Open Internet Stack Support for Scale (CSA)

The EU Funding & Tenders Portal has announced a forthcoming call for proposals titled "Open Internet Stack Support for Scale (CSA)" under the Horizon Europe program, specifically identified as HORIZON-CL4-2026-04-DATA-03. This initiative aims to create a robust framework for promoting, validating, and sustaining open-source solutions within the EU, emphasizing the importance of digital sovereignty.

The essential details include the following:

The call is categorized as a Coordination and Support Action (CSA) with a total budget of €4 million, focusing on reinforcing the European open-source ecosystem through a single-stage submission process. The call opens on January 15, 2026, with a submission deadline of April 15, 2026, at 17:00 CET.

The expected outcomes include establishing a centralized hub for cataloguing, reviewing, and validating open-source components, developing long-term sustainability models for these projects, and implementing a cohesive branding and training strategy. The scope of this call further involves conducting security and accessibility audits, screening European-funded open-source initiatives, and advising on sustainability, while fostering connections with national and pan-European initiatives.

Eligible applicants include any legal entity established in the EU, EEA, or Associated Countries, capable of managing the project without specific restrictions on organizational types. However, entities from China are explicitly excluded from participating in this action.

The funding is structured as a lump sum grant, simplifying budget management and providing full financial backing without requiring co-funding from beneficiaries. This call emphasizes the digital technology sector, focusing on areas such as open-source software and trustworthy ICT.

Projects supported by this funding will span a duration of approximately 36 months, aiming to consolidate efforts within the European open-source landscape rather than pursue novel research or technological developments.

Overall, this Horizon Europe initiative represents a strategic investment in the development and scaling of a sovereign open internet stack, aligning with the EU's broader objectives of enhancing digital sovereignty and competitiveness in the global marketplace.

The EU Funding & Tenders Portal presents a call for proposals under the Horizon Europe (HORIZON) program, specifically the DIGITAL (HORIZON-CL4-2026-04) call, focusing on Open Internet Stack Support for Scale (CSA). The topic ID is HORIZON-CL4-2026-04-DATA-03. This is a HORIZON Coordination and Support Action (HORIZON-CSA) with a HORIZON Lump Sum Grant [HORIZON-AG-LS] Model Grant Agreement (MGA).

The call is forthcoming with a single-stage deadline model. The planned opening date is January 15, 2026, and the deadline for submission is April 15, 2026, at 17:00:00 Brussels time.

The expected outcomes of the projects are: a common approach and hub for cataloguing, packaging, reviewing, and validating Open Internet Stack components and projects; long-term viability by advising on Open Source sustainability and maintenance models, including business and foundation aspects, and promotion of the EU and Associated Countries as ideal locations for Open Source Foundation sieges; a common branding, marketing, training, and communication plan ensuring consistent perception and scale-up; and a close interleave with policy development through a dedicated policy sandbox.

The scope of the call includes applicants devising a plan for: cataloguing solutions in a structured and easy-to-discover way; performing security and accessibility audits on the selected solutions under the Open Internet Stack; screening and selecting European-funded Open Source projects, including by exploring the relevant Horizon Europe programs, and devising a strategy for the Open Internet Stack to become a central hub for those solutions; establishing links and mutual support with national, multi-country, and pan-European initiatives supporting Open Source sovereign solutions; advising on sustainability models (both for and non-for profit), on standardisation, licencing schemes, or localisation/internationalisation; elaborating a common branding with associated marketing and communication tools; developing training material on these solutions that stresses their value in terms of EU legislation compliance (GDRP, DSA/DMA, CRA…), security (e.g. reference to security audits, list of dependencies), use cases, funding/business model, deployment requirements (server side, user side), link to repository and community resource (maintainers, community manager, discussion board…), with training material tailored to each target audience: Operators of infrastructure, Integrators, Government & verticals IT, end users; implementing measures to identify/attract technology adopters (e.g. services providers, integrators, OSPOs in governments/verticals) to become promoters of these technologies; developing sandbox tools for ensuring smooth compliance-by-design of the Open Internet Stack with relevant existing or futures EU policies; and supporting Open Source awards scheme and sustainability models after the action is finished.

