Device Control Reference (Device Hub, devicectl, simctl)

Reference for controlling iOS simulators and physical devices from outside Xcode. On Xcode 27, Device Hub is the GUI that replaces Simulator.app and manages simulators and physical devices together — but it is a front-end over the devicectl and simctl command-line tools, so every operation also has a scriptable, headless counterpart. This page maps the tools to their jobs and answers the question "what can I do without Xcode running?"

When to Use This Reference

Use this reference when:

• You want to drive a simulator or device from a script or CI without keeping Xcode open
• Your workflow depends on the Xcode MCP bridge (xcrun mcpbridge) and breaks whenever Xcode isn't running, and you want an Xcode-independent path
• You're deciding between devicectl and simctl for a given operation
• You need to script Face ID / Touch ID, orientation, appearance, or simulated location
• You're parsing devicectl --json-output in CI and need the stable keys
• You want to know what the Xcode 27 Device Hub GUI offers and how it maps to the CLI

Example Prompts

• "Can I control the simulator without Xcode running?"
• "How do I script Face ID enrollment and a match in a UI test?"
• "What's the difference between devicectl and simctl?"
• "What is Device Hub in Xcode 27, and do I need to open Xcode to use it?"
• "How do I list physical devices and simulators together from the command line?"
• "Which device operations still require the Xcode MCP server?"

What's Covered

Tool map

• Which tool owns which job — devicectl, simctl, xcui, xclog, xcsym, xcprof, Device Hub, and mcpbridge
• The "needs Xcode running?" column (only the MCP bridge does)

devicectl (Core Device CLI)

• Unified list devices inventory (physical + simulated, Reality column)
• Install / launch / inspect by -d <udid>
• --json-output stability contract and the keys to parse
• devicectl-vs-simctl division of labor (interaction vs lifecycle)
• Verified simulator-capable subcommand matrix
• Face ID / Touch ID as a CI primitive; the CoreDeviceError 1001 "device-only" signal

Device Hub (Xcode 27 GUI)

• Compact vs full window, the interactive canvas
• The five-panel inspector and what each panel is for

Documentation Scope

This page documents the device-control-ref reference skill (in the axiom-tools suite). It is the canonical home for the devicectl / simctl / Device Hub facts that the build, testing, and tools skills cross-reference.

• For the bundled Axiom CLI tools this reference sits alongside, see xcui (simulator UI & accessibility), Console Capture (xclog), and Crash Symbolication (xcsym)
• For the Xcode MCP path (and why it needs Xcode running), see the Xcode MCP Integration skill
• For the debugging workflow that uses Device Hub to reproduce a device-only bug on a simulator, that lives in the axiom-build xcode-debugging skill
• For the agent that drives simulator state live, see the simulator-tester agent

Related

• xcui – validates the on-screen UI that devicectl sets up; the two compose
• simulator-tester – the agent that applies device state and asserts on the result