computer-use MCP: browsers reported "(not installed)" on macOS when Spotlight is disabled, despite LaunchServices having them registered

Summary

On macOS 26.4 with Claude Code 2.1.154, the computer-use MCP's request_access permission dialog reports all browsers as "(not installed)" and offers to allow "0 apps" for the session — even though the browsers are physically installed, have valid Info.plist bundle identifiers, and are fully registered in LaunchServices.

The dialog is functionally unusable for any browser-targeted task because no app can ever be granted.

Environment

• macOS: 26.4 (Darwin 25.4.0, arm64 Mac16,8)
• Claude Code: 2.1.154
• Spotlight: intentionally disabled by the user for performance reasons (mdutil -s / → Indexing disabled.)

Evidence that browsers ARE installed and registered

All four browsers exist with valid Info.plist:

Safari               bundle=com.apple.Safari        version=26.4
Google Chrome        bundle=com.google.Chrome       version=148.0.7778.216
Firefox              bundle=org.mozilla.firefox     version=151.0.2
Microsoft Edge       bundle=com.microsoft.edgemac   version=148.0.3967.96

lsregister -dump shows full LaunchServices records for each, including teamID, version, executables, claimed UTIs and schemes. Excerpts:

identifier:  com.google.Chrome           teamID: EQHXZ8M8AV
identifier:  org.mozilla.firefox         teamID: 43AQ936H96       version: 15126.5.25
identifier:  com.microsoft.edgemac       teamID: UBF8T346G9       version: 148.0.3967

Safari resolves correctly via path to application id "com.apple.Safari" → /System/Volumes/Preboot/Cryptexes/App/System/Applications/Safari.app/.

What the dialog shows

Computer Use wants to control these apps

View the Tailscale admin console you have open so I can point you to the
exact Aperture delete control instead of guessing.

  o com.apple.Safari (not installed)
  o com.brave.Browser (not installed)
  o com.google.Chrome (not installed)

> 1. Allow for this session (0 apps)
  2. Deny, and tell Claude what to do differently

(A second variant of the dialog used app names instead of bundle IDs — same "(not installed)" result.)

Reproduction

1. Disable Spotlight: sudo mdutil -i off / (and /System/Volumes/Data)
2. Install Chrome / Firefox / Edge into /Applications (LaunchServices registers them automatically on first launch)
3. Verify with lsregister -dump | grep -E "com.google.Chrome|org.mozilla.firefox|com.microsoft.edgemac" — entries are present
4. Have a Claude Code session call mcp__computer-use__request_access with browsers in the app list
5. Observe: every browser labeled (not installed), "Allow for this session (0 apps)"

Suspected cause

The detection mechanism in request_access likely uses Spotlight (mdfind / kMDItemCFBundleIdentifier) rather than LaunchServices APIs (NSWorkspace.urlForApplication(toOpen:) or LSCopyApplicationURLsForBundleIdentifier). With Spotlight disabled, the Spotlight query returns nothing — but LaunchServices is still authoritative for installed apps and should be the source of truth.

Suggested fix

Detect installed apps via LSCopyApplicationURLsForBundleIdentifier(bundleID, kLSRolesAll, NULL) or NSWorkspace.shared.urlForApplication(withBundleIdentifier:). Both work independent of Spotlight indexing state.

Workaround on the user side

Until fixed, users with Spotlight off can use the playwright MCP for browser automation (works across Chromium / Firefox / WebKit and does its own browser launching) or install claude-in-chrome for Chrome / Edge.

Related issues searched (not duplicates)

• #50735 — computer-use TCC permission grant ignored (different symptom, comprehensive TCC granted, here apps just aren't detected)
• #50719 / #42153 — Dock layer-20 hit-test blocks clicks (different — about input, not detection)
• #38783 — Windows-only Cowork registration

None match this macOS-specific detection-vs-LaunchServices discrepancy.