Skip to main content

EUID SDK for Python (Server-Side) Reference Guide

You can use the EUID SDK for Python (Server-Side) to facilitate:

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

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


This SDK simplifies integration with EUID for any DSPs who are using Python for their server-side coding. The following table shows the functions it supports.

Encrypt Raw EUID to EUID TokenDecrypt EUID TokenGenerate EUID Token from Personal DataRefresh EUID Token
Not SupportedSupportedSupportedSupported

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.


The SDK supports Python 3.6 and above.

GitHub Repository/Package

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

The package is published in this location:


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

RoleCreate Instance of ClassLink to Instructions
PublisherUid2PublisherClientUsage for Publishers
DSPBidstreamClientUsage for DSPs
Sharer (not currently supported for EUID)SharingClientNot applicable

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

base_urlThe endpoint for the EUID service. See Environments.
auth_keyThe API key. See EUID Credentials.
secret_keyThe client secret. See EUID Credentials.


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.


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

Decryption Response Content

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

statusThe decryption result status. For a list of possible values and definitions, see Decryption Response Statuses.
uidThe raw EUID for the corresponding EUID token.
establishedThe 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.

SUCCESSThe EUID token was decrypted successfully and a raw EUID was returned.
NOT_AUTHORIZED_FOR_KEYThe requester does not have authorization to decrypt this EUID token.
NOT_INITIALIZEDThe client library is waiting to be initialized.
INVALID_PAYLOADThe incoming EUID token is not a valid payload.
EXPIRED_TOKENThe incoming EUID token has expired.
KEYS_NOT_SYNCEDThe client has failed to synchronize keys from the EUID service.
VERSION_NOT_SUPPORTEDThe client library does not support the version of the encrypted token.
DOMAIN_NAME_CHECK_FAILEDThe domain name doesn't match the domain of the encrypted token.
INVALID_TOKEN_LIFETIMEThe token has an invalid timestamp.

Usage for Publishers

  1. Create an instance of Uid2PublisherClient:

    client = Uid2PublisherClient(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:

    token_generate_response = client.generate_token(TokenGenerateInput.from_email(emailAddress).do_not_generate_tokens_for_opted_out())
    • Be sure to call the POST /token/generate endpoint only when you have obtained legal basis to convert the user’s personal data to EUID tokens for targeted advertising.

    • Always apply do_not_generate_tokens_for_opted_out(). 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 EUID SDK for JavaScript Integration Guide), follow this step:

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


    If the user has opted out, this method returns None, so be sure to handle that case.

Server-Only Integration

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

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

    If the user has opted out, this method returns None, so be sure to handle that case.

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

    identity = token_generate_response.get_identity()
    if identity:
    advertising_token = identity.get_advertising_token()
  3. Periodically check if the user's EUID token should be refreshed. This can be done at fixed intervals using a timer, or can be done whenever the user accesses another page:

    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:

      identity = IdentityTokens.from_json_string(identityJsonString)

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

      if not identity or not identity.is_refreshable(): # 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.is_due_for_refresh()):

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

    token_refresh_response = client.refresh_token(identity)

  5. Store token_refresh_response.get_identity_json_string() in the user's session.

    If the user has opted out, this method returns None, indicating that the user's identity should be removed from the session. To confirm optout, you can use the token_refresh_response.is_optout() function.

Usage for DSPs

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

  1. Create a BidstreamClient:
  1. Refresh once at startup, and then periodically (recommended refresh interval is hourly):
  1. 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, pass instead.
  • If the bid request originated from a mobile app, pass the app name.
  • Otherwise, pass null.
decrypted = client.decrypt_token_into_raw_uid(uid_token, domainOrAppName)
# If decryption succeeded, use the raw EUID.
if decrypted.success:
# Use decrypted.uid
# Check decrypted.status for the failure reason.

For a full example, see the in examples/


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