Parallax beta.9: your agent can now tap on a real iPhone

The agent on an iPhone 13 in the Parallax window: a tap, the perf lab opened and closed, and "Привет мир" typed into a field. 2× speed.

Parallax is a desktop app and an MCP server that give you and your coding agent the same live view of a running React Native app: the
screen, the component tree, logs, network and state. In beta.8 a real iPhone joined the window, watch only: you saw its screen and
pointed at its elements, but the agent could only take screenshots. In beta.9 the agent and you can act on it.

What you get

After a one-time setup, the agent's device_tap, device_swipe and device_type work on the iPhone, and so do the window's clicks, drags
and typing. device_ui reads the phone's own accessibility tree, which shows what React can't, such as system dialogs. The screen around
each action is still read from the app's React tree first, as on simulators and Android phones since beta.7, with the phone's tree as the
fallback.

Two checks keep the agent from acting blind:

• If the phone is locked or your app is not in front, the action refuses with a message that says so, instead of tapping on the wrong screen.
• If a tap was slow and nothing on the screen changed, the agent gets a warning, so it doesn't assume the tap worked.

How it works

On iOS 26 and earlier, sending a tap to a real iPhone needs a UI test runner on the phone. Parallax uses WebDriverAgent, an open-source
runner (BSD licence). It downloads a pinned version of its source, checks it against a hash, builds it with xcodebuild and your Apple
developer team, and starts it on the phone. It is never shipped prebuilt, because it has to be signed with your team.

With the cable plugged in, the commands go over USB, and a round trip to the runner takes about 7 ms. It also works over Wi-Fi alone, but
then there is no picture in the window.

The setup

A plugged-in iPhone starts as watch only: its picture is dimmed under a card that says so. Press Set up agent control on that card
(or Just watch to put it away). The sheet walks you through five steps:

1. Turn on Developer Mode on the phone.
2. Turn on Settings › Developer › Enable UI Automation on the phone.
3. Pick the Apple developer team that signs the runner.
4. Build the agent helper. Parallax registers the iPhone in your Apple account and creates a development profile. On a company team, that uses one of the account's yearly device slots. The build takes about 16 s.
5. Start it on the iPhone. The first start takes about 30 s. On the first start on a phone, and only then, it waits for you to type the passcode on the iPhone. Later starts take 3 to 7 s with no one at the phone.

While it runs, the button on the card says what is going on ("Setting up…", "Setup needs you"), and the card goes away once the phone can
be controlled.

If a step fails, it says what to do, with the raw xcodebuild output under Details. After a restart of the window, or after you
unplug the phone and plug it back in, control comes back by itself with no passcode, because the permission belongs to the phone.

How fast it is

Slower than a simulator. Measured on an iPhone 13 with iOS 26.7:

• a tap: about 1 s (median 1.02 s), and 10 of 10 landed
• a swipe: about 3.3 s
• typing: 0.6 to 0.7 s, ASCII and Cyrillic, typed exactly
• device_ui: 2.3 to 2.7 s

For comparison, a tap on a Galaxy S24 takes 0.6 to 0.8 s. On the iPhone, most of a tap is Apple's XCTest: the runner's own tap takes
about 0.65 s by itself, and turning off XCTest's idle waits made no difference. The USB round trip is 7 ms.

The limits

• The agent's tools on a real iPhone need the Parallax window open.
• Leave the phone alone while the agent acts. Touching it yourself at the same time gives undefined results.
• You need your own Apple developer team. A free personal team was not tried. Its profile would expire after 7 days, and Parallax would rebuild it then.
• The setup registers the iPhone in your Apple account. The runner, the "Enable UI Automation" permission and that registration stay until you remove them. The guide says how.
• The first start on each phone needs you at the phone to type the passcode.
• Taps and swipes are slower than on a simulator or an Android phone. In the window, a drag is sent as one gesture when you release the button, so it feels slow.
• Tested on one iPhone 13 with iOS 26.7, Xcode 27 and one test app.
• macOS 26 or later, on Apple silicon only.

The desktop app is in closed beta: ask for an invite at https://parallax-rn.dev/download. Corrections to anything above are welcome.