XCUITest alternatives: keep XCUITest, add an agent

Pick Mobster if a coding agent is writing your SwiftUI screens: it checks each one from outside your Xcode project, with no test target and no test code, and returns pass or fail from the same accessibility tree XCUITest reads.

We make Mobster, and every XCUITest fact here comes from Apple’s own documentation, listed under Sources.

Four reasons to pick Mobster

1. Your coding agent checks the screen it wrote

An agent that changes a SwiftUI view needs to know the view works before it says so. With Mobster it builds for the simulator, calls verify_start with the steps in plain English and what must be true, drives the app with screen, tap, type_text and swipe, and calls verify_finish. The expectations are fixed before the agent touches the app, so it can’t bend them to fit what it sees. There’s no test target to add and no test code to compile. Paste this into CLAUDE.md or AGENTS.md and the agent does it after every UI change:

## Verifying UI changesAfter you change a screen in this iOS app, verify it before you say it works.1. Build for the simulator:   xcodebuild -scheme <Scheme> -destination 'generic/platform=iOS Simulator' -derivedDataPath .mobster/build CODE_SIGNING_ALLOWED=NO build2. Call mobster's verify_start with app_path set to the absolute path of   .mobster/build/Build/Products/Debug-iphonesimulator/<App>.app, the steps in plain English, and expect:   what must be true when the steps are done.3. Drive with screen, tap, type_text and swipe, then call verify_finish.4. If the verdict is failed, fix the code and verify again. Report the verdict and the report path.

2. A check is a small file anyone can read

Daybreak, the sample app in Mobster’s repository, ships this one as .mobster/checks/paywall.yaml:

# Launch-only: no steps and no model calls. Mobster installs Daybreak, opens the paywall by# deep link, and checks it against the accessibility tree.#   mobster verify --check .mobster/checks/paywall.yamlversion: 1name: The paywall shows three plans with Annual at $39.99 a yearapp:  bundle: dev.mobster.daybreak  path: .build/Build/Products/Debug-iphonesimulator/Daybreak.applaunch:  url: daybreak://paywallexpect:  - text: Choose your plan  - count: { id: /^plan_/ }    equals: 3  - value: { id: plan_annual }    equals: $39.99 / year  - visible: { label: Restore Purchases, role: button }  - no_text: Loading

mobster verify --check runs it, and the exit code is the verdict. Any run becomes a file like this with --save, or with save_check from your agent.

3. Proof a person can read

Every run writes frames, an overlay that outlines every element Mobster read and each asserted element in green or red, result.json, and a one-file HTML report with no external requests. When text isn’t found, the assertion line lists up to 5 near misses from the screen, so the agent fixes the right code and you can trust the verdict without rerunning it.

4. Simulators handled for you, and your iPhone too

Mobster creates its own simulators, boots them headless, builds WebDriverAgent once per Xcode version and resets the app before each run. It never opens Simulator.app and never touches your own simulators. On a warm simulator, Daybreak’s five-assertion paywall check took 6.8 s and 8.6 s (n = 2, 28 September 2026, an M5 Max with Xcode 26.4 and the iOS 26.4 simulator). On your USB iPhone, with Developer Mode on, mobster verify --device checks an app you already installed there, without clearing its data.

When XCUITest fits

Keep XCUITest for the regression suite that compiles with your app and runs in any CI or Xcode Cloud. Give the controls you check an accessibility identifier, such as .accessibilityIdentifier("plan_annual"), and XCUITest queries and Mobster’s id selector both use it.

Try Mobster on your app

$ curl -fsSL https://mobster.dev/install.sh | sh
$ mobster sim doctor --fix
$ xcodebuild -scheme <Scheme> -destination 'generic/platform=iOS Simulator' \
  -derivedDataPath .mobster/build CODE_SIGNING_ALLOWED=NO build
$ mobster verify --app .mobster/build/Build/Products/Debug-iphonesimulator/<App>.app \
  --text "Welcome" --save first-check

Getting started with verify walks through the rest, and Maestro vs XCUITest vs Mobster adds Maestro to the comparison.