Install the Warmr Automation Runner on Each iPhone

The Warmr runner is a small helper that lives on each iPhone and lets your Mac drive the device: tapping, scrolling, and posting inside the real apps. Every iPhone needs the runner installed once before it can warm up or post. This is the single most important setup step, and the one most people skip.

You install the runner once per iPhone. After that it stays on the device, and runner updates ship inside the Warmr Mac app. You never reinstall it for an app update.

Before you start

Connect and trust the iPhone

The device must be plugged in and showing in Warmr’s Devices panel. See Connect iPhones.

Prepare the iPhone's settings

Developer Mode must be on (and a few other settings configured). See Prepare each iPhone. Do this first, or the install will fail.

Install Xcode (free, from the Mac App Store)

Xcode is required for the manual signing path, and its developer tools back the one-button path too. Open it once after installing so it finishes its first-launch setup.

Choose a signing method

Apple requires every app installed on an iPhone to be signed. Warmr offers two ways to do this. Pick based on whether you have a paid Apple Developer account.

App Store Connect API: recommended

For paid Apple Developer accounts ($99/year). One-button install, and Warmr re-signs automatically. The certificate is valid for 1 year.

Sign via Xcode: free

Works with a free Apple ID, no paid account needed. The trade-off: the certificate expires every 7 days, so you re-sign weekly.

App Store Connect API (recommended)
Sign via Xcode (free Apple ID)

This is the fastest path, about two minutes. Warmr builds, signs, and installs the runner for you and auto-creates the matching certificate for your team. No Xcode windows, no command line, and no Apple ID password stored in the app.

Is this safe?

Yes. This is the official, Apple-supported way to authenticate with your developer account. Warmr signs locally with short-lived JWT tokens generated from your .p8 key. The key never leaves your machine, no Apple ID password is stored, and your account’s 2FA is untouched. Warmr only creates Development certificates and provisioning profiles, the same kind Xcode makes when you run a project on a connected iPhone. Your App Store / TestFlight / Distribution certificates are never touched, and revoking the key in App Store Connect cuts off access immediately.

Create an App Store Connect API key

Go to App Store Connect → Users and Access → Integrations → App Store Connect API. Generate a Team key (not an Individual key) with the role Admin or App Manager.

The key must be a Team key with role Admin or App Manager. A key with the Developer role cannot create provisioning profiles, and the install will fail.

Download the .p8 key file

After generating the key, click Download to save the .p8 file. Apple only lets you download it once: keep it somewhere safe. Note the Key ID and Issuer ID shown on the same page.

Enter your key in Warmr

In Warmr, open the Devices tab and choose App Store Connect API. Paste your Issuer ID and Key ID, then select the .p8 file you downloaded.

Test the connection

Click Test connection. Warmr verifies the key can talk to Apple and auto-detects your Team ID. Fix any errors before continuing. A failed test almost always means the wrong key role or a typo in the IDs.

If your team is brand new with no registered identifiers yet, Warmr may ask for your Team ID: the 10-character string in the top-right corner at developer.apple.com/account.

Sign & Install on each device

Click Sign & Install next to the iPhone. Warmr builds, signs, and installs the runner, about 30–60 seconds the first time. Repeat for each connected iPhone.

With a paid account, Warmr re-signs the runner automatically as the certificate nears expiry. There’s no weekly maintenance.

No paid account? Sign the runner yourself in Xcode with any Apple ID. It’s a few more clicks, and the signature lasts 7 days before you re-sign.

Add your Apple ID to Xcode first

Open Xcode → Settings → Accounts (⌘,), click +, choose Apple ID, and sign in. Your name appears as a Personal Team: that’s your free signing team. If you have two-factor auth, enter the code Apple pushes to your trusted device.

Then install the runner:

Download the Xcode project

In Warmr, open the Devices tab and click Download Xcode Project. A ZIP lands in your Downloads folder. Unzip it.

Open WarmrRunner.xcodeproj

Inside the unzipped folder, double-click WarmrRunner.xcodeproj to open it in Xcode. Wait for Xcode to finish indexing (the progress bar at the top goes idle).

