Auth0 Ionic Angular (Capacitor) Integration

Add authentication to an Ionic Angular application using the @auth0/auth0-angular SDK with Capacitor plugins for native iOS and Android. This skill covers login, logout, user profile display, and secure token management using the system browser (SFSafariViewController on iOS, Chrome Custom Tabs on Android) via Capacitor's Browser plugin.

When NOT to Use

Detailed Documentation

• Setup Guide — Auth0 configuration, Auth0 CLI setup, Capacitor platform setup, deep linking
• Integration Patterns — Login/logout flows, token management, user profile, error handling, Capacitor lifecycle
• API Reference & Testing — AuthService API, configuration options, claims reference, testing checklist

WebAuth Method

Ionic with Capacitor uses the Web Auth method for authentication:

1. User taps Log In → app calls loginWithRedirect with a custom openUrl that uses Browser.open()
2. Capacitor's Browser plugin opens the Auth0 Universal Login page in the system browser (SFSafariViewController / Chrome Custom Tabs)
3. User authenticates → Auth0 redirects to the custom URL scheme callback
4. OS routes the deep link to your app → appUrlOpen event fires
5. handleRedirectCallback(url) processes the auth code exchange inside ngZone.run()
6. Browser.close() dismisses the system browser
7. auth.isAuthenticated$ emits true, and auth.user$ emits the user profile

Related Skills

• auth0-ionic-react — Ionic React with Capacitor
• auth0-ionic-vue — Ionic Vue with Capacitor
• auth0-angular — Angular SPA (browser-only)
• auth0-swift — Native iOS (Swift)
• auth0-android — Native Android (Kotlin)

Quick Reference

References

• Auth0 Angular SDK — GitHub
• Auth0 Ionic Angular Quickstart
• Auth0 Angular SDK — API Reference
• Capacitor Browser Plugin
• Capacitor App Plugin — Deep Links
• Ionic Framework — Angular

Prerequisites

• Node.js 20+ and npm 10+
• Ionic CLI (npm install -g @ionic/cli)
• Capacitor 5+ configured in the project
• Auth0 CLI (for automatic setup): brew install auth0/auth0-cli/auth0
• An Auth0 account (free tier works)

Quick Start Workflow

Agent instruction: Follow these steps in order. Always use AskUserQuestion to let the developer choose between Automatic Setup and Manual Setup before proceeding — even if credentials are already provided in the prompt.

SECURITY — Never display credentials: After obtaining Auth0 credentials (domain, client ID) via the CLI or from a file, NEVER print, echo, or display them in your text output. Write them directly to the config file (src/environments/environment.ts) silently. Do NOT produce output like "Domain: xxx" or "Client ID: yyy". Instead, confirm that the config file has been written and tell the user where to find it.

UI reuse: Before creating new login/logout components, search the existing project for login/logout handlers or buttons. If found, hook Auth0 into the existing UI rather than creating duplicate components.

Step 1: Install Dependencies

npm install @auth0/auth0-angular @capacitor/browser @capacitor/app

Step 2: Configure Auth0

Agent instruction: Always present the setup choice using AskUserQuestion — even if the user has already provided credentials:

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AskUserQuestion:
  question: "How would you like to configure Auth0 for your Ionic Angular app?"
  options:
    - label: "Automatic Setup (Recommended)"
      description: "Uses the Auth0 CLI to create a Native application, configure callback URLs, and store credentials in your project automatically."
    - label: "Manual Setup"
      description: "You provide an .env file with your Auth0 Domain and Client ID, and the agent reads it and writes the project configuration for you."

Follow the chosen path in the Setup Guide which has the full step-by-step instructions for both options.

Auth0 Dashboard settings (Native application type):

Replace PACKAGE_ID with your appId from capacitor.config.ts (e.g., com.example.myapp) and YOUR_DOMAIN with your Auth0 domain.

Note: For Automatic Setup, these URLs are configured automatically by the Auth0 CLI. For Manual Setup, the user must configure them in the Auth0 Dashboard.

Note: For local web development (ionic serve), also add http://localhost:8100 to Allowed Callback URLs, Allowed Logout URLs, and Allowed Web Origins.

Step 3: Configure the SDK

In src/app/app.module.ts (NgModule) or src/app/app.config.ts (standalone):

The provideAuth0() function (or AuthModule.forRoot()) is the Angular equivalent of Auth0Provider — it acts as the provider/wrapper that wraps the app and makes AuthService available everywhere. For local web development with ionic serve, the callback URL is http://localhost:8100.

