desktop app (macOS) does not open the target in the registered OS handler. Relative-path hrefs open in the built-in file viewer, but vscode://, cursor://, idea://, x-github-client://, obsidian://, etc. appear to be inert.

Expected behavior

Clicking [label](vscode://file/Users/me/proj/src/foo.py) should hand the URL off to the OS (open <url> on macOS) so the registered handler — VS Code in this case — takes over and jumps to the file.

This matters for users who prefer to read code in their editor rather than the built-in viewer, and for :line deep links.

Actual behavior

Clicking the link does nothing. The vscode:// scheme is not dispatched to the OS.

Reproduction

1. In Claude Code Desktop (macOS), ask Claude for a file walkthrough.
2. Tell it: \"use vscode://file/<abs-path> as the href so I can click into VS Code.\"
3. Claude produces e.g.

\\\
[churn/config.py](vscode://file/Users/me/project/churn/config.py)
\\\

1. Click the link in the chat pane.
2. VS Code does not open. (Running \open 'vscode://file/Users/me/project/churn/config.py'\ from a standalone shell works, so the OS handler is registered.)

Suggested fix

When a rendered markdown link's href is not a relative path and not http(s)://, pass it through to the OS via open / xdg-open / start instead of silently ignoring or routing it through the internal file viewer. At minimum, support vscode://, cursor://, file://, idea://, and other schemes the user has registered at the OS level.

Alternatively, expose a setting like preferredEditor: \"vscode\" | \"cursor\" | \"builtin\" that rewrites relative-path file links to the corresponding deep link on render — so users don't have to prompt for absolute-path vscode:// URLs every time.

Environment

• Claude Code Desktop app (macOS)
• Claude Code version: 2.1.114
• macOS: 15.6
• VS Code: installed, vscode:// handler registered at OS level (verified via open vscode://file/... working from standalone shell)