Claude Opus 5 Closes Gap with Fable 5 at Half the Price

Anthropic's Claude Opus 5 launches at the same price as Opus 4.8 ($5/$25 per million tokens) while scoring 79.2% on SWE-bench Pro, just 1.1 points behind Fable 5's 80.3% at half the cost. However, thinking is enabled by default, which can truncate responses if max_tokens is set too low, and disabling thinking with high effort levels now returns errors. Prompt caching now works with prompts as short as 512 tokens, down from 1024.