[BUG] Invalid API key · Fix external API key

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?

While using Cowork desktop app on Mac - version Claude 1.5354.0 (9a9e3d) 2026-04-29T01:14:34.000Z, I keep encountering "Invalid API key · Fix external API key" which makes Cowork unusable :( Regular chat works fine however

I tried everything - reinstall / security keys etc - this seems like an issue with the desktop app. As a workaround, I installed desktop version from earlier in April to get Cowork working :P However, when the app restarts, it switches to the latest version which seems to have this bug

What Should Happen?

Cowork should work fine w/o errors

Error Messages/Logs

Invalid API key · Fix external API key

There is nothing more informative

Steps to Reproduce

1. Upgrade to the latest version of Claude desktop app
2. Try to use Cowork

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Version from earlier in April 2026

Claude Code Version

Claude 1.5354.0 (9a9e3d) 2026-04-29T01:14:34.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Extremely crippling - reported on discord too but with no response