> For the complete documentation index, see [llms.txt](/llms.txt).

# Custom authentication

Custom authentication is a way to authenticate users with your custom authentication service. For example, while authenticating with Google, you can use your own Google Client ID to authenticate users directly.

This feature, with Multi-Factor Authentication (MFA) turned off, can even make Embedded Wallets invisible to the end user.

note

This is a paid feature and the minimum [pricing plan](https://web3auth.io/pricing.html) to use this SDK in a production environment is the **Growth Plan**. You can use this feature in Web3Auth Sapphire Devnet network for free.

## Getting an Auth Connection ID[​](#getting-an-auth-connection-id "Direct link to Getting an Auth Connection ID")

prerequisite

To enable this, you need to [create a connection](/embedded-wallets/dashboard/authentication/) from the **Authentication** tab of your project from the [Embedded Wallets dashboard](https://developer.metamask.io) with your desired configuration.

To configure a connection, you need to provide the particular details of the connection in the Embedded Wallets dashboard. This enables us to map a `authConnectionId` with your connection details. This `authConnectionId` helps us to identify the connection details while initializing the SDK. You can configure multiple connections for the same project, and you can also update the connection details anytime.

tip

Learn more about the [auth provider setup](/embedded-wallets/authentication/) and the different configurations available for each connection.

## Configuration[​](#configuration "Direct link to Configuration")

warning

**"Auth Connection"** is called **"Verifier"** in the Android SDK. It is the older terminology which we will be updating in the upcoming releases.

Consequentially, you will see the terms **"Verifier ID"** and **"Aggregate Verifier"** used in the codebase and documentation referring to **"Auth Connection ID"** and **"Grouped Auth Connection"** respectively.

To use custom authentication (using supported Social providers or Login providers like Auth0, AWS Cognito, Firebase, or your own custom JWT login), you can add the configuration using `loginConfig` parameter during the initialization.

The `loginConfig` parameter is a key value map. The key should be one of the `Web3AuthProvider` in its string form, and the value should be a `LoginConfigItem` instance.

After creating the verifier, you can use the following parameters in the `LoginConfigItem`.

- Table
- Interface

| Parameter              | Description                                                                                                                                                                                                                                                                                                                 |
| ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| verifier               | The name of the verifier that you have registered on the Embedded Wallets dashboard. It's a mandatory field, and it accepts a string value.                                                                                                                                                                                 |
| typeOfLogin            | Type of login of this verifier, this value will affect the login flow that is adapted. For example, if you choose google, a Google sign-in flow will be used. If you choose jwt, you should be providing your own JWT token, no sign-in flow will be presented. It's a mandatory field, and accepts TypeOfLogin as a value. |
| clientId               | Client ID provided by your login provider used for custom verifier. for example, Google's Client ID or Web3Auth's client ID if using JWT as TypeOfLogin. It's a mandatory field, and it accepts a string value.                                                                                                             |
| name?                  | Display name for the verifier. If null, the default name is used. It accepts a string value.                                                                                                                                                                                                                                |
| description?           | Description for the button. If provided, it renders as a full length button. else, icon button. It accepts a string value.                                                                                                                                                                                                  |
| verifierSubIdentifier? | The field in JWT token which maps to verifier ID. Please make sure you selected correct JWT verifier ID in the developer dashboard. It accepts a string value.                                                                                                                                                              |
| logoHover?             | Logo to be shown on mouse hover. It accepts a string value.                                                                                                                                                                                                                                                                 |
| logoLight?             | Light logo for dark background. It accepts a string value.                                                                                                                                                                                                                                                                  |
| logoDark?              | Dark logo for light background. It accepts a string value.                                                                                                                                                                                                                                                                  |
| mainOption?            | Show login button on the main list. Is a boolean value. Default value is false.                                                                                                                                                                                                                                             |
| showOnModal?           | Whether to show the login button on modal or not. Default value is true.                                                                                                                                                                                                                                                    |
| showOnDesktop?         | Whether to show the login button on desktop. Default value is true.                                                                                                                                                                                                                                                         |
| showOnMobile?          | Whether to show the login button on mobile. Default value is true.                                                                                                                                                                                                                                                          |

```
data class LoginConfigItem(
    var verifier: String,
    private var typeOfLogin: TypeOfLogin,
    private var name: String? = null,
    private var description: String? = null,
    private var clientId: String,
    private var verifierSubIdentifier: String? = null,
    private var logoHover: String? = null,
    private var logoLight: String? = null,
    private var logoDark: String? = null,
    private var mainOption: Boolean? = false,
    private var showOnModal: Boolean? = true,
    private var showOnDesktop: Boolean? = true,
    private var showOnMobile: Boolean? = true,
)

enum class TypeOfLogin {
    @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("email_password")
    EMAIL_PASSWORD,
    @SerializedName("jwt")
    JWT
}

