[BUG] MCP servers configured via CLI don't load in VSCode extension

[shubhi-agarwal]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

Bug:

Environment:

• VSCode Extension: 2.1.38
• macOS: Darwin 25.2.0
• MCP servers: figma, atlassian (both HTTP)

Configuration:

• Servers in ~/.claude.json (user scope): ✓
• Servers in .mcp.json (project scope): ✓
• enabledMcpjsonServers set: ✓
• CLI works: ✓ (claude mcp list shows connected)
• VSCode extension: ✗ (/mcp shows nothing, tools not available)

What Should Happen?

mcp connections should reflect in the vs code extension

Error Messages/Logs

Steps to Reproduce

Steps tried:

• Reloaded VSCode window
• Fully quit and restarted VSCode
• Reset project choices
• Added to user scope
• No errors in extension logs

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

2.1.38

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Claude Code For VS Code does not use mcp servers at all #19054
2. [BUG] MCP tools not available in VS Code extension due to tool search experiment (tengu_tst_kx7) #23490
3. [BUG] Windows: Duplicate project entries created with different drive letter capitalization (d:/ vs D:/), causing MCP servers to not load #18122

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
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🤖 Generated with Claude Code

[samjfleming]

Update: Found a race condition/initialization issue

Reproduction:

1. VSCode extension starts with MCP servers configured in ~/.claude/settings.json
2. /mcp command shows no servers (servers not loaded)
3. Running claude mcp list in the CLI triggers initialization
4. MCP servers suddenly become available in VSCode extension

Evidence:

• CLI claude mcp list shows 8 connected servers
• After running CLI commands to check MCP status, ListMcpResourcesTool in VSCode extension successfully returns 100+ resources from Honeycomb and Snowflake
• No configuration changes were made - simply checking the MCP status triggered the load

Root cause hypothesis:
The VSCode extension appears to have a lazy initialization or race condition where MCP servers don't connect on startup, but DO connect when triggered by:

• Running claude mcp list in CLI
• Possibly checking/reading the settings.json file
• Some other initialization trigger

Expected behavior:
MCP servers should connect automatically when VSCode extension starts, without requiring manual triggers.

Environment:

• VSCode Extension: 2.1.38
• macOS: Darwin 25.2.0
• MCP servers: github, glean, honeycomb, snowflake-logs, datadog, buildkite, sentry, snowflake, select-star
• All configured in ~/.claude/settings.json under mcpServers key

[cylentra-bert]

Confirming this on Windows as well.

Environment:

• OS: Windows 11 Pro 10.0.26100
• VSCode: 1.109.4
• Claude Code Extension: 2.1.44
• Claude Code CLI: 2.1.44
• MCP servers: 9 configured in ~/.claude.json (subcog, ms365, atlassian, microsoft-learn, sequential-thinking, fetch, time, tempo, memory)

Reproduction:

1. Open VSCode with Claude Code extension
2. Run /mcp — shows no servers
3. Run claude /mcp in PowerShell CLI from the same working directory — shows all 9 user MCP servers + cloud connectors + built-in plugins (20 total)
4. Despite /mcp showing nothing in VSCode, the MCP tools are functional — I can successfully call tools from all configured servers (verified via subcog_status, ToolSearch, etc.)

Key difference from original report: The servers appear to actually be connected and working in VSCode (tools respond correctly), but /mcp simply doesn't display them. This suggests it may be purely a display/reporting bug in the /mcp command rather than a connection issue.

[Lionad-Morotar]

same on Mac. Working great on terminal but failed in Panel UI

[TristanSpeakEasy]

I'm noticing similar but different behaviour, basically if the mcp is in ~/.claude.json at the per project level the vs code extension won't load it, but if its in a local .mcp.json it does where as the CLI is fine with either