EUID SDK for Java Reference Guide

You can use the EUID SDK for Java on the server side to facilitate the following:

• Generating EUID advertising tokens
• Refreshing EUID advertising tokens
• Decrypting EUID tokens to access the raw EUIDs
• Mapping personal data to raw EUIDs

note

This SDK is valid for UID2 and EUID. Some of the code naming and URLs are labelled as UID2. These apply equally to EUID.

Functionality

This SDK simplifies integration with EUID for any publishers, DSPs, advertisers, and data providers who are using Java for their server-side coding. The following table shows the functions it supports.

Encrypt Raw EUID to EUID Token	Decrypt EUID Token	Generate EUID Token from Personal Data	Refresh EUID Token	Map Personal Data to a Raw EUID
Not Supported	Supported	Supported	Supported	Supported

API Permissions

To use this SDK, you'll need to complete the EUID account setup by following the steps described in the Account Setup page.

You'll be granted permission to use specific functions offered by the SDK, and given credentials for that access. Bear in mind that there might be functions in the SDK that you don't have permission to use. For example, publishers get a specific API permission to generate and refresh tokens, but the SDK might support other activities that require a different API permission.

For details, see API Permissions.

Version

The SDK requires Java version 1.8 or later.

GitHub Repository/Binary

This SDK is in the following open-source GitHub repository:

• SDK for Java

  The SDK, and some of its technical components, are named UID2, but are equally applicable for EUID.

The binary is published on the Maven repository:

• https://central.sonatype.com/artifact/com.uid2/uid2-client

Initialization

The initialization step depends on the role, as shown in the following table.

Role	Create Instance of Class	Link to Instructions
Publisher	PublisherUid2Client	Usage for Publishers
Advertiser/Data Provider	IdentityMapClient	Usage for Advertisers/Data Providers
DSP	BidstreamClient	Usage for DSPs
Sharer (not currently supported for EUID)	SharingClient	Not applicable

You will need to provide the values necessary for the SDK to authenticate with the EUID service.

Parameter	Description
baseUrl/uid2BaseUrl	The endpoint for the EUID service. See Environments.
clientApiKey	The API key. See EUID Credentials.
base64SecretKey	The client secret. See EUID Credentials.

Interface

The BidstreamClient class allows you to decrypt EUID tokens into raw EUIDs.

For details on the bidding logic for handling user opt-outs, see DSP Integration Guide.

The SharingClient class allows you to encrypt raw EUIDs into EUID tokens and decrypt EUID tokens into raw EUIDs.

note

When you use an SDK, you do not need to store or manage decryption keys.

Encryption Response Content

When encrypting with the SharingClient class, the SDK returns the information shown in the following table.

Method	Description
getStatus()	The encryption result status. For a list of possible values and definitions, see Encryption Response Statuses.
getEncryptedData()	The encrypted EUID token.

Encryption Response Statuses

Encryption response codes, and their meanings, are shown in the following table.

Value	Description
SUCCESS	The raw EUID was successfully encrypted and an EUID token was returned.
NOT_AUTHORIZED_FOR_KEY	The requester does not have authorization to use the encryption key.
NOT_AUTHORIZED_FOR_MASTER_KEY	The requester does not have authorization to use the master key.
NOT_INITIALIZED	The client library is waiting to be initialized.
KEYS_NOT_SYNCED	The client has failed to synchronize keys from the EUID service.
ENCRYPTION_FAILURE	A generic encryption failure occurred.

Decryption Response Content

Whether decrypting with the BidstreamClient class, the SDK returns the information shown in the following table.

Methods	Description
getStatus()	The decryption result status. For a list of possible values and definitions, see Decryption Response Statuses.
getSiteId()	The raw EUID for the corresponding EUID token.
getEstablished()	The timestamp indicating when a user first established the EUID with the publisher.

Decryption Response Statuses

Decryption response codes, and their meanings, are shown in the following table.

Value	Description
SUCCESS	The EUID token was decrypted successfully and a raw EUID was returned.
NOT_AUTHORIZED_FOR_KEY	The requester does not have authorization to decrypt this EUID token.
NOT_INITIALIZED	The client library is waiting to be initialized.
INVALID_PAYLOAD	The incoming EUID token is not a valid payload.
EXPIRED_TOKEN	The incoming EUID token has expired.
KEYS_NOT_SYNCED	The client has failed to synchronize keys from the EUID service.
VERSION_NOT_SUPPORTED	The client library does not support the version of the encrypted token.
INVALID_TOKEN_LIFETIME	The token has an invalid timestamp.

