Does Mistral-Medium-3.5-128B support zero data retention?

Yes. Mistral-Medium-3.5-128B is available with zero data retention on evroc through the Opper gateway.

Where is Mistral-Medium-3.5-128B hosted?

Mistral-Medium-3.5-128B runs on EU hosting routes through the Opper gateway, with contractually enforced residency on supported providers.

Is Mistral-Medium-3.5-128B trained on prompts and outputs?

Training behaviour varies by route. See the per-route data-handling section for each provider's training posture.

Is a GDPR DPA available for Mistral-Medium-3.5-128B?

Yes. A GDPR Data Processing Agreement is available on at least one route serving Mistral-Medium-3.5-128B. Contact hello@opper.ai to receive it.

Mistral-Medium-3.5-128B

by Mistral

Mistral Medium 3.5 is a dense 128 billion parameter model released April 2026, handling instruction-following, reasoning, and coding in a single set of weights with a configurable reasoning effort. With a 256k token context window and an open-weight release under a modified MIT license, it balances frontier capability with self-hosting accessibility on as few as four GPUs. Built for agentic systems and software development, the model consolidates Mistral's prior reasoning, coding, and chat lines, supporting function calling, agent orchestration, structured outputs, and multimodal understanding. It scores 77.6% on SWE-Bench Verified, making it well suited to autonomous systems, reasoning-heavy applications, and complex coding tasks.

Call Mistral-Medium-3.5-128B on Opper with the OpenAI SDK. Sign up without a credit card. Get started

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Key info

Input

Output

Features

Context window

—

Max output

—

Input price

$1.72 /1M

Output price

$6.88 /1M

EU residency available
Zero data retention on pay-as-you-go
GDPR DPA available

Available routes

Mistral-Medium-3.5-128B runs on 2 different routes through the Opper gateway. Compare residency, zero data retention and training posture at a glance, with full data-handling detail per route below.

Provider	Region	Zero data retention	Training	Input	Output	Cache read
evroc	EU		No	$1.72	$6.88	Input price
GreenPT	EU		—	$2.06	$10.31	Input price

Data handling per route

Each route hosting Mistral-Medium-3.5-128B has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.

evroc — Sweden🇸🇪

Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.

Zero data retention: Yes. Nothing is logged, held for abuse monitoring or used for training.
Training: No training on customer data.
Logging: None
Abuse monitoring: No classifier
Subprocessor access: No subprocessor reads content
GDPR DPA: DPA available
Transfer mechanism: Not applicable — data stays in EU

GreenPT — EU🇪🇺

Zero data retention posture is not established for this route. Training posture pending review. EU; DPA available.

Zero data retention: Not established.
Logging: None
Caching: Content cached for replay
Subprocessor access: Subprocessors may read content
GDPR DPA: DPA available
Transfer mechanism: Not applicable — data stays in EU

Get started

Call Mistral-Medium-3.5-128B through the Opper gateway with one API key. Opper is drop-in compatible with the OpenAI, Anthropic and Google AI SDKs.

Mistral-Medium-3.5-128B is a premium model on Opper. Sign up needs no credit card: you get an API key straight away and the free models work in the playground and the API. Add a card to use premium models, pay-as-you-go with no minimum.

Set it up with your agent

Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.

Or call it directly

1import OpenAI from "openai";
2
3const client = new OpenAI({
4  apiKey: process.env.OPPER_API_KEY,
5  baseURL: "https://api.opper.ai/v3/compat",
6});
7
8const completion = await client.chat.completions.create({
9  model: "mistral-medium-3.5-128b",
10  messages: [{ role: "user", content: "Hello" }],
11});
12console.log(completion.choices[0].message.content);