https://www.anthropic.com/pricing#api
Opus 4 is $15 / m tokens in, $75 / MTok out Sonnet 4 is the same $3 / MTok in, $15 / MTok out
> Pricing remains consistent with previous Opus and Sonnet models: Opus 4 at $15/$75 per million tokens (input/output) and Sonnet 4 at $3/$15.