The call specifies that proposals with an overall duration of typically 36 months would allow these outcomes to be addressed appropriately, but other durations are not precluded. Beneficiaries that intend to transfer ownership or grant an exclusive licence must formally notify the granting authority (i.e. DG-CNECT and HaDEA) before the intended transfer or licensing takes place, and the granting authority may object to a transfer of ownership or the exclusive licensing of results up to four years after the end of the action.

The topic destination is "Developing an agile and secure single market and infrastructure for data-services and trustworthy artificial intelligence services (2026-27)". This destination emphasizes the importance of digital sovereignty and competitiveness through the convergence of Telco-Edge-Cloud continuum (3C) with open orchestration platforms to unlock the transformative potential of AI across strategic sectors. It also highlights the building of a sovereign Open Internet Stack, rooted in open-source, interoperable, and standard-based solutions, to reinforce trust, resilience, and innovation. Decentralized and federated approaches to AI data processing, combined with breakthroughs in sustainable data centers, are expected to help overcome Europe’s compute bottlenecks and dependencies and reduce the environmental footprint of AI. The destination aligns with the Data Union Strategy and Common European Data Spaces to deliver secure, compliant, and adaptive data-sharing frameworks. Legal entities established in China are not eligible to participate in both Research and Innovation Actions (RIAs) and Innovation Actions (IAs) falling under this destination.

The general conditions for this call include:

1. Admissibility Conditions: Proposal page limit and layout are described in Annex A and Annex E of the Horizon Europe Work Programme General Annexes and in Part B of the Application Form available in the Submission System.

2. Eligible Countries are described in Annex B of the Work Programme General Annexes. Specific provisions may exist for non-EU/non-Associated Countries, as detailed in the Horizon Europe Programme Guide.

3. Other Eligible Conditions are subject to restrictions for the protection of European communication networks and are described in Annex B of the Work Programme General Annexes.

4. Financial and operational capacity and exclusion are described in Annex C of the Work Programme General Annexes.

5a. Evaluation and award: Award criteria, scoring and thresholds are described in Annex D of the Work Programme General Annexes.

5b. Evaluation and award: Submission and evaluation processes are described in Annex F of the Work Programme General Annexes and the Online Manual.

5c. Evaluation and award: Indicative timeline for evaluation and grant agreement are described in Annex F of the Work Programme General Annexes.

6. Legal and financial set-up of the grants: The granting authority may object to a transfer of ownership or to the exclusive licensing of results up to 4 years after the end of the action, as set out in the specific provision of Annex 5. Eligible costs will take the form of a lump sum as defined in the Decision of 7 July 2021. This is further described in Annex G of the Work Programme General Annexes. Specific conditions are described in the specific topic of the Work Programme.

The application and evaluation forms and model grant agreement (MGA) include: Application form templates (Standard application form (HE CSA)), Evaluation form templates (Standard evaluation form (HE CSA)), the HE Programme Guide, Lump Sum MGA, Call-specific instructions, Detailed budget table (HE LS), and Guidance: "Lump sums - what do I need to know?".

Additional documents include: HE Main Work Programme 2026-2027 – 1. General Introduction, HE Main Work Programme 2026-2027 – 7. Digital, Industry and Space, HE Main Work Programme 2026-2027 – 15. General Annexes, HE Programme Guide, HE Framework Programme 2021/695, HE Specific Programme Decision 2021/764, EU Financial Regulation 2024/2509, Decision authorising the use of lump sum contributions under the Horizon Europe Programme, Rules for Legal Entity Validation, LEAR Appointment and Financial Capacity Assessment, EU Grants AGA — Annotated Model Grant Agreement, Funding & Tenders Portal Online Manual, Funding & Tenders Portal Terms and Conditions, and Funding & Tenders Portal Privacy Statement.

The budget overview includes several topics, with HORIZON-CL4-2026-04-DATA-03 having a budget of EUR 4,000,000 and an indicative number of 1 grant. The opening date is 2026-01-15 and the deadline is 2026-04-15.

Partner search announcements are available, and LEARs, Account Administrators, or self-registrants can publish partner requests.

The submission system is planned to be opened on the date stated on the topic header.

General FAQs and support are available, including the Online Manual, Horizon Europe Programme Guide, Funding & Tenders Portal FAQ, Research Enquiry Service, National Contact Points (NCPs), Enterprise Europe Network, IT Helpdesk, European IPR Helpdesk, CEN-CENELEC Research Helpdesk and ETSI Research Helpdesk, The European Charter for Researchers and the Code of Conduct for their recruitment, and Partner Search.

