Anthropic released Claude Sonnet 5 on June 30, 2026, positioning agentic capability as table stakes at every price tier. Sonnet 5 promises performance close to Opus 4.8 at lower cost — 10 per million input/output tokens through August 31, 2026, then 15.
Benchmarks cited: 63.2% agentic coding (vs Opus 4.8 69.2%, Sonnet 4.6 58.1%). Sonnet 5 slightly outperforms Opus 4.8 on knowledge work in one benchmark. Default model for Free and Pro plans.
Safety: lower undesirable behaviors than Sonnet 4.6; much lower cybersecurity capability than Opus/Mythos. Zapier, Lovable, and other partners cited for end-to-end automation and safety refusals.
Competitive context: OpenAI GPT-5.6 Sol and Google Gemini 3.5 Flash also pitched as agentic; differentiation shifts to cost and reliability.