Fugu Ultra v2

Sakana AIMCP Tool CallReasoning

sakana/fugu-ultra-v2Closed API

Quality-first multi-agent model for hard research, analysis, and competitions

Benchmark Pricing$5.00 / 1M in$30.00 / 1M out$0.50 cache read

Context: 1,000,000 tokens•Max Output: 128,000 tokens•Knowledge: 2026-08-28•Released: 2026-09-11

TECHNICAL SPECIFICATIONS

Context Window1,000,0001M tokens

Max Output128,000128K tokens

LicenseProprietaryCloud API only

Input Modalities

TextVisionPDF

Function / Tool CallingSupported (MCP Ready)

Structured OutputsGuaranteed Schema

MODEL CONTEXT PROTOCOL (MCP) READINESS

✓ Fugu Ultra v2 natively supports OpenAI / Anthropic format tool calling and is fully compatible with MCP servers and agent loops.

MCP Context Window Recommendations

With a context capacity of 1,000,000 tokens, this model can handle extremely large MCP resource manifests, complete database schemas, and multiple active server tool definitions simultaneously without degradation.

API CALL INVOCATION EXAMPLE

// Example: Calling Fugu Ultra v2 via OpenAI SDK
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.SAKANA_API_KEY,
});

const response = await client.chat.completions.create({
  model: "sakana/fugu-ultra-v2",
  messages: [{ role: "user", content: "Hello! Can you inspect MCP tools?" }],
});

console.log(response.choices[0].message.content);