Mistral · Open weights

Mistral Medium 3.5

Added Apr 29, 2026Open weights

Mistral Medium 3.5 is a 128B dense open-weights flagship model for instruction-following, reasoning, coding, long-horizon agentic work, tool use, structured output, and multimodal prompts. It supports a 256k context window and configurable reasoning effort.

Reasoning
Tools
Vision
Structured output

Input: Text, Images
Output: Text
Reasoning effort: none · high
Discovery tier: Open weights

Pricing

USD per 1M tokens

Input: $1.50
Output: $7.50

Reference prices as published by the model provider. API example

Specifications

Context window: 256K
Max output: 32.8K

Side by side

Mistral Medium 3.5 compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

Limits
	Mistral Medium 3.5MistralThis model	Mistral Large 4MistralRemove
Provider	Mistral	Mistral
Discovery tier	Open weights	Open weights
Added	Apr 29, 2026	Oct 6, 2026
Context window	256K	524.29KBest
Max output	32.77K	—
Pricing, USD per 1M tokens
Input	$1.50	$0.68Best
Output	$7.50	$2.09Best
Cache read	—	$0.07
Performance
Request success (24h)	100.0%Best	68.9%
Capabilities
Reasoning	Yes	Yes
Tools	Yes	Yes
Vision	Yes	Yes
Structured output	Yes	Yes
Reasoning effort	none, high	none, high

Public evaluations

Benchmarks

There are no public benchmark results for these models yet.

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Request success (24h): 100.0%; Reliable

Hourly request success · last 72 hoursLowest hour 100.0%

Healthy (98% or more)
Degraded (90–98%)
Down (under 90%)
No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart

curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mistralai/mistral-medium-3.5",
    "reasoning_effort": "none",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'

import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="mistralai/mistral-medium-3.5",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

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