Logto is an Auth0 alternative designed for modern apps and SaaS products. It offers both Cloud and Open-source services to help you quickly launch your identity and management (IAM) system. Enjoy authentication, authorization, and multi-tenant management all in one.
We recommend starting with a free development tenant on Logto Cloud. This allows you to explore all the features easily.
In this article, we will go through the steps to quickly build the Twilio sign-in experience (user authentication) with iOS (Swift) and Logto.
Prerequisites
- A running Logto instance. Check out the introduction page to get started.
- Basic knowledge of iOS (Swift).
- A usable Twilio account.
Create an application in Logtoβ
Logto is based on OpenID Connect (OIDC) authentication and OAuth 2.0 authorization. It supports federated identity management across multiple applications, commonly called Single Sign-On (SSO).
To create your Native app application, simply follow these steps:
- Open the Logto Console. In the "Get started" section, click the "View all" link to open the application frameworks list. Alternatively, you can navigate to Logto Console > Applications, and click the "Create application" button.
- In the opening modal, click the "Native app" section or filter all the available "Native app" frameworks using the quick filter checkboxes on the left. Click the "iOS (Swift)" framework card to start creating your application.
- Enter the application name, e.g., "Bookstore," and click "Create application".
π Ta-da! You just created your first application in Logto. You'll see a congrats page which includes a detailed integration guide. Follow the guide to see what the experience will be in your application.
Integrate Logto SDKβ
Add Logto SDK as a dependencyβ
Use the following URL to add Logto SDK as a dependency in Swift Package Manager.
https://github.com/logto-io/swift.git
Since Xcode 11, you can directly import a Swift package w/o any additional tool.
We do not support Carthage and CocoaPods at the time due to some technical issues.
Carthageβ
Carthage needs a xcodeproj
file to build, but swift package generate-xcodeproj
will report a failure since we are using binary targets
for native social plugins. We will try to find a workaround later.
CocoaPodsβ
CocoaPods does not support local dependency and monorepo, thus it's hard to create a .podspec
for this repo.
Init LogtoClientβ
Initialize the client by creating a LogtoClient
instance with a LogtoConfig
object.
import Logto
import LogtoClient
let config = try? LogtoConfig(
endpoint: "<your-logto-endpoint>", // E.g. http://localhost:3001
appId: "<your-app-id>"
)
let client = LogtoClient(useConfig: config)
By default, we store credentials like ID Token and Refresh Token in the Keychain. Thus the user doesn't need to sign in again when he returns.
To turn off this behavior, set usingPersistStorage
to false
:
let config = try? LogtoConfig(
// ...
usingPersistStorage: false
)
Sign inβ
Before we dive into the details, here's a quick overview of the end-user experience. The sign-in process can be simplified as follows:
- Your app invokes the sign-in method.
- The user is redirected to the Logto sign-in page. For native apps, the system browser is opened.
- The user signs in and is redirected back to your app (configured as the redirect URI).
Regarding redirect-based sign-inβ
- This authentication process follows the OpenID Connect (OIDC) protocol, and Logto enforces strict security measures to protect user sign-in.
- If you have multiple apps, you can use the same identity provider (Logto). Once the user signs in to one app, Logto will automatically complete the sign-in process when the user accesses another app.
To learn more about the rationale and benefits of redirect-based sign-in, see Logto sign-in experience explained.
Configure redirect URIβ
Let's switch to the Application details page of Logto Console. Add a Redirect URI io.logto://callback
and click "Save changes".
The Redirect URI in iOS SDK is only for internal use. There's NO NEED to add a Custom URL Scheme until a connector asks.
Sign-in and sign-outβ
Before calling .signInWithBrowser(redirectUri:)
, make sure you have correctly configured Redirect URI
in Admin Console.
You can use client.signInWithBrowser(redirectUri:)
to sign in the user and client.signOut()
to sign out the user.
For example, in a SwiftUI app:
struct ContentView: View {
@State var isAuthenticated: Bool
init() {
isAuthenticated = client.isAuthenticated
}
var body: some View {
VStack {
if isAuthenticated {
Button("Sign Out") {
Task { [self] in
await client.signOut()
isAuthenticated = false
}
}
} else {
Button("Sign In") {
Task { [self] in
do {
try await client.signInWithBrowser(redirectUri: "${
props.redirectUris[0] ?? 'io.logto://callback'
}")
isAuthenticated = true
} catch let error as LogtoClientErrors.SignIn {
// error occured during sign in
} catch {
// other errors
}
}
}
}
}
}
}
Checkpoint: Test your applicationβ
Now, you can test your application:
- Run your application, you will see the sign-in button.
- Click the sign-in button, the SDK will init the sign-in process and redirect you to the Logto sign-in page.
