Fugu Ultra v2

The higher-performance tier of Sakana AI's Fugu orchestration family, released September 11 2026. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system — a language model trained to route tasks across a fixed, swappable pool of open-weight and specialized models and to recursively call instances of itself — detailed in Sakana's ICLR 2026 TRINITY (evolved LLM coordinator) and Conductor (RL-discovered natural-language coordination) papers. v2 prioritizes answer quality on complex multi-step reasoning, autonomous research, and full-stack software development, and notably does not include any proprietary frontier model in its pool: no Claude Fable 5, Fable 5.1, or GPT-6 Astra, routing instead over open-weights and specialized models including NVIDIA Nemotron via partnership, which Sakana positions as resilience against single-vendor and export-control risk. Supports configurable reasoning effort (high, xhigh, max), function calling, structured outputs, image and PDF input, and built-in web search. Pricing is $5/$30 per Mtok (cached input $0.50), with a premium tier of $10/$45/$1.00 above 272K-token context. Vendor-reported: 48.3 on Chartography (a visual reasoning / data-interpretation benchmark) versus 27.3 for Anthropic's Opus 5 and 29.5 for Fable 5 — achieved without either closed model in its pool — plus 74.3 on DeepSWE. Parameter count and context ceiling are undisclosed, the figures describe an orchestrated system rather than one set of weights, and all are unverified at launch.