[BUG] Official Greptile Plugin won't Authenticate: Error: SDK auth failed: Incompatible auth server: does not support dynamic client registration

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?

When I run /mcp in Claude Code I get this:

<img width="1428" height="742" alt="Image" src="https://github.com/user-attachments/assets/2313cb38-e7dc-4f8f-b0fc-e033837312b7" />

When I select the greptile entry, and then select "Authenticate", I get this:

<img width="1428" height="903" alt="Image" src="https://github.com/user-attachments/assets/2d8f44b0-9d62-4a04-827c-44546c30feb0" />

Error:

Error: SDK auth failed: Incompatible auth server: does not support dynamic client registration

What Should Happen?

Claude should authenticate the Greptile MCP.

Error Messages/Logs

Error: SDK auth failed: Incompatible auth server: does not support dynamic client registration

Steps to Reproduce

1. Install Claude Code
2. Run claude
3. Type /mcp and press enter
4. Navigate down to greptile and press enter
5. Select "Authenticate" and observe error

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.97 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_