Sakana AI: Fugu Ultra v2
Fugu Ultra v2 is a reasoning model from Sakana AI released on Sep 11, 2026. It reads text, images and files and writes text, with a 1M token context window and up to 128K tokens per reply.
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It costs $5 per million input tokens and $30 per million output tokens. Cached input bills at $0.50, 90% less than fresh input.
It supports tool calling, structured JSON output and prompt caching.
3 providers serve it, including Vercel AI Gateway, Kilo Gateway and AI/ML API.
- Modalities
- In / out price
- $5 / $30 per 1M
- Context
- 1M
- Max output
- 128K
- Released
- Sep 11, 2026
- Knowledge cutoff
- Aug 2026
- Tool calling
- Structured output
- Reasoning
- Prompt caching
- Open weights
- Free to use
Fugu Ultra v2 pricing
USD, as listed on Oct 15, 2026. Most bills are input heavy, so the cached input rate matters as much as the headline price.
| Input | $5 / 1M tokens | |
|---|---|---|
| Output | $30 / 1M tokens | |
| Cached input (read) | $0.50 / 1M tokens | 90% off input |
Fugu Ultra v2 providers
3 providers serve it, including Vercel AI Gateway, Kilo Gateway and AI/ML API. Each host sets its own price and limits, so the cheapest one is not always the one with the longest context.
| Provider | Input /M | Output /M | Cache read /M | Context | Max output |
|---|---|---|---|---|---|
| Vercel AI Gateway | $5 | $30 | $0.50 | 1M | 1M |
| Kilo Gateway | $5 | $30 | $0.50 | 1M | 128K |
| AI/ML API | $6.88 | $41.26 | $0.6877 | 1M | 128K |
What Fugu Ultra v2 costs per month
Pick a workload close to yours or type your own volumes.
Supported request parameters
What you can set when you call Fugu Ultra v2 through an OpenAI compatible API.
- Tools
tools - Structured outputs
structured_outputs - Reasoning
reasoning
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Fugu Ultra v2 questions
How much does the Fugu Ultra v2 API cost?
$5 per million input tokens and $30 per million output tokens, with cached input at $0.50. The estimator on this page turns that into a monthly bill for your own workload.
What is the context window of Fugu Ultra v2?
1,000,000 tokens of input, and it can write up to 128,000 tokens in one reply. As a rough guide, a million tokens is around 750,000 English words.
Which providers serve Fugu Ultra v2?
3 providers serve it, including Vercel AI Gateway, Kilo Gateway and AI/ML API. Prices differ by host, so the Providers table on this page lists each one with its input and output price.
Does Fugu Ultra v2 support tool calling?
Yes. It accepts tool definitions and can return JSON that matches a schema, which is what an agent needs to call your APIs.
Is Fugu Ultra v2 open source?
No. Sakana AI serves it through an API only, so you cannot download the weights or host it yourself.
When was Fugu Ultra v2 released?
Sep 11, 2026, with training data up to Aug 2026.
Catalog data from models.dev (MIT licensed), refreshed daily, last on Oct 15, 2026. The summary is written from these facts.