Claude Opus 5.5 is Anthropic’s advanced AI model for agentic coding, complex knowledge work, computer use, research, and long-running professional tasks. It is designed to handle large codebases, multi-step workflows, financial analysis, document creation, software audits, and other demanding workloads with improved efficiency over Claude Opus 5. Anthropic reports that Opus 5.5 uses fewer tokens per task, produces output more than 30% faster, and costs less to run than its predecessor. The model also improves communication quality by putting important information first, reducing unnecessary jargon, and following writing instructions more consistently. Safety enhancements include stronger prompt-injection resistance, action screening, sandboxing support, code review, behavioral alignment testing, and safeguards for high-risk cybersecurity & biology. Claude Opus 5.5 is available through Claude, Claude Code, the Claude Platform API, Amazon Web Services, Google Cloud, and Microsoft Azure.