inference.eu

Chat · Swiss AI Initiative (EPFL, ETH Zurich, CSCS)

Run Apertus 70B in Europe through an OpenAI-compatible API

Apertus 1.5 70B is the flagship of Switzerland's fully open language model, built by EPFL, ETH Zurich and the Swiss National Supercomputing Centre. Weights, training data and recipes are all public. On inference.eu you call it with the OpenAI or Anthropic request format, with requests processed in EU data centres and never used for training.

Contact salesExample request
  1. 0170B
  2. 02EU data centres
  3. 03Apache 2.0

What Apertus 1.5 70B is

Apertus is the open language model of the Swiss AI Initiative, a partnership between EPFL, ETH Zurich and the Swiss National Supercomputing Centre (CSCS). Version 1.5 of the 70-billion-parameter model was released on 24 July 2026 under the Apache 2.0 licence, after training on the Alps supercomputer in Lugano.

Version 1.5 continues training the first Apertus with 2 trillion extra tokens of text and multimodal data, for a total of about 17 trillion tokens. It adds image understanding, experimental audio input, an optional thinking mode and a context window of 262,144 tokens, four times that of Apertus 1.0. Unusually, the training data, code and intermediate checkpoints are published alongside the weights.

What it does well, and where it falls short

Apertus is built for transparency and language breadth. Its makers say it was trained only on publicly available data, respecting robots.txt opt-outs, and that it covers well over a thousand languages. That makes it a natural choice for public bodies, universities and companies that must explain where their model comes from.

On raw benchmark strength it is not the leader: large open models such as Qwen3, GLM-5.3 or DeepSeek V4 are stronger at hard reasoning and coding. Audio input is still described as experimental. Choose Apertus when openness, documentation and multilingual coverage matter more than the last few points of benchmark performance.

Calling Apertus 70B through the API

inference.eu speaks the OpenAI request format, so the OpenAI SDKs, LangChain, LlamaIndex and the Vercel AI SDK work as they are. Set the base URL to the inference.eu API, use your inference.eu key and set the model to apertus-70b.

Images go in as image_url content parts next to your text. The thinking mode is a chat-template option; use it for maths and multi-step problems and leave it off for ordinary chat. Streaming and tool calls work as usual, and the Anthropic Messages format is also available, so tools built for Claude can switch with a new base URL, key and model name.

A Swiss model, processed in the EU

Apertus comes from Swiss public research, and its makers publish documentation under the EU AI Act's code of practice for general-purpose models. On inference.eu your prompts, images and responses are processed in data centres in the European Union and are never used to train any model.

Every customer gets a data processing agreement under Article 28 of the GDPR and our subprocessor list, so you can show exactly where data goes. Billing is in euros. Because Apache 2.0 allows commercial use without user limits, and the training data is public, Apertus is one of the easiest models to defend in a procurement or compliance review.

apertus-70b · Python
import os
from openai import OpenAI

client = OpenAI(base_url="https://api.inference.eu/v1", api_key=os.environ["INFERENCE_EU_API_KEY"])

response = client.chat.completions.create(
    model="apertus-70b",
    messages=[{"role": "user", "content": "Summarise this contract in five bullet points."}],
)
print(response.choices[0].message.content)

What teams use it for

  • 1

    Public-sector assistants

    Answer questions from citizens with a model whose training data and methods are fully documented and open to inspection.

  • 2

    Multilingual services in small languages

    Serve users in languages and dialects that most models handle poorly, including many smaller European languages.

  • 3

    Research and education

    Teach and study language models with weights, data and intermediate checkpoints that are all openly available.

Apertus 1.5 70B: common questions

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