What are 'Const Type Parameters' and how do they benefit API contracts?

Const type parameters (TS 5.0+) allow generics to infer literal and readonly types automatically without 'as const' at the call site[cite: 1].

TS usually widens types (e.g., 'red' becomes string). Adding const to a generic definition ensures the compiler prefers literal types and readonly structures during inference. This makes APIs cleaner for the end-user by automating literal inference[cite: 1].