```

### Usage[​](#usage "Direct link to Usage")

- Google
- Facebook
- Auth0
- JWT

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf("google" to LoginConfigItem(
      verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
      typeOfLogin = TypeOfLogin.GOOGLE,
      clientId = getString(R.string.google_client_id) // Google's client id
    ))
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
    LoginParams(Provider.GOOGLE)
)

```

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf(
      "facebook" to LoginConfigItem(
        verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
        typeOfLogin = TypeOfLogin.FACEBOOK,
        clientId = getString(R.string.facebook_client_id) // Facebook's client id
      )
    )
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(Provider.Facebook)
)


```

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf("jwt" to LoginConfigItem(
      verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
      typeOfLogin = TypeOfLogin.JWT,
      clientId = getString (R.string.auth0_project_id) // Auth0's client id
    ))
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
    LoginParams(Provider.JWT)
)

```

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf(
      "jwt" to LoginConfigItem(
        verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
        typeOfLogin = TypeOfLogin.JWT,
      )
    )
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(Provider.JWT)
)


```

## Configure extra login options[​](#configure-extra-login-options "Direct link to Configure extra login options")

Additional to the `LoginConfig` you can pass extra options to the `login` function to configure the login flow for cases requiring additional info for enabling login. The `ExtraLoginOptions` accepts the following parameters.

### Parameters[​](#parameters "Direct link to Parameters")

- Table
- Interface

| Parameter                  | Description                                                                                                                                                                                                                      |
| -------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| additionalParams?          | Additional params in HashMap format for OAuth login, use id_token(JWT) to authenticate with web3auth.                                                                                                                            |
| domain?                    | Your custom authentication domain in string format. For example, if you are using Auth0, it can be example.au.auth0.com.                                                                                                         |
| client_id?                 | Client ID in string format, provided by your login provider used for custom verifier.                                                                                                                                            |
| leeway?                    | The value used to account for clock skew in JWT expirations. The value is in the seconds, and ideally should no more than 60 seconds or 120 seconds at max. It accepts a string value.                                           |
| verifierIdField?           | The field in JWT token which maps to verifier ID. Please make sure you selected correct JWT verifier ID in the developer dashboard. It accepts a string value.                                                                   |
| isVerifierIdCaseSensitive? | Boolean to confirm whether the verifier ID field is case sensitive or not.                                                                                                                                                       |
| display?                   | Allows developers the configure the display of UI. It takes Display as a value.                                                                                                                                                  |
| prompt?                    | Prompt shown to the user during authentication process. It takes Prompt as a value.                                                                                                                                              |
| max_age?                   | Max time allowed without reauthentication. If the last time user authenticated is greater than this value, then user must reauthenticate. It accepts a string value.                                                             |
| ui_locales?                | The space separated list of language tags, ordered by preference. For instance fr-CA fr en.                                                                                                                                      |
| id_token_hint?             | It denotes the previously issued ID token. It accepts a string value.                                                                                                                                                            |
| id_token?                  | JWT (ID token) to be passed for login.                                                                                                                                                                                           |
| login_hint?                | Used to specify the user's email address or phone number for email/SMS passwordless login flows. It accepts a string value. For the SMS, the format should be: +{country_code}-{phone_number} (for example +1-1234567890)        |
| acr_values?                | acc_values                                                                                                                                                                                                                       |
| scope?                     | The default scope to be used on authentication requests. The defaultScope defined in the Auth0Client is included along with this scope. It accepts a string value.                                                               |
| audience?                  | The audience, presented as the aud claim in the access token, defines the intended consumer of the token. It accepts a string value.                                                                                             |
| connection?                | The name of the connection configured for your application. If null, it will redirect to the Auth0 login page and show the login widget. It accepts a string value.                                                              |
| state?                     | State                                                                                                                                                                                                                            |
| response_type?             | Defines which grant to execute for the authorization server. It accepts a string value.                                                                                                                                          |
| nonce?                     | nonce                                                                                                                                                                                                                            |
| redirect_uri?              | It can be used to specify the default URL, where your custom JWT verifier can redirect your browser to with the result. If you are using Auth0, it must be allowlisted in the allowed callback URLs in your Auth0's application. |

```
data class ExtraLoginOptions(
  private var additionalParams : HashMap<String, String>? = null,
  private var domain : String? = null,
  private var client_id : String? = null,
  private var leeway : String? = null,
  private var verifierIdField : String? =null,
  private var isVerifierIdCaseSensitive : Boolean? = null,
  private var display : Display? = null,
  private var prompt : Prompt? = null,
  private var max_age : String? = null,
  private var ui_locales : String? = null,
  private var id_token : String? = null,
  private var id_token_hint : String? = null,
  private var login_hint : String? = null,
  private var acr_values : String? = null,
  private var scope : String? = null,
  private var audience : String? = null,
  private var connection : String? = null,
  private var state : String? = null,
  private var response_type : String? = null,
  private var nonce : String? = null,
  private var redirect_uri : String? = null
)

