> For the complete documentation index, see [llms.txt](/llms.txt). # Sign in a user To sign in a user, use the `connectTo` method. It triggers the sign-in flow and opens an in-app browser so the user can authenticate with the selected provider. Pass supported `AuthConnection` values for social logins (such as Google, Apple, Facebook) or custom JWT connections. ## Parameters The `connectTo` method takes `LoginParams` as a required input. **Table** | Parameter | Description | | -------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `authConnection` | Sets the OAuth sign-in method to use. Supported values include `google`, `facebook`, `reddit`, `discord`, `twitch`, `github`, `apple`, `kakao`, `linkedin`, `twitter`, `weibo`, `wechat`, `line`, `email_passwordless`, `email_password`, `custom`, `sms_passwordless`, and `farcaster`. | | `authConnectionId?` | Auth connection ID from the Embedded Wallets dashboard. Required for `custom` connections. | | `groupedAuthConnectionId?` | Grouped auth connection ID for aggregate connections. | | `extraLoginOptions?` | OAuth options for the corresponding `authConnection`. For example, pass the user's email address as `login_hint` for `email_passwordless`. Defaults to `null`. | | `appState?` | Tracks app state when the user returns after sign-in. Defaults to `null`. | | `mfaLevel?` | Customizes the MFA screen during OAuth authentication. Takes `MFALevel.OPTIONAL`, `MFALevel.MANDATORY`, or `MFALevel.NONE`. `MFALevel.DEFAULT` was removed in v8. See [MFA](/embedded-wallets/sdk/flutter/advanced/mfa/). | | `dappShare?` | Custom connection logins can return a dapp share after successful sign-in. Useful if your dapp uses this share to let users sign in without repeating the full flow. | | `curve?` | Determines the public key encoded in the JWT returned by `getUserInfo`. Does not change the private key format from Web3Auth. `getPrivateKey` always returns secp256k1. Use `getEd25519PrivateKey` for ed25519. Defaults to `Curve.secp256k1`. | | `idToken?` | JWT (ID token) for `custom` connections. Pass Firebase, Auth0, or other provider tokens here instead of `extraLoginOptions.id_token`. | | `loginHint?` | Optional login hint (for example, email or phone number) passed directly on `LoginParams`. | | `recordId?` | Optional audit record ID sent with the sign-in request. When `null`, the native SDK generates a UUID. | | `loginSource?` | Audit login source sent with the sign-in request. Defaults to `web3auth-flutter`. You don't need to set this. | **Class** ```dart class LoginParams { final AuthConnection authConnection; final String? authConnectionId; final String? groupedAuthConnectionId; final String? appState; final MFALevel? mfaLevel; final ExtraLoginOptions? extraLoginOptions; final String? dappShare; final Curve? curve; final String? dappUrl; String? loginHint; final String? idToken; final String? recordId; final String? loginSource; LoginParams({ required this.authConnection, this.authConnectionId, this.groupedAuthConnectionId, this.appState, this.mfaLevel, this.extraLoginOptions, this.dappShare, this.curve = Curve.secp256k1, this.dappUrl, this.loginHint, this.idToken, this.recordId, this.loginSource, }); } enum AuthConnection { google, facebook, reddit, discord, twitch, github, apple, kakao, linkedin, twitter, weibo, wechat, line, email_passwordless, email_password, custom, sms_passwordless, farcaster, } ``` ## Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.google), ); ``` ## Response `connectTo` returns a `Web3AuthResponse`. You can also read the current response later with [getWeb3AuthResponse](/embedded-wallets/sdk/flutter/usage/get-web3auth-response/). | Name | Description | | ------------------------ | -------------------------------------------------------------------------------------------------------- | | `privateKey?` | secp256k1 private key, compatible with EVM chains. | | `ed25519PrivateKey?` | ed25519 private key, compatible with Solana and other ed25519 chains. | | `userInfo?` | The signed-in user's information. See [getUserInfo](/embedded-wallets/sdk/flutter/usage/get-user-info/). | | `sessionId?` | Current session ID. | | `coreKitKey?` | secp256k1 SFA key, returned when `useSFAKey` is `true` in `Web3AuthOptions`. | | `coreKitEd25519PrivKey?` | ed25519 SFA key, returned when `useSFAKey` is `true` in `Web3AuthOptions`. | | `factorKey?` | Factor key, if available. | | `signatures?` | Session signatures as a `List`. | | `tssShareIndex?` | TSS share index. | | `tssPubKey?` | TSS public key. | | `tssShare?` | TSS share. | | `tssTag?` | TSS tag. | | `tssNonce?` | TSS nonce. | | `nodeIndexes?` | Node indexes as a `List`. | | `keyMode?` | Key mode of the account. | | `error?` | Error message, if any. | ## Handle errors Error handling differs by platform in v8: - **Android:** every `connectTo` failure, including a closed sign-in tab, throws `UserCancelledException`. Call `Web3AuthFlutter.setCustomTabsClosed()` when the app resumes so the SDK can detect a closed custom tab. See [Handle custom tabs](/embedded-wallets/sdk/flutter/#handle-custom-tabs). - **iOS:** failures, including cancellation, throw a `PlatformException` with the code `LoginFailedException`. ```dart import 'dart:developer'; import 'package:flutter/services.dart'; try { final response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.google), ); } on UserCancelledException { // Android: sign-in was cancelled or failed. log("Sign-in cancelled or failed."); } on PlatformException catch (e) { // iOS: e.code is "LoginFailedException". log("Sign-in failed: ${e.code} ${e.message}"); } ``` ## Examples **Google** Usage ```dart Future initWeb3Auth() async { late final String redirectUrl; if (Platform.isAndroid) { redirectUrl = 'w3a://com.example.w3aflutter'; } else if (Platform.isIOS) { redirectUrl = 'com.example.w3aflutter://auth'; } else { throw UnKnownException('Unknown platform'); } await Web3AuthFlutter.init(Web3AuthOptions( clientId: "WEB3AUTH_CLIENT_ID", web3AuthNetwork: Web3AuthNetwork.sapphire_mainnet, redirectUrl: redirectUrl, )); try { await Web3AuthFlutter.initialize(); } catch (e) { // No active session } } // Sign in final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.google), ); ``` **Facebook** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.facebook), ); ``` **Discord** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.discord), ); ``` **Twitch** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.twitch), ); ``` **Email Passwordless** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams( authConnection: AuthConnection.email_passwordless, extraLoginOptions: ExtraLoginOptions(login_hint: "hello@web3auth.io"), ), ); ``` **SMS Passwordless** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams( authConnection: AuthConnection.sms_passwordless, extraLoginOptions: ExtraLoginOptions(login_hint: "+91-9911223344"), ), ); ``` **Farcaster** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams(authConnection: AuthConnection.farcaster), ); ``` **Custom JWT** Usage ```dart final Web3AuthResponse response = await Web3AuthFlutter.connectTo( LoginParams( authConnection: AuthConnection.custom, authConnectionId: "YOUR_AUTH_CONNECTION_ID", idToken: "YOUR_JWT_TOKEN", ), ); ```