Set your Team on BOTH targets

Select the WarmrRunner project in the left sidebar, open the Signing & Capabilities tab, and set Team to your Apple ID. Then do it again for the second target.

You must set the Team on both targets: WarmrRunner and WarmrRunnerUITests in the TARGETS list. Setting one does not set the other. If WarmrRunnerUITests has no team, the runner fails to install with a code-signature error.

The Bundle Identifier becomes com.<your-team-id>.warmrrunner automatically once you pick your Team — unique to you, so it registers cleanly. Don’t edit it by hand; a custom value stops Warmr from finding the runner you install.

Plug in and unlock your iPhone

Connect the iPhone via USB and unlock it. If iOS shows Trust This Computer?, tap Trust and enter your passcode.

Select the WebDriverAgentRunner scheme

In the scheme selector at the top of Xcode, choose WebDriverAgentRunner (not WarmrRunner), and pick your iPhone as the destination.

Build with Product → Test (⌘U)

Open the Product menu and click Test (⌘U). This builds WebDriverAgent (about a minute the first time) and installs the runner on your iPhone.

Use Test (⌘U), not the ▶ Run button (⌘R). The Run button installs the app but not the automation runner, and then your warmups silently can’t connect. This is the #1 cause of “the runner is installed but nothing happens.”

Xcode will say “the test runner exited with code 45” and the new WarmrRunner icon may open and immediately close if you tap it. Both are normal — the runner is a long-running automation host with no interface of its own, so its ⌘U test never “finishes.” The icon appearing on your phone means the install worked. Your next step is to trust the developer certificate (next section) so iOS will let Warmr launch it.

Repeat for each iPhone

Switch the destination to the next device and press ⌘U again. One free Apple ID covers up to 3 devices.

Tell Warmr your Team ID

In Warmr, open Devices → “Sign via Xcode Manually” and paste your 10-character Team ID into Your Apple Team ID, then click Save. This points Warmr at the exact runner you just installed (com.<your-team-id>.warmrrunner) instead of the default. Find the ID at developer.apple.com/account → Membership, or read it from Xcode’s build log.

Xcode says "Failed to register bundle identifier"

With a current runner project this shouldn’t happen: picking your Team makes the bundle identifier com.<your-team-id>.warmrrunner automatically — unique to your team. Leave the Bundle Identifier field alone; typing a custom value there stops Warmr from finding the runner you install. If you still see this, re-download a fresh project from Devices → Download Xcode Project and set your Team again on both targets.

"Maximum App ID limit reached"

Free Apple IDs are capped at 10 unique App IDs per 7 days. Wait it out, use a different Apple ID, or move to a paid Apple Developer account.

Every 7 days: a free Apple ID signature expires and the runner stops launching. To refresh it, plug in the iPhone, open the same WarmrRunner.xcodeproj, pick the device, and press Product → Test (⌘U) again. Tired of the weekly refresh? A paid Apple Developer account extends signing to a year and lets Warmr re-sign automatically.

Trust the runner on your iPhone

The first time the runner is installed with a free or personal Apple ID, iOS doesn’t trust the developer certificate yet. Allow it by hand:

Open device management settings

On the iPhone, go to Settings → General → VPN & Device Management.

Trust your developer profile

Under Developer App, tap the row with your Apple ID, then tap Trust and confirm.

Launch the runner once

Find the WarmrRunner icon on the home screen and tap it. It opens to a blank white screen. That’s expected; the runner has no interface of its own. Swipe it closed. You won’t need to open it again.

Verify it worked

Back in Warmr’s Devices panel, the iPhone should now show a green status and a runner-installed badge. The fastest confirmation is to start a short warmup on the device. If it runs, the install is good.

Runner installed and trusted? You’re ready to add an account and start warming.

Stuck on any step? See Setup troubleshooting for the exact fix to each common error.

​Before you start

​Choose a signing method

App Store Connect API: recommended

Sign via Xcode: free

​Trust the runner on your iPhone

​Verify it worked

Before you start

Choose a signing method

Trust the runner on your iPhone

Verify it worked