[BUG] Session names update to later messages instead of staying anchored to the first message

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?

Session names in the Sessions panel appear to reflect a recent message in the conversation rather than the first message. This makes it hard to identify what a session was originally about, especially after follow-up messages are sent.

Expected behavior: The session name should be set from the first message (or a short summary of the overall work) and remain stable throughout the conversation.

Actual behavior: The session name appears to update mid-conversation to reflect a later message. For example, a session that started with a code change request is showing the name "Ok that is working. Next change is this needs to a..." — which is clearly a follow-up message, not the opening one.

Steps to reproduce:

Start a session with an initial request
Continue the conversation with follow-up messages
Observe that the session name in the Sessions panel reflects a later message rather than the first
Environment: Claude Code desktop app (Mac) (using both Claude Code and Copilot interfaces)

<img width="430" height="116" alt="Image" src="https://github.com/user-attachments/assets/630f61a7-cca1-4b80-9cc1-a43310f55153" />

What Should Happen?

Expected behavior: The session name should be set from the first message (or a short summary of the overall work) and remain stable throughout the conversation.

Error Messages/Logs

Steps to Reproduce

Start a session with an initial request
Continue the conversation with follow-up messages
Observe that the session name in the Sessions panel reflects a later message rather than the first
Environment: Claude Code desktop app (Mac) (using both Claude Code and Copilot interfaces)

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.159

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_