Summary The proposed Cloud and AI Development Act (CADA) designates the Interoperable Europe portal as the mandatory hosting infrastructure for the new EU Open Source Solutions Catalogue (EU OSS Catalogue). As proposed in Article 43(2) of CADA, the Commission must host this catalogue on the portal established under Article 8 of Regulation (EU) 2024/903 (the Interoperable Europe Act). This integration ensures that open-source software developed by Union entities and public sector bodies is centrally discoverable, accessible free of charge, and interoperable with the broader EU digital ecosystem. While the Interoperable Europe Act is already in force, CADA remains a proposal; if adopted, it would legally bind public bodies to route their open-source releases through this specific portal to reduce vendor lock-in and enhance technological sovereignty.

Detail

The relationship between the proposed Cloud and AI Development Act (CADA) and the Interoperable Europe portal is a critical example of how the EU is layering new sovereignty measures onto existing digital infrastructure. The Interoperable Europe portal is not a new creation under CADA; rather, it is the operational backbone of the Interoperable Europe Act (Regulation (EU) 2024/903). This Act was designed to facilitate the sharing and reuse of interoperability solutionsβ€”such as software, standards, and specificationsβ€”across public administrations to prevent fragmentation and ensure cross-border compatibility.

CADA, as proposed in COM(2026) 502 final, leverages this existing, legally established infrastructure to operationalize its open-source strategy. The proposal identifies open source as a primary lever for strengthening the EU's technological sovereignty, reducing dependency on non-EU proprietary vendors, and fostering a competitive European cloud and AI ecosystem. To achieve this, CADA introduces a centralized mechanism for discovering and reusing public-sector software, explicitly tethering it to the Interoperable Europe portal.

The Legal Mandate: Article 43(2) and Regulation (EU) 2024/903

The core of this relationship is defined in Article 43 of the CADA proposal, which establishes the EU Open Source Solutions Catalogue. The text of Article 43(2) is precise regarding the hosting location:

"The EU OSS Catalogue shall be hosted on the Interoperable Europe portal referred to in Article 8 of Regulation (EU) 2024/903 and shall be accessible electronically free of charge."

This provision creates a direct statutory link between the two regulations. By referencing Article 8 of Regulation (EU) 2024/903, CADA does not merely suggest a technical integration; it legally mandates that the catalogue reside on the specific portal established by the Interoperable Europe Act. This ensures that the catalogue benefits from the portal's existing security protocols, user authentication mechanisms, and interoperability standards.

The Interoperable Europe Act (Regulation (EU) 2024/903) defines the portal as a central access point for interoperability solutions. Article 8 of that regulation specifically tasks the Commission with establishing and maintaining this portal. By anchoring the EU OSS Catalogue here, CADA ensures that open-source software is treated as a key interoperability solution, rather than an isolated asset. This alignment supports the "once-only" principle and the broader goal of a seamless digital single market.

The Function of the EU OSS Catalogue

The EU OSS Catalogue serves as a centralized repository for software made available for reuse by Union entities (EU institutions, agencies, and bodies) and public sector bodies (national, regional, and local authorities). Its primary functions, as outlined in Article 43(1), are to:

  1. Centralize Discovery: Provide a single point of search for public administrations looking for software solutions.
  2. Ensure Accessibility: Guarantee that the catalogue is accessible electronically free of charge, removing financial barriers to reuse.
  3. Facilitate Reuse: Enable the sharing of software developed with public funds, thereby maximizing the value of public expenditure and reducing duplication of effort.

The catalogue is not intended to replace existing code repositories like GitHub or GitLab. Instead, it acts as a meta-catalogue or index. Article 42 of CADA clarifies this relationship: when a Union entity or public sector body voluntarily decides to make software available for reuse under an open-source license, it must do so using a catalogue or repository that is connected to and made accessible through the EU OSS Catalogue.

This means that while the code may physically reside on a provider's own infrastructure, the metadata, licensing information, and access points must be registered in the EU OSS Catalogue on the Interoperable Europe portal. Article 43(3) empowers the Commission to decide, based on objective criteria, which external catalogues or repositories qualify for this connection, ensuring a unified and high-quality user experience.

Strategic Rationale: Sovereignty and Interoperability

The decision to host the catalogue on the Interoperable Europe portal is driven by strategic policy goals:

  • Technological Sovereignty: By centralizing the discovery of open-source solutions, the EU aims to reduce reliance on proprietary, non-EU software stacks. Open source allows for greater auditability, security, and control over the software supply chain, which is a core objective of CADA's sovereignty framework.
  • Interoperability by Design: Hosting the catalogue on the Interoperable Europe portal ensures that software listed there is inherently aligned with EU interoperability standards. This reduces the technical debt associated with integrating disparate systems across Member States.
  • Efficiency and Transparency: A single, free-to-access portal prevents the fragmentation of public-sector software assets. It allows for better tracking of public investment in software development and promotes transparency regarding what solutions are available for reuse.

