Anthropic unveils Claude Sonnet 4.5 as the best AI coding model yet
Claude Sonnet 4.5 is Anthropic’s latest AI model, boasting benchmark-leading coding performance, stronger safeguards, and new developer tools, including the Claude Agent SDK.
Anthropic has released Claude Sonnet 4.5, its most advanced AI model yet, claiming state-of-the-art results in coding benchmarks. The company says the model can build production-ready applications, rather than limited prototypes, making it more reliable than earlier versions.
Claude Sonnet 4.5 is available through the Claude API and chatbot at the same price as its predecessor, with $3 per million input tokens and $15 per million output tokens.
Early enterprise tests suggest the model can autonomously code for extended periods, integrate databases, secure domains, and perform compliance checks such as SOC 2 audits.
Industry leaders have endorsed the launch, with Cursor and Windsurf calling it a new generation of AI coding models. Anthropic also emphasises more substantial alignment, noting reduced risks of deception and sycophancy, and improved resistance to prompt injection attacks.
Alongside the model, the company has introduced a Claude Agent SDK to let developers build customised agents, and launched ‘Imagine with Claude’, a research preview showing real-time code generation.
A release that highlights the intense competition in AI, with Anthropic pushing frequent updates to keep pace with rivals such as OpenAI, which has recently gained ground on coding performance with GPT-5.
Claude Sonnet 4.5 follows just weeks after Anthropic’s Claude Opus 4.1, underlining the rapid development cycles driving the sector.
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