GDPR Enforcement Module

This module requires the EU GDPR consent management module (the base consent module), which reads consent values from the Consent Management Platform (CMP). The GDPR Enforcement Module will then enforce the results. See the base module page for general background, usage, and legal disclaimers.

Overview

The base consent module performs the following actions:

  1. Fetches the user’s GDPR consent data from the CMP.
  2. Incorporates this data into the auction objects for adapters to collect.

The GDPR Enforcement Module adds the following:

  1. Allows the page to define which activities should be enforced at the Prebid.js level.
  2. Actively enforces those activities based on user consent data.

The following table details the Prebid.js activities that fall under the Transparency and Consent Framework (TCF) scope:

In-Scope Activity TCF Legal Basis Required Enforcement Activity Prebid.js Version
Invoke usersync pixels Purpose 1 - Store and/or access information on a device May prevent one or more vendor usersyncs. 3.14+
Invoke user ID modules Purpose 1 - Store and/or access information on a device May prevent one or more UserID modules from activating. 3.14+
Read and write data to device Purpose 1 - Store and/or access information on a device May prevent one or more adapters or modules from being able to read or write cookies or localstorage in the user’s browser. 3.14+
Perform header bidding auction Purpose 2 - Basic ads May prevent one or more bid adapters from participating in the auction. 4.0+

There are plans to add more TCF Purposes and activities in future releases.

Page Integration

A page needs to define configuration rules about how Prebid.js should enforce each in-scope activity.

Important Legal Note: Prebid.org cannot provide legal advice about GDPR or any other governmental regulation. Our aim is to provide a toolkit of functionality that will let publishers configure header bidding as defined by their legal counsel. We will consider feature suggestions, and review any code offered by the community.

To turn on Prebid.js enforcement you must: 1) Include the gdprEnforcement module in the Prebid.js build and 2) setConfig consentManagement.gdpr.cmp to either ‘iab’ or ‘static’

The following fields related to GDPR enforcement are supported in the consentManagement.gdpr object:

Param Type Description Example
gdpr.rules Array of Objects Lets the publisher override the default behavior.  
gdpr.rules[].purpose String Supported values: “storage” (Purpose 1), “basicAds” (Purpose 2) “storage”
gdpr.rules[].enforcePurpose Boolean Determines whether to enforce the purpose consent. The default in Prebid.js 3.x is not to enforce purposes. Prebid.js 4.0 enforces legal basis for Purposes 1 and 2 by default. true
gdpr.rules[].enforceVendor Boolean Determines whether to enforce vendor signals for this purpose. The default in Prebid.js 3.x is not to enforce vendor signals. Prebid.js 4.0 enforces legal basis for Purposes 1 and 2 by default. true
gdpr.rules[].vendorExceptions Array of Strings Defines a list of biddercodes or module names that are exempt from the enforcement of this Purpose. [“bidderA”, “userID-module-B”]

Note:

  • To accomodate Prebid.js modules and adapters that don’t have GVL IDs, the vendorExceptions list is based on Prebid.js biddercodes instead of Global Vendor List (GVL) IDs (i.e. “rubicon” instead of “52”).

Examples

The following examples cover a range of use cases and show how Prebid.js supports configuration of different business rules.

1) Enforce device access activity and basic ads. These are the default values (in Prebid.js 4.0) if the module is included in the build.

pbjs.setConfig({
  consentManagement: {
    gdpr: {
      cmpApi: 'iab',   // activates the enforcement module
      defaultGdprScope: true,
      rules: [{        // these are the default values
        purpose: "storage",
        enforcePurpose: true,
        enforceVendor: true
      },{
        purpose: "basicAds",
        enforcePurpose: true,
        enforceVendor: true
      }]
    }
  }
});

2) Enforce that the user consents to DeviceAccess as an activity and consider their per-vendor selection. However, idSystemA is a special case - the publisher has confirmed that this system obtains a user ID every auction and does not write to the local device.

  ...
  rules: [{
    purpose: "storage",
    enforcePurpose: true,
    enforceVendor: true,
    vendorExceptions: ["idSystemA"]
  }]

3) Enforce legal basis for both storage and basicAds, with the exception of “firstPartyBidder”, which is always allowed to run an auction. Assumes the publisher has special legal basis for this entity.

  ...
  rules: [{
    purpose: "storage",
    enforcePurpose: true,
    enforceVendor: true
  },{
purpose: "basicAds",
enforcePurpose: true,
enforceVendor: true,
    vendorExceptions: ["firstPartyBidder"]
  }]

4) Turn off enforcement of Purpose 1: don’t enforce either the user’s DeviceAccess consent or their per-vendor selection.

  ...
  rules: [{
    purpose: "storage",
    enforcePurpose: false,
    enforceVendor: false
  }]

Basic Enforcement

Prebid.js does not have access to the Global Vendor List (GVL), so it implements a “basic” form of TCF ‘legal basis’ validation using the supplied consent string.

A goal of basic enforcement is to confirm that there’s enough evidence of consent to pass data on to vendors who do have access to the GVL and can fully parse and enforce.

Before allowing an activity tied to a TCF-protected Purpose for a given vendor, one of these scenarios must be true:

  • Configuration rules enforce both consent and vendor signals and either:
    • Prebid.js has the user’s purpose consent and the user’s vendor consent, or
    • (for Purpose 2 only) we’ve confirmed the user’s Legitimate Interest (LI) Transparency is established for this purpose
  • Configuration rules enforce only purpose consent and either:
    • Prebid.js has the user’s purpose consent, or
    • (for Purpose 2 only) we confirmed the user’s LI Transparency is established for this purpose.
  • Configuration rules enforce only vendor signals and we have the user’s vendor consent
  • Configuration rules enforce neither purpose consent nor vendor signal.

See the IAB TCF Consent String Format for details.

Build the Package

Follow the basic build instructions in the GitHub Prebid.js repo’s main README. Include the base consent management module and this enforcement module as additional options on the gulp build command:

gulp build --modules=consentManagement,gdprEnforcement,bidAdapter1,bidAdapter2

You can also use the Prebid.js Download page.

Further Reading