verified-email

• Overview of Digital Credentials: Learn about cryptographically verifiable documents and the role of Credential Manager.
• Glossary : Definitions for

  dcql_query

  ,

  UserInfoCredential

  , and

  GetDigitalCredentialOption

  .

• OpenID4VP Standard: The specification used to create digital credentials requests.
• Digital Credentials Demo: Example requests and cross-platform testing tool.
• W3C Verifiable Credentials: The data model for cryptographically secured claims.
• SD-JWT: Selective Disclosure JSON Web Token format used for responses.
• mdoc: ISO/IEC 18013-5 standard for mobile documents.

• SDK Version: Minimum SDK 28 (Android 9) is required.
• GMS Version: Google Play services version 25.49.x or higher.

• Account Creation/Sign-up: Remove friction by skipping manual email verification.
• Account Recovery: Securely verify email ownership during recovery flows.
• Re-authentication: Versatile verification for high-risk actions, independent of the initial sign-in method.

• Workspace Accounts: Google does not issue verifiable credentials for Google Workspace Accounts.
• Freshness: For non-@gmail.com addresses, Google verifies the email at account creation but there is no freshness claim; implement an additional challenge like an OTP.

• SignUpScreen

• "Email address"

• "Recover Account"

• "Account Recovery"

• "Forgot password?"

• "Delete Account"

• Keywords :

  signup

  ,

  registration

  ,

  create_account

  ,

  forgot_password

  ,

  recovery

  ,

  verify_email

  .
• Code Pattern : Search for

  NavHost

  or

  composable

  destinations using these strings.

• Keywords :

  SignUpViewModel

  ,

  AuthViewModel

  ,

  RegistrationRepository

  .
• Code Pattern : Look for methods like

  onCrea teAccount

  ,

  onRecoverAccount

  , or

  validateEmail

  .

• Keywords :

  ChangePassword

  ,

  UpdatePayment

  ,

  DeleteAccount

  ,

  UpdateDetails

  ,

  EditUserDetails

• Construct a Digital Credential Request and present it to the user.
• Make sure to follow the request JSON structure as mentioned in documentation.
• While presenting the request to the user, check if result credential is DigitalCredential and credential.credentialJson as responseJsonString
• Parse the response from the client.
• Offer a passkey creation option if one is not already present.
• Assume a local

  SdJwtParser

  to parse raw SD-JWT and return a

  JSONObject

  .
• Use a

  VerifiedUserInfo

  data class to store the parsed name and email.
• Leave a TODO for developers to handle the app's server-side validation and parsing.
• Direct users to the home screen after API call success and show a snackbar with user details for reference purpose only.

GetCredentialRequest

GetDigitalCredentialOption

requestJson

"digital": {"requests": [...]}

    val nonce = generateSecureRandomNonce()

    // This request follows the OpenID4VP spec
    val openId4vpRequest = """
{
  "requests": [
    {
      "protocol": "openid4vp-v1-unsigned",
      "data": {
        "response_type": "vp_token",
        "response_mode": "dc_api",
        "nonce": "$nonce",
        "dcql_query": {
          "credentials": [
            {
              "id": "user_info_query",
              "format": "dc+sd-jwt",
               "meta": { 
                  "vct_values": ["UserInfoCredential"] 
               },
              "claims": [ 
                {"path": ["email"]}, 
                {"path": ["name"]},  
                {"path": ["given_name"]},
                {"path": ["family_name"]},
                {"path": ["picture"]},
                {"path": ["hd"]},
                {"path": ["email_verified"]}
              ]
            }
          ]
        }
      }
    }
  ]
}
"""

    val getDigitalCredentialOption = GetDigitalCredentialOption(requestJson = openId4vpRequest)
    val request = GetCredentialRequest(listOf(getDigitalCredentialOption))

• DCQL query : The

  dcql_query

  specifies the credential type and the claims being requested (

  email_verified

  ). You can request other claims to determine the level of verification. A few possible claims are as follows:

  • email_verified

    : In the response, this is a Boolean that indicates whether the email is verified.

  • hd

    (hosted domain): In the response, this is empty.

  [!NOTE] Note: If

  email_verified

  is

  true

  and

  hd

  is empty in the response, it implies that the account is an authorized Google Account. Currently, Google does not issue verifiable credentials for Google Workspace Accounts. However, the

  hd

  field is present in verifiable credentials issued for non-workspace accounts. You are encouraged to implement handling this field to future-proof your app.

• If the email is non-@gmail.com, Google verified this email when the Google Account was created, but there is no freshness claim. Therefore, for non-Google emails, you should consider an additional challenge, such as an OTP, to verify the user. To understand the schema of the credential and the specific rules for validating fields like

  email_verified

  , refer to the Google Identity guides.
• nonce: A unique, cryptographically secure random value is generated for each request. This is critical for security, as it prevents replay attacks.