This Horizon Europe call aims to foster the development and scaling of a sovereign Open Internet Stack within the EU. It seeks to create a comprehensive ecosystem by cataloguing, securing, and promoting open-source solutions, ensuring their long-term sustainability, and aligning them with EU policies. The call encourages collaboration among various stakeholders, including researchers, businesses, and public administrations, to strengthen Europe's digital sovereignty and competitiveness in the global data and AI landscape. The funding supports coordination and support actions to build a trusted, resilient, and innovative digital infrastructure that empowers European citizens and businesses.

Eligible Applicant Types: The eligible applicant types are not explicitly defined in the provided text. However, based on the nature of Horizon Europe calls, eligible applicants typically include universities, research institutes, SMEs, large enterprises, and other legal entities capable of conducting research and innovation activities. The specific eligibility criteria are detailed in Annex B of the Work Programme General Annexes and the Horizon Europe Programme Guide.

Funding Type: The primary financial mechanism is a grant, specifically a HORIZON Lump Sum Grant. The call includes Research and Innovation Actions (RIA), Innovation Actions (IA), and Coordination and Support Actions (CSA). Eligible costs will take the form of a lump sum as defined in the Decision of 7 July 2021 authorising the use of lump sum contributions under the Horizon Europe Programme.

Consortium Requirement: The text does not explicitly state whether a single applicant or a consortium is required. However, given the scope and nature of the activities, particularly for RIAs and IAs, a consortium is highly probable. The specific requirements are likely detailed in the specific topic descriptions within the Work Programme.

Beneficiary Scope (Geographic Eligibility): The primary geographic eligibility is focused on EU and associated countries. However, the text mentions that a number of non-EU/non-Associated Countries that are not automatically eligible for funding have made specific provisions for making funding available for their participants in Horizon Europe projects. See the information in the Horizon Europe Programme Guide. Legal entities established in China are not eligible to participate in both Research and Innovation Actions (RIAs) and Innovation Actions (IAs) falling under this destination.

Target Sector: The program targets the digital sector, specifically focusing on developing an agile and secure single market for data and trustworthy AI services. It also addresses the convergence of the Telco-Edge-Cloud continuum (3C) and the development of a sovereign Open Internet Stack. The targeted sectors include mobility, energy, health, and manufacturing.

Mentioned Countries: China is explicitly mentioned as a country whose legal entities are not eligible to participate in Research and Innovation Actions (RIAs) and Innovation Actions (IAs) falling under this destination. The primary geographic focus is on the EU and associated countries.

Project Stage: The program supports various project stages, including research (Research and Innovation Actions), development and demonstration (Innovation Actions), and coordination and support (Coordination and Support Actions).

Funding Amount: The funding amounts vary depending on the type of action:
HORIZON-RIA: €7,000,000 to €17,000,000, €18,000,000, €10,000,000, €45,000,000, €16,800,000, €20,500,000
HORIZON-CSA: €1,000,000 to €4,000,000, €2,000,000, €3,000,000
HORIZON-IA: €6,000,000 to €46,500,000, €30,000,000

Application Type: The application type is an open call with a single-stage submission process.

Nature of Support: Beneficiaries will receive money in the form of a lump sum grant.

Application Stages: The application process involves a single stage.

Success Rates: The success rates are not mentioned in the text.

Co-funding Requirement: The text does not explicitly mention a co-funding requirement.

Summary: This opportunity is a Horizon Europe call (DIGITAL, HORIZON-CL4-2026-04) focused on supporting the development and scaling of an Open Internet Stack within the EU. It aims to foster digital sovereignty and competitiveness by promoting open-source, interoperable, and standard-based solutions. The call includes various funding instruments: Research and Innovation Actions (RIA), Innovation Actions (IA), and Coordination and Support Actions (CSA), each with different funding ranges. Eligible applicants include a wide range of entities such as universities, research institutions, SMEs, and large enterprises from the EU and associated countries. Projects should contribute to cataloguing, packaging, reviewing, and validating Open Internet Stack components, advising on sustainability models, and developing training and communication plans. The call emphasizes alignment with EU policies such as GDPR, DSA/DMA, and CRA, and aims to build a secure, compliant, and adaptive data-sharing framework. Legal entities from China are not eligible for RIAs and IAs under this call. The application process is a single-stage submission, and funding is provided as a lump sum.