Standalone (Angular 17+):

import { ApplicationConfig } from '@angular/core';
import { provideAuth0 } from '@auth0/auth0-angular';

// Replace with your capacitor.config.ts appId and Auth0 domain
const appId = 'com.example.myapp';
const domain = 'YOUR_AUTH0_DOMAIN';
const callbackUri = `${appId}://${domain}/capacitor/${appId}/callback`;

export const appConfig: ApplicationConfig = {
  providers: [
    provideAuth0({
      domain,
      clientId: 'YOUR_AUTH0_CLIENT_ID',
      useRefreshTokens: true,
      useRefreshTokensFallback: false,
      authorizationParams: {
        redirect_uri: callbackUri,
      },
    }),
  ],
};

NgModule (Angular 16 and earlier):

import { AuthModule } from '@auth0/auth0-angular';

const appId = 'com.example.myapp';
const domain = 'YOUR_AUTH0_DOMAIN';
const callbackUri = `${appId}://${domain}/capacitor/${appId}/callback`;

@NgModule({
  imports: [
    AuthModule.forRoot({
      domain,
      clientId: 'YOUR_AUTH0_CLIENT_ID',
      useRefreshTokens: true,
      useRefreshTokensFallback: false,
      authorizationParams: {
        redirect_uri: callbackUri,
      },
    }),
  ],
})
export class AppModule {}

Step 4: Handle Deep Link Callbacks (AppComponent)

Register the appUrlOpen listener at the app root so it persists across navigation:

import { Component, NgZone, OnInit } from '@angular/core';
import { AuthService } from '@auth0/auth0-angular';
import { Browser } from '@capacitor/browser';
import { App as CapApp } from '@capacitor/app';
import { mergeMap } from 'rxjs/operators';

@Component({
  selector: 'app-root',
  template: `<ion-app><ion-router-outlet></ion-router-outlet></ion-app>`,
})
export class AppComponent implements OnInit {
  constructor(
    private auth: AuthService,
    private ngZone: NgZone
  ) {}

  ngOnInit() {
    CapApp.addListener('appUrlOpen', ({ url }) => {
      this.ngZone.run(() => {
        if (url.includes('state') && (url.includes('code') || url.includes('error'))) {
          this.auth
            .handleRedirectCallback(url)
            .pipe(mergeMap(() => Browser.close()))
            .subscribe();
        }
      });
    });
  }
}

Step 5: Implement Login

import { Component } from '@angular/core';
import { AuthService } from '@auth0/auth0-angular';
import { Browser } from '@capacitor/browser';

@Component({
  selector: 'app-login',
  template: `<ion-button (click)="login()">Log In</ion-button>`,
})
export class LoginPage {
  constructor(public auth: AuthService) {}

  login() {
    this.auth
      .loginWithRedirect({
        async openUrl(url: string) {
          await Browser.open({ url, windowName: '_self' });
        },
      })
      .subscribe();
  }
}

Step 6: Implement Logout

import { Component } from '@angular/core';
import { AuthService } from '@auth0/auth0-angular';
import { Browser } from '@capacitor/browser';

@Component({
  selector: 'app-logout-button',
  template: `<ion-button (click)="logout()">Log Out</ion-button>`,
})
export class LogoutButtonComponent {
  constructor(public auth: AuthService) {}

  logout() {
    this.auth
      .logout({
        logoutParams: {
          returnTo: `YOUR_PACKAGE_ID://YOUR_AUTH0_DOMAIN/capacitor/YOUR_PACKAGE_ID/callback`,
        },
        async openUrl(url: string) {
          await Browser.open({ url, windowName: '_self' });
        },
      })
      .subscribe();
  }
}

Step 7: Display User Profile

import { Component } from '@angular/core';
import { AuthService } from '@auth0/auth0-angular';
import { AsyncPipe } from '@angular/common';

@Component({
  selector: 'app-profile',
  template: `
    <div *ngIf="auth.user$ | async as user">
      <img [src]="user.picture" [alt]="user.name" />
      <h2>{{ user.name }}</h2>
      <p>{{ user.email }}</p>
    </div>
  `,
})
export class ProfileComponent {
  constructor(public auth: AuthService) {}
}

Step 8: Build and Test

Agent instruction: After writing all code, verify the build succeeds:

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npm run build
npx cap sync

If the build fails, investigate errors and fix (up to 5-6 iterations). If still failing, use AskUserQuestion to ask the user for help.

Common Mistakes