simcap

The macOS helper loupe runs to stream and drive iOS simulators and physical iPhones. loupe starts it as a child process and talks to it over stdin and stdout; it isn't meant to be run by hand, though it can be.

simcap writes video in scrcpy's video wire format, so loupe reads an iOS screen with the same parser it uses for an Android device. Frames are encoded with VideoToolbox.

simcap <udid> [-bitrate bps] [-fps n]   stream a simulator
simcap <udid> -input                    inject a simulator's input
simcap <udid> -pasteboard               print a simulator's pasteboard on each change
simcap -hostpasteboard                  mirror this Mac's pasteboard
simcap -devices                         list physical iPhones and their HID capabilities
simcap <udid> -phone [name]             stream a physical iPhone on a cable
simcap <identifier> -phone-input        a physical iPhone's input
simcap <identifier> -phone-wifi [name]  stream a physical iPhone over Wi-Fi
simcap -caps                            print what this build can do

Each mode is documented at the top of its source file. loupe's docs/ios.md covers how the server uses them.

Private frameworks

simcap calls frameworks that Apple ships with Xcode but doesn't document or support: CoreSimulator, SimulatorKit and AccessibilityPlatformTranslation for simulators, and CoreDevice and CoreDeviceMediaStreamSupport for physical phones. They load from your own Xcode install. An Xcode update can change them and break simcap until it is fixed here.

Building

You need Xcode; the build uses xcrun swiftc.

make simcap               # writes .build/simcap, signed ad hoc
make simcap TEAM=<team>   # signs it with your Apple Development identity for that team

An ad hoc signature is enough for simulators. Streaming a phone needs camera access, and macOS ties that grant to the signature, so an ad hoc build asks again after every rebuild. Building with TEAM keeps the grant.

To use your build, copy .build/simcap to loupe's .build/simcap, or start loupe with -simcap <path>. release.sh builds the signed, notarized zip attached to loupe's releases.

License

Apache 2.0. See LICENSE.

iPhone, Mac, macOS and Xcode are trademarks of Apple Inc. simcap is not affiliated with Apple.