Mobile App Builder Architecture

mp-mobile-app-builder is a standalone repository whose sole purpose is producing signed, distributable native app packages for the iOS App Store and Google Play Store.

For the mobile app itself (development, features, OTA updates) see Mobile App Architecture. For deployment steps see iOS Build and Android Build.

Why a Separate Repo?

mp-mobile-app (the main patient app) and mp-mobile-app-builder serve different purposes and deliberately stay separated:

	mp-mobile-app	mp-mobile-app-builder
Purpose	Active development, web deployment, OTA updates	Native app store package production only
Nuxt version	Nuxt 4 (latest)	Nuxt 3 (older — may lag behind)
Dependencies	Full dev toolchain, mobile plugins, Capacitor	Minimal — only what's needed for a static build + Fastlane
Used by	Developers daily	CI/CD + release engineers on release day
Native repos	`ios/` + `android/` submodules	`ios/` + `android/` submodules (separate native repos)

Why keep the Nuxt version older in the builder?

The builder only needs to produce a static bundle (nuxt generate). Upgrading it in lockstep with mp-mobile-app every time would add risk to release builds with no benefit. The builder is upgraded deliberately when needed.

How a Native Build Works

mp-mobile-app-builder
  │
  ├─ nuxt generate              → .output/public/ (static web bundle)
  │
  ├─ npx cap sync               → copies .output/public/ into ios/App/public/
  │                               and android/app/src/main/assets/public/
  │
  ├─ Fastlane ios beta          → xcodebuild archive → IPA → TestFlight
  │
  └─ Fastlane android internal  → gradle bundle Release → AAB → Play Store internal

Step 1 — Static generation

nuxt generate produces a fully static bundle in .output/public/. This is the web content that will run inside the native WebView.

Step 2 — Capacitor sync

npx cap sync copies the generated web bundle into the native projects and installs any Capacitor plugin native code changes.

Step 3 — Fastlane build + upload

Fastlane handles code signing, archiving, and store upload. See iOS Build and Android Build for full lane documentation.

Repository Structure

mp-mobile-app-builder/
  ios/                              ← git submodule → mp-mobile-app-ios-native
    App/
      fastlane/
        Fastfile                    ← beta lane: setup_ci + match + build + upload
        Appfile                     ← com.medipal.sigil + team/issuer IDs
      App.xcodeproj/
      capacitor.config.json
  android/                          ← git submodule → mp-mobile-app-android-native
    fastlane/
      Fastfile                      ← internal lane: gradle bundle + play store upload
      Appfile                       ← com.medipal.sigil
    app/
      src/
  nuxt.config.ts
  capacitor.config.ts
  package.json

Git Submodules

The native Xcode and Android Studio projects live in separate repositories to keep platform-specific build artifacts, provisioning data, and IDE files isolated from the web codebase.

Submodule path	Repository
`ios/`	`mp-mobile-app-ios-native`
`android/`	`mp-mobile-app-android-native`

After cloning mp-mobile-app-builder, always initialize submodules:

bash

git clone --recurse-submodules <mp-mobile-app-builder>
# or:
git submodule update --init --recursive

When the native projects are updated (Xcode project settings, Capacitor plugin native code), update the submodule pointer:

bash

cd ios && git pull origin main && cd ..
git add ios && git commit -m "chore: update ios native submodule"

Live Update Bundle

When the USE_LIVE_UPDATE environment variable is set, npm run generate additionally produces:

live-update.zip — compressed web bundle for OTA delivery
manifest.json — { hash, version, timestamp, contentUrl }

These are uploaded to the updates.{env}.medipal.dev CDN endpoint (served by mp-frontend-nginx-proxy). The running app checks this manifest on startup and downloads the zip if its local hash is stale.

bash

USE_LIVE_UPDATE=true npm run generate

See Mobile App Architecture — Live Update for the full OTA update flow.

Key Environment Variables

Variable	Used in	Purpose
`API_URL`	Nuxt build	Backend API base URL baked into the bundle
`API_KEY`	Nuxt build	API key baked into the bundle
`CRYPTO_KEY`	Nuxt build	AES key for deep-link token decryption
`LIVE_UPDATE_URL`	Nuxt build	OTA update server URL
`USE_LIVE_UPDATE`	Nuxt generate	Enables live-update zip + manifest generation
`APP_STORE_CONNECT_API_KEY_ID`	Fastlane (iOS)	App Store Connect API authentication
`APP_STORE_CONNECT_API_ISSUER_ID`	Fastlane (iOS)	App Store Connect API authentication
`APP_STORE_CONNECT_API_KEY_CONTENT`	Fastlane (iOS)	`.p8` key content
`MATCH_PASSWORD`	Fastlane (iOS)	Passphrase for `mp-fastlane-certificates` decryption
`ANDROID_KEYSTORE_*`	Fastlane (Android)	APK/AAB signing

npm Scripts

Script	What it does
`npm run build`	`nuxt generate` (web bundle only)
`npm run build:ios`	`nuxt generate` + `cap sync ios`
`npm run build:android`	`nuxt generate` + `cap sync android`

Mobile App Builder Architecture ​

Why a Separate Repo? ​

How a Native Build Works ​

Step 1 — Static generation ​

Step 2 — Capacitor sync ​

Step 3 — Fastlane build + upload ​

Repository Structure ​

Git Submodules ​

Live Update Bundle ​

Key Environment Variables ​

npm Scripts ​

See Also ​

Mobile App Builder Architecture

Why a Separate Repo?

How a Native Build Works

Step 1 — Static generation

Step 2 — Capacitor sync

Step 3 — Fastlane build + upload

Repository Structure

Git Submodules

Live Update Bundle

Key Environment Variables

npm Scripts

See Also