  Extending earlier results by Paulos, we discuss further the use of the
embedding formalism and Mellin transform in the calculation of tree-level
correlators of scalar and vector fields in AdS/CFT. We present an iterative
procedure that builds amplitudes by sewing together lower-point off-shell
diagrams. Both scalar and vector correlators are shown to be given in terms of
Mellin amplitudes. We apply the procedure to the explicit calculation of
three-, four- and five-point correlators.
