[BUG]Xcode 26.3 Claude Agent -Xcode 26.5 downloads darwin-arm64 binary on Intel Macs (workaround inside)"

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?

[BUG] Xcode 26.3 Claude Agent - API Error 401 Invalid Bearer Token on Intel Mac (x86_64)

Environment

• Mac: Intel Core i9 (x86_64)
• macOS: 26.3 (25D125)
• Xcode: 26.3 (17C529)
• Claude Code: 2.1.69
• Subscription: Claude Pro (claude.ai OAuth)

Problem
Claude Agent in Xcode 26.3 returns a 401 Invalid Bearer Token error on every prompt, despite Claude Code working correctly in Terminal with the same credentials.

Steps to Reproduce

1. Install Xcode 26.3
2. Go to Settings → Intelligence → Claude Agent → Sign In with Claude.ai account
3. Open a project and send any prompt to Claude Agent
4. Immediately receives: API Error: 401 {"type":"error","error":{"type":"authentication_error","message":"Invalid bearer token"}}

Additional Context

• Xcode downloads the ARM64 binary on Intel Macs — manually replaced with x86_64 binary (darwin-x64 from release manifest)
• Both the terminal binary and Xcode binary report correct auth status via claude auth status
• Valid token confirmed in Keychain under "Claude Code-credentials"
• Token is not expired
• Basic Claude Sonnet 4.5 assistant in Xcode works fine — only Claude Agent affected
• This appears to be a widespread issue also affecting Apple Silicon users (Apple Developer Forums thread/816369)
• The 401 persists after signing out and back in, clearing keychain entries, and re-authenticating

Workaround
Using an Anthropic API key instead of OAuth sign-in works, but requires separate billing on top of existing Pro subscription.

Expected Behaviour
Claude Agent should authenticate using the same OAuth credentials that work in Terminal.

What Should Happen?

Expected Behaviour
Claude Agent should authenticate using the same OAuth credentials that work in Terminal.

Error Messages/Logs

Claude Agent in Xcode 26.3 returns a 401 Invalid Bearer Token error on every prompt, despite Claude Code working correctly in Terminal with the same credentials.

Steps to Reproduce

1. Install Xcode 26.3
2. Go to Settings → Intelligence → Claude Agent → Sign In with Claude.ai account
3. Open a project and send any prompt to Claude Agent
4. Immediately receives: API Error: 401 {"type":"error","error":{"type":"authentication_error","message":"Invalid bearer token"}}

Additional Context

• Xcode downloads the ARM64 binary on Intel Macs — manually replaced with x86_64 binary (darwin-x64 from release manifest)
• Both the terminal binary and Xcode binary report correct auth status via claude auth status
• Valid token confirmed in Keychain under "Claude Code-credentials"
• Token is not expired
• Basic Claude Sonnet 4.5 assistant in Xcode works fine — only Claude Agent affected
• This appears to be a widespread issue also affecting Apple Silicon users (Apple Developer Forums thread/816369)
• The 401 persists after signing out and back in, clearing keychain entries, and re-authenticating

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.69

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_