Workflow: Physical Device Setup from Zero

The first time you connect a physical iPhone to work with Quern, there are several one-time setup steps. Here’s the complete flow — what you need to do, what your agent handles, and what to expect.

Prerequisites

iPhone or iPad connected to your Mac via USB (Lightning or USB-C)
Xcode installed with your Apple Developer account signed in
Quern running (quern start)
tunneld installed for iOS 17+ devices (done automatically by quern setup)

Step 1: Trust the Mac

When you first plug in the device, iOS shows “Trust This Computer?” on the device screen. Tap Trust and enter your passcode. Without this, the device is invisible to everything — Quern, Xcode, all of it.

Step 2: Enable Developer Mode (iOS 16+)

On iOS 16 and later, developer mode must be explicitly enabled:

Settings > Privacy & Security > Developer Mode > toggle on > restart device > confirm

Your device will reboot. After it comes back, confirm the prompt to enable developer mode. This is a one-time step — it persists across reboots and updates.

Step 3: Verify the Device Appears

“List my devices — do you see my iPhone?”

Your agent should show the physical device in the list. If it doesn’t appear:

Check the USB connection (try a different cable or port)
Make sure you tapped Trust
On iOS 17+, check that tunneld is running: quern tunneld status

Step 4: Set Up WDA (Quern Driver)

“Set up WDA on my iPhone”

Your agent will:

Check your Xcode signing identities — if you have multiple teams, it’ll ask which to use
Build WDA (first time takes a minute or two)
Install “Quern Driver” on the device

If you’re on a free developer account: Your agent will warn you about the 7-day profile expiry and the App ID slot limits. See WDA Guide for details.

If the install fails with a trust error: You need to trust the developer profile on the device: Settings > General > VPN & Device Management > [your name] > Trust. This only applies to free accounts.

Step 5: Verify UI Automation

“Take a screenshot of my iPhone and show me in Preview”

If you get a screenshot, WDA is working. Your agent can now tap, swipe, type, and read the screen.

“What’s on the screen right now?”

Your agent reads the accessibility tree via WDA and describes what it sees.

Step 6: Set Up Network Capture (Optional)

If you want to see your app’s network traffic:

“Install the proxy certificate on my iPhone”

Your agent can do this automatically via WDA — it navigates Settings, installs the certificate profile, and enables trust. Or you can do it manually (see Physical Device Proxy Setup).

After the cert is installed, configure the Wi-Fi proxy on the device. Your agent will tell you the IP and port to use.

Step 7: Start the Live Preview (Optional)

“Show me the device screen”

A live video preview window opens showing the device in real time. Useful for watching what happens when your agent interacts with the device.

On iOS 18+, the device may show a “headphones or other device?” dialog — tap Other to dismiss it.

Step 8: Start Working

Everything’s set up. You can now:

“Build and install my app on the iPhone” “Launch the app and show me what API calls it makes” “Tap the login button and walk me through what happens”

What Persists

After this setup, here’s what survives across sessions:

What	Persists?	Re-setup when?
Device trust	Yes (permanent)	Only after device restore/wipe
Developer mode	Yes (permanent)	Only after device restore/wipe
WDA build (paid account)	1 year	Profile expiry or signing change
WDA build (free account)	7 days	Every week — tell your agent to rebuild
Proxy certificate	Yes (permanent)	After iOS updates (occasionally untrusted)
Wi-Fi proxy config	Per-network	When you switch Wi-Fi networks

Most of this is truly one-time. A returning session usually just means plugging in the cable and starting to work.