Sign in your user with Credential Manager

Credential Manager is a Jetpack API that supports multiple sign-in methods, such as username and password, passkeys, and federated sign-in solutions (such as Sign-in with Google) in a single API, thus simplifying the integration for developers.

Furthermore, for users, Credential Manager unifies the sign-in interface across authentication methods, making it clearer and easier for users to sign into apps, regardless of the method they choose.

This page explains the concept of passkeys and the steps to implementing client-side support for authentication solutions, including passkeys, using the Credential Manager API. There is also a separate FAQ page that provides answers to more detailed, specific questions.

Your feedback is a crucial part of improving the Credential Manager API. Share any issues you find or ideas for improving the API using the following link:

Give feedback

About passkeys

Passkeys are a safer and easier replacement for passwords. With passkeys, users can sign in to apps and websites using a biometric sensor (such as a fingerprint or facial recognition), PIN, or pattern. This provides a seamless sign-in experience, freeing your users from having to remember usernames or passwords.

Passkeys rely on WebAuthn (Web Authentication), a standard jointly developed by the FIDO Alliance and the World Wide Web Consortium (W3C). WebAuthn uses public-key cryptography to authenticate the user. The website or app that the user is signing into can see and store the public key, but never the private key. The private key is kept secret and safe. And because the key is unique and tied to the website or app, passkeys are un-phishable, adding further security.

Credential Manager allows users to create passkeys and store them in Google Password Manager.

Prerequisities

To use Credential Manager, complete the steps in this section.

Use a recent platform version

Credential Manager is supported on Android 4.4 (API level 19) and higher.

Add dependencies to your app

Add the following dependencies to your app module's build script:

Kotlin

dependencies {
    implementation("androidx.credentials:credentials:1.0.0-alpha08")

    // optional - needed for credentials support from play services, for devices running
    // Android 13 and below.
    implementation("androidx.credentials:credentials-play-services-auth:1.0.0-alpha08")
}

Groovy

dependencies {
    implementation "androidx.credentials:credentials:1.0.0-alpha08"

    // optional - needed for credentials support from play services, for devices running
    // Android 13 and below.
    implementation "androidx.credentials:credentials-play-services-auth:1.0.0-alpha08"
}

Preserve classes in ProGuard file

In your module's proguard-rules.pro file, add the following directives:

-if class androidx.credentials.CredentialManager
-keep class androidx.credentials.playservices.** {
  *;
}

Learn more about how to shrink, obfuscate, and optimize your app.

Add support for Digital Asset Links

To enable support for passkeys for your Android app, associate your app with a website that your app owns. You can declare this association by completing the following steps:

  1. Create a Digital Asset Links JSON file. For example, to declare that the website https://signin.example.com and an Android app with the package name com.example can share sign-in credentials, create a file named assetlinks.json with the following content:

    [{
  "relation": ["delegate_permission/common.get_login_creds"],
  "target": {
    "namespace": "web",
    "site": "https://signin.example.com"
  }
 },
 {
  "relation": ["delegate_permission/common.get_login_creds"],
  "target": {
    "namespace": "android_app",
    "package_name": "com.example",
    "sha256_cert_fingerprints": [
      SHA_HEX_VALUE
    ]
  }
 }]

    The relation field is an array of one or more strings that describe the relationship being declared. To declare that apps and sites share sign-in credentials, specify the string delegate_permission/common.get_login_creds.

    The target field is an object that specifies the asset the declaration applies to. The following fields identify a website:

    namespace web
    site

    The website's URL, in the format https://domain[:optional_port]; for example, https://www.example.com.

    The domain must be fully-qualified., and optional_port must be omitted when using port 443 for HTTPS.

    A site target can only be a root domain: you cannot limit an app association to a specific subdirectory. Don't include a path in the URL, such as a trailing slash.

    Subdomains are not considered to match: that is, if you specify the domain as www.example.com, the domain www.counter.example.com is not associated with your app.

    The following fields identify an Android app:

    namespace android_app
    package_name The package name declared in the app's manifest. For example, com.example.android
    sha256_cert_fingerprints The SHA256 fingerprints of your app's signing certificate.

  2. Host the Digital Assets Link JSON file at the following location on the sign-in domain:

    https://domain[:optional_port]/.well-known/assetlinks.json

    For example, if your sign-in domain is signin.example.com, host the JSON file at https://signin.example.com/.well-known/assetlinks.json.

