Auth0 Expo

Auth0 Expo Integration

Add authentication to Expo (React Native) applications using react-native-auth0 with the Expo Config Plugin.

Agent instruction: Before providing SDK setup instructions, fetch the latest release version by running:

gh api repos/auth0/react-native-auth0/releases/latest --jq '.tag_name'

Use the returned version in all dependency lines instead of any hardcoded version below. If the command fails, fall back to checking https://github.com/auth0/react-native-auth0/releases.

Prerequisites

• Expo SDK 53 or higher (react-native-auth0 v5.x requires Expo 53+)
• React 19 and React Native 0.78.0 or higher
• Node.js 20+ (for bootstrap script automation)
• Auth0 account with a Native application configured
• If Auth0 is not set up yet, use the auth0-quickstart skill first
• Not compatible with Expo Go — requires custom development client or EAS Build

When NOT to Use

Quick Start Workflow

Agent instruction: First, check whether the user's prompt already includes both Auth0 Client ID and Domain.

• If both are provided, skip the setup-choice question and proceed directly to Step 2 (Verify Expo Dev Client) using those values.
• If either value is missing, ask the user using AskUserQuestion: "How would you like to configure Auth0 for this Expo project?"
  • Automatic setup (Recommended) — runs a bootstrap script that creates the Auth0 app, database connection, callback URLs, and writes the plugin config to app.json
  • Manual setup — the user provides their Auth0 Client ID and Domain

Follow the matching section below based on their choice.

1. Configure Auth0

Automatic Setup

Agent instruction: Run these quick checks before the bootstrap script. Do NOT run auth0 login from the agent — it is interactive and will hang.

1. Check Node.js: node --version. If missing or below 20, ask user: install (brew install node) or switch to manual setup.
2. Check Auth0 CLI: command -v auth0. If missing, ask user: install (brew install auth0/auth0-cli/auth0) or switch to manual setup.
3. Check Auth0 login: auth0 tenants list --csv --no-input 2>&1. If it fails or returns empty:
   • Tell the user: "Please run auth0 login in your terminal and let me know when done."
   • Wait for the user to confirm, then re-run the check to verify.
4. Confirm active tenant: Parse the → line from the CSV output to identify the active tenant domain. Tell the user: "Your active Auth0 tenant is: <domain>. Is this the correct tenant?"
   • If yes, proceed.
   • If no, ask the user to run auth0 tenants use <tenant-domain> in their terminal, then re-run step 3 to confirm the new active tenant.

Once confirmed, run the bootstrap script:

cd <path-to-skill>/auth0-expo/scripts
npm install
node bootstrap.mjs <path-to-expo-project>

The script validates the Expo project, creates a Native Auth0 application, sets up a database connection, and writes the plugin config to app.json. The agent should NOT handle client_id or domain manually.

If the script fails due to session expiry, ask the user to run auth0 login again, then re-run the script. For other failures, fall back to Manual Setup below.

After the script completes, proceed to Step 2 (Verify Expo Dev Client).

Manual Setup (User-Provided Credentials)

Agent instruction: Ask the user for their Auth0 credentials using AskUserQuestion:

"I need your Auth0 credentials to set up authentication. Please provide:

1. Auth0 Domain (e.g., your-tenant.us.auth0.com)
2. Client ID (a 32-character alphanumeric string)

You can find both in the Auth0 Dashboard under Applications > Applications > your app > Settings. If you don't have an Auth0 app yet, create one with type Native and copy the domain and client ID from the settings page."

Then write the configuration to app.json and proceed to Step 2.

2. Verify Expo Dev Client

Agent instruction: Before installing the Auth0 SDK, check if the project has expo-dev-client installed. Read the project's package.json and look for expo-dev-client in dependencies or devDependencies.

• If expo-dev-client is found: Proceed to step 3.

• If expo-dev-client is NOT found: Use AskUserQuestion with the following message:

  "The react-native-auth0 SDK requires a custom Expo development client — it does not work with Expo Go. Your project does not have expo-dev-client installed.

  How would you like to proceed?

  1. Install it for me — I'll run npx expo install expo-dev-client and continue setup
  2. I'll set it up myself — skip this step and continue to Auth0 SDK installation"

  If the user picks option 1, run:

  npx expo install expo-dev-client
  

  Then proceed to step 3. If option 2, proceed to step 3 directly.

