[BUG] HTTP MCP servers with DCR OAuth don't work in Claude Code

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?

HTTP MCP servers with DCR OAuth don't work in Claude Code

What Should Happen?

Window should open asking to authenticate - same as with Claude.ai.

Error Messages/Logs

Steps to Reproduce

1. Add and MCP server: {"type": "http", "url": "[Server URL]"}
2. Click "Authenticate"
3. Expected: Browser opens for OAuth flow (works in claude.ai)
4. Actual: Nothing happens, no browser opens, no logs, status stays "not authenticated"

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.20

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_