Preflight MCP

The most comprehensive MCP (Model Context Protocol) server for iOS Simulator automation. Gives AI agents like Claude, ChatGPT, Cursor, Windsurf, and any MCP-compatible tool full control over iOS Simulators — tap, swipe, type, read accessibility trees, inspect app data, capture screenshots, record video, manage devices, and debug apps in real time.

82 tools across 14 categories. Zero cursor interference — works silently in the background while you use your Mac.

Inspired by Playwright MCP for web automation — Preflight brings the same structured accessibility-first approach to iOS.

Why Preflight?

• No disk clutter — Screenshots and video frames return directly in chat. No folders filling up.
• AI-optimized — Images compressed for minimal token usage. Video → key frames (most AI models can't view video files).
• Accessibility-first — Like Playwright's browser_snapshot, use simulator_snapshot to understand the screen without vision models.
• Cursor-free — Touch injection via idb (IndigoHID) — your Mac cursor stays put.
• 82 tools — From basic tap/swipe to StoreKit testing, network conditioning, memory profiling, and crash log analysis.

Quick Start

Prerequisites

• macOS with Xcode and iOS Simulator installed
• Node.js 18+
• Facebook idb (recommended for cursor-free operation)

Install idb (recommended)

brew tap facebook/fb
brew install idb-companion
pip3 install fb-idb

Without idb, the server falls back to CGEvent mouse injection (works but briefly moves your cursor).

Install via npm (recommended)

npm install -g preflight-ios-mcp

Build from Source

git clone https://github.com/EthanAckerman-git/Preflight.git
cd Preflight
npm install
npm run build

Setup by IDE / AI Tool

Add your Python bin directory to PATH if idb was installed via pip (e.g., ~/Library/Python/3.x/bin).

Claude Code

claude mcp add preflight -- npx preflight-ios-mcp

Or add to .mcp.json in your project root:

{
  "mcpServers": {
    "preflight": {
      "command": "npx",
      "args": ["preflight-ios-mcp"],
      "env": {
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (per-project):

{
  "mcpServers": {
    "preflight": {
      "command": "npx",
      "args": ["preflight-ios-mcp"],
      "env": {
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Then in Cursor: Settings → MCP — verify "preflight" shows as connected.

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "preflight": {
      "command": "npx",
      "args": ["preflight-ios-mcp"],
      "env": {
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Then in Windsurf: Settings → Cascade → MCP — verify "preflight" appears.

VS Code (Copilot / Cline / Continue)

Add to .vscode/mcp.json in your project:

{
  "servers": {
    "preflight": {
      "command": "npx",
      "args": ["preflight-ios-mcp"],
      "env": {
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

For Cline (VS Code extension), add to ~/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json:

{
  "mcpServers": {
    "preflight": {
      "command": "npx",
      "args": ["preflight-ios-mcp"],
      "env": {
        "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Zed

Add to ~/.config/zed/settings.json:

{
  "context_servers": {
    "preflight": {
      "command": {
        "path": "npx",
        "args": ["preflight-ios-mcp"],
        "env": {
          "PATH": "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin"
        }
      }
    }
  }
}

Any MCP-Compatible Client

Preflight uses the standard MCP stdio transport. Configure your client to run:

npx preflight-ios-mcp

Set the PATH environment variable to include idb's location for cursor-free touch injection.

Tools Reference

Observation (6 tools)

Tool	Description
simulator_screenshot	Take a JPEG screenshot optimized for AI chat (~200-400KB). Returns image inline.
simulator_list_devices	List simulators with name, UDID, state, runtime. Filter: booted, available, all.
simulator_list_apps	List installed apps with bundle IDs. Toggle includeSystem for system apps.
simulator_app_info	Get app metadata: name, version, bundle path, data path, type.
simulator_get_clipboard	Read the simulator's clipboard text.
simulator_get_screen_info	Window geometry, coordinate mapping, scale factor. Debug tap accuracy.