```

### Single verifier Usage[​](#single-verifier-usage "Direct link to Single verifier Usage")

- Auth0
- Custom JWT
- Email Passwordless
- SMS Passwordless

Auth0 has a special login flow, called the SPA flow. This flow requires a `client_id` and `domain` to be passed, and Web3Auth will get the JWT `id_token` from Auth0 directly. You can pass these configurations in the `ExtraLoginOptions` object in the login function.

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf("jwt" to LoginConfigItem(
      verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
      typeOfLogin = TypeOfLogin.JWT,
      clientId = getString (R.string.auth0_project_id) // Auth0's client id
    ))
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(
    Provider.JWT,
    extraLoginOptions = ExtraLoginOptions(
      domain: "https://username.us.auth0.com", // Domain of your Auth0 app
      verifierIdField: "sub", // The field in jwt token which maps to verifier id.
    )
  )
)

```

If you're using any other provider like Firebase/ AWS Cognito or deploying your own Custom JWT server, you need to put the JWT token into the `id_token` field of the `extraLoginOptions`, additionally, you need to pass over the `domain` field as well, which is mandatory. If you don't have a domain, just passover a string in that field.

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf("jwt" to LoginConfigItem(
      verifier = "verifier-name", // Get it from MetaMask Developer Dashboard
      typeOfLogin = TypeOfLogin.JWT,
    ))
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(
    Provider.JWT,
    extraLoginOptions = ExtraLoginOptions(
      id_token: "<Your JWT id token>",
    )
  )
)

```

To use the email passwordless login, you need to put the email into the `login_hint` parameter of the `ExtraLoginOptions`. By default, the login flow will be `code` flow, if you want to use the `link` flow, you need to put `flow_type` into the `additionalParams` parameter of the `ExtraLoginOptions`.

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(
    Provider.EMAIL_PASSWORDLESS,
    extraLoginOptions = ExtraLoginOptions(login_hint = "hello@web3auth.io")
  )
)

```

To use the SMS Passwordless login, send the phone number as the `login_hint` parameter of the `ExtraLoginOptions`. Please ensure the phone number takes the format: +{country_code}-{phone_number}, that is, (+91-09xx901xx1).

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
  )
)

val loginCompletableFuture: CompletableFuture<Web3AuthResponse> = web3Auth.login(
  LoginParams(
    Provider.SMS_PASSWORDLESS,
    extraLoginOptions = ExtraLoginOptions(login_hint = "+91-9911223344")
  )
)


```

### Aggregate verifier Usage[​](#aggregate-verifier-usage "Direct link to Aggregate verifier Usage")

You can use aggregate verifier to combine multiple login methods to get the same address for the users regardless of their login providers. For example, combining a Google and email passwordless login, or Google and GitHub via Auth0 to access the same address for your user.

```
import com.web3auth.core.Web3Auth
import com.web3auth.core.types.Web3AuthOptions

val web3Auth = Web3Auth(
  Web3AuthOptions(
    context = this,
    clientId = "YOUR_WEB3AUTH_CLIENT_ID", // Pass your Web3Auth Client ID, ideally using an environment variable
    network = Network.MAINNET,
    redirectUrl = Uri.parse("{YOUR_APP_PACKAGE_NAME}://auth"),
    loginConfig = hashMapOf(
      "google" to LoginConfigItem(
        verifier = "aggregate-sapphire",
        verifierSubIdentifier= "w3a-google",
        typeOfLogin = TypeOfLogin.GOOGLE,
        name = "Aggregate Login",
        clientId = getString(R.string.web3auth_google_client_id)
      ),
      "jwt" to LoginConfigItem(
        verifier = "aggregate-sapphire",
        verifierSubIdentifier= "w3a-a0-email-passwordless",
        typeOfLogin = TypeOfLogin.JWT,
        name = "Aggregate Login",
        clientId = getString(R.string.web3auth_auth0_client_id)
      )
    )
  )
)

// Google Login
web3Auth.login(LoginParams(Provider.GOOGLE))

// Auth0 Login
web3Auth.login(LoginParams(
  Provider.JWT,
  extraLoginOptions = ExtraLoginOptions(
    domain = "https://web3auth.au.auth0.com",
    verifierIdField = "email",
    isVerifierIdCaseSensitive = false
  )
))

```