Usage for Publishers

As a publisher, there are two ways to use the EUID SDK for Java:

1. Basic Usage is for publishers who want to use this SDK's HTTP implementation (synchronous OkHttp).
2. Advanced Usage is for publishers who prefer to use their own HTTP library.

For an example application that demonstrates both Basic and Advanced usage, see Java Integration Example.

Basic Usage

If you're using the SDK's HTTP implementation, follow these steps.

1. Create an instance of PublisherUid2Client as an instance variable:

   private final PublisherUid2Client publisherUid2Client = new PublisherUid2Client(EUID_BASE_URL, EUID_API_KEY, EUID_SECRET_KEY);

2. Call a function that takes the user's email address as input and generates a TokenGenerateResponse object. The following example uses an email address:

   TokenGenerateResponse tokenGenerateResponse = publisherUid2Client.generateTokenResponse(TokenGenerateInput.fromEmail(emailAddress).doNotGenerateTokensForOptedOut());
   important

   • Be sure to call the POST /token/generate endpoint only when you have a legal basis to convert the user’s personal data to EUID tokens for targeted advertising.

   • Always apply doNotGenerateTokensForOptedOut(). This applies a parameter similar to setting optout_check=1 in the call to the POST /token/generate endpoint (see Unencrypted JSON Body Parameters).

Client-Server Integration

If you're using client-server integration (see Client-Server Integration Guide for JavaScript), follow this step:

• Send this identity as a JSON string back to the client (to use in the identity field), using the following:

  tokenGenerateResponse.getIdentityJsonString()
  note

  If the user has opted out, this method returns null, so be sure to handle that case.

Server-Side Integration

If you're using server-side integration (see Publisher Integration Guide, Server-Side), follow these steps:

1. Store this identity as a JSON string in the user's session, using the tokenGenerateResponse.getIdentityJsonString() function.

   If the user has opted out, this method returns null, so be sure to handle that case.

2. To retrieve the user's EUID token, use the following:

   IdentityTokens identity = tokenGenerateResponse.getIdentity();
   if (identity != null) { String advertisingToken = identity.getAdvertisingToken(); }

3. When the user accesses another page, or on a timer, determine whether a refresh is needed:

   1. Retrieve the identity JSON string from the user's session, and then call the following function that takes the identity information as input and generates an IdentityTokens object:

      IdentityTokens identity = IdentityTokens.fromJsonString(identityJsonString);

   2. Determine if the identity can be refreshed (that is, the refresh token hasn't expired):

      if (identity == null || !identity.isRefreshable()) { we must no longer use this identity (for example, remove this identity from the user's session) }

   3. Determine if a refresh is needed:

      if (identity.isDueForRefresh()) {..}

4. If needed, refresh the token and associated values:

   TokenRefreshResponse tokenRefreshResponse = publisherUid2Client.refreshToken(identity);

5. Store tokenRefreshResponse.getIdentityJsonString() in the user's session.

   If the user has opted out, this method returns null, indicating that the user's identity should be removed from the session. To confirm optout, you can use the tokenRefreshResponse.isOptout() function.

Advanced Usage

1. Create an instance of PublisherUid2Helper as an instance variable:

   private final PublisherUid2Helper publisherUid2Helper = new PublisherUid2Helper(EUID_SECRET_KEY);

2. Call a function that takes the user's email address or phone number as input and creates a secure request data envelope. See Encrypting requests. The following example uses an email address:

   EnvelopeV2 envelope = publisherUid2Helper.createEnvelopeForTokenGenerateRequest(TokenGenerateInput.fromEmail(emailAddress).doNotGenerateTokensForOptedOut());

3. Using an HTTP client library of your choice, post this envelope to the POST token/generate endpoint, including headers and body:

   1. Headers: Depending on your HTTP library, this might look something like the following:

      .putHeader("Authorization", "Bearer " + EUID_API_KEY)
.putHeader("X-UID2-Client-Version", PublisherUid2Helper.getVersionHeader())

   2. Body: envelope.getEnvelope()

   important

   • Be sure to call the POST /token/generate endpoint only when you have a legal basis to convert the user’s personal data to EUID tokens for targeted advertising.

   • Always apply doNotGenerateTokensForOptedOut(). This applies a parameter similar to setting optout_check=1 in the call to the POST /token/generate endpoint (see Unencrypted JSON Body Parameters).

4. If the HTTP response status code is not 200, see Response Status Codes to determine next steps. Otherwise, convert the EUID identity response content into a TokenGenerateResponse object:

   TokenGenerateResponse tokenGenerateResponse = publisherUid2Helper.createTokenGenerateResponse({response body}, envelope);

Client-Server Integration

If you're using client-server integration (see Client-Server Integration Guide for JavaScript), follow this step:

• Send this identity as a JSON string back to the client (to use in the identity field) using the following:

  tokenGenerateResponse.getIdentityJsonString()
  caution

  This method returns null if the user has opted out, so be sure to handle that case.

