Today, we are releasing an update to our Fugu orchestration model: Fugu Cyber. Available as a new API endpoint, Fugu-Cyber is purpose-built for the complexities of modern cyber defense. Fugu-Cyber achieves state-of-the-art performance on the industry’s most challenging security benchmarks, reaching a success rate of 86.9% on CyberGym and 72.1% on CTI-REALM, comparable to leading cybersecurity-focused frontier models such as GPT-5.5-Cyber and Mythos-Preview.
Fugu-Cyber achieves state-of-the-art performance on real-world security benchmarks, matching cyber-focused frontier models like GPT-5.5-Cyber and Mythos Preview.
Together, these benchmarks test the core pillars of enterprise defense: CyberGym evaluates an agent’s ability to analyze complex codebases to verify real-world vulnerabilities, while CTI-REALM measures its capacity to translate raw threat intelligence reports into working detection rules.
Like our original Fugu orchestration model, Fugu-Cyber is a multi-agent system that behaves like a single model. You send a request to one endpoint, and the system dynamically orchestrates a pool of specialized agents to tackle complex, multi-step tasks without the risk of single-vendor dependency. It is now available as a new API endpoint in sakana.ai/fugu
The Reality Check on Frontier Cyber Capabilities
Achieving high scores on an evaluation is only the beginning of the story.
Recently, there has been a lot of fearmongering about the cyber capabilities of frontier models. Much of the industry narrative suggests that simply granting an organization access to a frontier model with cyber capabilities will instantly solve their security challenges.
We believe it is time to ground this conversation in reality.
As highlighted in a recent Nikkei Digital Governance report (in Japanese), simply having access to a frontier model like Anthropic’s Mythos does not magically solve enterprise security. In reality, large organizations, including major financial institutions, often struggle to operationalize these tools. Without specialized internal talent and deep integration into proprietary source code, a frontier model, even with state-of-the-art cyber capabilities, cannot easily uncover or patch real-world vulnerabilities.
The challenges pointed out in the Nikkei article also reflect Sakana AI’s own experience as we work with the largest Japanese enterprises to tackle cybersecurity challenges. Successful deployments require having both the human expertise in cybersecurity and access to frontier capabilities.
A highly capable API with strong cyber reasoning is an incredibly important piece of the puzzle. It is not the entire solution.
Beyond the API
When deployed in isolation, raw models will inevitably generate false positives. They will struggle to understand the nuances of a live production environment without the right harness. True enterprise defense requires more than just having access to a frontier model.
In our experience, cybersecurity solutions require deploying frontier models with deep, localized cybersecurity human expertise and rigorous verification workflows. If an AI system surfaces a potential vulnerability, it must be validated by sub-agents specialized in cybersecurity and human-in-the-loop processes to confirm whether it would actually trigger in a real environment before a patch is proposed.
This is the exact challenge that Sakana AI is solving.
The Enterprise Solution: Bridging the Gap Between Frontier Capabilities of Fugu-Cyber and Enterprise Security
This is where Sakana AI’s Applied Enterprise team comes in. We are not just building the core engine; we are building the infrastructure required to use it safely.
We are currently working closely with major Japanese institutions to build the specialized harnesses and workflows required to deploy these models into production. By combining the raw reasoning power of Fugu-Cyber with the real-world experience of security professionals, we are helping enterprises build automated vulnerability verification and other subsequent tasks that are both highly capable and deeply reliable.
As industry experts have noted, the future of cyber defense relies on systems that can combine multiple AI models to achieve higher performance than any single model could alone. By orchestrating the world’s best models into a unified system, we are delivering the realistic, resilient blueprint required for AI sovereignty.
Responsible Deployment
Because Fugu-Cyber deals with sensitive security workflows, we are committed to its safe and responsible release.
To ensure safe deployment, Fugu-Cyber is being released under an updated Acceptable Usage Policy that prohibits offensive misuse and aligns with the industry’s safety standards.
The Fugu-Cyber API will be available for the Token Plan. Users will also need to apply for access by submitting an access request form detailing their intended use case and providing verified contact information. Our team will manually rigorously review and approve each application before granting users access to Fugu-Cyber.
We will continue to vet our systems and work alongside our enterprise partners to ensure this technology is used to fortify and defend critical infrastructure.
Sakana Fugu-Cyber is available today as a new model at our API endpoint on sakana.ai/fugu.
To learn more about our enterprise solutions, please reach out to our Applied team.
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