Agentic
3 milestones in AI history
Claude 4 / Opus 4: Frontier Reasoning
Anthropic released Claude 4 Opus, a model with significantly enhanced reasoning, extended thinking capabilities, and the ability to sustain complex multi-step problem-solving over long contexts. It excelled at agentic tasks, code generation, and nuanced analysis.
Claude 4.5 / 4.6 Opus: Frontier Agentic Capability
Anthropic released Claude 4.5 and 4.6 Opus, representing the frontier of AI capability in early 2026. These models demonstrated unprecedented reasoning depth, coding ability, and capacity for autonomous multi-step work. They could sustain complex agentic workflows, manage entire projects, and collaborate with other AI agents.
Claude Fable 5 and Mythos 5: A New Model Tier
Anthropic released Claude Fable 5 and Claude Mythos 5, the first models in the Claude 5 family and a new 'Mythos-class' tier positioned above Opus in capability. The two share the same underlying model: Fable 5 shipped for general availability with additional safeguards on dual-use capabilities, while Mythos 5 was restricted to approved organizations. The Mythos class had been introduced in April 2026 through Claude Mythos Preview, released via Project Glasswing to a limited set of cyberdefense and infrastructure organizations.