--- title: "Cursor and the iOS simulator: MCP setup | Mobster" description: "Add Mobster to Cursor's mcp.json with the full path to the command, then let Cursor's agent check your iOS app's screens on a simulator Mobster manages." canonical: "https://mobster.dev/integrations/cursor" last-updated: "2026-10-08" --- Add Mobster to Cursor's mcp.json with the full path to the command, then let Cursor's agent check your iOS app's screens on a simulator Mobster manages. # Cursor and the iOS simulator: MCP setup Add Mobster to Cursor's mcp.json with the full path to the command, then let Cursor's agent check your iOS app's screens on a simulator Mobster manages. ## The short version Install Mobster CLI, then run: ``` mobster mcp install cursor ``` Config file: ~/.cursor/mcp.json, or .cursor/mcp.json in a project **From the docs.** This setup follows Anysphere's MCP documentation, read on 8 October 2026. Mobster's MCP server is tested with Claude Code; we haven't run it in Cursor ourselves yet. [Anysphere’s MCP docs](https://cursor.com/docs/mcp). Cursor’s agent can write a SwiftUI screen, and then someone has to open the simulator and look at it. With `mobster mcp` in Cursor, the agent does that part: it states what the screen must show, drives your app on a headless simulator Mobster manages, and gets a verdict of passed or failed from assertions on the accessibility tree. It can also use a real iPhone on your Mac’s USB. You need an Apple silicon Mac with macOS 15 or later and Xcode with an iOS Simulator runtime. A real iPhone also needs Developer Mode and the WebDriverAgent runner, set up in Mobster for Mac or with `mobster serve --manage-device` ([Device setup](https://docs.mobster.dev/device-setup)). ## Install Mobster CLI ``` curl -fsSL https://mobster.dev/install.sh | sh ``` or ``` brew install radishsoftware/tap/mobster ``` Then find the full path to the command, which Cursor needs, and prepare the simulator once: ``` mobster version which mobster mobster sim doctor --fix ``` `which mobster` prints `/opt/homebrew/bin/mobster` for a Homebrew install, or a path ending in `.local/bin/mobster` in your home folder for the install script. ## Add the server Cursor reads `.cursor/mcp.json` in a project and `~/.cursor/mcp.json` for every project. Put this in one of them, with your own path from `which mobster`: ``` { "mcpServers": { "mobster": { "type": "stdio", "command": "/opt/homebrew/bin/mobster", "args": ["mcp"] } }} ``` Or let Mobster write that entry, with the full path filled in: `mobster mcp install cursor` adds it to `~/.cursor/mcp.json`. Two details matter. Cursor’s docs say `command` must be on the system path or a full path, and as a GUI app Cursor may not see the `PATH` your shell sets up, so the full path is the safe choice. Cursor’s field table also lists `"type": "stdio"` as required while its examples leave it out; the block above includes it, which works either way. Save the file and restart Cursor. For Smart, where Mobster runs the steps itself on your OpenAI or Anthropic key, add your env file to `args`: `["mcp", "--env-file", "~/.config/mobster/agent.env"]`. Mobster expands the `~` itself. Key-less checks need no key. Cursor’s docs don’t state a tool-call timeout. Mobster doesn’t depend on a long one: every call returns within 45 seconds and `wait` within 50, and longer work, such as the first simulator boot, continues under a `run_id` that the agent polls with `wait`. ## Check it’s connected Open Customize, then MCPs: mobster should be there, switched on, with its tools listed. If it isn’t, the Output panel (Cmd+Shift+U) has a channel named MCP Logs with the server’s start-up errors. Then ask the agent: ``` Call mobster's status tool and tell me what it reports. ``` ## A first check: onboarding Daybreak, the sample app in the CLI’s repository, opens with a short onboarding that asks for notification permission. A prompt for Cursor’s agent: ``` Build Daybreak for the simulator, then verify that a new user can complete onboarding without allowing notifications and lands on the paywall. ``` The agent calls `verify_start` with the absolute `app_path`, the steps and the expectations, then taps through. A real key-less session on Daybreak’s onboarding, from Mobster’s own smoke script on 28 Sep 2026, with each call, how long it took and the first line it returned: ``` verify_start 3.94 s Run 20260928-151841-816e is ready. Drive the app with the refs below, then call verify_finish. tap 1.86 s Tapped “Continue”; the screen changed. tap 2.13 s Tapped “Continue”; the screen changed. tap 1.89 s Tapped “Turn on reminders”; the screen didn't change. screen 0.46 s Screen dev.mobster.daybreak 402×874 pt keyboard: none alert: "“Daybreak” Would Like to Send You Notifications …" alert 2.13 s Dismissed the alert "“Daybreak” Would Like to Send You Notifications …". tap 4.13 s Tapped “Get started”; the screen changed. wait_for 4.50 s All 1 hold (4.5 s). verify_finish 3.07 s Verdict: passed Complete onboarding. Don't allow notifications. (24.1 s) ``` The simulator was already up. Note the fourth line: the tap didn’t change the screen because the system alert came up, and `alert` answered it. `verify_finish` returns the verdict, the report path and the overlay frame. On `failed`, the agent fixes the code, rebuilds and verifies again. ## Add a project rule Cursor applies project rules from `.cursor/rules`, as `.mdc` files with front matter. With a description and `alwaysApply: false`, the agent reads the description and pulls the rule in when it’s relevant: ``` ---description: How to verify a change to this iOS app's screens with Mobster before saying it worksalwaysApply: false---After you change a screen in this iOS app, verify it before you say it works.1. Build for the simulator: xcodebuild -scheme -destination 'generic/platform=iOS Simulator' -derivedDataPath .mobster/build CODE_SIGNING_ALLOWED=NO build2. Call mobster's verify_start with the absolute app_path of .mobster/build/Build/Products/Debug-iphonesimulator/.app, the steps, and expect.