Fugu Ultra v2
by SakanaReleased Sep 11, 2026
sakana/fugu-ultra-v2- Reads images
- Reads files and PDFs
- Calls tools
- Answers in a JSON schema
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...
- Input / 1M tokens
- $6.00
- Output / 1M tokens
- $36.00
- Context
- 1M
- Longest answer
- 128K
What it costs
What each call is charged to the token's AI credit.
| Billed for | You pay |
|---|---|
| Input tokens | $6.00 / 1M |
| Output tokens | $36.00 / 1M |
| Cached input, read | $0.60 / 1M |
| Each web search | $0.01 |
| Prompts over 272,000 tokens | $12.00 in, $54.00 out |
A typical call
A short chat turn: 2,000 tokens in, 500 out.
- per call
- $0.03
- calls per $20
- 666
What it can do
From its listing. The router passes every field through.
- Reads imagesYes
- Reads files and PDFsYes
- Hears audioNo
- Calls toolsYes
- Answers in a JSON schemaYes
- Reasons before it answersYes
- Searches the webYes
- Caches long promptsYes
- Draws imagesNo
Call it
Any router key works, in the format your SDK already speaks.
import OpenAI from "openai";const ai = new OpenAI({ baseURL: "https://relayfor.si/api/v1", apiKey: process.env.RELAYFOR_ROUTER_KEY,});const reply = await ai.chat.completions.create({ model: "sakana/fugu-ultra-v2", messages: [{ role: "user", content: "Welcome the 1,000th holder in one line." }],});Specifications
What its maker and providers list for it.
- Reads
- Text, Images, and Files
- Writes
- Text
- Context
- 1,000,000 tokens
- Longest answer
- 128,000 tokens
- Reasoning effort
- high to max
- Knowledge cutoff
- Aug 28, 2026
- Released
- Sep 11, 2026
- Moderation
- None
Request fields
The fields its providers accept, passed through as you send them.
- include_reasoning
- reasoning
- reasoning_effort
- structured_outputs
- tool_choice
- tools
- web_search_options
Questions
How much does Fugu Ultra v2 cost?
$6.00 per million input tokens and $36.00 per million output tokens, paid from the token's AI credit. A call of 2,000 tokens in and 500 out costs about $0.03.
How do I call Fugu Ultra v2?
Make a router key for one of your tokens on the dashboard, point any OpenAI or Anthropic SDK at https://relayfor.si/api/v1 and send the model id sakana/fugu-ultra-v2. The token's AI credit pays for each call.
How long a prompt can Fugu Ultra v2 take?
Up to 1,000,000 tokens of context, and up to 128,000 tokens in one answer.
Are my prompts stored?
No. The RFS Router passes each call through and keeps only its token counts and cost, for the token's usage page.
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