User Interaction (6 tools)

Tool	Description
simulator_tap	Tap at (x, y) in simulator screen points. Cursor-free via idb.
simulator_swipe	Swipe between two points. Supports edge-swipe-back from x=1.
simulator_long_press	Long press with configurable duration. Context menus, drag initiation.
simulator_type_text	Type text into the focused field.
simulator_press_key	Press special keys (return, escape, arrows, F-keys) with modifiers.
simulator_navigate_back	Navigate back via Cmd+[. Workaround for edge-swipe limitations.

Playwright-Inspired (3 tools)

Tool	Description
simulator_snapshot	Preferred over screenshots. Structured accessibility tree — roles, labels, values, positions. No vision model needed. Like Playwright's browser_snapshot.
simulator_wait_for_element	Wait for an element to appear (by label, role, or text). Polls with configurable timeout. Like Playwright's browser_wait_for.
simulator_element_exists	Quick boolean check: does an element matching criteria exist on screen right now?

Device Management (6 tools)

Tool	Description
simulator_boot	Boot a device by name or UDID. Optional waitForBoot polling.
simulator_shutdown	Shut down a running simulator.
simulator_erase	Factory reset — erases all content and settings.
simulator_open_url	Open URLs or deep links (e.g., myapp://screen).
simulator_open_simulator	Open the Simulator.app application.
simulator_get_booted_sim_id	Get the UDID of the currently booted simulator.

App Management (4 tools)

Tool	Description
simulator_launch_app	Launch by bundle ID with optional args and env vars.
simulator_terminate_app	Force-terminate a running app.
simulator_install_app	Install a .app bundle or .ipa from a local path.
simulator_uninstall_app	Uninstall by bundle ID.

Debugging & Diagnostics (9 tools)

Tool	Description
simulator_get_logs	Query device logs. Filter by process, subsystem, level, time range, message content.
simulator_stream_logs	Live log streaming with start/read/stop lifecycle. Configurable buffer.
simulator_get_app_container	Get filesystem path to app's bundle, data, or shared group container.
simulator_list_app_files	Browse an app's Documents/, Library/, Caches/, tmp/ directories.
simulator_read_app_file	Read plists (→JSON), SQLite (→schema), and text files from app data.
simulator_get_crash_logs	Retrieve crash reports with stack traces and thread states.
simulator_diagnose	Xcode version, disk usage, booted devices, system info.
simulator_accessibility_audit	Full iOS accessibility tree — real UIButton/UILabel elements with labels, frames, roles.
simulator_describe_point	Returns the accessibility element at given coordinates.

System Simulation (5 tools)

Tool	Description
simulator_set_location	Set GPS coordinates (lat/lng). Test location-based features.
simulator_send_push	Send push notifications with full APNs payload JSON.
simulator_set_clipboard	Set the simulator clipboard text.
simulator_add_media	Add photos/videos to the camera roll from local files.
simulator_grant_permission	Grant, revoke, or reset permissions (camera, location, photos, contacts, microphone, etc.).

UI Configuration (4 tools)

Tool	Description
simulator_set_appearance	Switch between light and dark mode.
simulator_override_status_bar	Set time, battery, signal, carrier, network type.
simulator_record_video	Start screen recording. On stop, key frames are extracted as images for AI chat.
simulator_stop_recording	Stop recording. Returns key frames inline (no disk clutter). Optional savePath to keep the video.

Advanced Debugging & Testing (18 tools)

