[BUG] Windows desktop app rejects dotted slash commands (e.g. /smithy.fix) — parses "." as a separator

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?

In a Claude Code session hosted inside the Claude desktop app on Windows, slash commands whose names contain a dot (e.g. /smithy.fix, /smithy.strike) appear in the autocomplete picker but fail when submitted. The app returns:

"/smithy isn't a recognized command here. Some commands only work in the Claude Code terminal."

Note the error references "/smithy", not "/smithy.fix" — the client appears to be truncating the command name at the first "." and looking up only the prefix. The full command is correctly deployed at .claude/commands/smithy.fix.md and is listed in autocomplete.

The same command, same repo, same deployed file works in:

• Claude Code TUI (CLI)
• Claude iPad app (Code session)

It fails only in the Windows desktop app's Code session. It worked in the Windows desktop app yesterday, so this is a recent regression.

What Should Happen?

Submitting "/smithy.fix" should invoke the command backed by .claude/commands/smithy.fix.md, matching the behavior of the CLI and iPad app. Dots should be treated as part of the command name, not as a namespace/command separator.

Error Messages/Logs

/smithy isn't a recognized command here. Some commands only work in the Claude Code terminal.

Steps to Reproduce

1. Clone a repo that deploys a dotted slash command. Minimal repro:

git clone https://github.com/balexda/smithycli
This copies the public repo with .claude/commands/smithy.fix.md (and other /smithy.* commands). While these are custom commands they exhibit the works in some places not others behavior being reported perfectly.

1. Open the repo in a Claude Code session via the Claude desktop app on Windows.
2. In the prompt box, type "/smithy." — autocomplete lists "smithy.fix" and other /smithy.* commands. Select "smithy.fix" (or type it out).
3. Submit the prompt.
4. Observe the response: "/smithy isn't a recognized command here. Some commands only work in the Claude Code terminal."
5. For comparison, run the same command in Claude Code TUI (claude in a terminal) against the same repo — it executes correctly.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

I had last updated around 4/9 or 4/10. It used the old UI look and feel.

Claude Code Version

Claude for Windows | Claude 1.3109.0 (35cbf6) 2026-04-16T20:32:01.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Commands do appear in the auto-complete list, and auto-complete works, it just refuses to run the command.