Here is an interesting treatment of a zipper set in a seam. Edges are stitched first and the zipper is applied to the back of the seam only using a backstitch. This is from “Sew The French Way” by Line Jacque
5. Strengthen the corners on the wrong side. For a skirt with a fabric waistband, sew the tape into the belt. Otherwise, turn in the ends and stitch them down carefully.
Note: For fabrics with a raised design, the stitching joining the fastener to the opening ought not too show. In such cases, turn in the opening just once and sew in the fastener by hand as when stitching along an edge-stitched or tuck seam, making your stitches as nearly invisible as possible.