### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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? In a Cowork conversation on Claude Desktop for Windows, tools work normally in text mode (including a local MCP server — Obsidian — that reads/writes my v

[BUG] Cowork (Windows): tools/MCP connectors become unavailable as soon as voice mode is activated

Status Open

Maintainer reply None cached

Activity 4 comments · opened Sep 28, 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?

In a Cowork conversation on Claude Desktop for Windows, tools work normally in text mode (including a local MCP server — Obsidian — that reads/writes my vault). As soon as I switch the same conversation to voice mode, the tools become unavailable: Claude can no longer call the Obsidian MCP server (or other tools) and says it has no access to them. Switching back to text restores them.

This blocks the main use case of voice mode in Cowork: talking hands-free for long sessions while Claude works on local files/connectors (e.g. reviewing and cleaning up an Obsidian vault by voice).

What Should Happen?

Voice mode in Cowork should have access to the same tools and connectors (including local MCP servers, especifically Obsidian in my case) as text mode in the same conversation, so Claude can keep calling them while I talk.

Error Messages/Logs

No visible error message in the UI. Claude simply reports that the tools are not available once voice mode is on.

Steps to Reproduce

On Windows, open Claude Desktop and start a Cowork conversation.
Make sure a local MCP server is configured and connected (in my case: obsidian, shown as connected).
In text mode, ask Claude to use it (e.g. list or read a note in the vault) — it works.
In the same conversation, activate voice mode.
Ask Claude by voice to do the same thing.
Claude can no longer call the tool / says the tools are unavailable.
Switch back to text mode — the tools work again.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop 2.9939.2 (Windows x64, Electron 44.4.3) — Cowork, not the Claude Code CLI

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Surface: Claude Desktop → Cowork, voice mode (not dictation).
Local MCP server affected: obsidian (state: connected/announced in the desktop app).
Related reports: #77312 (same symptom in claude.ai voice mode: connector tools fail with "tool is not registered" only in voice, text works in the same chat — closed as invalid for this repo) and anthropics/claude-ai-mcp#146 (connectors not discovered in voice chat). I couldn't find an open report for Cowork on Windows, so filing this one.
The Help Center still says voice mode isn't available in Cowork, but it is available in my Cowork app, and that's where tools drop.

View original on GitHub ↗

3 Comments

stonianua · 17 days ago

Clear repro shape — same Cowork conversation, text mode can call the connected Obsidian MCP, voice mode immediately loses tools (Claude reports no access), text restores them. That points at a voice-session tool registry / connector attach path, not the Obsidian server itself dying.

A few peer checks that help pin voice-mode tool drop vs a Windows-only Cowork quirk:

Confirm the MCP stays "connected" in the UI while voice is active. After switching to voice (before asking Claude to use a tool), check Settings / Connectors / the Obsidian row. If the UI still shows connected/announced but Claude says tools are unavailable, this is a voice-session tool exposure bug (tools not registered into the voice turn), not an MCP process crash. If the connector flips to disconnected/error on voice enter, capture that state change instead.
Ask for a tool-name / "what tools do you have?" probe in voice. In the same voice turn, ask Claude to list available tools or specifically name obsidian tools. Note the exact reply ("none", "not registered", empty list, or a subset). That distinguishes "zero tools in voice" from "MCP tools omitted but built-ins remain."
Compare built-in vs MCP in voice. Still in voice: try a built-in that does not need Obsidian (e.g. a simple read of an already-attached project file, or whatever non-MCP tool Cowork exposes for you). If built-ins work and only MCP/connectors fail, the regression is connector injection into the voice session. If all tools fail, it is a broader voice tool-channel disable.
One log breadcrumb around the mode switch. On Desktop 2.9939.2, when you flip text → voice → text, check main.log (or the Desktop log folder) for MCP reconnect, tools/list, session connector refresh, or any "tool is not registered" style lines at the switch — even if the UI shows no error. Timestamps at enter-voice and leave-voice are enough; no need for a huge dump.
Cross-check related surfaces you already linked. #77312 / anthropics/claude-ai-mcp#146 describe the same "voice loses connectors, text fine" pattern on other surfaces. If you can note whether any non-Obsidian connector (or a second local MCP) also disappears in Cowork voice on this Windows build, that locks it as session-mode tool wiring rather than Obsidian-specific.

Interim workaround: stay in text for any turn that must call MCP; use voice only for planning/dictation, then switch back to text for tool calls — painful for the hands-free vault cleanup loop, but matches the text/voice split you already measured.

If anyone else on Cowork Windows (or macOS) sees MCP/connectors vanish only while voice is on, with the connector UI still green, that single confirmation would nail this as a voice-session tool registry gap.

lencho13 · 16 days ago

Thanks for the detailed checklist. Partial answers from the original session (Sept 27):

Points 2/3: In voice mode, built-in tools still worked (Claude's internal tool search ran and returned results), but every Obsidian MCP tool was reported as "not registered" and could not be found via tool search. So it looks like MCP/connector tools are omitted from the voice session while built-ins remain.
Switching back to text in the same conversation restored the MCP tools immediately; the Obsidian server was never restarted.
Additional observation: after returning to text, MCP write calls were intermittent for about 40 minutes (several timeouts with no response, then normal). Unclear if related.

I will check point 1 (connector status in the UI while in voice), point 4 (main.log around the mode switch) and point 5 (whether another connector also disappears) and report back.

diegorepurpose · 10 days ago

Also observed on Claude Desktop for Mac.

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