[BUG] COWORK || Local / desktop MCP tools not exposed to claude cowork, all the tools work properly in claude chat

[asaddcorp123]

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?

The tools added as local dev or via mcpb files do not work in claude desktop cowork, but work properly in claude chat. the tools added as http via custom connectors work in cowork.

What Should Happen?

All the tools regardless of how it is added to claude desktop, must work on claude cowork. everything that works on claude desktop chat, should work on claude cowork aswell.

Error Messages/Logs

Steps to Reproduce

ask claude in cowork mode to list mcp tools present and you will see the list populated only for HTTP MCPs added via custom connector. all other types of MCPS do not get listed to cowork mode, the same queries in chat mode work as expected.

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

Claude 1.1.673 (5a47b0) 2026-01-22T18:12:14.000Z

Platform

Other

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Notion MCP blocked by proxy in Cowork sessions - mcp.notion.com not on allowlist #18671
2. [BUG] find tool returns "Anthropic client not available" error With Claude Cowork #17896
3. [BUG] Cowork mode: MCP connectors (Asana, Google Calendar) return 403 errors despite working in Claude Chat #18194

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

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[asaddcorp123]

This issue us much more detailed, and is for local dev mcps, extensions and it clarifies what works what doesn't, and what's the difference between what works and what doesn't very clearly

[poorbengunn]

I have identical issues, and it makes Cowork effectively pointless.

[dial481]

I have the same issue as recently as today with Claude 1.1.1093 (5a5517) 2026-01-27T17:57:04.000Z

#17896 was supposed to resolve this but did not.

[graceclarify]

My node-based local MCP servers are available, but the python-based ones are not. I'm Claude 1.1.1200 (46e533) 2026-01-28T03:42:34.000Z

[dial481]

I'm on Claude 1.1.1200 (46e533) 2026-01-28T03:42:34.000Z now. No local MCPs work for me in Cowork. They all work in Chat.

The agent says:

The toggle shows it's enabled, but the tools aren't actually available to me. This usually means one of:

MCP server isn't actually running/connected - the toggle is on but the connection failed
Session needs restart - MCPs enabled mid-session sometimes don't load until you start a new conversation
Configuration issue - the MCP might not be properly configured (SSH keys, host, etc.)

EDIT: I saw there was another update pending after 1.1.1200 but the problem remains on Claude 1.1.1520 (48ced7) 2026-01-30T03:29:40.000Z

[aserechenko]

Claude 1.1.1520 (48ced7) 2026-01-30T03:29:40.000Z

Confirm all local MCPs are gone in Cowork/Code. Available in the Chat.