Chat · Mistral AI
Run Mistral Small 4 in the EU through an OpenAI-compatible API
Mistral Small 4 is a 119-billion-parameter mixture-of-experts model from Paris-based Mistral AI that combines instruction following, reasoning and coding in one set of weights. 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.
- 01119B · 6.5B
- 02EU data centres
- 03Apache 2.0
What Mistral Small 4 is
Mistral Small 4, published as Mistral-Small-4-119B-2603, is a mixture-of-experts model with 128 experts, four of which are active per token. It has 119 billion parameters in total and about 6.5 billion active per token, with a context window of 256K tokens and image input alongside text.
Mistral describes it as a merger of three model families that used to be separate: the general Instruct models, the Magistral reasoning models and the Devstral coding models. You choose how much it reasons per request, so one model can handle quick replies and harder multi-step problems. The weights are released under the Apache 2.0 licence.
What it does well, and where it falls short
Mistral Small 4 is a strong choice for European companies that want one versatile model: it handles chat, document analysis, coding help, image understanding and agent tool calls. The model card lists support for more than twenty languages, including English, French, German, Spanish, Italian, Portuguese, Polish, Romanian and Swedish, and it follows system prompts closely.
With only about 6.5 billion active parameters per token it is efficient to serve, but it does not reach the depth of the very large open models such as GLM-5.3 or Kimi K3 on long, hard agentic coding tasks. Reasoning mode adds output tokens and time, so switch it off for simple requests. It reads images but does not produce them.
Calling Mistral Small 4 through the API
inference.eu uses the OpenAI request format, so the OpenAI SDKs, LangChain, LlamaIndex, the Vercel AI SDK and the Mistral-compatible tools that accept a custom base URL all work. Set the base URL to the inference.eu API, use your inference.eu key and set the model to mistral-small-4-119b.
Send images as image_url content parts, just as you would with OpenAI vision models. Use the reasoning_effort parameter to ask for more or less reasoning on each request. Tool calls, streaming and JSON output work as usual, and the Anthropic Messages format is also available for tools built around Claude.
A French model, processed in the EU
Mistral Small 4 is one of the few strong open models built in Europe. On inference.eu it also runs in Europe: your prompts, images and responses are processed in data centres in the European Union, and they are never used to train any model.
We sign a data processing agreement under Article 28 of the GDPR with every customer and share our subprocessor list, so you can document where data goes for your records of processing. Billing is in euros. The Apache 2.0 licence allows commercial use without user limits or revenue thresholds, which keeps the legal review short.
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="mistral-small-4-119b",
messages=[{"role": "user", "content": "Summarise this contract in five bullet points."}],
)
print(response.choices[0].message.content)What teams use it for
- 1
One model for a whole product
Use the same model for chat, summaries, image questions and tool calls instead of maintaining separate models for each task.
- 2
Document and screenshot analysis
Read scanned forms, charts and screenshots together with text instructions and return structured answers.
- 3
European-language assistants
Build assistants for French, German, Spanish, Italian, Polish or Romanian users on a model trained by a European lab.
Mistral Small 4 119B: common questions
The questions buyers, developers and legal teams ask us most. Something missing? Ask us directly.
Related
- Magistral Small 1.2Run Magistral Small 1.2, Mistral AI's open 24B reasoning model, on inference.eu through an OpenAI-compatible API with processing in EU data centres.Reasoning
- Devstral Small 2Run Devstral Small 2, Mistral AI's open 24B coding agent model, on inference.eu with OpenAI and Anthropic APIs and processing in EU data centres.Code
- Gemma 4 26B A4BRun Google's Gemma 4 26B A4B on inference.eu: a fast mixture-of-experts model with image input and 256K context, processed in EU data centres.Vision
- EuroLLM 22B InstructRun EuroLLM 22B Instruct, the European open model trained for all 24 official EU languages, on inference.eu with an OpenAI-compatible API.Chat
Move your AI workloads to EU infrastructure
Tell us which models you use and roughly how much traffic you have. We reply within one working day with pricing and next steps.
- Reply within one working day
- Pricing for your volume
- DPA ready to sign