Claude Opus 5.5 is a frontier AI model from Anthropic built for coding, research, business analysis, computer use, and complex agentic workflows. The model is particularly suited to long-running software engineering tasks such as codebase migrations, audits, debugging, optimization, and large-scale refactoring. Anthropic also positions Opus 5.5 for professional knowledge work including financial analysis, legal workflows, research reports, spreadsheets, presentations, and business automation. Compared with Claude Opus 5, the model is designed to use fewer tokens, generate responses more quickly, and reduce typical workload costs. Its communication style has also been refined to make outputs clearer, easier to scan, and more consistent with user-defined writing requirements. Opus 5.5 includes stronger defenses against prompt injection and is less likely to take irreversible or out-of-bounds actions during autonomous tasks. Enterprise safety features include action classification, an auditable open-source sandbox, code review capabilities, preserved thinking protections, and configurable safeguards for sensitive domains. The model supports zero data retention and is available with additional verification programs for vetted life sciences and cybersecurity organizations. Claude Opus 5.5 is accessible through Anthropic’s applications and API as well as AWS, Google Cloud, and Microsoft Azure.