diff --git a/epdb/legacy_api.py b/epdb/legacy_api.py
index fd85c65c..26e57277 100644
--- a/epdb/legacy_api.py
+++ b/epdb/legacy_api.py
@@ -1771,6 +1771,29 @@ def create_package_pathway(
         return 403, {"message": str(e)}
 
 
+@router.post("/package/{uuid:package_uuid}/pathway/{uuid:pathway_uuid}")
+def update_pathway(request, package_uuid, pathway_uuid):
+    try:
+        p = get_package_for_write(request.user, package_uuid)
+
+        if request.POST.get("scenario"):
+            pw = Pathway.objects.get(package=p, uuid=pathway_uuid)
+            scen = Scenario.objects.get(package=p, url=request.POST.get("scenario"))
+
+            pw.scenarios.add(scen)
+            pw.save()
+
+            return redirect(f"{pw.url}")
+
+        else:
+            return 400, {"message": "No scenario specified!"}
+
+    except ValueError:
+        return 403, {
+            "message": f"Deleting Pathway with id {pathway_uuid} failed due to insufficient rights!"
+        }
+
+
 @router.delete("/package/{uuid:package_uuid}/pathway/{uuid:pathway_uuid}")
 def delete_pathway(request, package_uuid, pathway_uuid):
     try:
@@ -2036,6 +2059,10 @@ def add_pathway_edge(request, package_uuid, pathway_uuid, e: Form[CreateEdge]):
             for pr in e.products.split(","):
                 products.append(Node.objects.get(pathway=pw, url=pr.strip()))
 
+        multi_step = None
+        if e.multistep and e.multistep.strip() == "true":
+            multi_step = True
+
         new_e = Edge.create(
             pathway=pw,
             start_nodes=educts,
@@ -2043,13 +2070,9 @@ def add_pathway_edge(request, package_uuid, pathway_uuid, e: Form[CreateEdge]):
             rule=None,
             name=None,
             description=e.edgeReason,
+            multi_step=multi_step,
         )
 
-        if e.multistep and e.multistep.strip() == "true":
-            reaction = new_e.edge_label
-            reaction.multi_step = True
-            reaction.save()
-
         # Update depths as sideeffect of above operation
         pw.update_depths()
 
diff --git a/epdb/models.py b/epdb/models.py
index 6ff6c9bf..b1b1bb20 100644
--- a/epdb/models.py
+++ b/epdb/models.py
@@ -2458,6 +2458,8 @@ class Edge(EnviPathModel, AliasMixin, ScenarioMixin, AdditionalInformationMixin)
         rule: Optional[Rule] = None,
         name: Optional[str] = None,
         description: Optional[str] = None,
+        *args,
+        **kwargs,
     ):
         e = Edge()
         e.pathway = pathway
@@ -2487,7 +2489,7 @@ class Edge(EnviPathModel, AliasMixin, ScenarioMixin, AdditionalInformationMixin)
             educts=[n.default_node_label for n in e.start_nodes.all()],
             products=[n.default_node_label for n in e.end_nodes.all()],
             rules=rule,
-            multi_step=False,
+            multi_step=kwargs.get("multi_step", False),
         )
 
         e.edge_label = r