Implementation and Governance

The proposal outlines a governance structure to support this integration. Article 44 establishes a network of Open Source Programme Offices (OSPOs) to facilitate cooperation and the exchange of best practices. These offices would play a crucial role in ensuring that public bodies correctly connect their repositories to the EU OSS Catalogue.

Furthermore, Article 41 encourages Union entities and public sector bodies to prioritize open standards and open-source components when building their cloud and AI ecosystems. The EU OSS Catalogue serves as the practical tool to fulfill this encouragement, providing a curated list of vetted, reusable components.

What this means for you

For technology leaders, developers, and public sector administrators, the linkage between CADA and the Interoperable Europe portal has significant operational implications.

For Public Sector CTOs and IT Directors

  • Compliance Pathways: If your organization develops software and chooses to release it under an open-source license, you must ensure it is listed in a repository that connects to the EU OSS Catalogue. You cannot simply publish to a generic public repository and consider the obligation met; the metadata must flow to the Interoperable Europe portal.
  • Procurement Strategy: When sourcing software, the Interoperable Europe portal will become a primary search tool. You are expected to prioritize solutions found here, as they are pre-vetted for interoperability and open-source compliance. This could shift procurement away from proprietary vendors toward EU-based open-source alternatives.
  • Metadata Management: Preparing software for the catalogue requires attention to metadata standards defined by the Interoperable Europe Act. This includes detailed descriptions of functionality, licensing terms, and technical dependencies.

For SMEs and Private Software Providers

  • Market Visibility: The EU OSS Catalogue will highlight gaps in the market. If public bodies are seeking specific open-source solutions that are not yet available, SMEs can identify these needs and develop compliant solutions to fill them.
  • Competitive Advantage: Demonstrating that your software is compatible with or listed on the EU OSS Catalogue can be a significant advantage in public tenders. CADA encourages the use of open-source solutions, and alignment with the portal signals adherence to EU policy goals.
  • Access to Resources: The portal will host not just software, but also interoperability solutions and standards. SMEs can leverage these resources to build products that are natively compatible with public sector requirements.

Actionable Steps

  1. Monitor the Portal: Keep a close watch on the Interoperable Europe portal for updates regarding the launch and operational details of the EU OSS Catalogue.
  2. Audit Internal Repositories: Public sector organizations should review their software release policies to ensure they can technically and legally connect their repositories to the EU OSS Catalogue.
  3. Engage with OSPOs: Consider joining or engaging with the network of Open Source Programme Offices established under CADA to stay informed about best practices and collaboration opportunities.

Common misconceptions

Misconception 1: The Interoperable Europe portal is only for IT professionals. While the portal is a technical resource, its impact extends to legal, procurement, and strategic roles. CTOs must collaborate with legal teams to ensure open-source licenses comply with EU law and that metadata meets regulatory requirements. Procurement officers must understand how to leverage the portal to find cost-effective, compliant solutions.

Misconception 2: All public sector software must be open-sourced and listed on the portal. CADA does not mandate that all software developed by public sector bodies must be open-sourced. Article 42 applies only to software that a Union entity or public sector body voluntarily decides to make available for reuse under an open-source license. However, if they choose to do so, they must use a repository connected to the EU OSS Catalogue. The act encourages open-source use but does not force it for all internal tools.

Misconception 3: The EU OSS Catalogue replaces existing open-source repositories like GitHub or GitLab. The EU OSS Catalogue does not replace these platforms. Instead, it acts as a central index or aggregator. Public sector bodies can still host their code on GitHub or GitLab, but they must ensure that their repository is connected to and discoverable through the EU OSS Catalogue on the Interoperable Europe portal. This ensures visibility for other public sector bodies seeking reusable solutions.

Misconception 4: CADA is already in force and these rules are mandatory today. CADA is a proposal (COM(2026) 502 final) and is not yet in force. The text provided is the Commission's proposal, which must still be adopted by the European Parliament and the Council. While the Interoperable Europe Act (Regulation (EU) 2024/903) is already in force, the specific requirements linking it to the EU OSS Catalogue under CADA will only apply if and when CADA is adopted and enters into force. Organizations should prepare for these changes but are not yet legally bound by CADA's specific provisions.

Related

This is general information about a draft EU regulation, not legal advice.