The Simulator card

If your agent is building an iOS app, the fastest feedback loop is watching it run. The Simulator card mirrors a Simulator running on the host onto your board — and your taps and typing go back into it.

Available on macOS hosts only; a Linux host has no Simulator to mirror.

Using it

Add a Simulator card and pick a device. The card streams the Simulator’s screen live and forwards your input:

• Tap and drag with mouse or finger.
• Type with your keyboard, or the phone’s.
• High Definition trades bandwidth for a sharper image — worth it on a fast local network, less so over the relay.

Because the Simulator runs on the host, the build the agent just produced is the build you are looking at. There is no upload step and no separate device.

From the phone

An iOS Simulator running on your Mac at home, mirrored onto the iPhone in your hand, driven by your thumb. Good for “does the layout break on this screen?”, and for marking what to fix instead of describing it.

Details

• The Simulator is driven by a small broker that Offsite installs as a LaunchAgent in the host’s GUI login session. That is a requirement, not an implementation detail: simctl and the Simulator app need a real window server, so a host that never logs in graphically cannot mirror.
• The screen arrives as an AVCC video stream; input goes back over a separate channel, so a slow frame never delays a tap.
• Only simulator is a valid mirror target today. The card type on the wire is mirror.
• If the card says Simulator unavailable, the usual causes are: no Simulator runtime installed, the host is not logged in graphically, or the broker has not been installed yet.
• Related: Deploy to this phone puts the same build on real hardware, and Testing what you build ties both together.