Swiss AI model Apertus now available inside Proton’s Lumo assistant

What happened

On 17 September 2026 ETH Zurich announced that Apertus 1.5, the open AI model built by EPFL, ETH Zurich and the Swiss National Supercomputing Centre (CSCS), is now a model option in Lumo, the AI assistant from Geneva-based Proton (ETH Zurich). Users can choose to send anonymised feedback on its answers to the researchers. Proton says chats stay protected by its “zero-access encryption”.

Why it matters for your business

Until now, trying Apertus meant downloading it or finding an IT partner to host it. Now anyone with a Lumo account can pick it and ask it real questions. That makes it easy to test a Swiss-built model on your own tasks, such as drafting a letter in French or summarising a German document, without any setup.

Keep expectations realistic. A swissinfo review earlier in September found Apertus still well behind similarly sized open models in programming, maths and reasoning, and short of the agent skills needed for multi-step tasks (swissinfo.ch). For everyday office writing it is worth a test. For complex analysis, compare its answers with the tool you use today.

Proton’s Director of AI, Eamonn Maguire, put the motive plainly: “We don’t want to spend the next decade relying on other countries for the AI we use every day” (Startupticker).

The Swiss angle

Both the model and the assistant are Swiss. Lumo has a free plan and paid plans, with business versions under Proton’s workspace offer. Proton’s business page says Lumo does not log chats and never uses your data to train AI (Proton). Proton’s pricing pages offer CHF billing; check the current prices before you budget. The announcement did not say which Lumo plans include Apertus.

What to do

If data location is the reason you’ve held back on AI, open a free Lumo account, select Apertus and give it three tasks you do every week. Compare the results with your current tool. Do not paste client data into any tool until you’ve read its terms.

Sources

ETH Zurich, “Apertus partners with Proton’s Lumo AI assistant”, 17 September 2026: https://ethz.ch/en/news-and-events/eth-news/news/2026/09/apertus-partners-with-protons-lumo-ai-assistant.html
Startupticker, “Proton to integrate Apertus into its AI assistant”, 17 September 2026: https://www.startupticker.ch/en/news/proton-to-integrate-apertus-into-its-ai-assistant
swissinfo.ch, “One year on, has Swiss AI model Apertus lived up to the hype?”, 2 September 2026: https://www.swissinfo.ch/eng/swiss-ai/one-year-on-has-swiss-ai-model-apertus-lived-up-to-the-hype/91984276
Proton, Lumo for Business (checked October 2026): https://proton.me/business/lumo