Open Measurement

The IMA SDK for HTML5 includes the Open Measurement (OM) SDK, an industry standard developed by the Interactive Advertising Bureau (IAB) to enable third-party viewability and verification measurement. When using the IMA SDK for HTML5, the included OM SDK automatically parses the <AdVerifications> tag within VAST ad tags and sends viewability data to the specified measurement vendors using the OMID API. You can optionally set access mode rules for each request to control what content the verification script can access.

The IMA SDK supports OM SDK v1.4.


  • If using VAST 4.1 or higher, ads must be configured to supply verification using <AdVerifications>. If using previous VAST versions, ads must use <Extension type="AdVerifications">.

  • If your ads are trafficked through Ad Manager, configure a viewability provider for your Ad Manager network and assign that viewability provider to your line item. For more information, see Configure a viewability provider for your Ad Manager network.

Access modes

The OM SDK supports running verification scripts in four different access modes which controls how much the verification script can access:

  • FULL: The verification script has direct access to the creative and the publisher page.

  • CREATIVE: The verification script and creative are sandboxed from the publisher page. However, the script has direct access to the creative.

  • DOMAIN: The verification script is sandboxed and cannot access the creative or publisher page. However, the script is loaded in such a way that it can directly confirm what publisher domain it is on.

  • LIMITED: The verification script is sandboxed and cannot access the creative or publisher page, and cannot directly confirm what publisher domain it is on.

Some viewability providers might not support all access modes. Contact your viewability providers to verify which modes are supported.

Set the access mode rules for a request

Access mode rules must be set at the StreamRequest level. To set different access modes for different verification script providers, pass a dictionary that maps each OmidVerificationVendor to one of the access modes listed above. The OmidVerificationVendor.OTHER field is used to set the default access mode for all vendors not explicitly included in the dictionary. If no access mode rules are specified, verification scripts run in LIMITED access mode for vendors.

See the following example which sets GOOGLE to google.ima.dai.api.OmidAccessMode.FULL. All other providers, including those listed in OmidVerificationVendor, default to how OmidVerificationVendor.OTHER is set.

request.omidAccessModeRules = {};
    = google.ima.dai.api.OmidAccessMode.FULL;
    = google.ima.dai.api.OmidAccessMode.DOMAIN;

To implement CREATIVE access mode, you must follow both of the following steps:

  1. Sandbox your video player in a secure iframe, isolated from the rest of your site.

  2. Set the OmidAccessMode for your viewability partner to FULL.