- After you signed in, you will be redirected back to your application and see the sign-out button.
- Click the sign-out button to clear token storage and sign out.
Add Twilio connectorβ
SMS connector is a method used to send one-time passwords (OTPs) for authentication. It enables Phone number verification to support passwordless authentication, including SMS-based registration, sign-in, two-factor authentication (2FA), and account recovery. You can easily connect Twilio as your SMS provider. With the Logto SMS connector, you can set this up in just a few minutes.
To add a SMS connector, simply follow these steps:
- Navigate to Console > Connector > Email and SMS connectors.
- To add a new SMS connector, click the "Set up" button and select "Twilio".
- Review the README documentation for your selected provider.
- Complete the configuration fields in the "Parameter Configuration" section.
- Customize the SMS template using the JSON editor.
- Test your configuration by sending a verification code to your Phone number.
If you are following the in-place Connector guide, you can skip the next section.
Set up Twilio SMS connectorβ
Register Twilio accountβ
Create a new account on Twilio. (Jump to the next step if you already have one.)
Set up senders' phone numbersβ
Go to the Twilio console page and sign in with your Twilio account.
Purchase a phone number under "Phone Numbers" -> "Manage" -> "Buy a number".
Sometimes you may encounter the situation that SMS service is not supported in specific countries or areas. Pick a number from other regions to bypass.
Once we have a valid number claimed, nav to the "Messaging" -> "Services". Create a new Message Service by clicking on the button.
Give a friendly service name and choose Notify my users as our service purpose.
Following the next step, choose Phone Number
as Sender Type, and add the phone number we just claimed to this service as a sender.
Each phone number can only be linked with one messaging service.
Get account credentialsβ
We will need the API credentials to make the connector work. Let's begin from the Twilio console page.
Click on the "Account" menu in the top-right corner, then go to the "API keys & tokens" page to get your Account SID
and Auth token
.
Back to "Messaging" -> "Services" settings page starting from the sidebar, and find the Sid
of your service.
Compose the connector JSONβ
Fill out the accountSID, authToken and fromMessagingServiceSID fields with Account SID
, Auth token
and Sid
of the corresponding messaging service.
You can add multiple SMS connector templates for different cases. Here is an example of adding a single template:
- Fill out the
content
field with arbitrary string-typed contents. Do not forget to leave{{code}}
placeholder for random verification code. - Fill out the
usageType
field with eitherRegister
,SignIn
,ForgotPassword
,Generic
for different use cases. In order to enable full user flows, templates with usageTypeRegister
,SignIn
,ForgotPassword
andGeneric
are required.
Test Twilio SMS connectorβ
You can enter a phone number and click on "Send" to see whether the settings can work before "Save and Done".
That's it. Don't forget to Enable connector in sign-in experience.
Config typesβ
Name | Type |
---|---|
accountSID | string |
authToken | string |
fromMessagingServiceSID | string |
templates | Templates[] |
Template Properties | Type | Enum values |
---|---|---|
content | string | N/A |
usageType | enum string | 'Register' | 'SignIn' | 'ForgotPassword' | 'Generic' |
Save your configurationβ
Double check you have filled out necessary values in the Logto connector configuration area. Click "Save and Done" (or "Save changes") and the Twilio connector should be available now.
Enable Twilio connector in Sign-in Experienceβ
Once you create a connector successfully, you can enable phone number-based passwordless login and registration.
- Navigate to Console > Sign-in experience > Sign-up and sign-in.
- Set up sign-up methods (Optional):
- Select "Phone number" or "Email or phone number" as the sign-up identifier.
- "Verify at sign-up" is forced to be enabled. You can also enable "Create a password" on registration.
- Set up sign-in methods:
- Select Phone number as one of sign-in identifiers. You can provide multiple available identifiers (email, phone number, and username).
- Select "Verification code" and / or "Password" as the authentication factor.
- Click "Save changes" and test it in "Live preview".
In addition to registration and login via OTPs, you can also have password recovery and -based security verification enabled, as well as linking Phone number to profile. See End-user flows for more details.
Testing and Validationβ
Return to your iOS (Swift) app. You should now be able to sign in with Twilio. Enjoy!
Further readingsβ
End-user flows: Logto provides a out-of-the-box authentication flows including MFA and enterprise SSO, along with powerful APIs for flexible implementation of account settings, security verification, and multi-tenant experience.
Authorization: Authorization defines the actions a user can do or resources they can access after being authenticated. Explore how to protect your API for native and single-page applications and implement Role-based Access Control (RBAC).
Organizations: Particularly effective in multi-tenant SaaS and B2B apps, the organization feature enable tenant creation, member management, organization-level RBAC, and just-in-time-provisioning.
Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.