Tool	Description
simulator_set_content_size	Set Dynamic Type preferred size (13 categories from extra-small to accessibility-XXXL).
simulator_set_increase_contrast	Toggle Increase Contrast accessibility setting.
simulator_location_scenario	Run predefined GPS routes: Freeway Drive, City Run, City Bicycle Ride.
simulator_location_route	Simulate movement along custom waypoints with configurable speed.
simulator_memory_warning	Trigger simulated memory warning (didReceiveMemoryWarning).
simulator_keychain	Add root certificates, add certificates, or reset the device keychain.
simulator_icloud_sync	Trigger iCloud synchronization on the device.
simulator_verbose_logging	Enable/disable verbose device logging for deep debugging.
simulator_install_app_data	Install .xcappdata packages to restore test data snapshots.
simulator_get_env	Read environment variables from the running simulator.
simulator_biometric	Enroll, unenroll, match, or fail Face ID / Touch ID for auth testing.
simulator_network_status	Get network configuration — DNS, interfaces, connectivity status.
simulator_defaults_read	Read UserDefaults from inside the simulator (inspect app prefs, feature flags).
simulator_defaults_write	Write UserDefaults inside the simulator (set flags, inject test config).
simulator_rotate	Rotate the simulator left or right.
simulator_notify_post	Post a Darwin notification to trigger system events.
simulator_set_locale	Set device locale for internationalization testing.
simulator_trigger_siri	Invoke Siri for voice command testing.

Accessibility Settings (4 tools)

Tool	Description
simulator_set_reduce_motion	Toggle Reduce Motion accessibility setting (via defaults write + notification).
simulator_set_smart_invert	Toggle Smart Invert Colors (via defaults write + notification).
simulator_set_bold_text	Toggle Bold Text (via defaults write + notification).
simulator_set_reduce_transparency	Toggle Reduce Transparency (via defaults write + notification).

Device Creation & Management (4 tools)

Tool	Description
simulator_create_device	Create a new simulator with device type and runtime.
simulator_delete_device	Permanently delete a simulator device.
simulator_rename_device	Rename an existing device.
simulator_clone_device	Clone a device with all its state.

StoreKit Testing (6 tools) — Xcode 14-16

Tool	Description
simulator_storekit_config	Enable or disable StoreKit test mode.
simulator_storekit_transactions	List all StoreKit test transactions.
simulator_storekit_delete_transactions	Clear all test transactions.
simulator_storekit_manage_subscription	Expire or force-renew a subscription.
simulator_storekit_manage_transaction	Refund, approve, or decline ask-to-buy transactions.
simulator_storekit_reset_eligibility	Reset introductory offer eligibility for all products.

Network Testing (2 tools)

Tool	Description
simulator_network_condition	Apply network throttling with presets (3G, LTE, Edge, WiFi, 100% loss) or custom bandwidth/latency/loss.
simulator_network_capture	Capture network activity summary — active connections, DNS, interfaces.

Debugging & Profiling (5 tools)

Tool	Description
simulator_leak_check	Check a running app for memory leaks via Apple's leaks tool.
simulator_heap_info	Dump heap allocation summary — object counts by class, total memory.
simulator_vmmap	Show virtual memory map — regions, sizes, permissions.
simulator_sample_process	Sample a process for CPU hotspot detection and hang analysis.
simulator_thermal_state	Simulate thermal pressure state changes (nominal, fair, serious, critical).

Architecture

src/
├── index.ts                    # MCP server entry, 82 tool registrations
├── helpers/
│   ├── idb.ts                  # Facebook idb CLI wrapper (cursor-free touch)
│   ├── simctl.ts               # xcrun simctl command wrapper
│   ├── applescript.ts          # Keyboard input + CGEvent fallback
│   ├── coordinate-mapper.ts    # Simulator points → macOS screen coords
│   ├── mouse-events.swift      # Native Swift CGEvent binary (fallback)
│   └── logger.ts               # Structured stderr logging
└── tools/
    ├── screenshot.ts           # JPEG capture optimized for AI chat
    ├── interaction.ts          # Tap, swipe, long press, type, key
    ├── device.ts               # Boot, shutdown, erase, open URL
    ├── app.ts                  # Install, launch, terminate, list
    ├── system.ts               # Location, push, clipboard, media, permissions
    ├── ui.ts                   # Appearance, status bar, video recording, navigate back
    ├── debug.ts                # Logs, files, crash reports, accessibility
    ├── advanced.ts             # Dynamic Type, keychain, iCloud, biometric, defaults, accessibility, rotation, locale
    ├── storekit.ts             # StoreKit testing — transactions, subscriptions, eligibility
    ├── network.ts              # Network conditioning (dnctl/pfctl) and capture
    ├── profiling.ts            # Memory profiling — leaks, heap, vmmap, sample, thermal
    └── playwright.ts           # Snapshot, wait_for_element, element_exists

