  For an exact dg category $\mathcal A$, we introduce its bounded dg derived
category $\mathcal{D}^b_{dg}(\mathcal A)$ and establish the universal exact
morphism from $\mathcal A$ to $\mathcal{D}^b_{dg}(\mathcal A)$. We prove that
the dg quotient of an exact dg category by a subcategory of
projective-injectives carries a canonical exact structure. We show that exact
dg categories reproduce under tensor products and functor dg categories. We
apply our results to 0-Auslander extriangulated categories and confirm a
conjecture by Fang-Gorsky-Palu-Plamondon-Pressland for the algebraic case.