    The MIME type for the Digital Assets Link file needs to be JSON. Make sure the server sends a Content-Type: application/json header in the response.

  3. Ensure that your host permits Google to retrieve your Digital Asset Link file. If you have a robots.txt file, it must allow the Googlebot agent to retrieve /.well-known/assetlinks.json. Most sites can simply allow any automated agent to retrieve files in the /.well-known/ path so that other services can access the metadata in those files: 

    User-agent: *
Allow: /.well-known/

  4. Declare the association in the Android app:

    1. Add an asset_statements string resource to the strings.xml file. The asset_statements string is a JSON object that specifies the assetlinks.json files to load. You must escape any apostrophes and quotation marks you use in the string. For example:

        <string name="asset_statements" translatable="false">
  [{
    \"include\": \"https://signin.example.com/.well-known/assetlinks.json\"
  }]
  </string>

        > GET /.well-known/assetlinks.json HTTP/1.1
  > User-Agent: curl/7.35.0
  > Host: signin.example.com

  < HTTP/1.1 200 OK
  < Content-Type: application/json

Configure the Credential Manager

To configure and initialize a CredentialManager object, add logic similar to the following:

Kotlin

// Use your app or activity context to instantiate a client instance of
// CredentialManager.
val credentialManager = CredentialManager.create(context)

Java

// Use your app or activity context to instantiate a client instance of
// CredentialManager.
CredentialManager credentialManager = CredentialManager.create(context)

Sign in your user

To retrieve all the passkeys and password options that are associated with the user's account, complete these steps:

  1. Initialize the password and passkey authentication options:

    Kotlin

    // Retrieves the user's saved password for your app from their
// password provider.
val getPasswordOption = GetPasswordOption()

// Get passkeys from the user's public key credential provider.
val getPublicKeyCredentialOption = GetPublicKeyCredentialOption(
    requestJson = requestJson,
    preferImmediatelyAvailableCredentials = preferImmediatelyAvailableCredentials
)

    Java

    // Retrieves the user's saved password for your app from their
// password provider.
GetPasswordOption getPasswordOption = new GetPasswordOption();

// Get passkeys from the user's public key credential provider.
GetPublicKeyCredentialOption getPublicKeyCredentialOption =
        new GetPublicKeyCredentialOption(requestJson, preferImmediatelyAvailableCredentials);

  2. Build the sign-in request, using the options retrieved from the previous step:

    Kotlin

    val getCredRequest = GetCredentialRequest(
    listOf(getPasswordOption, getPublicKeyCredentialOption)
)

    Java

    GetCredentialRequest getCredRequest = new GetCredentialRequest.Builder()
    .addCredentialOption(getPasswordOption)
    .addCredentialOption(getPublicKeyCredentialOption)
    .build();

  3. Launch the sign-in flow:

    Kotlin

    coroutineScope.launch {
    try {
        val result = credentialManager.getCredential(
            request = getCredRequest,
            activity = activity,
        )
        handleSignIn(result)
    } catch (e : GetCredentialException) {
        handleFailure(e)
    }
}

fun handleSignIn(result: GetCredentialResponse) {
    // Handle the successfully returned credential.
    val credential = result.credential

    when (credential) {
        is PublicKeyCredential -> {
            responseJson = credential.authenticationResponseJson
            fidoAuthenticateWithServer(responseJson)
        }
        is PasswordCredential -> {
            val username = credential.id
            val password = credential.password
            passwordAuthenticateWithServer(username, password)
        }
        else -> {
            // Catch any unrecognized credential type here.
            Log.e(TAG, "Unexpected type of credential")
        }
    }
}

    Java

    credentialManager.getCredentialAsync(
    getCredRequest,
    activity,
    cancellationSignal,
    requireContext().getMainExecutor(),
    new CredentialManagerCallback<GetCredentialResponse, GetCredentialException>() {
        @Override
        public void onResult(GetCredentialResponse result) {
            // Handle the successfully returned credential.
            Credential credential = result.getCredential();
            if (credential instanceof PublicKeyCredential) {
                String responseJson = ((PublicKeyCredential) credential)
                        .getAuthenticationResponseJson();
                fidoAuthenticateToServer(responseJson);
            } else if (credential instanceof PasswordCredential) {
                Log.d(TAG, "Got PasswordCredential");
                String id = ((PasswordCredential) credential).getId();
                String password = ((PasswordCredential) credential)
                        .getPassword();
                firebaseSignInWithPassword(id, password);
            } else {
              Log.e(
                  TAG,
                  "Unexpected type of credential: " +
                  credential.getClass().getName());
            }
        }

