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Sakana AI: Sakana Fugu Ultra v2NEW

sakana/fugu-ultra-v2
textVisionFilesReasoning

Fugu Ultra v2 is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route tasks across a fixed pool of open and specialized models and to recursively call instances of itself. Fugu Ultra v2 prioritizes answer quality on complex multi-step reasoning, autonomous research, and full-stack software development, and does not rely on individual proprietary frontier models in its pool. It supports configurable reasoning effort (high, xhigh, max), function calling, structured outputs, image and PDF input, and built-in web search. Prompts above 272K tokens are billed at a higher rate. Orchestration tokens consumed by the system are billed as standard input/output tokens.

Price in / out
Cache, read / write
Context / Max output
1M / 128K
Released
Sep 11, 2026

Additional rates

Above 272K prompt tokens the upstream charges more: 2× input, 1.5× output. Per-route rates are in the table below.

Parameters

messagesrequired
reasoning_efforthigh · xhigh · max
max_tokensoptional · alias max_completion_tokens
streamtrue · false
toolsfunction calling (OpenAI format)
tool_choiceauto · none · required
web_search · · ·
providerrouting: order · only · ignore · sort
stream_options{"include_usage": true}
image_urlimage (data: URL)
filePDF · DOCX · TXT · CSV · XLSX · PPTX (data: URL)

How to use via API

from openai import OpenAI

client = OpenAI(base_url="https://api.mixen.ai/v1", api_key="mxn-...")
resp = client.chat.completions.create(
    model="sakana/fugu-ultra-v2",
    messages=[{"role": "user", "content": "Привет"}],
    reasoning_effort="high",  # high · xhigh · max
    max_tokens=1024,
    stream=False,
)
print(resp.choices[0].message.content)

# Стриминг: stream=True — ответ приходит чанками
for chunk in client.chat.completions.create(
    model="sakana/fugu-ultra-v2",
    messages=[{"role": "user", "content": "Привет"}],
    stream=True,
):
    print(chunk.choices[0].delta.content or "", end="", flush=True)

# с файлом (PDF · DOCX · TXT · CSV · XLSX · PPTX)
doc = client.chat.completions.create(
    model="sakana/fugu-ultra-v2",
    messages=[{"role": "user", "content": [
        {"type": "text", "text": "Кратко перескажи документ"},
        {"type": "file", "file": {
            "filename": "doc.pdf",
            "file_data": "data:application/pdf;base64,JVBERi0...",
        }},
    ]}],
)
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