Haze

Live wallpapers, a matching screensaver, and animated Metal gradients for macOS.
Native, light on your Mac, free and open source.

     

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Haze turns videos, GIFs, images, and animated Metal gradients into your live desktop wallpaper and your idle screensaver — driven by one shared rendering core, with aggressive power management so it stays out of the way and off your fans.

The hero feature is the gradient engine: silky 2D gradients and Fluid 3D gradients (inspired by shadergradient.co) you can tune live — palette, speed, blur, grain — or pick from the 27 bundled presets.

Note

What “while sleeping” really means. When a Mac is truly asleep the display is off — there’s nothing to draw. Haze covers the two surfaces that actually exist: the live wallpaper (and the lock screen, which macOS derives from it) and the screensaver shown while the Mac is idle.

Features

Live wallpapers Looping video (H.264 and HEVC, hardware‑decoded), animated GIFs, stills and gradients, on the desktop behind your windows.	Gradient engine Animated Classic (2D) and Fluid (3D) Metal gradients. Change the palette, speed, blur and grain live, or start from a preset.	A matching screensaver A real .saver plugin on the same renderers. Leave it on “Match wallpaper” and it follows your live wallpaper.
Light by design Pauses when the desktop is fully covered, the display sleeps, the screen locks, or (optionally) on battery and Low Power Mode. Resolution and frame rate are capped: ~0% CPU when covered.	Menu‑bar picker No Dock icon. What’s playing pinned at the top, recent wallpapers one click away, the rest in a searchable, filterable grid, with pause and a speed slider.	Matches macOS Optionally sets a still of your wallpaper as the system desktop picture, so Mission Control, the lock screen and login match the live one.

And around it:

• Native Liquid Glass UI — real Liquid Glass on macOS 26, graceful .ultraThinMaterial fallback on 15.
• Launch at login — optional, one toggle.
• Hide the menu‑bar icon — optional. Open Haze again from Applications or Spotlight to get the window back.
• In‑app auto‑updates — checks daily (or on demand), shows the changelog, and installs in place (Sparkle, signed appcast).
• Signed and notarized — Developer ID, hardened runtime, Apple‑notarized with the ticket stapled, so it opens on a double‑click.

Presets

Every preset that ships in the app, 19 Fluid 3D and 8 Classic 2D, in its real colours: the swatches are drawn from Sources/HazeKit/Gradient/*Presets.swift by assets/make_svgs.py, so they follow the code. In the app each one is a live Metal gradient you can tune.

Download

Grab the latest Haze.dmg from Releases, drag it to Applications, and launch. From v0.1.4 the app is signed with a Developer ID and notarized by Apple, with the ticket stapled — it opens on a double‑click, with no Gatekeeper warning and no xattr incantation, and it keeps itself up to date from there.

Important

Already running v0.1.3 or earlier? Update by hand, once. Those builds were ad‑hoc signed, and an ad‑hoc copy can never auto‑update — so they will sit on their version forever, silently, without ever telling you an update exists. Download the DMG above and replace the app; every update after that is automatic.

Why: Sparkle refuses an update whose code signature doesn't match the installed app's, and an ad‑hoc binary's designated requirement is its own cdhash, which changes with every build — so the check can never pass, whatever the update is signed with. Verified on‑device across three runs: ad‑hoc → Developer ID fails, ad‑hoc → ad‑hoc fails (which rules out the certificate change as the cause), and Developer ID → Developer ID installs and relaunches cleanly. Sparkle logs Code signature of the new version doesn't match the old version and stops.

A build you compile yourself is ad‑hoc signed unless you pass a Developer ID (see Signed local installs), so it will trip Gatekeeper on first open: System Settings → Privacy & Security → Open Anyway, or xattr -cr /Applications/Haze.app.

Requirements

• macOS 15.0+ (built and tested on macOS 26–27, Apple Silicon)
• Xcode 26 with the Metal Toolchain component
• XcodeGen — brew install xcodegen

# one‑time, if the Metal toolchain isn't installed:
xcodebuild -downloadComponent MetalToolchain

Build & run

make run          # generate the project, build, and launch
# or step by step:
make generate     # xcodegen → Haze.xcodeproj
make build        # debug build
make test         # run the HazeKit unit tests (101)
make release      # optimized build

Haze launches as a menu‑bar item. Click the glyph for the wallpaper picker, or open the full window from there to import media and edit gradients.

