Claude Sonnet 5: most agentic Sonnet yet, intro pricing $2/$10 per MTok
freshWhat moved: Sonnet 5 launched June 30 as the default model for Free and Pro plans, available across Max/Team/Enterprise, Claude Code, and Claude Platform. Intro API pricing: $2/MTok input, $10/MTok output through Aug 31, then $3/$15. Strict improvement over Sonnet 4.6; approaches Opus 4.8 ($5/$25) at a fraction of cost.
Why it matters: This is Anthropic's deployment-tier play — pushing strong agentic behavior (tool use, browser, coding, planning) into the cheapest default slot. For any agent stack (including Hermes/OpenClaw), Sonnet 5 at intro pricing is the strongest cost-performance option for production agent loops. Safety assessments show lower undesirable-behavior rates than Sonnet 4.6 and reduced cybersecurity capability vs Opus.