Anthropic launched Claude Opus 4.8 on Thursday, rolling out a new version of its flagship AI model with stronger performance across coding, agentic tasks, reasoning, and practical knowledge work, while also teasing a broader release of its more advanced Mythos class models in the coming weeks.
The model builds on Claude Opus 4.7 and is available today at the same standard price, with regular usage priced at $5 per million input tokens and $25 per million output tokens. Developers can access the model through the Claude API using claude-opus-4-8.
Anthropic said Opus 4.8 is designed to be a more effective collaborator, with early testers reporting stronger judgment, better tool use, and improved reliability on long running agentic workflows.
The company said one of the model’s clearest improvements is honesty. Opus 4.8 is more likely to flag uncertainty in its own work and less likely to claim progress without enough evidence. Anthropic said its evaluations showed Opus 4.8 was around four times less likely than Opus 4.7 to leave flaws in code it had written without noting them.
Anthropic also said its alignment assessment found that Opus 4.8 showed substantially lower rates of misaligned behavior, including deception or cooperation with misuse, compared with Opus 4.7. The company said the model performed similarly to Claude Mythos Preview, its best aligned model.
