DescopeKit

DescopeKit is the Descope SDK for Swift. It provides convenient access to the Descope user management and authentication APIs for applications written in Swift. You can read more on the Descope Website.

Setup

Add the DescopeKit package using the Swift package manager.

The SDK supports iOS 13 and above, and macOS 12 and above.

Quickstart

A Descope Project ID is required to initialize the SDK. Find it on the project page in the Descope Console.

import DescopeKit

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    Descope.projectId = "<Your-Project-Id>"
    return true
}

You can authenticate a user in your application by starting one of the authentication methods. For example, let's use OTP via email:

// sends an OTP code to the given email address
try await Descope.otp.signUp(with: .email, loginId: "[email protected]", details: nil)

We finish the authentication by verifying the OTP code the user entered:

// if the user entered the right code the authentication is successful  
let authResponse = try await Descope.otp.verify(with: .email, loginId: "[email protected]", code: code)

// we create a DescopeSession object that represents an authenticated user session
let session = DescopeSession(from: authResponse)

// the session manager takes care of saving the session to the keychain and
// refreshing it for us as needed
Descope.sessionManager.manageSession(session)

The session manager will automatically load the session from the keychain the next time the application is launched. At that point we might check if there's a logged in user to decide which screen to show:

func initialViewController() -> UIViewController {
    // check if we have a valid session from a previous launch and that it hasn't expired yet 
    if let session = Descope.sessionManager.session, !session.refreshToken.isExpired {
        print("Authenticated user found: \(session.user)")
        return MainViewController()
    }
    return LoginViewController()
}

We use the active session to authenticate an outgoing API request to the application's backend:

var request = URLRequest(url: url)
try await request.setAuthorizationHTTPHeaderField(from: Descope.sessionManager)
let (data, response) = try await URLSession.shared.data(for: request)

Session Management

The DescopeSessionManager class is used to manage an authenticated user session for an application.

The session manager takes care of loading and saving the session as well as ensuring that it's refreshed when needed. For the default instances of the DescopeSessionManager class this means using the keychain for secure storage of the session and refreshing it a short while before it expires.

Once the user completes a sign in flow successfully you should set the DescopeSession object as the active session of the session manager.

let authResponse = try await Descope.otp.verify(with: .email, loginId: "[email protected]", code: "123456")
let session = DescopeSession(from: authResponse)
Descope.sessionManager.manageSession(session)

The session manager can then be used at any time to ensure the session is valid and to authenticate outgoing requests to your backend with a bearer token authorization header.

var request = URLRequest(url: url)
try await request.setAuthorizationHTTPHeaderField(from: Descope.sessionManager)
let (data, response) = try await URLSession.shared.data(for: request)

If your backend uses a different authorization mechanism you can of course use the session JWT directly instead of the extension function. You can either add another extension function on URLRequest such as the one above, or you can do the following.

try await Descope.sessionManager.refreshSessionIfNeeded()
guard let sessionJwt = Descope.sessionManager.session?.sessionJwt else { throw ServerError.unauthorized }
request.setValue(sessionJwt, forHTTPHeaderField: "X-Auth-Token")

When the application is relaunched the DescopeSessionManager loads any existing session automatically, so you can check straight away if there's an authenticated user.

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    Descope.projectId = "..."
    if let session = Descope.sessionManager.session {
        print("User is logged in: \(session)")
    }
    return true
}

When the user wants to sign out of the application we revoke the active session and clear it from the session manager:

guard let refreshJwt = Descope.sessionManager.session?.refreshJwt else { return }
try await Descope.auth.logout(refreshJwt: refreshJwt)
Descope.sessionManager.clearSession()

You can customize how the DescopeSessionManager behaves by using your own storage and lifecycle objects. See the documentation for more details.

Authentication Methods

Here are some examples for how to authenticate users:

OTP Authentication

Send a user a one-time password (OTP) using your preferred delivery method (email / SMS). An email address or phone number must be provided accordingly.

The user can either sign up, sign in or sign up or in

// Every user must have a loginId. All other user details are optional:
try await Descope.otp.signUp(with: .email, loginId: "[email protected]", details: SignUpDetails(
    name: "Andy Rhoads"
))

The user will receive a code using the selected delivery method. Verify that code using:

let authResponse = try await Descope.otp.verify(with: .email, loginId: "[email protected]", code: "123456")
let session = DescopeSession(from: authResponse)
Descope.sessionManager.manageSession(session)

Magic Link

Send a user a Magic Link using your preferred delivery method (email / SMS). The Magic Link will redirect the user to page where the its token needs to be verified. This redirection can be configured in code, or globally in the Descope Console

The user can either sign up, sign in or sign up or in

// If configured globally, the redirect URI is optional. If provided however, it will be used
// instead of any global configuration
try await Descope.magiclink.signUp(with: .email, loginId: "[email protected]", details: nil)