• UserInfoCredential

  : This value implies a specific type of digital credential that contains user attributes. Including this in the request is pivotal to distinguish the email verification use case.

openId4vpRequest

GetDigitalCredentialOption

GetCredentialRequest

getCredential()

try {
    // Requesting Digital Credential from user...
    val result = credentialManager.getCredential(activity, request)

    when (val credential = result.credential) {
        is DigitalCredential -> {
            val responseJsonString = credential.credentialJson

            // Successfully received digital credential response.

            // Next, parse this response and send it to your server.
            // ...
        }

        else -> {
            // handle Unexpected State() - Up to the developer
        }
    }
} catch (e: Exception) {
    // handle exceptions - Up to the developer
}

[!NOTE] Note: There is no equivalent of Sign in with Google's

preferImmediatelyAvailableCredentials

for Digital Credentials. If no verifiable credential is found (for example, no eligible account on device), the user will be shown a "No options available" or similar system screen.

[!IMPORTANT] Important: This step is not for validation. Full cryptographic verification must be performed on your server.

// 1. Parse the outer JSON wrapper to get the `vp_token`
val responseData = JSONObject(responseJsonString)
val vpToken = responseData.getJSONObject("vp_token")

// 2. Extract the raw SD-JWT string
val credentialId = vpToken.keys().next()
val rawSdJwt = vpToken.getJSONArray(credentialId).getString(0)

// 3. Use your parser to get the verified claims
// Server-side validation/parsing is highly recommended.

// Assumes a local parser like the one in our SdJwtParser.kt sample
val claims = SdJwtParser.parse(rawSdJwt)
Log.d("TAG", "Parsed Claims: ${claims.toString(2)}")

// 4. Create your VerifiedUserInfo object with REAL data
val userInfo = VerifiedUserInfo(
    email = claims.getString("email"),
    displayName = claims.optString("name", claims.getString("email"))
)

DigitalCredential

responseJsonString

/*
// Example of the raw JSON response from credential.credentialJson:
{
  "vp_token": {
    // This key matches the 'id' you set in your dcql_query
    "user_info_query": [
      // The SD-JWT string (Issuer JWT ~ Disclosures ~ Key Binding JWT)
      "eyJhbGciOiJ...~WyI...IiwgImVtYWlsIiwgInVzZXJAZXhhbXBsZS5jb20iXQ~...~eyJhbGciOiJ..."
    ]
  }
}

// Example of the parsed and verified claims from the SD-JWT on your server:
{
  "cnf": {
    "jwk": {..}
  },
  "exp": 1775688222,
  "iat": 1775083422,
  "iss": "https://verifiablecredentials-pa.googleapis.com",
  "vct": "UserInfoCredential",
  "email": "jane.doe.246745@gmail.com",
  "email_verified": true,
  "given_name": "Jane",
  "family_name": "Doe",
  "name": "Jane Doe",
  "picture": "http://example.com/janedoe/me.jpg",
  "hd": ""
}
 */

[!NOTE] Note: We highly recommend that after receiving the verified email, you trigger Credential Manager's passkey creation.

vp_token

responseJsonString

• Authenticity of the data : Verifying the issuer (

  iss

  ) URL and the

  SD-JWT

  signature proves that a trusted authority issued this data.
• Identity of the presenter : Verifying the

  cnf

  field and the Key Binding (

  kb

  ) signature confirms that the credential is being shared by the same device it was originally issued to, preventing it from being intercepted or used on another device.

• Verify issuer : Ensure the

  iss

  (issuer) field matches

  https://verifiablecredentials-pa.googleapis.com

  .
• Verify signature: Check the signature of the SD-JWT using the public keys (JWKs) available at https://verifiablecredentials-pa.googleapis.com/.well-known/vc-public-jwks.

[!NOTE] Note: Use a standard library (such as @sd-jwt/sd-jwt-vc for Node.js) to perform the verification steps as outlined in the OpenID for Verifiable Presentations specification.

nonce

try {
    // Send the raw credential response and the original nonce to your server.
    // Your server must validate the response. createAccountWithVerifiedCredentials
    // is a custom implementation per each RP for server side verification and account creation.
    val serverResponse = createAccountWithVerifiedCredentials(responseJsonString, nonce)

    // Server returns the new account info (e.g., email, name)
    val claims = JSONObject(serverResponse.json)

    val userInfo = VerifiedUserInfo(
        email = claims.getString("email"),
        displayName = claims.optString("name", claims.getString("email"))
    )

    // handle response - Up to the developer
} catch (e: Exception) {
    // handle exceptions - Up to the developer
}

• Overview of verified email retrieval
• Credential Manager

• Server-side Validation : Never trust claims parsed on the client for security-sensitive operations like account creation. Send the complete, raw

  responseJsonString

  and the original

  nonce

  to the app's server for full verification.
• Nonce Integrity : Generate a unique, cryptographically secure nonce for every request and never reuse a nonce across multiple requests to prevent replay attacks.
• Cryptographic Checks : The app's server must validate the issuer (

  iss

  ) field, the SD-JWT signature, and the presenter identity using the

  cnf

  field.