Sakana Fugu
: How to use it, features, and the business problems it solves

What is Sakana Fugu

Sakana Fugu is a multi-agent platform that dynamically bundles multiple specialist LLMs internally, orchestrates them, and serves them as a single API. Built by Japan's Sakana AI, its concept is to "deliver a multi-agent system as a single model API." You send a request to one endpoint, and internally the roles are divided, delegated, verified, and integrated automatically — it behaves as if it were one high-performance model.

Source: Sakana AI Fugu official site (the image below is from the same source)

Use a multi-agent system as "one model"

• Multi-agent orchestration: Internally bundles multiple specialist LLMs dynamically, handling role assignment, delegation, verification, and integration automatically. You treat it as a single API.
• Avoid vendor dependence: If a particular provider restricts access, it reroutes to another model and keeps going — embodying the "AI sovereignty" that Sakana champions.
• OpenAI-compatible API: Use it from existing OpenAI-compatible clients just by swapping the endpoint and model name. Also usable via OpenRouter, Vercel, opencode, and more.
• Grounded in the latest research: It is built on two ICLR 2026 papers that learn model orchestration — "TRINITY" (an evolutionary LLM coordinator) and "Conductor" (learning to marshal agents in natural language). Rather than being wired by hand, the system itself learns how to compose and coordinate specialist agents per task.

Three models

You can choose among three models by purpose (all available via the OpenAI-compatible API).

• Fugu — The standard model balancing performance and latency. For everyday coding, code review, and responsive chatbots.
• Fugu Ultra — Coordinates a broader pool of specialist agents to maximise answer quality on hard, important problems. For Kaggle, paper reproduction, security analysis, patent research, and the like.
• Fugu Cyber — Specialised for cybersecurity. For workflows where depth and precision matter — security analysis, vulnerability research, threat detection.

Performance (benchmarks)

Across coding, reasoning, and science benchmarks, it posts scores that match or surpass single frontier models (such as Fable 5 and Mythos Preview).

On the coding metric SWE Bench Pro, Fugu 59.0 / Fugu Ultra 73.7 are published — above the compared frontier models (54.2–69.2).

Pricing

Pricing has two pillars: a monthly subscription and token-based billing.

Subscription (monthly)

Token-based billing (per 1M tokens)

• Above a 272K-token context, Fugu Ultra becomes $10 / $45 / $1.00 and Fugu Cyber becomes $12 / $54 / $1.20.

Costs do not stack up as more agents run. No matter how many agents run internally, billing is calculated at "the rate of the single top model involved." That design is why costs stay predictable despite being a multi-agent platform.

Is there a free tier?

Sakana Fugu has no free tier or free trial. The minimum entry is either the Standard subscription ($20/month) or starting with token-based billing.

To try it cheaply first, a practical approach is to send a small number of requests on token billing and get a feel for it. Because it is an OpenAI-compatible API, you can benchmark it against your existing code just by swapping the endpoint and model name.

How to use

1. Sign up at console.sakana.ai.
2. Send requests to the OpenAI-compatible API endpoint, specifying a model (Fugu / Fugu Ultra / Fugu Cyber). It is also usable via OpenRouter, Vercel, and opencode.
3. If needed, exclude specific models or providers from the agent pool.

• It is currently not available in the EU / EEA.

Reputation and who it suits

What's praised

• Avoids vendor lock-in: Even if a provider restricts access, it can recompose the agent pool and keep going. When the risk of single-vendor dependence became real — as when Anthropic's Fable 5 / Mythos 5 were abruptly halted by a US government export-control order in June 2026 — this design becomes an easy-to-understand value.
• Near-zero migration cost: As an OpenAI-compatible API, there's no SDK swap. Just change the endpoint and API key to use it from existing clients.
• Benchmarks above single models: On SWE Bench Pro, Fugu 59.0 / Fugu Ultra 73.7 are published — above the compared frontier models (54.2–69.2).

Points to note

• Can't try it for free: As noted, there is no free tier, so even evaluation incurs cost.
• Not available in the EU / EEA.
• The model mix isn't fixed: The models used internally are chosen dynamically. As the flip side of avoiding lock-in, it doesn't suit a requirement to "always reproduce with the same model."

Who it suits: Organisations wanting to reduce dependence on a specific vendor, and people handling heavy tasks that require multi-step reasoning — Kaggle, paper reproduction, security analysis, patent research. Conversely, if you just want to run simple generation tasks cheaply at scale, using a single model's API directly is cheaper.

Learn more

For details on how Sakana Fugu works, its benchmarks, and pricing, see the explainer article too.

What is Sakana AI Fugu — a deep dive into the multi-agent API's performance, pricing, and usage

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Information on this page is based on what was published on the official site as of August 2026. The model lineup, benchmarks, pricing, and availability may change, so check the official site for the latest.