[BUG] Chrome extension steals focus and hijacks keyboard input during concurrent Cowork tasks (post-March 24 computer use update)

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?

Environment:

• macOS
• Claude Desktop (latest, post-March 24 2026 update)
• Claude in Chrome extension (latest)
• Cowork mode with computer use disabled

---

Since approximately March 24-25, 2026 (coinciding with the computer use update for Cowork), the Chrome extension aggressively steals cursor focus and keyboard input during Cowork browser tasks, even with computer use turned off.

The core problem: When Cowork uses the Claude in Chrome extension (priority 2 in the tool chain, via tabs_create_mcp / navigate), every browser action forces Chrome to the foreground and captures keyboard focus. This redirects whatever you are actively typing into whichever window Chrome has grabbed, typically an SSH session or other active application.

What makes this untenable:

1. Single task + user conflict: Even one Cowork task using the Chrome extension will repeatedly yank focus away from the user's active work. There is a visible "app use glow spike" on Chrome immediately before focus is stolen.
2. Multiple task conflict: When two or more Cowork tasks are running concurrently and both need browser access, they fight each other and the user for the single shared cursor/keyboard. Keystrokes intended for the user's own work land in the wrong window.
3. This defeats Cowork's core value proposition. The entire point of Cowork is to run tasks in the background while you continue working. Focus stealing makes this impossible for any task involving browser automation.

This is new behaviour

This was not happening prior to the March 24 update. The Chrome extension previously handled browser tasks without aggressively foregrounding Chrome on every navigation or tab creation event.

What Should Happen?

Cowork browser tasks via the Chrome extension should operate in the background without stealing focus. Chrome's native API already supports this: chrome.tabs.create({ active: false }) and chrome.tabs.update({ active: false }) allow tab creation and navigation without foregrounding the browser window.

Suggested Fix: Add an active parameter (default false when called from Cowork) to tabs_create_mcp and navigate MCP tools, as previously requested in #31119. This is a one-line change on the extension side and would resolve the focus-stealing entirely for Cowork background tasks.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Desktop, switch to Cowork mode (computer use OFF)
2. Start a Cowork task that requires browser research or web interaction via the Chrome extension
3. Switch to another application (terminal, IDE, text editor) and begin typing
4. Observe: Chrome is foregrounded and keyboard input is redirected to Chrome

Worse case:

1. Start a second Cowork task that also requires browser interaction
2. Observe: both tasks now compete for Chrome focus, and the user's own typing is continuously intercepted

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Pre-March 24, 2026 update

Claude Code Version

Latest (Claude Desktop with Cowork mode)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Related Issues

• #31119 - Claude-in-Chrome: background tab creation + tab cleanup (describes the same underlying API gap, filed pre-computer-use launch)
• #28722 - AskUserQuestion steals focus and triggers unintended selection (same focus-stealing pattern in Claude Code VSCode)
• #32726 - VSCode extension: add option to prevent panel from stealing focus
• #31771 - Cowork browser tools connect to Chrome Canary even without extension installed (related: browser MCP tool targeting issues)

Impact

High. This renders concurrent Cowork tasks unusable for anyone who needs to continue working on their machine while Cowork runs. It is particularly disruptive for users working in terminals/SSH sessions, as stolen keystrokes can execute unintended commands.