diff --git a/internal/model/api/shape.go b/internal/model/api/shape.go
index <HASH>..<HASH> 100644
--- a/internal/model/api/shape.go
+++ b/internal/model/api/shape.go
@@ -35,6 +35,7 @@ type Shape struct {
 	Type          string
 	Exception     bool
 	Enum          []string
+	Flattened     bool
 
 	refs []*ShapeRef
 }
@@ -119,6 +120,10 @@ func (ref *ShapeRef) GoTags(toplevel bool) string {
 		code += `" `
 	}
 
+	if ref.Shape.Flattened {
+		code += `flattened:"true" `
+	}
+
 	if toplevel {
 		if ref.Shape.Payload != "" {
 			code += `payload:"` + ref.Shape.Payload + `" `
Add flattened traits to generated model field tags