Sakana Fugu is now available inside OpenCode, the open-source coding agent that Sakana's own team used while developing Fugu's orchestration system. The integration is more than a distribution milestone: it closes a loop where the tool that helped verify Fugu's multi-agent behavior is now powered by Fugu itself. But to understand why that matters, you need to understand what Fugu actually is.
Not a model. A conductor.
Sakana Fugu is a multi-agent system that behaves like a single model. You send a request to one endpoint, and Fugu decides how to handle it: solving it directly when that is enough, or assembling and coordinating a team of expert models when a task calls for more. It manages model selection, delegation, verification, and synthesis internally, so the complexity of a multi-agent system never reaches your code.
Fugu owns no frontier weights of its own. It is a small orchestrator that learns to combine existing models like GPT-5.5, Claude Opus 4.8, Gemini 3.1 Pro, and a bench of open-source LLMs into one collective. The routing is proprietary, and it never even tells you which underlying model answered.
The research behind the curtain
The system rests on two ICLR 2026 papers. TRINITY is a roughly 0.6B-parameter coordinator, evolved with CMA-ES (an evolutionary optimization algorithm), that assigns Thinker, Worker, and Verifier roles across a pool of much larger worker models. Conductor is a 7B model trained with reinforcement learning to discover natural-language coordination strategies, and it can call itself recursively to scale compute at test time. The orchestrator is tiny; the heavy lifting is delegated to a swappable pool of frontier models behind the scenes.
The key insight from both papers is that coordination should be learned, not hand-wired. Most multi-agent systems require developers to define which model handles which task. Fugu learns this. The orchestrator model is trained to decide when to delegate, how agents should communicate, and how to combine their outputs into a single answer. In practice, this means you never write a LangChain graph or a CrewAI workflow , Fugu figures out the topology on its own.
Two tiers, one API
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