Fugu Ultra API

Model details

Context window

1M tokens

Max output

—

Input

Text, images

Output

Text

Capabilities

Reasoning, Vision, Tool calling, Streaming, JSON output

Interfaces

OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses

Why teams pick it

• Fugu Ultra for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.

Call Fugu Ultra

Fugu Ultra answers on any of the APIs below — pick the one your code already speaks and just swap in your Inferray key.

curl https://api.inferray.com/v1/chat/completions \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "fugu-ultra",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/messages \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "fugu-ultra",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/responses \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "fugu-ultra",
  "input": "Hello"
}'

Use Fugu Ultra in your tools

Every coding agent below has a setup guide. Set the model to fugu-ultra.

• Claude Code
• Codex
• opencode
• Cline
• Roo Code
• Aider
• Continue

More from Sakana AI

Alternatives to Fugu Ultra

• GPT-5.5A new class of intelligence for coding and professional work.OpenAI
• Claude Opus 5State-of-the-art agentic coding for enterprise work.Anthropic
• Kimi K3 FastKimi K3 Fast for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.Moonshot AI

Questions about this model

How much does the Fugu Ultra API cost?

Fugu Ultra costs $5 per 1M input tokens and $30 per 1M output tokens on Inferray, and cached input is $0.5 per 1M. That is the list price, with no gateway fee on top.

Is there a free tier for Fugu Ultra?

No. You add credit and pay Fugu Ultra's list rate for each request — seats, projects, and API keys are free, and pay-as-you-go credit never expires.

Am I charged for failed requests?

No. A request that fails without returning a result is not billed. If a response fails part-way, the tokens already processed before the failure are charged.

Is Fugu Ultra included in Token Plans?

No. Fugu Ultra is pay-as-you-go only; Token Plans cover the other text models in the catalog.

Can I use Fugu Ultra in Claude Code?

Yes. Set ANTHROPIC_BASE_URL to https://api.inferray.com, ANTHROPIC_AUTH_TOKEN to your Inferray key, and ANTHROPIC_MODEL to fugu-ultra. The same key works in Codex, opencode, Cline, and other agents.

Does Fugu Ultra support tool calling and vision?

Fugu Ultra supports tool calling, image input, reasoning, JSON output and streaming on Inferray.

Is it the real Fugu Ultra?

Yes. A request for fugu-ultra is answered by Fugu Ultra from Sakana AI, billed at its published list price. Inferray never substitutes a different or smaller model.