[BUG] Desktop sign-in magic link is consumed by the mobile app, so no verification code is ever shown

Environment

• Claude Desktop for Linux (beta), package version 1.34493.1
• Claude mobile app installed on the phone, signed in with the same account
• Sign-in method: email verification

What happens

1. Start Claude Desktop on the Linux machine and choose to sign in.
2. The desktop asks for the account email and states that a verification

message has been sent.

1. Open that message on the phone and follow the link.
2. The phone's browser hands the URL straight to the Claude mobile app

(Android App Links / iOS Universal Links).

1. The mobile app opens and shows the workspace. **No verification code is

displayed anywhere**, so there is nothing to enter on the desktop.

1. The desktop sign-in cannot be completed.

Expected

Following a desktop sign-in link should present the verification code (or
complete the desktop authorisation), regardless of which app handles the URL.
A link issued for a desktop session should not be redeemed as a mobile
session.

Confirmation of the cause

Removing the Claude mobile app from the phone makes the same link open in the
browser, which then displays the code as intended. The deep-link handler is
therefore what breaks the flow.

Opening the link "in the browser" from the mail app does not help — the
platform link handler still forwards it to the installed app.

Impact

Any user whose phone has the Claude app installed cannot complete a desktop
sign-in using that phone. A second device without the app is required.

This is aggravated on machines that do not retain sessions between reboots
(kiosk-style or otherwise stateless deployments), where sign-in is needed at
every start rather than once.

Possible directions

• Simplest fix: put the verification code in the email itself, next to (or

instead of) the magic link. The code is then readable wherever the message is
opened, and no link handler can intercept it. This also helps users who read
mail on a device that is not the one signing in.

• Exclude desktop sign-in URLs from the mobile app's link handling.
• If the mobile app does handle such a link, have it display the verification

code and state which device the request came from, instead of opening the
workspace.

---
Reported from a Linux workstation running the official Claude Desktop beta (1.34493.1).