Expo IOS Deployment

Expo iOS Deployment

Purpose

Get an Expo/React Native app running on a physical iOS device through an EAS development build (ad hoc distribution) — covering expo-dev-client setup, automatic certificate and provisioning profile generation, device UDID registration, and the eas.json iOS fields required before submission. This is the iOS development testing loop, distinct from production store submission.

When to use

When you need to test an Expo iOS app on a real device and Expo Go is not an option (SDK 56+ removed it) or you need native modules. Apply during development, before production build and store submission. For production build and submit, use eas-build-submit; for App Store Connect listing, use app-store-listing.

Inputs expected

• An Expo project with eas.json (or to be created)
• EAS CLI installed and logged in (eas login)
• An Apple Developer Program membership
• The physical iOS device(s) you intend to test on
• Bundle identifier for the app

Guiding principles

• Install expo-dev-client before building. EAS cannot produce an iOS development build without it. The EAS CLI detects when it is missing and offers to install it automatically during eas build --platform ios --profile development, but installing it up front avoids the interruption.
• The development build flow has three steps that must run in order. First eas credentials (generates the distribution certificate and provisioning profile automatically), then eas device:create (registers the device UDID), then eas build --platform ios --profile development. Building before the device is registered produces a build the device cannot install.
• EAS manages all certificates — do not touch the Apple Developer portal manually. eas credentials creates and stores the distribution certificate and provisioning profile for you. Manual certificate work in the Apple Developer portal is unnecessary and risks conflicts with EAS-managed credentials.
• Register devices with eas device:create using the Website option. This produces a registration URL to open on the target device, which captures its UDID and adds it to the provisioning profile. Ad hoc distribution only installs on devices registered this way — an unregistered device cannot install the build.
• A development build is ad hoc distribution, not the App Store. It installs only on registered devices and is for development/testing. It is a separate artefact from the production build you later submit to the App Store via eas-build-submit.
• eas.json needs the Apple Team ID and ascAppId before submission. The Apple Team ID is shown in the Apple Developer Portal header on the Certificates, Identifiers & Profiles page. The numeric ascAppId is obtained after creating the app in App Store Connect. Both belong under submit.production.ios in eas.json before running eas submit.

Process

1. Install expo-dev-client. Run npx expo install expo-dev-client so EAS can produce a development build.
2. Generate credentials. Run eas credentials and let EAS create the distribution certificate and provisioning profile automatically.
3. Register the test device. Run eas device:create, choose the Website option, and open the resulting URL on the target iOS device to capture its UDID.
4. Build the development profile. Run eas build --platform ios --profile development. Install the resulting build on the registered device.
5. Record iOS submission config. Add the Apple Team ID and ascAppId under submit.production.ios in eas.json ahead of production submission.

Output format

1. Prerequisite check — expo-dev-client installed, EAS CLI logged in
2. Credential summary — distribution certificate and provisioning profile generated by EAS
3. Device registration — device(s) registered via eas device:create, UDID captured
4. Build result — development build produced and installed on the registered device
5. eas.json iOS config — Apple Team ID and ascAppId recorded under submit.production.ios

Quality checklist

• expo-dev-client installed before building
• Credentials generated via eas credentials — no manual Apple portal certificate work
• Target device registered with eas device:create (Website option) before building
• Development build installs and runs on the registered device
• Apple Team ID and ascAppId set under submit.production.ios in eas.json

Avoid

• Building an iOS development build without expo-dev-client installed — it will not work
• Running the steps out of order — register the device before building, or it cannot install the result
• Doing manual certificate work in the Apple Developer portal — let eas credentials manage them
• Expecting a development build to install on an unregistered device — ad hoc distribution requires UDID registration
• Running eas submit before the Apple Team ID and ascAppId are set in eas.json

Example usage

"I'm on Expo SDK 56 so Expo Go won't work for iOS testing. Get my app onto my iPhone with an EAS development build — I'm on Windows with the phone plugged in — and set up eas.json so I can submit to the App Store later."

Source: This skill is sourced from the Matrix Skills library. Learn more at the AI Agent Skills Library.