anthropic--claude-4.5-sonnet

Claude 4.5 Sonnet sits in the middle of Anthropic's Claude family as a flagship-class large language model engineered to push the boundary on practical, agent-driven work. It is designed to excel at coding, multi-step reasoning, and direct computer use, taking on long-running projects where the model has to plan, execute tools, and stay coherent across many turns. Anthropic highlights its ability to maintain focus on complex tasks for over thirty hours, a leap from the roughly seven-hour stamina of earlier Claude agents, which makes it useful for sustained software engineering sessions and for orchestrating browser-based or desktop workflows. The model accepts text, images, and PDFs as input while producing text output, enabling workflows that combine visual context from screenshots or documents with code generation, document creation, and structured analysis in fields like finance, law, medicine, and STEM. The release positions Sonnet 4.5 as Anthropic's most capable Sonnet-class model to date, posting state-of-the-art results on agentic benchmarks such as SWE-bench Verified, where it averages 77.2 percent over ten trials, and OSWorld at 61.4 percent, both serving as real-world measures of coding and computer-use competence. Anthropic also emphasizes meaningful gains in reasoning, mathematics, and specialized domain knowledge, alongside reduced concerning behaviors like sycophancy, deception, and prompt-injection susceptibility, reflecting the company's safety and alignment work for frontier deployments. In practice, Claude 4.5 Sonnet fits well as the reasoning and orchestration engine inside software development pipelines, autonomous research or data-analysis agents, and professional assistants that need to read documents, call tools, and write code or structured output over extended sessions, while staying responsive enough for everyday conversational use.

Claude 4.5 Sonnet fits naturally as the central reasoning layer in agent-driven systems, where it can plan tool calls, navigate interfaces, and keep state across long workflows without losing thread. Anthropic's benchmark focus on SWE-bench Verified and OSWorld signals that the model is tuned not just for static question answering but for grounded action: reading a codebase, editing files, running code, or driving a browser through multi-step procedures. Combined with its ability to ingest screenshots, documents, and PDFs, the model can serve as a bridge between visual information and structured execution, which is valuable for automating back-office tasks, building retrieval-augmented assistants, or prototyping software features end to end. Because Anthropic highlights the model's reduced susceptibility to prompt injection and other safety concerns, Claude 4.5 Sonnet is positioned for enterprise-facing deployments where trust and controllability matter as much as raw capability. Its long-context handling and sustained attention make it a practical choice for projects that span many hours of autonomous work, such as overnight code refactors or multi-stage research workflows, while remaining usable for shorter interactive sessions. Overall, the model is best understood as a balanced, agent-ready frontier system: strong enough on coding and reasoning to be the workhorse in a production agent stack, and aligned enough to be deployed where reliability and safety have to keep pace with autonomy.