Claude code now uses Opus by default – beware if you use API
If you are using the API (rather than subscription), beware that the latest claude code will switch to Opus by default and it will cost you.
However it seems, the change is reverted. Just today /model gives 3 options instead of 4:
│ 1. Default (recommended) Use the default model (currently Sonnet 4) · $3/$15 per Mtok │ │ 2. Opus Opus 4.1 for complex tasks · $15/$75 per Mtok │ │ 3. Opus Plan Mode Use Opus 4.1 in plan mode, Sonnet 4 otherwise