Design Philosophy

Accessibility-first, like Playwright MCP:

1. Use simulator_snapshot to understand the screen (structured text, no vision model)
2. Use coordinates from the snapshot to simulator_tap, simulator_swipe, etc.
3. Use simulator_screenshot when you need visual verification
4. Use simulator_wait_for_element before interacting with elements that appear after transitions

No disk clutter:

• Screenshots return as base64 in chat — no folders filling up your Desktop
• Video recordings extract key frames as inline images on stop
• Optional savePath parameter if you actually need files on disk

Touch Injection Pipeline

simulator_tap(x=200, y=400)
    │
    ├─ idb available? ──YES──► idb ui tap --udid <UDID> 200 400
    │                           (IndigoHID → real iOS touch event)
    │                           (zero cursor movement)
    │
    └─ idb unavailable? ──► coordinate mapper → macOS screen coords
                             → Swift CGEvent binary → mouse down/up

Demo App

A SwiftUI demo app is included in demo-app/ for testing all MCP features:

cd demo-app
xcodebuild -project MCPDemo.xcodeproj -scheme MCPDemo \
  -destination 'platform=iOS Simulator,name=iPhone 16 Pro' \
  build

The demo app has 7 tabs exercising every tool category:

• Interactions: Buttons, text fields, long-press zones, navigation stack, scrollable lists
• Location: Live GPS display for testing simulator_set_location
• Notifications: Push notification display for testing simulator_send_push
• Settings: Clipboard, file I/O, accessibility toggles, UserDefaults
• StoreKit: Mock purchases and subscriptions for testing StoreKit tools
• Network: Connection monitoring and latency testing for network conditioning
• Debug: Memory/CPU stress tests, thermal state, accessibility settings observer, biometric auth

Configuration

Environment Variables

Variable	Default	Description
LOG_LEVEL	info	Logging level: debug, info, warn, error
PREFLIGHT_FILTERED_TOOLS	(none)	Comma-separated list of tool names to disable
PREFLIGHT_IDB_PATH	(auto-detect)	Custom path to idb binary
PATH	System PATH	Must include idb binary location

Example Prompts

QA Testing

"Boot the iPhone 16 Pro simulator, install my app at ./build/MyApp.app, launch it, and take a screenshot of the home screen. Then tap the login button, type test@email.com in the email field, and verify the form validation works."

Accessibility-First Workflow (Playwright-style)

"Take a snapshot of the current screen to see what elements are available. Then tap the button labeled 'Sign In' and wait for the email text field to appear."

Debugging

"My app is crashing on launch. Check the crash logs for MyApp, then get the last 5 minutes of device logs filtered to the MyApp process."

Dark Mode Testing

"Switch to dark mode, take a screenshot, then switch to light mode and screenshot again."

Troubleshooting

idb not detected

If tools show [CGEvent fallback] instead of [cursor-free]:

1. Verify idb is installed: which idb or check ~/Library/Python/3.x/bin/idb
2. Add the idb path to your MCP config's PATH env var
3. Or set PREFLIGHT_IDB_PATH directly

Simulator not found

1. Open Simulator.app: open -a Simulator
2. Boot a device: use simulator_boot or xcrun simctl boot "iPhone 16 Pro"

Accessibility permission errors

1. Go to System Settings → Privacy & Security → Accessibility
2. Add your terminal app (Terminal.app, iTerm, Claude Code, Cursor, Windsurf, etc.)

Development

npm run dev    # Watch mode (TypeScript only)
npm run build  # Full rebuild (TypeScript + Swift binary)
node dist/index.js  # Run directly

License

MIT License — see LICENSE for details.