[BUG]

Environment

• Platform (select one):
• [●] Anthropic API
• Claude CLI version: <!-- 1.0.83 (Claude Code) -->
• Operating System: <!-- macOS 15.5 -->
• Terminal: <!-- zsh -->

Bug Description

<!-- API Error: 401 -->

Steps to Reproduce

1. <!-- First step -->

Expected Behavior

<!-- login succeed -->

Actual Behavior

<!-- API Error: 401
{"type":"error","error":{"type":"authentication_error","message":"OAuth
authentication is currently not supported."}} -->

Additional Context

<!--
I encountered a persistent API error when trying to use the Claude plugin in VSCode on my MacBook Air. As a Pro user, when logging in, I selected "Claude account with subscription (starting at $20/mo for...)" instead of "Anthropic Console account (API usage billing)." After successfully logging in, I immediately received the following unexpected API error when attempting to use it:
API Error: 401
{"type":"error","error":{"type":"authentication_error","message":"OAuth authentication is currently not supported."}}
I've tried troubleshooting this with AI assistance multiple times, but without success.
Later, I returned to my Mac mini, where Claude had been working perfectly fine for several days. I was able to interact with Claude normally. However, after I performed a logout from Claude in VSCode on my Mac mini and then attempted to log back in, I experienced the exact same API error as on my MacBook Air.
Given this reproducible behavior across two different machines and specifically after a logout/login action, I strongly believe this is not a local issue on my end, but rather a problem with your system.
-->