Unclear It is not clear whether this check is switched on for everyone or depends on a setting.
A session is one saved conversation with Claude Code. If you resume one that was started under a different account, Claude Code now stops and shows a dialog titled "This session belongs to another account." It lists the account the session was "Started as" and the one you are "Logged in as," and offers:
- "Exit Claude Code", which runs
/exit - "Change login", which runs
/login - "Copy to (your account) and continue", which asks you to confirm with "Continue" or "Go Back"
The confirmation warns that continuing in the new account shares the conversation's history with that account, including files Claude read. When you branch (fork) a conversation into a new session, the new session now also records which account owns it.
Resuming under a different login used to carry on without saying anything. Now you choose before any history moves between accounts.
It is not clear whether this check is switched on for everyone or depends on a setting.