[terminalshort]

For one thing it seems to splitting up the work and making some determination of complexity, then allocating it out to a model based on that complexity to save resources. When I run Claude with Opus 4.5 and run /cost I see tokens for Opus 4.5, but also a lot in Sonnet and Haiku, with the majority of tokens actually being used by Haiku.

[nyellin]

Haiku is called often, but not always the way you think. E.g. every time you write something CC invokes Haiku multiple times to generate the 'delightful 1-2 word phrase used to indicate progress to the user' (Doing Stuff, Wizarding, etc)

[dkdcio]

it’s also used in the Explore agent and for other things too