For the past eighteen months, the TTPA's repository obligation has been the one part of the regulation that nobody could fully prepare for. The rule was clear: every online political advertisement published in the EU must be submitted to a central European repository, publicly accessible and searchable for seven years. But the technical specification — the format, the data structure, the API — was still to come.
On 9 April 2026, the first piece arrived.
The European Commission published Implementing Regulation (EU) 2026/818, a legally binding act that defines the architecture of the European repository for online political advertisements — the common data structure, standardised metadata, authentication requirements, and the common API that all providers will eventually use to submit political ads. The regulation is in force. The repository is being built. But the actual developer documentation, schema definitions, and API endpoints are not yet publicly available.
What the regulation defines — and what it doesn't
The implementing act sets out the requirements for the repository at a structural level. Every online political advertisement must be submitted with standardised metadata including all the fields from the transparency notice — sponsor identity, paying entity, controlling entity, election information, campaign budget, targeting parameters — plus a permanent URL pointing to where the ad is accessible, identification information for the ad, and for audio and video content, automated transcripts or subtitles.
The data must be formatted in JSON or XML and submitted via a common API. Interoperability with the DSA's advertising repositories is built into the specification. The European Data Protection Supervisor was consulted in January 2026 and confirmed the GDPR implications have been considered.
What the regulation does not yet provide is the actual API documentation. The schema definitions, endpoint specifications, controlled vocabulary, and technical integration guide will be published on the repository's public portal — but only sufficiently in advance of the repository going live. That go-live date has not yet been announced.
In short: the legal requirements are defined, but developers cannot yet build the integration. There is simply nothing to integrate against yet.
What can be done now
That said, there is meaningful groundwork that can be started. The fields required in the repository metadata are fully specified in the earlier implementing regulation (EU 2025/1410, Annex II, point 3) — the same fields that already appear in TTPA transparency notices. Any platform that has already built its transparency notice infrastructure has the underlying data model in place. When the API documentation does arrive, the integration work will be substantially about connecting existing data to a new endpoint — not building new data collection from scratch.
The Commission's TTPA hub at political-advertising.ec.europa.eu is where the go-live announcement and full technical documentation will appear. That is the page to watch.
Why this still matters now
The repository obligation is not just a filing exercise. It creates a public, searchable, machine-readable record of every political ad that runs in the EU — accessible to journalists, researchers, civil society organisations, regulators, and citizens. Any gap between what appears in the transparency notice and what is submitted to the repository will be visible. The seven-year retention period means accountability extends well beyond the election that prompted the campaign.
For political parties and advertisers, this is both a legal and reputational exposure. For publishers and adtech providers, it reinforces something that has been true since October 2025: running political advertising without infrastructure that can support the full compliance chain — labelling, transparency notices, data retention, and eventually repository submission — is an increasingly risky position.
What this means for Adnuntius customers
We are tracking the repository specification closely and will build the submission integration as soon as the API documentation is published. Our data model already captures all the fields defined in the implementing regulation, since they mirror the transparency notice data we collect today. When the technical documentation arrives, the integration will follow — and for campaigns running through our platform, submission will be handled automatically, the same way labelling, transparency notices, and the 7-year archive are handled now.
The repository is the last major technical piece of the TTPA puzzle. The legal framework is now defined. The technical implementation is coming. We will keep you updated as the Commission publishes further details.
Get in touch at adnuntius.com/political