        @Override
        public void onError(GetCredentialException e) {
            Log.e(TAG, "Sign in failed with exception", e);
        }
    }
);

The following snippet shows an example of how to format the JSON request when you get a passkey:

{
  "challenge": "T1xCsnxM2DNL2KdK5CLa6fMhD7OBqho6syzInk_n-Uo",
  "allowCredentials": [],
  "timeout": 1800000,
  "userVerification": "required",
  "rpId": "credential-manager-app-test.glitch.me"
}

The following code snippet shows an example JSON response after you get a public key credential:

{
  "id": "KEDetxZcUfinhVi6Za5nZQ",
  "type": "public-key",
  "rawId": "KEDetxZcUfinhVi6Za5nZQ",
  "response": {
    "clientDataJSON": "eyJ0eXBlIjoid2ViYXV0aG4uZ2V0IiwiY2hhbGxlbmdlIjoiVDF4Q3NueE0yRE5MMktkSzVDTGE2Zk1oRDdPQnFobzZzeXpJbmtfbi1VbyIsIm9yaWdpbiI6ImFuZHJvaWQ6YXBrLWtleS1oYXNoOk1MTHpEdll4UTRFS1R3QzZVNlpWVnJGUXRIOEdjVi0xZDQ0NEZLOUh2YUkiLCJhbmRyb2lkUGFja2FnZU5hbWUiOiJjb20uZ29vZ2xlLmNyZWRlbnRpYWxtYW5hZ2VyLnNhbXBsZSJ9",
    "authenticatorData": "j5r_fLFhV-qdmGEwiukwD5E_5ama9g0hzXgN8thcFGQdAAAAAA",
    "signature": "MEUCIQCO1Cm4SA2xiG5FdKDHCJorueiS04wCsqHhiRDbbgITYAIgMKMFirgC2SSFmxrh7z9PzUqr0bK1HZ6Zn8vZVhETnyQ",
    "userHandle": "2HzoHm_hY0CjuEESY9tY6-3SdjmNHOoNqaPDcZGzsr0"
  }
}

Registration flows

You can register a user for authentication using either a passkey or a password.

Create a passkey

To give users the choice to enroll a passkey and use it for reauthentication, register a user credential using a CreatePublicKeyCredentialRequest object:

Kotlin

fun createPasskey(requestJson: String, preferImmediatelyAvailableCredentials: Boolean) {
    val createPublicKeyCredentialRequest = CreatePublicKeyCredentialRequest(
        // Contains the request in JSON format. Uses the standard WebAuthn
        // web JSON spec.
        requestJson = requestJson,
        // Defines whether you prefer to use only immediately available credentials,
        // not hybrid credentials, to fulfill this request. This value is false
        // by default.
        preferImmediatelyAvailableCredentials = preferImmediatelyAvailableCredentials,
    )

    // Execute CreateCredentialRequest asynchronously to register credentials
    // for a user account. Handle success and failure cases with the result and
    // exceptions, respectively.
    coroutineScope.launch {
        try {
            val result = credentialManager.createCredential(
                request = createPublicKeyCredentialRequest,
                activity = activity,
            )
            handlePasskeyRegistrationResult(result)
        } catch (e : CreateCredentialException){
            handleFailure(e)
        }
    }

    fun handleFailure(e: CreateCredentialException) {
        when (e) {
            is CreatePublicKeyCredentialDomException -> {
                // Handle the passkey DOM errors thrown according to the
                // WebAuthn spec.
                handlePasskeyError(e.domError)
            }
            is CreateCredentialCancellationException -> {
                // The user intentionally canceled the operation and chose not
                // to register the credential.
            }
            is CreateCredentialInterruptedException -> {
                // Retry-able error. Consider retrying the call.
            }
            is CreateCredentialProviderConfigurationException -> {
                // Your app is missing the provider configuration dependency.
                // Most likely, you're missing the
                // "credentials-play-services-auth" module.
            }
            is CreateCredentialUnknownException -> ...
            is CreateCustomCredentialException -> {
                // You have encountered an error from a 3rd-party SDK. If you
                // make the API call with a request object that's a subclass of
                // CreateCustomCredentialRequest using a 3rd-party SDK, then you
                // should check for any custom exception type constants within
                // that SDK to match with e.type. Otherwise, drop or log the
                // exception.
            }
            else -> Log.w(TAG, "Unexpected exception type ${e::class.java.name}")
        }
    }
}

