[BUG]

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?

Way too early into each of my Claude Code sessions, I keep getting this error.

What Should Happen?

I shouldn't be getting this error. There's no reason for this error right now.

Error Messages/Logs

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.1.content.4: tool_use ids must be unique"},"request_id":"req_011CYseJGJ4Sv6ZZbDEVRTvK"}

Steps to Reproduce

Steps to reproduce: I just opened a Claude session and started coding and it would just appear randomly.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Latest. Version as of 3/9/26

Platform

Anthropic API

Operating System

Other

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_