Server-Side Integration

If you're using server-side integration (see Publisher Integration Guide, Server-Side):

1. Store this identity as a JSON string in the user's session, using: tokenGenerateResponse.getIdentityJsonString().

   This method returns null if the user has opted out, so be sure to handle that case.

2. To retrieve the user's EUID token, use:

   IdentityTokens identity = tokenGenerateResponse.getIdentity();
   if (identity != null) { String advertisingToken = identity.getAdvertisingToken(); }

3. When the user accesses another page, or on a timer, determine whether a refresh is needed:

   1. Retrieve the identity JSON string from the user's session, and then call the following function that generates an IdentityTokens object:

      IdentityTokens identity = IdentityTokens.fromJsonString(identityJsonString);

   2. Determine whether the identity can be refreshed (that is, the refresh token hasn't expired):

      if (identity == null || !identity.isRefreshable()) { we must no longer use this identity (for example, remove this identity from the user's session) }

   3. Determine whether a refresh is needed:

      if (identity.isDueForRefresh()) {..}

4. If a refresh is needed, call the POST token/refresh endpoint, with the following:

   1. Headers: Depending on your HTTP library, this might look something like the following:

      .putHeader("Authorization", "Bearer " + EUID_API_KEY)
.putHeader("X-UID2-Client-Version", PublisherUid2Helper.getVersionHeader()).

   2. Body: identity.getRefreshToken()

5. If the refresh HTTP response status code is 200:

   TokenRefreshResponse tokenRefreshResponse = PublisherUid2Helper.createTokenRefreshResponse({response body}, identity);

6. Store tokenRefreshResponse.getIdentityJsonString() in the user's session.

   If the user has opted out, this method returns null, indicating that the user's identity should be removed from the session. To confirm optout, you can use the tokenRefreshResponse.isOptout() function.

Usage for Advertisers/Data Providers

1. Create an instance of IdentityMapClient as an instance variable.

   final private IdentityMapClient identityMapClient = new IdentityMapClient(EUID_BASE_URL, EUID_API_KEY, EUID_SECRET_KEY);

2. Call a function that takes email addresses or phone numbers as input and generates an IdentityMapResponse object. The following example uses email addresses:

   IdentityMapResponse identityMapResponse = identityMapClient.generateIdentityMap(IdentityMapInput.fromEmails(Arrays.asList("email1@example.com", "email2@example.com")));

note

The SDK hashes input values before sending them. This ensures that raw email addresses and phone numbers do not leave your server.

3. Retrieve the mapped and unmapped results as follows:

   Map<String, IdentityMapResponse.MappedIdentity> mappedIdentities = identityMapResponse.getMappedIdentities();
   Map<String, IdentityMapResponse.UnmappedIdentity> unmappedIdentities = identityMapResponse.getUnmappedIdentities();`

4. Iterate through the mapped and unmapped results, or do a lookup. The following example does a lookup:

   IdentityMapResponse.MappedIdentity mappedIdentity = mappedIdentities.get("email1@example.com");
   if (mappedIdentity != null) {
        String rawUid = mappedIdentity.getRawUid();
   } else {
        IdentityMapResponse.UnmappedIdentity unmappedIdentity = unmappedIdentities.get("email1@example.com");
        String reason = unmappedIdentity.getReason();
   }

Usage for DSPs

The following instructions provide an example of how a DSP can decode bidstream tokens using the EUID SDK for Java.

1. Create a BidstreamClient:

Bidstream client = new BidstreamClient(EUID_BASE_URL, EUID_API_KEY, EUID_SECRET_KEY);

2. Refresh once at startup, and then periodically (recommended refresh interval is hourly):

client.refresh();

3. Decrypt a token into a raw EUID. Pass the token, and then do one of the following:

• If the bid request originated from a publisher's website, pass the domain name. The domain name must be all lower case, without spaces and without subdomain. For example, for Subdomain.DOMAIN.com, pass domain.com instead.

• Otherwise, pass null.

DecryptionResponse decrypted = client.decryptTokenIntoRawUid(uidToken, domainOrAppName); 
//If decryption succeeded, use the raw EUID.
if (decrypted.isSuccess()) 
{
    //Use decrypted.getUid()
}
else 
{
    // Check decrypted.getStatus() for the failure reason.
}

For a full example, see the ExampleBidStreamClient method in test/IntegrationExamples.java.

FAQs

For a list of frequently asked questions for DSPs, see FAQs for DSPs.