Signed local installs

Builds are ad‑hoc signed by default, which needs no certificate — but the identity changes on every build, so macOS re‑asks for any permission it had granted. With an Apple Developer ID certificate in your keychain:

make install      # Developer ID-signed Release build → /Applications, relaunched
make notarize     # submit to Apple and staple the ticket
make verify-signature

make notarize needs a one-time notarytool keychain profile (it is never stored in the repo). Create an App Store Connect API key under Users and Access → Integrations → Team Keys, download the .p8 (once only — it cannot be re-downloaded), then:

xcrun notarytool store-credentials haze --key AuthKey_XXXX.p8 --key-id KEYID --issuer ISSUER-UUID

The identity is prefix-matched, so nothing personal lives in the repo; override it with make install SIGN_ID="Apple Development".

Cutting a release

make release-publish TAG=v0.1.4

Builds a signed Release, notarizes and staples it, packages the DMG and the Sparkle archive, generates the signed appcast, then tags and publishes the GitHub release — asking for confirmation before anything becomes public. Every precondition (clean tree, unused tag, certificate, notary profile, Sparkle key) is checked up front, so a failure never leaves a half-published release.

The one-time setup is the notary profile above. Nothing else: the certificate is already in your keychain.

Releasing from CI instead

.github/workflows/release.yml does the same on a tag push, but a runner has no keychain — which is the only reason it needs the certificate exported as a .p12, base64-encoded, and split across repo secrets (MACOS_CERTIFICATE, MACOS_CERTIFICATE_PWD, MACOS_SIGN_IDENTITY, APPLE_TEAM_ID, NOTARY_KEY, NOTARY_KEY_ID, NOTARY_ISSUER_ID, plus SPARKLE_ED_PRIVATE_KEY). Without all of them it falls back to an ad-hoc build — which cannot auto-update, so prefer the local path unless you need releases without your Mac.

Installing the screensaver

In the app: Screensaver → Install, then Open Screen Saver Settings and choose HazeSaver. macOS owns the idle timer, so set the start delay there. The app bundles the .saver and copies it to ~/Library/Screen Savers/. Leave the screensaver on “Match wallpaper” and it follows whatever your live wallpaper is.

How it works

HazeKit (framework)            shared by the app + the screensaver
├─ Model        ContentItem · GradientConfig · ShaderGradientConfig · AppSettings
├─ Library      LibraryManager (import, thumbnails, JSON manifest)
├─ Render       WallpaperRenderer → Video · AnimatedImage · Gradient · ShaderGradient · Static
│               (CappedMTKView caps the drawable so smooth gradients sip GPU)
├─ Gradient     Metal shaders (fBm + domain warp · 3D fluid mesh) · presets
├─ Display      WallpaperWindow (desktop level) · DisplayManager (per‑screen)
├─ Power        PlaybackPolicy (pure, unit‑tested) · PowerMonitor (sleep/lock/battery/occlusion)
└─ Shared       ContentStore · JSONStore · Logger

Haze (app)                     LSUIElement menu‑bar agent + SwiftUI Liquid‑Glass UI
HazeSaver (.saver)             ScreenSaverView reusing HazeKit renderers

State lives in ~/Library/Application Support/Haze/ (manifest · media · settings). Both the app and the screensaver are non‑sandboxed and run as you, so no App Group is needed — the screensaver just reads the same files.

Resource discipline. PlaybackPolicy is a pure function of environment + preferences (fully unit‑tested). PowerMonitor feeds it from NSWorkspace sleep notifications, screen‑lock notifications, IOKit power‑source changes, and occlusion detection. When it says don’t render, every renderer pauses (video stops decoding, MTKView.isPaused = true) — zero GPU/decode work.

Roadmap

• Static login‑window background (admin‑only, OS‑restricted)
• Per‑display independent content
• GIF → HEVC transcode‑on‑import for lighter playback
• In‑app auto‑update (Sparkle) with signed appcast
• Developer ID signing, notarization and stapling — shipped in v0.1.4, one command (make release-publish)

Distribution notes

Haze is non‑sandboxed — desktop‑window placement and screensaver installation are incompatible with the App Store sandbox, which also makes it incompatible with the Mac App Store (and GPL‑3.0 is too).

Signing is opt‑in everywhere, so the project builds with no certificate at all. Set HAZE_CODE_SIGN_IDENTITY / HAZE_DEVELOPMENT_TEAM (as make install does) to sign with a Developer ID; the release workflow does the same, plus notarization and stapling, once its signing secrets are set — and falls back to the ad‑hoc build until then. Hardened Runtime is always on.

Releases must be Developer ID‑signed. Not for Gatekeeper — for Sparkle: an ad‑hoc signed copy can never install an update (see Download above), so an ad‑hoc release strands everyone who installs it.

Contributing

Issues and PRs welcome. Keep changes focused, run make test before opening a PR, and match the existing style (small focused files, value types, no force‑unwraps).

License

GPL‑3.0 © 2026 Haze contributors. Free and open source.