Anthropic launches Claude Opus 4.8, prepares Mythos-class models for all customers
Anthropic has released Claude Opus 4.8 and outlined plans for broader access to its Mythos-class models, which the company expects to make available to all customers in the coming weeks.
Claude Opus 4.8 (Source: Anthropic)
Claude Opus 4.8 is available to all users, with pricing unchanged from Opus 4.7.
Anthropic highlighted improvements in model honesty, noting that Opus 4.8 is more likely to acknowledge when it lacks sufficient information and less likely to make unsupported claims.
“Early testers have found Claude Opus 4.8 to be more reliable and sharper in its judgement when it’s performing agentic tasks,” the company wrote.
According to Anthropic, evaluations showed Opus 4.8 was around four times less likely than its predecessor to allow flaws in code it generated to go unremarked.
Anthropic reported lower rates of deceptive behavior and misalignment in testing. Opus 4.8 performed at a level similar to Claude Mythos Preview on measures of whether systems act in accordance with user interests and instructions.
Alongside the new model, Anthropic introduced Dynamic Workflows, a feature available in research preview that allows Claude to take on larger tasks in Claude Code. The feature enables Claude to plan work, run hundreds of parallel subagents within a single session, and verify outputs before returning results to the user.
“For example, Claude Code with Opus 4.8 can now carry out codebase-scale migrations across hundreds of thousands of lines of code from kickoff to merge, with the existing test suite as its bar,” Anthropic noted.
Dynamic Workflows is available for Claude Code users on Enterprise, Team, and Max plans.
The release also includes controls that allow users to adjust how much effort the model spends on a task. The setting can be used to balance response speed, reasoning depth, and cost.
Anthropic also revealed plans for a new class of AI model that it says will surpass Opus in intelligence. Mythos-class models, currently being tested by a limited number of organizations through Project Glasswing, are expected to become available to all customers in the coming weeks once additional cyber safeguards are in place.
“There’s still more to be done: we’re working on developing and releasing models that provide many of the same capabilities as Opus at a lower cost,” the company concluded.