Claude Sonnet 5 vs Opus 4.8 vs GPT-5.5: agent cost math
Anthropic launched Claude Sonnet 5 on 30 June 2026 at an introductory 2/10 dollars per million tokens, posting 63.2% on SWE-bench Pro and near-Opus agentic performance at 40-60% of the cost per task. We run the cost math against Opus 4.8 and GPT-5.5, set out a routing framework for when the cheap model wins, and draw the continuity lesson from the eighteen-day Fable and Mythos export-control pause.
Gemini 3.5 Flash vs GPT-5.5 vs Claude Opus 4.7 at I/O 2026
Google shipped Gemini 3.5 Flash on day one of I/O 2026, the third frontier agentic coding model in five weeks after Claude Opus 4.7 and GPT-5.5, alongside a $100/month developer tier and the Antigravity 2.0 agent platform. For Azure-first teams the practical response is a reusable evaluation harness and a documented cost comparison for renewal leverage, not a migration.