[BUG] Authentication token header is failing again for AWS Bedrock

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?

I am currently using Claude Code v2.1.119 via AWS Bedrock, and when I try to send a prompt, it enters into the retry loop. All I am doing is sending a simple "hello" prompt to it.

What Should Happen?

Get a response back.

Error Messages/Logs

403 {"Message":"Authentication failed: Please make sure your API Key is valid."}

Steps to Reproduce

Run Claude Code via AWS Bedrock, set up your environment variables, on a Ubuntu 24.04 machine, start it up with claude, and then feed it a hello prompt.

Claude Model

Other

Is this a regression?

Yes, this worked in a previous version

Last Working Version

v2.1.117

Claude Code Version

v2.1.119

Platform

AWS Bedrock

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

I remember this being a issue about a week or two back, where they mentioned that updating a aws sdk dependency bricked the Bedrock auth, which I am assuming one of the agents likely did again...