[BUG] Desktop Personal marketplace no longer accepts custom Git hosts even when domain allowlist permits them

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?

Claude Desktop Personal plugin marketplaces appear to reject custom/private Git hosts before network/domain allowlist settings can apply.

This looks like a regression. Previously, I was able to use a private/self-hosted Git marketplace host when it was reachable and allowed by Desktop settings. Now the Desktop UI rejects the host earlier in the flow as unsupported.

Because the host is blocked before sync starts, private/internal plugin marketplaces on custom Git infrastructure are no longer usable through the Personal marketplace flow.

What Should Happen?

If a custom/private Git host is explicitly allowed by Claude Desktop network/domain settings, Claude Desktop should allow the marketplace sync attempt to proceed.

At minimum, marketplace host validation should not reject an explicitly allowed host before the network policy has a chance to apply.

<img width="1246" height="894" alt="Image" src="https://github.com/user-attachments/assets/781c2448-1e06-4ee3-a8cf-e4e25a09a195" />

Error Messages/Logs

Claude Desktop reports that the marketplace host is unsupported and blocks the add flow before sync begins.

Steps to Reproduce

1. Open Claude Desktop.
2. Enable Allow network egress.
3. Add a custom/private Git host to the Desktop domain allowlist.
4. Open Customize > Plugins.
5. Try to add a plugin marketplace from a private/self-hosted Git repository URL.
6. Observe that the Desktop UI rejects the host before sync begins.

Claude Model

Other

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.2581.0 (f10398) 2026-04-14T17:16:40.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_