To verify a magic link, your redirect page must call the validation function on the token (t) parameter (https://your-redirect-address.com/verify?t=<token>):

let authResponse = try await Descope.magiclink.verify(token: "<token>")

OAuth

Users can authenticate using their social logins, using the OAuth protocol. Configure your OAuth settings on the Descope console. To start a flow call:

// Choose an oauth provider out of the supported providers
// If configured globally, the redirect URL is optional. If provided however, it will be used
// instead of any global configuration.
// Redirect the user to the returned URL to start the OAuth redirect chain
let authURL = try await Descope.oauth.start(provider: .github, redirectURL: "exampleauthschema://my-app.com/handle-oauth")
guard let authURL = URL(string: url) else { return }

Take the generated URL and authenticate the user using ASWebAuthenticationSession (read more here). The user will authenticate with the authentication provider, and will be redirected back to the redirect URL, with an appended code HTTP URL parameter. Exchange it to validate the user:

// Start the authentication session
let session = ASWebAuthenticationSession(url: authURL, callbackURLScheme: "exampleauthschema") { callbackURL, error in

    // Extract the returned code
    guard let url = callbackURL else {return}
    let component = URLComponents(url: url, resolvingAgainstBaseURL: false)
    guard let code = component?.queryItems?.first(where: {$0.name == "code"})?.value else { return }

    // ... Trigger asynchronously

    // Exchange code for session
    let authResponse = try await Descope.oauth.exchange(code: code)
    let session = DescopeSession(from: authResponse)
    Descope.sessionManager.manageSession(session)
}

SSO/SAML

Users can authenticate to a specific tenant using SAML or Single Sign On. Configure your SSO/SAML settings on the Descope console. To start a flow call:

// Choose which tenant to log into
// If configured globally, the return URL is optional. If provided however, it will be used
// instead of any global configuration.
// Redirect the user to the returned URL to start the SSO/SAML redirect chain
let authURL = try await Descope.sso.start(emailOrTenantName: "my-tenant-ID", redirectURL: "exampleauthschema://my-app.com/handle-saml")
guard let authURL = URL(string: url) else { return }

Take the generated URL and authenticate the user using ASWebAuthenticationSession (read more here). The user will authenticate with the authentication provider, and will be redirected back to the redirect URL, with an appended code HTTP URL parameter. Exchange it to validate the user:

// Start the authentication session
let session = ASWebAuthenticationSession(url: authURL, callbackURLScheme: "exampleauthschema") { callbackURL, error in

    // Extract the returned code
    guard let url = callbackURL else {return}
    let component = URLComponents(url: url, resolvingAgainstBaseURL: false)
    guard let code = component?.queryItems?.first(where: {$0.name == "code"})?.value else { return }

    // ... Trigger asynchronously

    // Exchange code for session
    let authResponse = try await Descope.sso.exchange(code: code)
    let session = DescopeSession(from: authResponse)
    Descope.sessionManager.manageSession(session)
}

TOTP Authentication

The user can authenticate using an authenticator app, such as Google Authenticator. Sign up like you would using any other authentication method. The sign up response will then contain a QR code image that can be displayed to the user to scan using their mobile device camera app, or the user can enter the key manually or click on the link provided by the provisioningURL.

Existing users can add TOTP using the update function.

// Every user must have a loginID. All other user information is optional
let totpResponse = try await Descope.totp.signUp(loginId: "[email protected]", details: nil)

// Use one of the provided options to have the user add their credentials to the authenticator
// totpResponse.provisioningURL
// totpResponse.key

There are 3 different ways to allow the user to save their credentials in their authenticator app - either by clicking the provisioning URL, scanning the QR image or inserting the key manually. After that, signing in is done using the code the app produces.

let authResponse = try await Descope.totp.verify(loginId: "[email protected]", code: "987654")

Password Authentication

Authenticate users using a password.

Sign Up with Password

To create a new user that can later sign in with a password:

let authResponse = try await Descope.password.signUp(loginId: "[email protected]", password: "securePassword123!", details: SignUpDetails(
    name: "Andy Rhoads"
))

Sign In with Password

Authenticate an existing user using a password:

let authResponse = try await Descope.password.signIn(loginId: "an[email protected]", password: "securePassword123!")

Update Password

If you need to update a user's password:

try await Descope.password.update(loginId: "[email protected]", newPassword: "newSecurePassword456!", refreshJwt: "user-refresh-jwt")

Replace Password

To replace a user's password by providing their current password:

let authResponse = try await Descope.password.replace(loginId: "[email protected]", oldPassword: "SecurePassword123!", newPassword: "NewSecurePassword456!")

Send Password Reset Email

Initiate a password reset by sending an email:

try await Descope.password.sendReset(loginId: "[email protected]", redirectURL: "exampleauthschema://my-app.com/handle-reset")