Claude Mythos 5.1 - Anthropic's flagship model in the Claude series.

What is Claude Mythos 5.1?

Claude Mythos 5.1 is the flagship model in Anthropic's Claude 5.1 series, sharing the same underlying capabilities as Claude Fable 5.1. Designed for high-risk professional fields, it is only available to approved cybersecurity organizations and life science researchers, supporting cutting-edge research such as vulnerability defense and protein design. Users must apply for access through the Cyber Verification Program or the Life Sciences Verification Program, and it is currently primarily targeted at US institutions.

Main features of Claude Mythos 5.1

• Protein molecular designBy using open-source tools to design high-affinity binding proteins, experimental results show a hit rate of nearly 50%, which is 3–5 times higher than the typical level in the industry.
• Accelerating computational biologyBy developing custom GPU kernels and caching intermediate results, the inference speed of seven open-source genome deep learning models can be increased by up to 2.5 times, and research costs can be reduced by 30–60%.
• Network security defenseIt is open to auditing agencies through the Cyber Verification Program, supporting defensive vulnerability research and code security analysis, while prohibiting exploit development.
• Cutting-edge scientific research supportIt provides life science and cybersecurity professionals with research capabilities that go beyond publicly available models in a controlled environment, supporting complex molecular design and system security assessments.

Technical Principles of Claude Mythos 5.1

• Homologous twin architectureClaude Mythos 5.1 and Claude Fable 5.1 share the exact same underlying model weights and inference capabilities. The only difference is the degree of capability release achieved through the upper-level differentiated safety fence strategy, which enables the same model to serve both the public and professional high-risk scenarios.
• Controlled access mechanismIt employs a dual verification system of Cyber Verification Program and Life Sciences Verification Program, and is only open to professional organizations that have passed the background check, ensuring that high-risk capabilities are not abused.
• Dynamic safety fence: Establish dedicated security boundaries for cybersecurity and life sciences, while maintaining core alignment capabilities, to unlock more model potential for specialized defensive research.

How to use Claude Mythos 5.1

• Application for Trusteeship ProgramApplications must be submitted through Anthropic's Cyber Verification Program or Life Sciences Verification Program, and are only open to professional organizations that have passed the background check.
• Meet qualification requirementsCurrently, it is prioritized for cybersecurity defense agencies and life science researchers within the United States. International users will have to wait for further expansion plans after coordination with the US government.
• Use Claude Security productsEnterprises that have passed the review can directly use the Claude Security service, which is integrated with Mythos 5.1, to perform vulnerability scanning and remediation recommendations on their codebases.
• Awaiting review resultsAfter submitting the application, you need to wait for Anthropic and its partners to review your qualifications. Once approved, you will be granted access to the model. Unlike Fable 5.1, it cannot be used publicly directly.

Claude Mythos 5.1 project address

• Project official website：https://www.anthropic.com/claude-fable-and-mythos-5-1

Comparison of Claude Mythos 5.1 with similar competing products

Application scenarios of Claude Mythos 5.1

• Protein molecular design and drug developmentUsing open-source protein design tools, high-affinity binding proteins can be designed for specific targets. Experimental results show that the hit rate can be 3–5 times higher than the industry average, accelerating early drug discovery.
• Defensive cybersecurity researchIt is open to auditing agencies through the Cyber Verification Program, supporting code repository vulnerability scanning, defensive penetration testing, and vulnerability remediation recommendations to improve the security of critical infrastructure.
• Genomics and Computational Biology: Develop custom GPU kernels to optimize open-source genome deep learning models (such as Enformer and ProGen2), reducing the cost of whole genome analysis by 30–60% and accelerating variant detection and functional prediction.
• Long-term scientific experiment managementIt can run continuously for dozens of hours to perform complex scientific research tasks, such as designing experimental schemes, discovering and correcting data labeling errors, starting multiple sets of experiments in parallel and organizing the results.
• Scientific Data Reconstruction and ModelingThe neural network is trained based on historical observation data (such as NASA radar images) to generate high-resolution scientific maps or models, providing a basis for target selection for subsequent exploration missions.