We define module nuclearity and module injectivity for
-algebras which are -module over another -algebra
with compatible actions and extend Connes-Haagerup result to this context by showing that module
nuclearity is equivalent to module amenability. We also solve the module version of
an open problem of Alan L.T. Paterson, by showing that the -algebra of an inverse semigroup is module nuclear
over the -algebra of its idempotents if and only if is amenable.