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Mobile

Give your phone app the same sign-in, saved data, files, credits and AI tools as your web app. Use @gemmein/sdk/expo for Expo and React Native, or the GemmeinSwift package for Apple platforms.

import { createExpoGemmein } from "@gemmein/sdk/expo"
import { AppState, Platform } from "react-native"

export const g = createExpoGemmein({ appKey: "pk_live_..." }, { AppState, Platform })

await g.auth.sendEmailCode(email)
await g.auth.verifyEmailCode({ email, code })
const { records } = await g.collection("notes").list({ limit: 20 })

const me = await g.auth.currentUser()
if (me.authenticated && me.storeAccountToken) {
  // RevenueCat must know the buyer by this name
  await Purchases.configure({ apiKey: RC_KEY, appUserID: me.storeAccountToken })
  // already configured? Purchases.logIn(me.storeAccountToken)
}

What it is. The same Gemmein API from an Expo app or a Swift app. Expo uses @gemmein/sdk/expo, the same npm package with a second entry point. Swift uses GemmeinSwift (iOS 17+ and macOS 14+), with the same method names.

Does. Sign-in with an emailed sign-in code; your app's collections, private records included; sealed files and files.link; credits; AI tools; the store account token (currentUser().storeAccountToken), the name you give RevenueCat as its app user id; sign out everywhere for a stolen phone; and secure persistence (the iOS Keychain and the Android Keystore through expo-secure-store, the Keychain through KeychainTokenStore in Swift), so the app relaunches still signed in.

Does not. Offer Google or Apple sign-in: sign-in codes are the only way to sign in, on every platform. Hold store billing: a store purchase reaches Gemmein through RevenueCat's webhook into a relay. Broadcast: one event acts on one person.

Needs something else when. The person buys a store product → RevenueCat and the three relay templates in Store purchases. They buy on the web, or the goods are not the store's → Stripe, the built-in path. Your app needs more sign-in codes than the limits allow → see Sign-in limits. The device cannot keep the session → sign-in throws secure_store_unavailable; the fix is in Codes.

Example. The Expo code above signs a person in, reads a private collection and gives RevenueCat the store account token. Swift shows the same three calls.

In this section

Expo, Swift and local development

Keys and sessions on a phone, Expo and React Native, Swift, the store account token, and gemmein dev.

Store purchases

App Store and Play purchases through RevenueCat and a relay.

Sign-in limits, billing and codes

Sign-in limits on a phone, sign out everywhere, billing, and the codes a mobile build meets.
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