[BUG] Bug: model emits the next user turn and system/hook markers inside its own assistant message
Status Open
Maintainer reply None cached
Activity 0 comments · opened Sep 18, 2026
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?
What Should Happen?
Error Messages/Logs
Steps to Reproduce
Claude Model
Opus
Is this a regression?
Yes, this worked in a previous version
Last Working Version
_No response_
Claude Code Version
21.6.0
Platform
Anthropic API
Operating System
macOS
Terminal/Shell
Terminal.app (macOS)
Additional Information
_No response_