Anthropic has released Claude Sonnet 4.5, saying it outperforms other artificial intelligence models in coding, building complex agents and using computers. “Claude Sonnet 4.5 is state-of-the-art on the SWE-bench Verified evaluation, which measures complex real-world software coding abilities,” the company said. Anthropic added in the post that Sonnet 4.5 leads a benchmark that tests AI models on real-world computer tasks, OSWorld, at 61.4%. Together with the release of Sonnet 4.5, Anthropic has released upgrades to its products. These include the addition of checkpoints to Claude Code, enabling users to save their progress and roll back to a previous state; the addition of a new context editing feature and memory tool to the Claude API, letting agents run longer and handle greater complexity; and the addition of code execution and file creation directly into the conversation in Claude apps. Anthropic also introduced Claude Agent SDK, which gives developers the ability to build AI agents with the same infrastructure that powers its frontier products. In addition, the Claude for Chrome extension is now available to Max users in the waitlist. “We recommend upgrading to Claude Sonnet 4.5 for all uses,” Anthropic said. “Whether you’re using Claude through our apps, our API, or Claude Code, Sonnet 4.5 is a drop-in replacement that provides much improved performance for the same price.”