Mutter Docs
GitHub ↗
Browse the docs

Mutter documentation

Mutter for iOS

The SwiftUI client connects directly to Mumble servers and uses libopus, Apple audio processing, and WebRTC screen viewing. It also provides Live Activities, Dynamic Island, and App Intents.

Commands below run from the repository root. Shared fonts and themes live in design/.

Build and install

Requirements: Xcode 26.6, iOS 17+ device or simulator, XcodeGen.

brew install xcodegen
cd mutter
xcodegen generate
open Mutter.xcodeproj

Signing reads your Team ID from Local.xcconfig, which is gitignored so it stays out of this public repo. Copy Local.xcconfig.example to Local.xcconfig, put your 10-character Team ID in it, and re-run xcodegen generate. Setting the team in Xcode's Signing & Capabilities tab instead works until the next regenerate, which throws it away.

Then build the Mutter scheme. Run the package tests with swift test from Packages/MumbleCore (macOS) or via the scheme's Test action.

For repeatable phone deployment, copy Local.deploy.json.example to the ignored Local.deploy.json. Set the paired device identifier from xcrun devicectl list devices and the paths to this Mac's existing build keychain and its owner-only password file. Then run:

python3 scripts/deploy-phone.py

The command unlocks the build keychain, puts it first while signing, and restores the previous keychain search order afterward. This avoids selecting duplicate signing keys from a locked login keychain. It then verifies the signature, installs the update, and launches Mutter. --device overrides the saved phone; optional derived_data and source_packages paths let you reuse an existing build and Swift package cache. Omit the keychain fields when using Xcode's ordinary interactive signing setup.

Git authentication is configured per checkout. If the Mac's default GitHub host uses another repository's deploy key, use an SSH URL and select the appropriate account key with local core.sshCommand. Keep machine paths and credentials out of committed files.

Build notes:

  1. Opus headers. Mutter/Audio/OpusShim/opus_shim.h includes <opus/opus.h> with fallbacks. If the OnBeep Opus xcframework lays out headers differently, adjust the include or swap the package in project.yml (sbooth/opus-binary-xcframework also works; it needs the ogg package). The shim exists because opus_encoder_ctl is variadic and Swift cannot call it.
  2. Swift concurrency warnings. The project currently uses Swift 5 language mode with minimal checking; moving to Swift 6 requires a separate concurrency pass.
  3. Keychain entitlement. Certificates live in the keychain; the entitlements file is generated by XcodeGen from project.yml.

Source layout

  • Mutter/: app state, SwiftUI screens, audio, and platform integration.
  • Packages/MumbleCore/: portable protocol codecs and Apple network transport.
  • MutterWidgets/: Live Activity and Dynamic Island extension.
  • MutterUITests/: appearance and interaction regression tests.

The Xcode project is generated from project.yml. Keep signing and deployment settings in the ignored local configuration files. See feature coverage for platform differences.