Java

public void createPasskey(String requestJson, boolean preferImmediatelyAvailableCredentials) {
    CreatePublicKeyCredentialRequest createPublicKeyCredentialRequest =
            // `requestJson` contains the request in JSON format. Uses the standard
            // WebAuthn web JSON spec.
            // `preferImmediatelyAvailableCredentials` defines whether you prefer
            // to only use immediately available credentials, not  hybrid credentials,
            // to fulfill this request. This value is false by default.
            new CreatePublicKeyCredentialRequest(
                requestJson, preferImmediatelyAvailableCredentials);

    // Execute CreateCredentialRequest asynchronously to register credentials
    // for a user account. Handle success and failure cases with the result and
    // exceptions, respectively.
    credentialManager.createCredentialAsync(
        createPublicKeyCredentialRequest,
        requireActivity(),
        cancellationSignal,
        requireContext().getMainExecutor(),
        new CredentialManagerCallback<CreateCredentialResponse, CreateCredentialException> {
            @Override
            public void onResult(CreateCredentialResponse result) {
                handleSuccessfulCreatePasskeyResult(result);
            }

            @Override
            public void onError(CreateCredentialException e) {
                if (e instanceof CreatePublicKeyCredentialDomException) {
                    // Handle the passkey DOM errors thrown according to the
                    // WebAuthn spec.
                    handlePasskeyError(((CreatePublicKeyCredentialDomException)e).getDomError());
                } else if (e instanceof CreateCredentialCancellationException) {
                    // The user intentionally canceled the operation and chose not
                    // to register the credential.
                } else if (e instanceof CreateCredentialInterruptedException) {
                    // Retry-able error. Consider retrying the call.
                } else if (e instanceof CreateCredentialProviderConfigurationException) {
                    // Your app is missing the provider configuration dependency.
                    // Most likely, you're missing the
                    // "credentials-play-services-auth" module.
                } else if (e instanceof CreateCredentialUnknownException) {
                } else if (e instanceof CreateCustomCredentialException) {
                    // You have encountered an error from a 3rd-party SDK. If
                    // you make the API call with a request object that's a
                    // subclass of
                    // CreateCustomCredentialRequest using a 3rd-party SDK,
                    // then you should check for any custom exception type
                    // constants within that SDK to match with e.type.
                    // Otherwise, drop or log the exception.
                } else {
                  Log.w(TAG, "Unexpected exception type "
                          + e.getClass().getName());
                }
            }
        }
    );
}

Format the JSON request

After you create a passkey, you must associate it with a user's account, and store the passkey's public key on your server. The following snippet shows an example of how to format the JSON request when you create a passkey.

This blog post about bringing seamless authentication to your apps shows you how to format your JSON request when you create passkeys and when you authenticate using passkeys. It also explains why passwords aren't an effective authentication solution, how to leverage existing biometric credentials, how to associate your app with a website that you own, how to create passkeys, and how to authenticate using passkeys.

{
  "challenge": "nhkQXfE59Jb97VyyNJkvDiXucMEvltduvcrDmGrODHY",
  "rp": {
    "name": "CredMan App Test",
    "id": "credential-manager-app-test.glitch.me"
  },
  "user": {
    "id": "2HzoHm_hY0CjuEESY9tY6-3SdjmNHOoNqaPDcZGzsr0",
    "name": "helloandroid@gmail.com",
    "displayName": "helloandroid@gmail.com"
  },
  "pubKeyCredParams": [
    {
      "type": "public-key",
      "alg": -7
    },
    {
      "type": "public-key",
      "alg": -257
    }
  ],
  "timeout": 1800000,
  "attestation": "none",
  "excludeCredentials": [],
  "authenticatorSelection": {
    "authenticatorAttachment": "platform",
    "requireResidentKey": true,
    "residentKey": "required",
    "userVerification": "required"
  }
}

Handle the JSON response

The following code snippet shows an example JSON response for creating a public key credential. Learn more about how to handle the returned public key credential.

