Claude Sonnet 4 coding

openrouter
anthropic
Claude Sonnet 4 significantly enhances the capabilities of its predecessor, Sonnet 3.7, excelling in both coding and reasoning tasks with improved precision and controllability. Achieving state-of-the-art performance on SWE-bench (72.7%), Sonnet 4 balances capability and computational efficiency, making it suitable for a broad range of applications from routine coding tasks to complex software development projects. Key enhancements include improved autonomous codebase navigation, reduced error rates in agent-driven workflows, and increased reliability in following intricate instructions. Sonnet 4 is optimized for practical everyday use, providing advanced reasoning capabilities while maintaining efficiency and responsiveness in diverse internal and external scenarios. Read more at the blog post here

Capabilities

Context Window 200k tokens
Max Output 64k tokens
Inputs
Outputs

Pricing (per 1M tokens)

Input $3.00
Output $15.00
Cache Read $0.30
Cache Write $3.75

Supported Parameters

include_reasoningmax_tokensreasoningstoptemperaturetool_choicetoolstop_ktop_p