# Fugu Ultra

> Fugu Ultra is a proprietary language model from Sakana, released on 15 Jun 2026. It accepts text and images and generates text, with a 1M-token context window and up to 128K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $5 per million input tokens and $30 per million output tokens (OpenRouter), across 2 providers we track.

Source page: https://www.aimodel.directory/models/fugu-ultra
Last verified: 4 Oct 2026

## Specifications

- **Developer:** Sakana
- **Release date:** 15 Jun 2026 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Status:** Generally available (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Weights:** Proprietary (API only) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Context window:** 1M (1,000,000 tokens) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Max output:** 128K tokens (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Input:** Text and images (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Output:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Reasoning mode:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Tool calling:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)
- **Structured output:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/openrouter/models/sakana/fugu-ultra.toml)

## API pricing (USD per 1M tokens)

| Provider | Input | Output | Cached input | Context |
|---|---|---|---|---|
| OpenRouter | $5 | $30 | $0.50 | 1M |
| Vercel AI Gateway | $5 | $30 | $0.50 | 1M |

## FAQ

### What is the context window of Fugu Ultra?

Fugu Ultra has a context window of 1,000,000 tokens (1M) and can generate up to 128,000 tokens in a single response, according to models.dev.

### How much does the Fugu Ultra API cost?

Fugu Ultra is listed from $5 per million input tokens and $30 per million output tokens (OpenRouter). Prices last verified 4 Oct 2026.

### Is Fugu Ultra open source?

No. Fugu Ultra is a proprietary model; Sakana has not released its weights. It is available through APIs including OpenRouter, Vercel AI Gateway.

### When was Fugu Ultra released?

Sakana released Fugu Ultra on 15 Jun 2026, according to models.dev.

### Which providers offer Fugu Ultra?

We track Fugu Ultra on 2 providers: OpenRouter, Vercel AI Gateway.

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Data licensed CC BY 4.0. Cite as: AI Model Directory, "Fugu Ultra", https://www.aimodel.directory/models/fugu-ultra