[BUG] Error: Error during compaction: Error: Failed to generate conversation summary - response did not contain valid text content

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?

<img width="1147" height="464" alt="Image" src="https://github.com/user-attachments/assets/96fa1d23-dd0a-4aaf-9260-4186f14a599e" />

What Should Happen?

auto-compacting error

Error Messages/Logs

Error: Error during compaction: Error: Failed to generate conversation summary - response did not contain valid text content

Steps to Reproduce

1. /compact
2. raise error: 'Error: Error during compaction: Error: Failed to generate conversation summary - response did not contain valid text content'

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.69

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_