Functorially, we have the following defintions:
- An affine scheme $U$ is a representable (covariant) functor $\mathsf{CRing} \to \mathsf{Sets}$.
- A scheme $X$ can be defined as a locally representable cosheaf of sets on $\mathsf{CRing}$.
How then, can I recover the "traditional" definition that $U = (\text{Spec} A, \mathcal{O}_{\text{Spec} A})$ and $X = (|X|, \mathcal{O}_X)$ so I could look at the rings of functions above $U$ and $X$, preferably functorially ?