3. Install SDK

npx expo install react-native-auth0

4. Configure Expo Config Plugin

Add the react-native-auth0 plugin to app.json (or app.config.js) with your Auth0 domain and a custom scheme. Also ensure bundleIdentifier (iOS) and package (Android) are set:

{
  "expo": {
    "ios": { "bundleIdentifier": "com.yourcompany.yourapp" },
    "android": { "package": "com.yourcompany.yourapp" },
    "plugins": [
      ["react-native-auth0", {
        "domain": "YOUR_AUTH0_DOMAIN",
        "customScheme": "YOUR_CUSTOM_SCHEME"
      }]
    ]
  }
}

The customScheme must be all lowercase with no special characters (e.g., auth0sample). See Setup Guide for HTTPS callbacks, multiple domains, EAS Build, and secret management.

Agent instruction: If you used automatic setup (Step 1), the bootstrap script already wrote the plugin config to app.json — verify it's correct but do not overwrite it. If you used manual setup, write the config now using the user-provided domain and a custom scheme.

5. Configure Callback URLs

Add to Allowed Callback URLs and Allowed Logout URLs in the Auth0 Dashboard:

YOUR_CUSTOM_SCHEME://YOUR_AUTH0_DOMAIN/ios/YOUR_BUNDLE_ID/callback,
YOUR_CUSTOM_SCHEME://YOUR_AUTH0_DOMAIN/android/YOUR_PACKAGE/callback

All values must be lowercase with no trailing slash. For HTTPS callback URLs (App Links / Universal Links), see Setup Guide.

6. Add Authentication with Auth0Provider

Wrap your app with Auth0Provider and use the useAuth0 hook:

Agent instruction: Before adding new UI elements, search the project for existing click handlers for login, logout, sign-in, or sign-out buttons. If existing handlers are found, hook the Auth0 code into them. Only create new buttons if no existing handlers are found.

import React from 'react';
import { Auth0Provider, useAuth0 } from 'react-native-auth0';
import { View, Button, Text, ActivityIndicator } from 'react-native';

function HomeScreen() {
  const { authorize, clearSession, user, isLoading, error } = useAuth0();

  const login = async () => {
    try {
      await authorize(
        { scope: 'openid profile email' },
        { customScheme: 'YOUR_CUSTOM_SCHEME' }
      );
    } catch (e) {
      console.error('Login error:', e);
    }
  };

  const logout = async () => {
    try {
      await clearSession({ customScheme: 'YOUR_CUSTOM_SCHEME' });
    } catch (e) {
      console.error('Logout error:', e);
    }
  };

  if (isLoading) {
    return <ActivityIndicator size="large" />;
  }

  return (
    <View>
      {user ? (
        <>
          <Text>Welcome, {user.name}!</Text>
          <Text>{user.email}</Text>
          <Button title="Log Out" />
        </>
      ) : (
        <Button title="Log In" />
      )}
      {error && <Text>{error.message}</Text>}
    </View>
  );
}

export default function App() {
  return (
    <Auth0Provider
      domain="YOUR_AUTH0_DOMAIN"
      clientId="YOUR_AUTH0_CLIENT_ID"
    >
      <HomeScreen />
    </Auth0Provider>
  );
}

7. Build & Verify

Agent instruction: After completing the integration, build the project to verify it compiles:

npx expo prebuild --clean
npx expo run:ios
# or
npx expo run:android

If the build fails, analyze the error output. Common integration build failures include:

• "Invariant Violation: Native module cannot be null": Using Expo Go instead of a development build — run npx expo run:ios or npx expo run:android instead of npx expo start
• Plugin not applied: Missing react-native-auth0 in app.json plugins array — verify the plugin configuration
• Pod install fails (iOS): Run npx expo prebuild --clean to regenerate native projects
• Manifest merge failure (Android): Conflicting auth0Domain placeholder — ensure only the config plugin sets the domain

Re-run the build after each fix. Track the number of build-fix iterations.

Failcheck: If the build still fails after 5–6 fix attempts, stop and ask the user using AskUserQuestion: "The build is still failing after several fix attempts. How would you like to proceed?"

• Let the skill continue fixing iteratively
• Fix it manually — show the remaining errors
• Skip build verification — proceed without a successful build

Detailed Documentation

• Setup Guide — Dev client requirement, automated setup, Expo config plugin, callback URLs, EAS Build, secret management
• Integration Patterns — Login/logout, credential management, biometric auth, token refresh, organizations, DPoP, error handling
• API Reference & Testing — Configuration options, useAuth0 hook API, testing checklist, common issues, security

Common Mistakes

Related Skills

• auth0-quickstart — Set up an Auth0 account and application
• auth0-react-native — Bare React Native CLI projects
• auth0-mfa — Configure multi-factor authentication

References

• Auth0 Expo Quickstart
• react-native-auth0 GitHub Repository
• react-native-auth0 API Documentation
• Expo Sample App
• EXAMPLES.md

Source: mhwatson/agent-skills — distributed by TomeVault.