OM SDK

The Open Measurement SDK (OM SDK) is IAB Tech Lab's shared library that apps and video players include so third-party verification code can measure ads, such as viewability, through one common interface.

Before Open Measurement, every verification vendor needed its own SDK inside every app, and many relied on VPAID wrappers in video. VAST 4.3 defines the OM SDK as an IAB-led common library that collects and exposes measurements of ad creatives at view time for verification. It defines OMID, the Open Measurement Interface Definition, as the API that verification code calls, and as the replacement for VPAID in verification (IAB Tech Lab, VAST 4.3).

The flow is simple. The app integrates the OM SDK once. Each ad response names its verification scripts, in VAST through the AdVerifications node. The SDK loads those scripts and feeds them geometry and playback events, while the app declares friendly obstructions, such as its own close button, so they do not count against viewability. IAB Tech Lab's web and JavaScript clients reached version 1.6.12 on 2 November 2026 (GitHub, Open-Measurement-JSClients).

Example: A streaming app with the OM SDK receives a VAST ad whose AdVerifications node lists one vendor's script. The SDK runs it, reports that the video was 100% on screen with sound on, and the vendor's report reaches the advertiser without a vendor SDK in the app.

Related terms: viewability, IVT, VAST, VPAID, MRAID, creative wrapper.

Authoritative source: IAB Tech Lab, VAST 4.3, definitions of "OMID" and "Open Measurement SDK (OM SDK)" (GitHub, accessed 9 November 2026).

Read the full guide: Viewability, attention metrics and brand safety.