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. ``` Save it as `.cursor/rules/mobster.mdc`. A plain `.md` file there is ignored. If you prefer plain Markdown, Cursor also reads an `AGENTS.md` at the project root. ## Use a real iPhone The agent calls `list_devices`, then passes a USB iPhone’s name as `device` to `screen`, `tap`, `type_text`, `swipe`, `alert`, `open_url`, `launch_app` and `home`, with no `run_id`. Mobster takes the phone’s lock for the session, and `stop` with the `device`, or 90 idle seconds, gives it back. Cursor asks for approval before MCP tools by default. Your approval covers a tool, not a device, so allowing `tap` while you test on a simulator allows it on your phone as well. Limit the server to the phones you mean: ``` "args": ["mcp", "--allow-device", "Test iPhone"] ``` To skip the prompt for reads only, list Mobster’s read-only tools in `mcpAllowlist` in `~/.cursor/permissions.json` or the workspace’s `.cursor/permissions.json`, as `server:tool` entries such as `"mobster:screen"`, `"mobster:status"` and `"mobster:list_devices"`. Avoid `"mobster:*"`, which also allows `tap` and `type_text` without asking. Mobster’s MCP annotations mark which tools only read, and its instructions tell the agent to ask before anything that sends, buys, posts or deletes on a real iPhone. A locked phone stops the call at once, and Mobster never enters a passcode. ## Troubleshooting | Symptom | Fix | |---|---| | mobster doesn’t start, or shows an error in MCP Logs | Use the full path from `which mobster` in `command`, then restart Cursor | | The server is listed, but every call asks for approval | That is Cursor’s default. Add the read-only tools to `mcpAllowlist` | | The first `verify_start` returns `status: "preparing"` | The simulator is booting and WebDriverAgent is building. The agent calls `wait`, or run `mobster sim doctor --fix` first | | `couldnt_run`, or no `verify` tool | `reason.fix` in the result says what to do. `status` says why Smart is off | The [MCP reference](https://docs.mobster.dev/mcp-server) lists every tool. [AI end-to-end tests for iOS](https://mobster.dev/blog/ai-e2e-tests-ios-assertions) explains how the verdict is decided. ## Questions - ### Why does Cursor fail to start the Mobster server? Cursor is a GUI app and may not see your shell's PATH. Cursor's docs say the command must be on the system path or a full path, so put the output of which mobster in the command field and restart Cursor. - ### Should the Cursor config include "type": "stdio"? Yes. Cursor's field table marks type as required for a local server while its examples leave it out. Including it works under both readings. - ### Can Cursor run Mobster's read-only tools without asking? Yes. Add entries such as mobster:screen and mobster:status to mcpAllowlist in Cursor's permissions.json. Keep the acting tools, like tap and type_text, out of the list so Cursor still asks before them. - ### How do I connect Cursor to the iOS Simulator? Add Mobster's MCP server to ~/.cursor/mcp.json, or run mobster mcp install cursor, then restart Cursor. Its agent can then run your app on a headless simulator Mobster manages, read each screen by element name, tap and type, and get passed or failed from assertions. ## Sources We read each of these on 8 October 2026. Reviewed by Andy Guo on 8 October 2026. Corrections are welcome at the [GitHub repo](https://github.com/RadishSoftware/mobster/issues). - [Cursor docs: Model Context Protocol (MCP)](https://cursor.com/docs/mcp) - [Cursor docs: rules](https://cursor.com/docs/rules) - [Cursor docs: permissions.json reference](https://cursor.com/docs/reference/permissions) - [MCP specification: ToolAnnotations (readOnlyHint)](https://modelcontextprotocol.io/specification/2025-11-25/schema) - [Apple: enabling Developer Mode on a device](https://developer.apple.com/documentation/xcode/enabling-developer-mode-on-a-device) - [Mobster docs: MCP server](https://docs.mobster.dev/mcp-server) - [Mobster docs: device setup](https://docs.mobster.dev/device-setup) Cursor’s logo is a trademark of Anysphere, shown only to name the product. Mobster isn’t affiliated with or endorsed by Anysphere. ## Read next - [Every MCP tool, in the reference](https://docs.mobster.dev/mcp-server) - [Getting started with verify](https://docs.mobster.dev/verify) ## Other agents - [Claude Code](https://mobster.dev/integrations/claude-code) - [Codex](https://mobster.dev/integrations/codex) - [VS Code](https://mobster.dev/integrations/vs-code) - [Claude Desktop](https://mobster.dev/integrations/claude-desktop) - [Gemini CLI](https://mobster.dev/integrations/gemini-cli) - [opencode](https://mobster.dev/integrations/opencode) - [Windsurf (Devin Desktop)](https://mobster.dev/integrations/windsurf)