Grok 4.20

GPT-6 Astra is OpenAI’s frontier AI model for computer use, software engineering, scientific research, cybersecurity, browsing, and complex professional work. It combines advanced reasoning with agentic capabilities that allow it to navigate software, use tools, conduct research, manipulate data, troubleshoot systems, and complete multistep workflows. Astra is also designed to produce polished documents, spreadsheets, presentations, websites, applications, and other business or technical artifacts while following existing templates and organizational standards. In Codex, the model introduces improved long-running context management that can preserve notes and retrieve information from earlier context windows during extended software engineering tasks. OpenAI positions Astra as its most aligned model to date, with improvements in respecting task boundaries, interpreting user intent, communicating limitations, and avoiding unauthorized actions.

Claude Mythos 5.1 is Anthropic’s newest Mythos-class model, designed for advanced cybersecurity, biology, scientific research, coding, and long-running knowledge work. It is the same underlying model as Claude Fable 5.1 but uses different safeguards: Fable 5.1 is generally available, while Mythos 5.1 is restricted to trusted access programs with safeguards specifically designed for cybersecurity and life sciences research. The model sets a new performance frontier for agentic coding and demonstrates the strongest cyber capabilities of any Anthropic model released to date. In scientific research, Mythos 5.1 can work with specialized tools and complex workflows across molecular design, computational biology, and other technical domains. In Anthropic’s experiments, it designed high-affinity protein binders across multiple targets and achieved its strongest measured hit rate to date. It also optimized seven open-source protein and genomics deep learning models.