This Online hackathon is an invitation to spend just over two weeks building with Apertus, Switzerland's fully open LLM. From 1–16 October, builders everywhere gather online to push Apertus 1.5 further. And, you're invited.

If you care about open and trustworthy AI that anyone can use, this is your place.

You'll work with both the 8B and 70B models, backed by our partners CSCS and Phoeniqs, and experienced mentors alongside you. Everything you ship stays open and reusable.
The strongest projects advances to the Grand Finals in May 2027 in St. Gallen, Switzerland where you'll compete for the Main «Hack Apertus» Award.

🎯🎯 TRACKS & CHALLENGES

🎯 TRACK 1 - APERTUS READINESS is about improving the model.
1 A: Red-Teaming Apertus
1 B: Swiss Voices

🎯TRACK 2 - APERTUS ADOPTION is about showing what the model can do. 
2 A: Academia Challenges
2 B: Own Project

👉🏼 All challenge descriptions can be found in our Getting Starting Guide (1 OCT, 12:00).

📅  FIRST STEPS & TIMELINE

a) Join our Discord, our main comms channel
b) Find team mates on Discord if you don't work solo (1-5 allowed)
c) 1. OCT, 12:00 CEST: Tracks and Challenges are released
d) Book a session with one of our mentors
e) Check for Online sessions to support you
f) Work remotely on your solution
g) 16. OCT, 12:00 CEST, Final submission deadline
h) Our expert jury reviews all submissions and selects the winners until 23 OCT 2026 

Note: This is the opening stage of a multi-month Hackathon journey. Over the following months, 6+ on-site hackathons across Switzerland follow. Join one Hack or all of them. Online and On-site run as separate phases, so you choose how far you go.
The Winners from each Hack will compete for 🏆 Main «Hack Apertus» Award on 14.05.2027 in St.Gallen.

👥 Who Should Participate?

Open to all, recommended for
AI/ML engineers, software developers, data scientists, researchers, and NLP practitioners, plus technical students (CS, data science, computational linguistics) and non-engineer domain experts (law, medicine, dialects, public sector).
Bring a team or find one on Discord.

👉🏼 Choose your track, find your team, and join a growing community advancing Apertus and showing where it can go next. Wherever you start, you'll help shape a sovereign, trustworthy foundation others can rely and build on.

New to Apertus? It's an open large language model built by teams from EPFL, ETH Zurich and CSCS and released fully in the open, trained across 1,811 languages. Free to use, free to build on.

• Track 1A
  Find details in challenge description
• Track 1B
  Find details in challenge description
• Track 2A
  Find details in challenge descriptions
• Track 2B
  - Purposeful use of AI - Technical rigour - Value, cost & scalability - Sovereign deployability - Implementation feasibility