Sign in a user

To sign in a user, use the connectTo method. It triggers the sign-in flow and opens a browser modal where the user can authenticate. Pass supported auth connections to connectTo for specific social sign-in providers such as GOOGLE, APPLE, and FACEBOOK, or use whitelabel sign-in.

Parameters

The connectTo method takes LoginParams as a required input.

Table

Parameter	Description
authConnection	It sets the OAuth sign-in method to be used. You can use any of the supported values are GOOGLE, FACEBOOK, REDDIT, DISCORD, TWITCH, APPLE, LINE, GITHUB, KAKAO, LINKEDIN, TWITTER, WEIBO, WECHAT, EMAIL_PASSWORDLESS, CUSTOM, SMS_PASSWORDLESS, and FARCASTER.
authConnectionId?	The connection ID for custom authentication. This is optional for social sign-in providers but required for custom JWT-based authentication.
groupedAuthConnectionId?	Used for aggregate verifiers. When multiple auth connections are grouped under a single verifier, this specifies the aggregate verifier ID.
loginHint?	Provides a hint for the sign-in process. For email passwordless, this should be the email address. For SMS passwordless, this should be the phone number.
idToken?	JWT token for SFA (Single Factor Auth) sign-in. When provided, sign-in uses SFA mode.
extraLoginOptions?	It can be used to set the OAuth sign-in options for corresponding authConnection. Default value for the field is null, and it accepts ExtraLoginOptions as a value.
appState?	It can be used to keep track of the app state when user will be redirected to app after sign-in. Default is null, and accepts String as a value.
mfaLevel?	Customize the MFA screen shown to the user during OAuth authentication. Default value for field is MFALevel.DEFAULT, which shows MFA screen every third sign-in. It accepts MFALevel as a value.
dappShare?	Custom verifier sign-in can return a dapp share after successful authentication. This is useful if the dapps want to use this share to allow users to sign in seamlessly. It accepts String as a value.
curve?	It will be used to determine the public key encoded in the jwt token which returned in getUserInfo function after the user signs in. This parameter won't change format of private key returned by Web3Auth. Private key returned by getPrivateKey is always secp256k1. To get the ed25519 key you can use getEd25519PrivateKey method. The default value is Curve.SECP256K1.
dappUrl?	URL of the dapp. This is used for analytics and debugging purposes.

Class

data class LoginParams(
    val authConnection: AuthConnection,
    val authConnectionId: String? = null,
    val groupedAuthConnectionId: String? = null,
    val appState: String? = null,
    val mfaLevel: MFALevel? = null,
    val extraLoginOptions: ExtraLoginOptions? = null,
    var dappShare: String? = null,
    val curve: Curve? = Curve.SECP256K1,
    var dappUrl: String? = null,
    var loginHint: String? = null,
    val idToken: String? = null,
)

enum class AuthConnection {
    @SerializedName("google")
    GOOGLE,
    @SerializedName("facebook")
    FACEBOOK,
    @SerializedName("reddit")
    REDDIT,
    @SerializedName("discord")
    DISCORD,
    @SerializedName("twitch")
    TWITCH,
    @SerializedName("apple")
    APPLE,
    @SerializedName("line")
    LINE,
    @SerializedName("github")
    GITHUB,
    @SerializedName("kakao")
    KAKAO,
    @SerializedName("linkedin")
    LINKEDIN,
    @SerializedName("twitter")
    TWITTER,
    @SerializedName("weibo")
    WEIBO,
    @SerializedName("wechat")
    WECHAT,
    @SerializedName("email_passwordless")
    EMAIL_PASSWORDLESS,
    @SerializedName("custom")
    CUSTOM, //for jwt
    @SerializedName("sms_passwordless")
    SMS_PASSWORDLESS,
    @SerializedName("farcaster")
    FARCASTER
}

Return Value: Web3AuthResponse

connectTo returns a CompletableFuture<Web3AuthResponse>. The response contains:

Field	Type	Description
privateKey	String?	secp256k1 private key (EVM). Use getPrivateKey() for safe retrieval.
ed25519PrivKey	String?	Ed25519 private key (Solana, Near, etc.). Use getEd25519PrivateKey() for safe retrieval.
userInfo	UserInfo?	User profile information. See getUserInfo for field details.
coreKitKey	String?	SFA key returned when useSFAKey = true.
coreKitEd25519PrivKey	String?	SFA Ed25519 key returned when useSFAKey = true.
factorKey	String?	Factor key for MFA flows.
sessionId	String?	Current session identifier.
signatures	List<String>?	Session token signatures for advanced use cases.
error	String?	Non-null when the session returned an error.

Prefer the typed methods getPrivateKey() and getEd25519PrivateKey() over reading privateKey directly; they correctly handle the useSFAKey flag and throw IllegalStateException instead of returning null when no key is available.

Usage

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(AuthConnection.GOOGLE)
)

Examples

Google

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(AuthConnection.GOOGLE)
)

Facebook

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(AuthConnection.FACEBOOK)
)

Discord

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(AuthConnection.DISCORD)
)

Twitch

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(AuthConnection.TWITCH)
)

Email Passwordless

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(
        AuthConnection.EMAIL_PASSWORDLESS,
        loginHint = "hello@web3auth.io"
    )
)

SMS Passwordless

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(
        AuthConnection.SMS_PASSWORDLESS,
        loginHint = "+91-9911223344"
    )
)

Farcaster

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
  LoginParams(AuthConnection.FARCASTER)
)

JWT

Usage

import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions
import org.torusresearch.fetchnodedetails.types.Web3AuthNetwork

val web3Auth = Web3Auth(
  Web3AuthOptions(
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass over your Web3Auth Client ID from Developer Dashboard
    web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
    redirectUrl = "{YOUR_APP_PACKAGE_NAME}://auth",
  ),
  this
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.connectTo(
    LoginParams(
        AuthConnection.CUSTOM,
        authConnectionId = "your_auth_connection_id",
        idToken = "your_jwt_token"
    )
)