AI dev workflow
Claude Opus vs Sonnet: what breaks when you swap the model string
Comparisons of Claude Opus, Sonnet and Haiku score capability, speed and price per token. None of them mention that the model string is part of your request contract. Swap it and thinking can turn itself on, your answer can move out of content[0], and a max_tokens you never touched can start truncating. Eight measured differences, September 2026.
13 min read13