MobileTestAI

AI-powered iOS app testing framework. Describe what you want tested in plain English, and an LLM agent autonomously navigates your app on iOS simulators.

Why MobileTestAI?

There are tools that let AI agents tap buttons on a phone. MobileTestAI is the only one that coordinates multiple AI agents across multiple simulators simultaneously.

Testing a multiplayer game? A chat app? A collaborative tool? You need two (or more) devices interacting with each other — Player 1 creates a room, Player 2 joins with the room code, both verify they're in the lobby. No other open-source tool does this.

What makes it different

Use cases

• Multiplayer apps — test game lobbies, matchmaking, real-time interactions across devices
• Chat/messaging — verify message delivery between users on separate simulators
• Collaborative tools — test shared documents, whiteboards, or workspaces
• Single-device testing — works great for standard UI testing too
• Regression testing — define YAML scenarios and rerun them after every build

How It Works

Each step of the agent loop:

1. Observe — captures the UI accessibility tree (and optionally a screenshot) from the simulator
2. Reason — sends the UI state to an LLM with the goal and action history
3. Act — executes the chosen action (tap, swipe, type, etc.) on the simulator
4. Repeat — continues until the agent reports "done", "fail", or hits the step limit

The agent uses structured text from the accessibility tree rather than vision alone — this is faster, cheaper, and more reliable than screenshot-only approaches.

Prerequisites

• macOS with Xcode 26+ and iOS simulators
• Python 3.11+ and uv
• At least one device backend (see below)
• At least one LLM provider (see below)

Installation

# Clone the repo
git clone https://github.com/TomMcGrath7/iOSTestAgents.git
cd iOSTestAgents

# Install Python dependencies
uv sync --extra dev

# Install XcodeBuildMCP (recommended device backend)
npm install -g xcodebuildmcp@latest

# Verify everything is set up
uv run iostestagents doctor

Setting Up an LLM Provider

MobileTestAI needs an LLM to read the UI and decide actions. It supports three providers and auto-detects which one to use based on available API keys.

Option 1: Ollama (local, free)

Run models locally on your Mac. No API key, no cost, no data leaves your machine.

# Install Ollama: https://ollama.com
brew install ollama
ollama serve

# Pull a model
ollama pull qwen3:8b

MobileTestAI auto-detects Ollama when it's running on localhost:11434.

Note on local models: Local models work but performance scales with model capability. Smaller models (7-8B parameters) can handle simple navigation tasks like "go to Settings > General". For complex multi-step flows, onboarding sequences, or apps with non-obvious UI patterns, cloud models (GPT-5.4, Claude) perform significantly better. We recommend starting with Ollama to try things out, then switching to a cloud provider for production use.

Option 2: OpenAI

Best balance of speed and capability. GPT-5.4 is the recommended model (current generation at the old gpt-4o price point); use gpt-5.5 for the premium flagship.

export OPENAI_API_KEY="sk-..."

Get your API key at platform.openai.com/api-keys.

Option 3: Anthropic (Claude)

The default model is claude-opus-4-8. For cheaper per-step costs on simple navigation tasks, use --model claude-haiku-4-5 ($1/$5 per 1M tokens vs $5/$25 for Opus).

export ANTHROPIC_API_KEY="sk-ant-..."

Get your API key at console.anthropic.com.

Choosing a provider

You can override the auto-detected provider with --provider and --model:

uv run iostestagents run --provider ollama --model qwen3:8b ...
uv run iostestagents run --provider openai --model gpt-5.4 ...
uv run iostestagents run --provider anthropic --model claude-haiku-4-5 ...  # cheap per-step option

Quick Start

Run a single-device test:

uv run iostestagents run \
  --device "iPhone 17" \
  --app com.apple.Preferences \
  --goal "Navigate to General > About"

Run with a specific provider and screen recording:

uv run iostestagents run \
  --device "iPhone 17" \
  --app com.apple.mobilesafari \
  --goal "Open Safari, tap the address bar, type apple.com, and verify the page loads" \
  --provider openai --model gpt-5.4 \
  --record

Run a multi-device scenario:

uv run iostestagents scenario scenarios/multiplayer_example.yaml

Multi-Device Scenarios

This is MobileTestAI's unique capability. Scenarios are YAML files that coordinate multiple agents across multiple simulators:

name: multiplayer_join_test
app_bundle_id: com.example.myapp
app_path: "/path/to/MyApp.app"
players: 2
device: "iPhone 17"
backend: xcodebuildmcp
provider: openai
model: gpt-5.4
max_steps: 30

steps:
  - player: 1
    action: "Create a new game room"
    capture: room_code

  - player: 2
    action: "Join game using room code {room_code}"

