Anthropic Launches Claude Sonnet 4.5 with Extended Thinking for Agentic Coding
Anthropic has released Claude Sonnet 4.5, a new AI model designed to improve performance on complex, multi-step coding tasks. The model pairs a 200,000-token context window with an 'extended thinking mode' that allows it to pause, reflect on intermediate results, and adjust its approach during a task rather than executing a single fixed plan. According to Anthropic's technical report, this approach reduces hallucination rates on multi-step agent benchmarks by roughly 30% compared to its predecessor, Sonnet 4. On the SWE-bench Verified benchmark for real-world GitHub issue resolution, Sonnet 4.5 scores approximately 77.2%, up from Sonnet 4's 68%, with particular strength in multi-file refactoring tasks. Developers should note that extended thinking mode incurs additional costs, as reasoning tokens are billed separately and must be budgeted explicitly via the API.
This is an AI-generated summary. ShortSingh links to the original source for the complete article.
Discussion (0)
Log in to join the discussion and vote.
Log in