Anthropic has officially launched Claude Opus 4.8 on May 28, 2026, introducing significant enhancements over its predecessor, Opus 4.7. The new AI model offers improved coding, reasoning, and agentic workflows, maintaining the same pricing structure. Early testers report increased reliability and sharper judgment, with the model being four times less likely to overlook coding flaws. Claude Opus 4.8 introduces features like Effort Control, allowing users to adjust the AI's thinking effort, and Dynamic Workflows in Claude Code, which supports large-scale code migrations. The Messages API has also been updated to allow mid-conversation system instructions. The model is available on claude.ai, Claude API, and major cloud platforms, with Anthropic planning to release lower-cost models and Mythos-class models soon.