ios-firebase-example

MetaMask Embedded Wallets — iOS Firebase Custom Connection Example

Demonstrates integrating MetaMask Embedded Wallets (formerly Web3Auth) on iOS with Firebase as a custom authentication provider. The user authenticates with Firebase (Email/Password in this example) and the resulting Firebase ID token is passed to the SDK to reconstruct their non-custodial wallet.

This is the most feature-rich example in the repo — it also demonstrates Wallet Services (in-app wallet UI for send/receive/swap), MFA setup, and the request method for signing via Wallet Services confirmation modal.

What This Example Covers

• Creating a custom connection for Firebase on the Web3Auth dashboard
• Fetching a fresh Firebase ID token and passing it via ExtraLoginOptions
• Launching Wallet Services — an in-app webview wallet UI with send, receive, swap, and WalletConnect
• Enabling MFA after initial login (enableMFA)
• Signing messages via the request method (routes through Wallet Services confirmation modal)
• Session management with custom session duration

How Custom Auth Works

1. User signs in with Firebase (Auth.auth().signIn(...)).
2. A fresh ID token is fetched via getIDTokenResult(forcingRefresh: true).
3. The token is passed to web3Auth.login(W3ALoginParams(..., extraLoginOptions: ExtraLoginOptions(id_token: token, ...))).
4. The SDK validates the JWT against your configured connection (Firebase JWKS endpoint) and reconstructs the private key.

Important: The Firebase ID token must be fetched fresh on every login call — it expires quickly and the SDK enforces a 60-second iat window.

Prerequisites

• Xcode 14+
• iOS 14.0+ deployment target
• A Web3Auth Client ID from dashboard.web3auth.io
• A Firebase project with Email/Password authentication enabled
• A custom connection configured on the Web3Auth dashboard for Firebase
• A GoogleService-Info.plist added to the Xcode project

Setting Up the Custom Connection

1. On the dashboard, go to Connections → Custom and create a new connection.
2. Set the JWKS endpoint to https://www.googleapis.com/service_accounts/v1/jwk/securetoken@system.gserviceaccount.com.
3. Set the user ID field to sub.
4. Copy the connection ID and use it as the verifier in loginConfig.

Installation

git clone https://github.com/Web3Auth/web3auth-ios-examples.git
cd web3auth-ios-examples/ios-firebase-example
open ios-firebase-example.xcodeproj

Uses Swift Package Manager — dependencies (Web3Auth, Firebase) resolve automatically. Add your own GoogleService-Info.plist from the Firebase console.

Configuration

Open ViewModel.swift and set your credentials:

import Web3Auth
import FirebaseAuth

class ViewModel: ObservableObject {
    var web3Auth: Web3Auth?
    private var clientId = "YOUR_WEB3AUTH_CLIENT_ID"
    private var network: Network = .sapphire_mainnet

    func setup() async throws {
        web3Auth = try await Web3Auth(W3AInitParams(
            clientId: clientId,
            network: network,
            redirectUrl: "web3auth.ios-firebase-example://auth",
            loginConfig: [
                TypeOfLogin.jwt.rawValue: .init(
                    verifier: "YOUR_FIREBASE_CONNECTION_ID", // from dashboard
                    typeOfLogin: .jwt,
                    clientId: clientId
                )
            ],
            mfaSettings: MfaSettings(
                deviceShareFactor: MfaSetting(enable: true, priority: 1),
                backUpShareFactor: MfaSetting(enable: true, priority: 2),
                socialBackupFactor: MfaSetting(enable: true, priority: 3),
                passwordFactor: MfaSetting(enable: true, priority: 4)
            ),
            sessionTime: 259200 // 3 days
        ))
    }
}

Login Flow

func loginViaFirebase(email: String, password: String) async throws {
    // 1. Sign in with Firebase
    try await Auth.auth().signIn(withEmail: email, password: password)

    // 2. Fetch a fresh ID token
    let tokenResult = try await Auth.auth().currentUser?.getIDTokenResult(forcingRefresh: true)

    // 3. Pass the token to Web3Auth
    let result = try await web3Auth?.login(
        W3ALoginParams(
            loginProvider: .JWT,
            extraLoginOptions: ExtraLoginOptions(
                id_token: tokenResult?.token,
                verifierIdField: "sub"
            ),
            mfaLevel: .NONE,
            curve: .SECP256K1
        )
    )
    // result.privKey → hex private key
}

Wallet Services (In-App Wallet UI)

Wallet Services provides an in-app webview with a fully functional wallet — send, receive, swap, WalletConnect interoperability, and NFT display. It requires an active Web3Auth session.

func launchWalletServices() async throws {
    try await web3Auth?.launchWalletServices(
        chainConfig: ChainConfig(
            chainId: "0xaa36a7",                                    // Ethereum Sepolia
            rpcTarget: "https://eth-sepolia.public.blastapi.io"
        )
    )
}

Signing via request

For EVM signing that routes through a Wallet Services confirmation modal:

func signMessage() async throws -> String? {
    var params = [Any]()
    params.append("Hello from iOS!")
    params.append(userAddress)

    let result = try await web3Auth?.request(
        chainConfig: ChainConfig(
            chainId: "0x89",
            rpcTarget: "https://polygon.llamarpc.com"
        ),
        method: "personal_sign",
        requestParams: params
    )
    return result?.success == true ? result?.result : result?.error
}

Project Structure

ios-firebase-example/
├── ios-firebase-example.xcodeproj
└── ios-firebase-example/
    ├── ContentView.swift         # Root navigation
    ├── LoginView.swift           # Firebase login UI
    ├── UserDetailView.swift      # Post-login: user info, Wallet Services, MFA, request
    ├── ViewModel.swift           # Web3Auth init, login, logout, Wallet Services, MFA
    └── web3RPC.swift             # EVM interactions via web3.swift

Resources

• iOS SDK Documentation
• Firebase Custom Connection Guide
• Custom Connections Overview
• Dashboard
• Builder Hub (Community & Support)

License

MIT — see LICENSE for details.