[BUG] API Error: Unexpected value(s) `interleaved-thinking-2025-05-14` for the `anthropic-beta` header. when using via Vertex AI

Status Fixed / completed

Maintainer reply ✓ Yes — bcherny

Activity 7 comments · opened May 22, 2025 · closed May 23, 2025

💡 Likely answer: A maintainer (bcherny, collaborator) responded on this thread — see the highlighted reply below.

Environment

Platform (select one):
[ ] Anthropic API
[ ] AWS Bedrock
[x] Google Vertex AI
[ ] Other:
Claude CLI version: 1.0.0 (Claude Code)
Operating System: Debian
Terminal: VS Code Terminal

Bug Description

I cannot use Claude Code today because all requests fail 🥲

Steps to Reproduce

Configure Claude Code to use Vertex AI
Say something to Claude Code, e.g. hello world

Expected Behavior

It should greet me back.

Actual Behavior

> hello world
  ⎿ API Error: 400 
    {"type":"error","error":{"type":"invalid_request_error","message":"Unexpected value(s) 
    `interleaved-thinking-2025-05-14` for the `anthropic-beta` header. Please consult our 
    documentation at docs.anthropic.com or try again without the header."}}

Additional Context

Screenshot:
<img width="757" alt="Image" src="https://github.com/user-attachments/assets/8a83a591-5643-4601-ab7a-05e11c0c25f4" />

View original on GitHub ↗

7 Comments

bcherny collaborator · 1 year ago

Hey, can you try again now and report back if you're still hitting this?

bcherny collaborator · 1 year ago

We've just validated that interleaved-thinking-2025-05-14 works for both Opus 4 and Sonnet 4 for all the regions we have them deployed in. Please re-open if this is still happening.

pokutuna · 1 year ago

I'm experiencing the same issue when using Claude Code with Vertex AI.
This issue is that claude-code send the beta header regardless of the model version.

Even when specifying an older model version that should be available:

ANTHROPIC_MODEL=claude-3-7-sonnet@20250219 claude

The interleaved-thinking-2025-05-14 header is still being sent automatically by claude-code, causing the request to fail with:

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"Unexpected value(s) `interleaved-thinking-2025-05-14` for the `anthropic-beta` header. Please consult our documentation at docs.anthropic.com or try again without the header."}}

dicksontsai collaborator · 1 year ago

Thank you for the report. We made the following changes to mitigate the Claude Code issues on Vertex.

In v1.0.2, we have adjusted Vertex requests to only send the header for Claude Opus 4 and Claude Sonnet 4.
In v1.0.1, we introduced the environment variable DISABLE_INTERLEAVED_THINKING to give you the option of disabling the header.

pokutuna · 1 year ago

Thank you!
I confirmed that in v1.0.2, the corresponding error no longer occurs even when specifying 3.7.

dtinth · 1 year ago

Thanks @dicksontsai and the team for the quick fix\! 🎉

I can confirm that v1.0.2 has resolved the issue - Claude Code now works perfectly with Vertex AI without the 400 error.

🤖 Generated with Claude Code

github-actions[bot] · 1 year ago

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.