Auth

Authenticate users with third-party identity providers (Google, Apple, Microsoft, MitID, and custom providers).

Access: startiapp.Auth

For step-by-step guides to setting up authentication — see Sign in with Google and Sign in with Apple.

Methods

`signIn(providerName, options?): Promise<AuthenticationOutcome>`

Starts the sign-in flow for the given provider. Returns the authentication result when the flow completes.

Parameters:

Parameter	Type	Required	Description
providerName	`AuthenticationProvider`	Yes	The provider to sign in with
options	`SignInOptions`	No	Additional sign-in options

Returns: Promise<AuthenticationOutcome<TProviderName>> —Either an AuthenticationResult (or AuthenticationResultApple for Apple) on success, or an AuthenticationFailure on failure.

Example:

// Basic sign in with Google
const result = await startiapp.Auth.signIn("google");

if (result.isSuccess) {
  console.log("Authorization code:", result.authorizationCode);
  console.log("Redirect URI:", result.redirectUri);
} else {
  console.error("Sign in failed:", result.errorMessage);
}

// Sign in with Apple (includes identity info)
const result = await startiapp.Auth.signIn("apple");

if (result.isSuccess) {
  console.log("User ID:", result.identity.userId);
  console.log("Email:", result.identity.email);
  console.log("ID Token:", result.identity.idToken);
  // Name is only available on the first sign-in
  console.log("Name:", result.identity.name);
}

// Sign in with MitID and request SSN
const result = await startiapp.Auth.signIn("signaturgruppenmitid", {
  scope: "openid mitid ssn ssn.details_name",
});

if (result.isSuccess) {
  console.log("Claims:", result.additionalClaims);
}

`signOut(): Promise<boolean>`

Signs out the current user.

Returns: Promise<boolean> —true if sign out was successful.

Example:

const success = await startiapp.Auth.signOut();
console.log("Signed out:", success);

`getCurrentSession(): Promise<AuthenticationResult | null>`

Returns the current authentication session, or null if the user is not authenticated.

Returns: Promise<AuthenticationResult | null>

Example:

const session = await startiapp.Auth.getCurrentSession();

if (session) {
  console.log("Logged in as provider:", session.providerName);
} else {
  console.log("Not authenticated");
}

`isAuthenticated(): Promise<boolean>`

Checks whether a user is currently authenticated.

Returns: Promise<boolean> —true if authenticated.

Example:

const loggedIn = await startiapp.Auth.isAuthenticated();

if (loggedIn) {
  console.log("User is logged in");
}

Types

`AuthenticationProvider`

The built-in provider names, or any custom string.

type AuthenticationProvider =
  | "apple"
  | "google"
  | "microsoft"
  | "signaturgruppenmitid"
  | (string & {});

`SignInOptions`

interface SignInOptions {
  scope?: string;
}

`AuthenticationOutcome`

A discriminated union — either a success result or a failure.

type AuthenticationOutcome<T extends AuthenticationProvider = string> =
  | AuthenticationResult<T>   // generic success
  | AuthenticationResultApple // when T is "apple"
  | AuthenticationFailure<T>;

Check isSuccess to discriminate:

const result = await startiapp.Auth.signIn("google");

if (result.isSuccess) {
  // result is AuthenticationResult
} else {
  // result is AuthenticationFailure
}

`AuthenticationSuccessBase`

Base interface shared by all successful authentication results.

interface AuthenticationSuccessBase<T extends AuthenticationProvider = string> {
  isSuccess: true;
  providerName: T;
  additionalClaims: Record<string, string>;
}

`AuthenticationResult`

The standard success result for most providers.

interface AuthenticationResult<T extends AuthenticationProvider = string>
  extends AuthenticationSuccessBase<T> {
  authorizationCode: string;
  codeVerifier: string;
  redirectUri: string;
}

`AuthenticationResultApple`

The success result specific to Apple sign-in. Includes an identity object with user details.

interface AuthenticationResultApple
  extends AuthenticationSuccessBase<"apple"> {
  authorizationCode: string;
  redirectUri: string;
  identity: {
    userId: string;
    email: string;
    /** Only available on the first sign-in. */
    name: string | null;
    idToken: string;
  };
}

`AuthenticationFailure`

Returned when sign-in fails or is cancelled.

interface AuthenticationFailure<T extends AuthenticationProvider = string> {
  isSuccess: false;
  providerName: T;
  errorMessage: string;
}

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