[BUG] MCP server failures cause terminal rendering issues on SSH sessions

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 MCP (Model Context Protocol) servers are configured for a platform (e.g., macOS) but Claude Code is running
on a different platform (e.g., Linux over SSH), failures to load those servers cause severe terminal rendering
issues that make the tool unusable.

What Should Happen?

Expected Behavior:
MCP server failures should:

1. Be handled gracefully with clear error messages (not silent failures)
2. Not affect terminal rendering or responsiveness
3. Disable themselves after repeated failures
4. Not accumulate effects over long sessions

Suggested Fixes:

1. Validate MCP server paths on startup - Check if paths exist before attempting to load
2. Graceful MCP failure handling - Don't affect terminal rendering if MCP fails
3. Warning messages - Alert user if MCP servers fail to load (don't fail silently)
4. SSH detection - Detect SSH sessions and disable expensive features like thinking by default
5. Platform validation - Warn if settings appear to be for a different platform

Error Messages/Logs

Just a jumping Terminal making it very hard to work. Event windows itself bace slow.

Steps to Reproduce

Use a MCP with not working path

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.22 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Windows Terminal

Additional Information

The gh CLI isn't available on this system, but here's the complete bug report you should file at
https://github.com/anthropics/claude-code/issues

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🐛 Bug Report: MCP Server Failures Cause Terminal Rendering Issues on SSH Sessions

Title: MCP server failures cause terminal rendering issues on SSH sessions

Description:

When MCP (Model Context Protocol) servers are configured for a platform (e.g., macOS) but Claude Code is running
on a different platform (e.g., Linux over SSH), failures to load those servers cause severe terminal rendering
issues that make the tool unusable.

Environment:

• Platform: Linux (SSH from Windows Terminal)
• Session type: Remote SSH connection over long duration
• Issue onset: Appeared later in session (after ~1 hour of use)
• Affected settings: Misconfigured MCP servers pointing to macOS paths

Symptoms:

• Screen updates on every keystroke
• Terminal buffer becomes unusable
• Makes it impossible to continue working
• Appears to accumulate/worsen over long SSH sessions

Root Cause:
Claude Code was configured with:

• alwaysThinkingEnabled: true
• MCP servers configured for macOS paths that don't exist on Linux

When MCP servers failed (silently) to load on each interaction, combined with thinking blocks, this caused
terminal rendering issues.

Expected Behavior:
MCP server failures should:

1. Be handled gracefully with clear error messages (not silent failures)
2. Not affect terminal rendering or responsiveness
3. Disable themselves after repeated failures
4. Not accumulate effects over long sessions

Suggested Fixes:

1. Validate MCP server paths on startup - Check if paths exist before attempting to load
2. Graceful MCP failure handling - Don't affect terminal rendering if MCP fails
3. Warning messages - Alert user if MCP servers fail to load (don't fail silently)
4. SSH detection - Detect SSH sessions and disable expensive features like thinking by default
5. Platform validation - Warn if settings appear to be for a different platform

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You can file this at: https://github.com/anthropics/claude-code/issues