Type Alias LiteralKey<T>

LiteralKey: { [K in keyof T]: string extends K ? never : K }[keyof T] & string

🔍 Expanded Type Evaluation (Compiler API)

type LiteralKey<T> = { [K in keyof T]: string extends K ? never : K; }[keyof T] & string

extracts only the Literal string keys (not index signatures) from an object/interface