Ad Tech Insights: Trusted Server, AdCP and the EU Digital Omnibus

In November, three themes stood out: practical lessons from Trusted Server, perspectives sparked by the AdCP protocol on the role of AI agents in buying and selling advertising, and interpretations of the EU's newly published Digital Omnibus package and its impact on publishers. In this summary, we outline what these developments mean in practice: how Trusted Server is progressing, the opportunities AdCP could bring to buyers' and sellers' workflows, and the implications of the new EU data, consent and AI regulatory framework.

•••

Trusted Server: Early Observations and Publisher Implications

Trusted Server is an open-source server-side solution developed by IAB Tech Lab.

It could shift more control to publishers outside the browser, which is a strong direction. But like any early framework, there are still technical wrinkles to iron out. Many publishers are unlikely to take on a setup this heavy entirely on their own, which makes a reliable partner important. That's also why we've taken a close look at Trusted Server, and we see a clear role for ourselves in helping publishers navigate the server-side complexity.

It's still far too early to say whether Trusted Server will become the next big standard. Adoption will decide its fate. For now, we're simply supporting the work, testing what fits and listening to what publishers actually want.

What we've learned so far

• Our Relevant Yield platform already aligns well with the Trusted Server model, with most functionality carrying over with only light adjustments.
• Because Trusted Server is fully server-side, publishers need strong Prebid Server support, which we have provided for the past five years.
• Our Header Bidding analytics are already largely compliant, keeping the transition straightforward for current users.
• Publisher interest is still relatively quiet, as expected for a brand-new framework competing with louder industry trends.
• Much of the current development focuses on signal verification, ensuring the buy side can trust the data it receives.
• While some concerns remain around bidders that are not yet server-side compatible, most major bidders already support the model, and the rest will need to catch up.

We have always offered Prebid Server at no additional cost to Relevant Yield's HB Manager users because we want publishers to be able to test and find the solutions that work best for them. Trusted Server further reinforces this mindset.

- Ronny Linder - CPO & Partner, Relevant Digital, Member of Several IAB Tech Lab Task Forces

•••

AdCP: What It Could Mean for Buyers, Sellers and Digital Advertising

AdCP is an open-standard protocol designed to let AI agents acting as buyers and sellers in advertising speak the same language: a kind of "universal ads API" built on the Model Context Protocol (MCP) framework. Market reaction has been cautiously optimistic. Many in ad tech call it the "OpenRTB for the AI era," liking the idea of reducing platform-specific integrations and improving transparency, while warning that adoption will take time and major players may drag their feet.

Where AdCP could help

If we focus on the actual idea of the protocol, which is to support and work alongside OpenRTB, there are clear benefits to be found. Too often, we struggle to get deals or creatives working and have to go back and forth to find a solution. This is one area where communication between agents using shared protocols could solve many inefficiencies.

It could also make various kinds of first-party data targeting options easier to create and more scalable. Of course, there is still a big question of trust when testing new targeting methods, but this could at least facilitate discovery and technical implementation when less established methods are being tested. Discovery could also help smaller publishers get found, although it remains to be seen what the tech costs of running this will be and, therefore, how feasible it is for those smaller publishers.

Even the "zero UI" approach seen in the launch webinar was interesting to an extent. Do I believe all media buying will happen through chat interfaces and agentic protocols, at least in the near future? No. But I certainly think it could make it easier, especially for smaller advertisers, to buy advertising. It could also help automate processes within systems, but I have a hard time seeing AdCP with zero-UI interfaces overtaking OpenRTB and large-scale media buying and selling anytime soon.

To sum up, I can easily see AdCP or something similar streamlining a lot of manual troubleshooting and other strenuous work in media buying and selling. It could also finally make open web programmatic buying a bit more open to small advertisers, although these would primarily be direct campaigns rather than what we traditionally think of as programmatic. For the longest time, the only real avenue to the open web for small advertisers has been Google Ads, clunkiness and all.

- Tuukka Aaltonen - Head of Programmatic, Relevant Digital, Vice Chair of IAB Finland's Data & Martech Working Group

•••

EU Digital Omnibus: Regulatory Easing or Reorganization of Existing Rules?

The European Commission's Digital Omnibus package, published on November 19, 2025, aims to streamline the EU's digital regulatory landscape. While the public messaging emphasizes "simplification" and "reducing administrative burden," the package does not amount to deregulation: the core structures of the GDPR and the AI Act remain intact. Instead, the legislation introduces clarifications and new procedures that will also shape publishers' day-to-day reality.

In data protection, the most visible changes concern cookie governance. The GDPR will be clarified to improve harmonized interpretation across Member States, and consent management will gradually shift to browser- and operating-system-level settings. This may reduce pop-up fatigue but also influence ad delivery, measurement and consent strategies. Narrower definitions of personal data and a broader legitimate-interest basis may increase non-consent inventory and revive specific modeling techniques, emphasizing the importance of contextual advertising, first-party data and intelligent optimization.

For the AI Act, the most significant change concerns timing. The application of high-risk system requirements will be postponed by up to 16 months and linked to the readiness of the necessary standards and tools. This adjustment is intended to ease practical implementation for technology providers and may indirectly affect the AI-based products publishers use.

Reporting obligations will also be streamlined by merging NIS2, GDPR and DORA notifications into a single reporting channel. Meanwhile, the Data Union Strategy and the European Business Wallet aim to improve access to high-quality data and simplify EU-level digital administration. Their impact on publishers will materialize later, as both require separate technical implementation and Member State adoption.

What happens next

Next, the Digital Omnibus will move to the European Parliament and the Council for consideration in early 2026. At the same time, the Digital Fitness Check consultation will run until March 2026 and may lead to further changes later in the year. The eventual impact on publishers will depend on how quickly new standards are finalized, how browsers and operating systems implement consent mechanisms and how consistently Member States apply the rules in practice.

- Suvi Leino - Head of Marketing, Relevant Digital