  - all_players:
    action: "Verify both players are in the lobby"
    parallel: true

Orchestration Features

• Cross-device variable passing — capture extracts a value from the screen (like a room code), {var} injects it into another player's step
• Barriers — all_players steps block until all devices reach that point
• Sequential or parallel — steps run one at a time by default, or parallel: true for simultaneous actions
• Failure handling — on_failure: continue to keep going when a step fails

See the scenarios/ directory for more examples.

CLI Reference

iostestagents run
  --device, -d    Simulator device name (required)
  --app, -a       App bundle identifier (required)
  --goal, -g      Natural language test goal (required)
  --max-steps     Maximum agent steps (default: 20)
  --backend, -b   Device backend: xcodebuildmcp or testbridge (default: testbridge)
  --provider      LLM provider: openai, anthropic, ollama (auto-detect if omitted)
  --model         LLM model to use (default per provider)
  --output, -o    Output directory (default: output)
  --verbose, -v   Verbose logging
  --step-delay    Delay between steps in seconds (default: 1.5)
  --record        Record screen video
  --no-reset      Skip app reset before run
  --app-path      Path to .app bundle for install
  --no-vision     Skip screenshots, use accessibility tree only (faster)

iostestagents scenario <path>
  Run a multi-device YAML scenario file

iostestagents doctor
  Check environment setup and backend availability

Writing Good Goals

Goals should be specific and include any gates (onboarding, login) the agent needs to get through:

# Good — specific with clear completion criteria
"Tap Get Started, complete onboarding by tapping Continue on each screen, then navigate to Settings"

# Bad — no clear completion criteria
"Explore the app"

# Bad — assumes the agent can skip onboarding
"Go to Settings"

Think of goals as instructions for someone who has never seen the app before.

Device Backends

TestBridge is a custom XCUITest HTTP bridge included in the testbridge/ directory. It starts an HTTP server on localhost:8615 giving the Python agent full control of a running simulator. No external dependencies — just Xcode.

XcodeBuildMCP is a third-party CLI by Sentry with 59+ tools for Xcode automation, including real device support.

Architecture

src/iostestagents/
├── cli.py                    # Typer CLI
├── agent/
│   ├── loop.py               # Core observe → reason → act loop
│   ├── prompts.py            # LLM prompt templates
│   ├── models.py             # Pydantic action/result models
│   └── ui_parser.py          # Accessibility tree parser
├── device/
│   ├── base.py               # DeviceBackend protocol
│   ├── xcodebuildmcp.py      # XcodeBuildMCP backend
│   ├── bridge.py             # TestBridge backend
│   ├── simulator.py          # Simulator lifecycle (simctl)
│   └── idb.py                # Legacy idb fallback
├── llm/
│   ├── base.py               # LLM provider protocol
│   ├── openai.py             # OpenAI provider
│   ├── anthropic.py          # Anthropic provider
│   ├── ollama.py             # Ollama (local) provider
│   └── registry.py           # Provider auto-detection
├── orchestrator/             # Multi-device coordination
│   ├── coordinator.py
│   ├── scenario.py
│   └── sync.py
└── util/
    └── logging.py

Development

# Run tests
uv run pytest

# Run tests with verbose output
uv run pytest -v

# Check environment
uv run iostestagents doctor

Limitations

• macOS only (requires Xcode and iOS simulators)
• Each simulator uses ~2GB RAM — a MacBook can handle 3-4 concurrent simulators, a Mac Studio 8+
• LLM agents are non-deterministic — the same goal may produce different action sequences across runs
• System dialogs (Mail compose, Share Sheet) are generally not automatable
• SwiftUI views may need .accessibilityIdentifier() for reliable element targeting
• describe_ui can take 1-3 seconds on complex view hierarchies
• Local models (7-8B) struggle with complex navigation — use cloud models for production

Related Projects

• XcodeBuildMCP — MCP server and CLI for Xcode automation (used as a backend)
• DroidRun — Similar concept for Android
• Arbigent — AI agent for testing Android, iOS, and Web apps
• Xcode MCP Bridge — Apple's native MCP for coding workflows (different niche — builds/tests, not UI automation)

License

Apache License 2.0 — see LICENSE for details.