Mythos 5 is a frontier model that redefines what AI can achieve.
It represents a breakthrough in autonomous reasoning, software engineering, and scientific research — setting new benchmarks across nearly every measure of AI capability.
What makes Mythos 5 different from previous models
State-of-the-art across all benchmarks
Mythos 5 achieves the highest scores on nearly every tested benchmark of AI capability, from software engineering to scientific reasoning.
Autonomous long-horizon reasoning
The model works autonomously for longer than any previous model, handling complex multi-step tasks that were previously out of reach.
Exceptional vision capabilities
New state-of-the-art in vision tasks including precise extraction from scientific figures and full source-code reconstruction from screenshots.
Built-in safety classifiers
Separate AI systems detect potential misuse including jailbreak attempts, ensuring the model remains safe for general use.
Evaluating Mythos 5
Mythos 5's capabilities exceed those of any previous model. It is state-of-the-art across software engineering, knowledge work, vision, and scientific research.
Software Engineering
Mythos 5 can work autonomously in multi-million-line codebases, performing migrations and complex refactors that would take teams months to complete manually.
Knowledge Work
Strong performance on complex analytical tasks including document-based reasoning, chart interpretation, and senior-level problem solving across domains.
Vision & Visual Reasoning
Extracts precise numbers from detailed scientific figures and performs complex vision tasks including rebuilding web app source code from screenshots alone.
Memory & Long Context
Stays focused across millions of tokens in long-running tasks and improves outputs using persistent file-based memory and self-generated notes.
Scientific Research
Produces novel, compelling scientific hypotheses and conducts autonomous research — designing custom models and analyzing data across millions of samples.
Drug Design & Biology
Accelerates aspects of drug design by around ten times, matching or beating skilled human operators in protein design and bioinformatics tasks.
The architecture behind Mythos 5's capabilities
A combination of advanced training techniques, novel architectures, and rigorous safety testing enables Mythos 5 to perform at unprecedented levels.
Core Architecture
Mythos 5 builds on a fundamentally improved training methodology. The model's architecture is designed for both breadth of knowledge and depth of reasoning, with specialized pathways for long-horizon tasks.
Advanced training methodology
Novel training techniques enable the model to generalize across domains while maintaining deep specialization in each area of capability.
Autonomous reasoning loop
The model proposes, evaluates, and iterates on solutions autonomously — keeping only improvements that demonstrably advance the task at hand.
Persistent memory system
File-based memory allows the model to maintain context across extremely long sessions, improving its outputs by referencing its own prior work.
Safety classifier network
Separate classifier systems detect potential misuse in real-time, routing sensitive queries to a secondary model while maintaining normal operation for the vast majority of requests.
Built-in safeguards for responsible deployment
Multi-layered safety architecture
Mythos 5 includes classifiers that detect potential misuse across cybersecurity, biology and chemistry, and distillation attempts. When flagged, requests are automatically handled by a secondary model instead. Early data shows over 95% of sessions involve no fallback at all.
Cybersecurity safeguards
Classifiers prevent the model from providing uplift in cyberattacks, covering both exploitation and offensive cyber tasks. External testing found Fable-grade safeguards to be the most robust of any model tested.
Biology and chemistry safeguards
For general use, biology and chemistry related requests fall back to a secondary model. A trusted access program enables legitimate biomedical researchers to access full capabilities.
The fastest answers to the questions people ask first
Mythos 5 is a frontier-class AI model that represents a significant leap in capability across software engineering, knowledge work, vision, and scientific research. It achieves state-of-the-art results on nearly all tested benchmarks.
Mythos 5 can work autonomously for longer, handle more complex multi-step tasks, and shows exceptional performance in long-horizon reasoning. It is the first model at this capability level made available for general use with appropriate safeguards.
Mythos 5 is offered at $10 per million input tokens and $50 per million output tokens, making it accessible for a wide range of use cases from development to research.
Mythos 5 includes a multi-layered safety system with classifiers that detect potential misuse. Sensitive queries fall back to a secondary model. Extensive red-teaming and external testing have validated the robustness of these safeguards.
Mythos 5 excels at autonomous software engineering (codebase-wide migrations, complex refactors), scientific research (hypothesis generation, experimental design), knowledge work (analytical reasoning, document analysis), and vision tasks.
It turns research judgment into something an agent can repeat.
Experience the capabilities of Mythos 5 for yourself. From autonomous coding to scientific discovery, the frontier of AI is here.