Dimsum

Dimsum is a minimalist macOS menu bar utility designed to eliminate the cognitive load of tracking active focus in cluttered workspaces. By automatically dimming background windows, it provides an immediate visual feedback loop that confirms exatly where your keystrokes are going. Keep your attention on what matters.

Requirements

• macOS 13 (Ventura) or later

Install

Download the latest release straight to /Applications from the terminal. Fetching via curl avoids the com.apple.quarantine xattr that browsers attach, so Gatekeeper won't block the app (which isn't notarized) on launch:

curl -L https://github.com/nshi/dimsum/releases/latest/download/Dimsum.zip -o /tmp/Dimsum.zip && unzip -o /tmp/Dimsum.zip -d /Applications && rm /tmp/Dimsum.zip && open /Applications/Dimsum.app

On first launch:

1. A menu bar icon (a small dim sum steamer basket) appears. There is no Dock icon.
2. macOS prompts for Accessibility permission — grant it in System Settings > Privacy & Security > Accessibility.
3. Dimming starts on its own once permission is granted. If macOS later stops trusting the app, the permission prompt comes back, and dimming resumes after you grant it again.

Usage

Click the menu bar icon to open the popover:

• Enable Dimming — master on/off toggle. When off, all overlays are removed.
• Dimming Intensity — slider from 0 (no dim) to 1 (fully black). Changes apply in real time.
• Start on Login — registers the app as a login item so it launches automatically. Requires the app to be in /Applications.

The app dims all unfocused windows across all displays. Switching focus (click, Cmd+Tab) animates overlays smoothly. Full-screen apps and Space transitions are handled automatically.

Development

Requirements

• Xcode 15+ with Swift 5.9+
• XcodeGen (for project generation)

Build

# Generate the Xcode project
xcodegen generate

# Build from command line
xcodebuild -scheme Dimsum -configuration Debug build

# Or open in Xcode
open Dimsum.xcodeproj

Signing

Builds are ad-hoc signed by default. macOS ties an ad-hoc app's Accessibility grant to the exact binary, so every rebuild silently loses it even though the toggle in System Settings stays on. To keep the grant across rebuilds, sign with a self-signed certificate:

scripts/create-signing-cert.sh
xcodegen generate

Debug builds use their own bundle ID (com.dimsum.app.debug) and show up as "Dimsum Debug" in System Settings, so they don't take over the installed app's grant.

The release workflow signs with the same certificate, read from the MACOS_SIGNING_P12_BASE64 and MACOS_SIGNING_P12_PASSWORD repo secrets. The script writes both files to build/signing/.

Tests

xcodebuild test -scheme Dimsum -destination 'platform=macOS'

Release Build

# Generate project (if not already done)
xcodegen generate

# Archive
xcodebuild archive \
  -scheme Dimsum \
  -configuration Release \
  -archivePath build/Dimsum.xcarchive

# Export the .app from the archive
xcodebuild -exportArchive \
  -archivePath build/Dimsum.xcarchive \
  -exportOptionsPlist ExportOptions.plist \
  -exportPath build/release

# The built app is at build/release/Dimsum.app

To install, drag build/release/Dimsum.app into /Applications.

Note: The app is not notarized. If you copied the .app from a browser download or another machine, macOS Gatekeeper may block it on first launch — either right-click the app and choose "Open" to bypass, or strip the quarantine attribute with xattr -dr com.apple.quarantine /Applications/Dimsum.app.