How a phone works

A phone is an iOS Simulator on a cloud Mac with Xcode 27.1, erased when it stops. Your agent drives it with its tools; there is no shell.

Start one

Connected to NoMac over MCP, your agent already has the phone: it calls phone with action start. The phone is ready in about 4 seconds. When every phone is in use, the start waits in line for up to 5 minutes, and the wait is free.

The phone alone: Any MCP client: https://mcp.nomac.app/simulator, with simulator-use's tool names (cloud, app_run, ui_look…).
A terminal: On macOS, Linux or Windows: npx simulator-use cloud start.
Your code: The REST API or the SDKs.

Devices

iphone: iPhone 17 Pro, iOS 27. The default, kept ready.
ipad: iPad Pro 11-inch (M5), iOS 27. Prepared when a start asks for it, in about a minute.
iphone-pro-max: iPhone 17 Pro Max, iOS 27. Prepared when a start asks for it, in about a minute.

The iPhone 17 Pro Max is the 6.9-inch size App Store Connect asks for, so its screenshots go straight to a listing.

Limits

Idle: Stops after 10 minutes without a tool call or a person's input through a control link; watching does not count. 60 seconds to an hour with idle_timeout_seconds.
Time: 2 hours by default, 8 at most (max_duration_seconds).
Spend: $5 at most by default (spend_cap_microunits).
At once: 2 phones per account, beside the account's Mac. For more, see NoMac Platform.

In its last 15 minutes before a limit or the end of the credit, every answer carries stop_notice: when the phone stops, why, and what to do. phone with action extend adds time, up to 8 hours in all.

Cost

$0.80 an hour, billed per minute from the account's prepaid credit, one minute at least: a 12-minute session costs 16 cents. Builds are included, and waiting in line is free. See Pricing and billing.

What is kept

Erased at stop: The phone, its apps and their data.
Kept for the next phone: The workspace: your projects and their build cache, so the next build is incremental. Deleted after 90 days unused.
Kept until deleted: Saved states: a phone's apps and data, by name.
Kept 7 days: The replay: a video of the screen beside every tool call.

Each phone runs under its own macOS user, on its own volume, behind a firewall, on Macs that run only phones. For a shell, macOS apps, signing or TestFlight, use a NoMac Session Mac.

Stop it

Terminal

simulator-use cloud stop

Over MCP, phone with action stop; over REST, DELETE /sessions/:id. Billing ends at the stop, and the answer links to the replay. A phone left alone stops at its idle timeout.