Anthropic: claude-sonnet-4-6-thinking

Claude Sonnet 4.6 is the mid-tier workhorse of Anthropic's 4.6 generation, bringing a 1M-token context window and 128K single-response output to the Sonnet price point. It uses the same adaptive thinking architecture as Opus 4.6, deciding reasoning depth on its own based on task complexity. It improves clearly over Sonnet 4.5 on coding, agentic workflows and long-document work while keeping the speed and cost profile the Sonnet line is known for.