{
  "id": "KEDetxZcUfinhVi6Za5nZQ",
  "type": "public-key",
  "rawId": "KEDetxZcUfinhVi6Za5nZQ",
  "response": {
    "clientDataJSON": "eyJ0eXBlIjoid2ViYXV0aG4uY3JlYXRlIiwiY2hhbGxlbmdlIjoibmhrUVhmRTU5SmI5N1Z5eU5Ka3ZEaVh1Y01Fdmx0ZHV2Y3JEbUdyT0RIWSIsIm9yaWdpbiI6ImFuZHJvaWQ6YXBrLWtleS1oYXNoOk1MTHpEdll4UTRFS1R3QzZVNlpWVnJGUXRIOEdjVi0xZDQ0NEZLOUh2YUkiLCJhbmRyb2lkUGFja2FnZU5hbWUiOiJjb20uZ29vZ2xlLmNyZWRlbnRpYWxtYW5hZ2VyLnNhbXBsZSJ9",
    "attestationObject": "o2NmbXRkbm9uZWdhdHRTdG10oGhhdXRoRGF0YViUj5r_fLFhV-qdmGEwiukwD5E_5ama9g0hzXgN8thcFGRdAAAAAAAAAAAAAAAAAAAAAAAAAAAAEChA3rcWXFH4p4VYumWuZ2WlAQIDJiABIVgg4RqZaJyaC24Pf4tT-8ONIZ5_Elddf3dNotGOx81jj3siWCAWXS6Lz70hvC2g8hwoLllOwlsbYatNkO2uYFO-eJID6A"
  }
}

Save a user's password

If the user provides a username and password for an authentication flow in your app, you can register a user credential that can be used to authenticate the user. To do so, create a CreatePasswordRequest object:

Kotlin

fun registerPassword(username: String, password: String) {
    // Initialize a CreatePasswordRequest object.
    val createPasswordRequest =
            CreatePasswordRequest(id = username, password = password)

    // Create credentials and handle result.
    coroutineScope.launch {
        try {
            val result =
                    credentialManager.createCredential(createPasswordRequest)
            handleRegisterPasswordResult(result)
        } catch (e: CreateCredentialException) {
            handleFailure(e)
        }
    }
}

Java

void registerPassword(String username, String password) {
    // Initialize a CreatePasswordRequest object.
    CreatePasswordRequest createPasswordRequest =
            new CreatePasswordRequest(username, password);

    // Register the username and password.
    credentialManager.createCredentialAsync(
        createPasswordRequest,
        requireActivity(),
        cancellationSignal,
        requireContext().getMainExecutor(),
        new CredentialManagerCallback<CreateCredentialResponse, CreateCredentialException> {
            @Override
            public void onResult(CreateCredentialResponse result) {
                handleResult(result);
            }

            @Override
            public void onError(CreateCredentialException e) {
                handleFailure(e)
            }
        }
    );
}

Support credential recovery

If a user no longer has access to a device where they had stored their credentials, they might need to recover from a secure online backup. To learn more about how to support this credential recovery process, read the section titled "Recovering access or adding new devices" in this blog post: Security of Passkeys in the Google Password Manager.

Troubleshoot common errors

The following table shows several common error codes and descriptions, and provides some information about their causes:

Error code and description Cause
On Begin Sign In Failure: 16: Caller has been temporarily blocked due to too many canceled sign-in prompts.

If you encounter this 24-hour cooldown period during development, you can reset it by clearing Google Play services' app storage.

Alternatively, to toggle this cooldown on a test device or emulator, go to the Dialer app and input the following code: *#*#66382723#*#*. The Dialer app clears all input and may close, but there isn't a confirmation message.
On Begin Sign In Failure: 8: Unknown internal error.
  1. The device is not set up properly with the Google account.
  2. The passkey JSON is being created incorrectly.
CreatePublicKeyCredentialDomException: The incoming request cannot be validated The app's package ID is not registered with your server. Validate this in your server-side integration.

Additional resources

To learn more about the Credential Manager API and about passkeys, view the following developer guides: