[BUG]
Status Open
Reported on v2.1.252
Maintainer reply None cached
Activity 0 comments · opened Aug 31, 2026
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 Code never sends the MCP server/discover negotiation probe — modern-only (2026-07-28) MCP servers are unreachable
What Should Happen?
Modern-only MCP servers should connect correctly. Verified as working on Linux, but not on macOS.
Error Messages/Logs
Steps to Reproduce
Claude Model
Opus
Is this a regression?
I don't know
Last Working Version
_No response_
Claude Code Version
2.1.252
Platform
Other
Operating System
macOS
Terminal/Shell
Other
Additional Information
macOS 15.7.9