Anthropic has recently released the Claude Sonnet 4.5 model, this highly anticipated AI model was officially launched on September 29th and is hailed as "the best coding model in the world," marking a major breakthrough in AI's complex task processing and autonomous agent fields. Here is a professional analysis based on the latest data.
Model Release and Key Highlights
Anthropic announced that Claude Sonnet 4.5 is now available globally, supporting the Claude.ai website, iOS and Android apps, as well as API interfaces.
The model achieved leading results on the SWE-bench Verified coding benchmark, with an actual autonomous working duration of over 30 hours, far exceeding the previous limit of 7 hours for Claude Opus4. This means that AI is no longer limited to simple prototype generation, but can handle complex, multi-step tasks across codebases, achieving "production-ready" application development.
In practical performance, the code editing accuracy of Claude Sonnet 4.5 improved from a 9% error rate in the previous version to 0%, with higher tool usage success rates and lower costs. It scored 61.4% on the OSWorld benchmark (testing real computer tasks), an increase of 19.2% compared to Sonnet4 four months ago. Additionally, the model's professional knowledge and reasoning capabilities in finance, law, medicine, and STEM fields have significantly improved, surpassing Opus4.1.
Technical Upgrades and Ecosystem Integration
This release comes with multiple product optimizations, further enhancing the practicality of the Claude ecosystem. In Claude Code, a new "checkpoint" feature has been introduced, allowing users to save progress at any time and roll back to previous states, preventing development interruptions.
At the same time, the API now includes context editing and memory tools, enabling agents to run longer sequence tasks; the Claude app directly integrates code execution and file generation (such as tables and slides), simplifying workflows. Anthropic also launched the Claude Agent SDK, allowing developers to build custom AI agents using natural language, manage memory, permissions, and coordinate sub-agents.
This SDK seamlessly integrates with the Claude for Chrome extension, which is now available to Max subscribers, supporting agent operations within the browser. In addition, platforms such as GitHub Copilot, Replit Agent, and Amazon Bedrock have quickly integrated Sonnet4.5, enhancing multi-step reasoning and code understanding capabilities. In terms of pricing, Claude Sonnet 4.5 maintains the same rates as Sonnet4: $3 per million tokens for input and $15 per million tokens for output. This not only lowers the entry barrier for enterprises but also demonstrates Anthropic's positioning as an infrastructure in the AI economy.
Safety and Alignment Innovations
Anthropic emphasized that Claude Sonnet 4.5 is its "most aligned cutting-edge model." Through extensive safety training, the model significantly reduces risky behaviors such as sycophancy, deception, seeking power, and encouraging delusions, and improves defense against prompt injection attacks. External expert assessments show that it exhibits more reliable ethical decision-making across multiple domains, making it suitable for high-risk enterprise scenarios.
Industry Impact and Future Outlook
The release of Claude Sonnet 4.5 coincides with the rise of the AI agent wave. It not only challenges the dominance of OpenAI's GPT-5 and Google's Gemini 2.5Pro in the coding field, but also injects new vitality into software development and automated workflows.
