Anthropic (ANTH.PVT) debuted its Claude Opus 5 AI model on Friday, the fourth in its Claude 5 family of models, which also includes its powerful Mythos 5 and Fable 5. Fable 5 is Anthropic's most capable publicly available model, meant for "days-long autonomous projects," the company said. The company is framing Opus 5 as the go-to AI model for most tasks, including knowledge work and automation. According to Anthropic, Opus 5 approaches Fable 5's competencies at half the cost. Anthropic filed confidential paperwork to go public in June, followed shortly by OpenAI, and Anthropic appears to be on track to hit the market later this year.