diff --git a/rsconcept/backend/apps/rsform/models/Constituenta.py b/rsconcept/backend/apps/rsform/models/Constituenta.py
index 03baa666..7f81f04d 100644
--- a/rsconcept/backend/apps/rsform/models/Constituenta.py
+++ b/rsconcept/backend/apps/rsform/models/Constituenta.py
@@ -95,10 +95,6 @@ class Constituenta(Model):
         verbose_name = 'Конституента'
         verbose_name_plural = 'Конституенты'
 
-    def get_absolute_url(self):
-        ''' URL access. '''
-        return reverse('constituenta-detail', kwargs={'pk': self.pk})
-
     def __str__(self) -> str:
         return f'{self.alias}'
 
diff --git a/rsconcept/backend/apps/rsform/serializers/data_access.py b/rsconcept/backend/apps/rsform/serializers/data_access.py
index 4791c0bb..cace4404 100644
--- a/rsconcept/backend/apps/rsform/serializers/data_access.py
+++ b/rsconcept/backend/apps/rsform/serializers/data_access.py
@@ -31,7 +31,7 @@ class CstSerializer(serializers.ModelSerializer):
         ''' serializer metadata. '''
         model = Constituenta
         fields = '__all__'
-        read_only_fields = ('id', 'order', 'alias', 'cst_type', 'definition_resolved', 'term_resolved')
+        read_only_fields = ('id', 'schema', 'order', 'alias', 'cst_type', 'definition_resolved', 'term_resolved')
 
     def update(self, instance: Constituenta, validated_data) -> Constituenta:
         data = validated_data  # Note: use alias for better code readability
diff --git a/rsconcept/backend/apps/rsform/tests/s_models/t_Constituenta.py b/rsconcept/backend/apps/rsform/tests/s_models/t_Constituenta.py
index 0d254249..cda9806b 100644
--- a/rsconcept/backend/apps/rsform/tests/s_models/t_Constituenta.py
+++ b/rsconcept/backend/apps/rsform/tests/s_models/t_Constituenta.py
@@ -20,12 +20,6 @@ class TestConstituenta(TestCase):
         self.assertEqual(str(cst), testStr)
 
 
-    def test_url(self):
-        testStr = 'X1'
-        cst = Constituenta.objects.create(alias=testStr, schema=self.schema1.model, order=1, convention='Test')
-        self.assertEqual(cst.get_absolute_url(), f'/api/constituents/{cst.pk}')
-
-
     def test_order_not_null(self):
         with self.assertRaises(IntegrityError):
             Constituenta.objects.create(alias='X1', schema=self.schema1.model)
diff --git a/rsconcept/backend/apps/rsform/tests/s_models/t_RSForm.py b/rsconcept/backend/apps/rsform/tests/s_models/t_RSForm.py
index 28333d03..187bc021 100644
--- a/rsconcept/backend/apps/rsform/tests/s_models/t_RSForm.py
+++ b/rsconcept/backend/apps/rsform/tests/s_models/t_RSForm.py
@@ -208,11 +208,11 @@ class TestRSForm(TestCase):
             definition_formal=x1.alias
         )
 
-        self.schema.substitute(x1, x2, True)
+        self.schema.substitute(x1, x2)
         x2.refresh_from_db()
         d1.refresh_from_db()
         self.assertEqual(self.schema.constituents().count(), 2)
-        self.assertEqual(x2.term_raw, 'Test')
+        self.assertEqual(x2.term_raw, 'Test2')
         self.assertEqual(d1.definition_formal, x2.alias)
 
 
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/__init__.py b/rsconcept/backend/apps/rsform/tests/s_views/__init__.py
index 1a564c03..84607134 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/__init__.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/__init__.py
@@ -1,6 +1,4 @@
 ''' Tests for REST API. '''
 from .t_cctext import *
-from .t_constituents import *
-from .t_operations import *
 from .t_rsforms import *
 from .t_rslang import *
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py b/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py
deleted file mode 100644
index 24159ea3..00000000
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py
+++ /dev/null
@@ -1,102 +0,0 @@
-''' Testing API: Constituents. '''
-from apps.rsform.models import Constituenta, CstType, RSForm
-from shared.EndpointTester import EndpointTester, decl_endpoint
-
-
-class TestConstituentaAPI(EndpointTester):
-    ''' Testing Constituenta view. '''
-
-    def setUp(self):
-        super().setUp()
-        self.rsform_owned = RSForm.create(title='Test', alias='T1', owner=self.user)
-        self.rsform_unowned = RSForm.create(title='Test2', alias='T2')
-        self.cst1 = Constituenta.objects.create(
-            alias='X1',
-            cst_type=CstType.BASE,
-            schema=self.rsform_owned.model,
-            order=1,
-            convention='Test',
-            term_raw='Test1',
-            term_resolved='Test1R',
-            term_forms=[{'text': 'form1', 'tags': 'sing,datv'}])
-        self.cst2 = Constituenta.objects.create(
-            alias='X2',
-            cst_type=CstType.BASE,
-            schema=self.rsform_unowned.model,
-            order=1,
-            convention='Test1',
-            term_raw='Test2',
-            term_resolved='Test2R'
-        )
-        self.cst3 = Constituenta.objects.create(
-            alias='X3',
-            schema=self.rsform_owned.model,
-            order=2,
-            term_raw='Test3',
-            term_resolved='Test3',
-            definition_raw='Test1',
-            definition_resolved='Test2'
-        )
-        self.invalid_cst = self.cst3.pk + 1337
-
-
-    @decl_endpoint('/api/constituents/{item}', method='get')
-    def test_retrieve(self):
-        self.executeNotFound(item=self.invalid_cst)
-        response = self.executeOK(item=self.cst1.pk)
-        self.assertEqual(response.data['alias'], self.cst1.alias)
-        self.assertEqual(response.data['convention'], self.cst1.convention)
-
-
-    @decl_endpoint('/api/constituents/{item}', method='patch')
-    def test_partial_update(self):
-        data = {'convention': 'tt'}
-        self.executeForbidden(data=data, item=self.cst2.pk)
-
-        self.logout()
-        self.executeForbidden(data=data, item=self.cst1.pk)
-
-        self.login()
-        response = self.executeOK(data=data, item=self.cst1.pk)
-        self.cst1.refresh_from_db()
-        self.assertEqual(response.data['convention'], 'tt')
-        self.assertEqual(self.cst1.convention, 'tt')
-
-        self.executeOK(data=data, item=self.cst1.pk)
-
-
-    @decl_endpoint('/api/constituents/{item}', method='patch')
-    def test_update_resolved_no_refs(self):
-        data = {
-            'term_raw': 'New term',
-            'definition_raw': 'New def'
-        }
-        response = self.executeOK(data=data, item=self.cst3.pk)
-        self.cst3.refresh_from_db()
-        self.assertEqual(response.data['term_resolved'], 'New term')
-        self.assertEqual(self.cst3.term_resolved, 'New term')
-        self.assertEqual(response.data['definition_resolved'], 'New def')
-        self.assertEqual(self.cst3.definition_resolved, 'New def')
-
-
-    @decl_endpoint('/api/constituents/{item}', method='patch')
-    def test_update_resolved_refs(self):
-        data = {
-            'term_raw': '@{X1|nomn,sing}',
-            'definition_raw': '@{X1|nomn,sing} @{X1|sing,datv}'
-        }
-        response = self.executeOK(data=data, item=self.cst3.pk)
-        self.cst3.refresh_from_db()
-        self.assertEqual(self.cst3.term_resolved, self.cst1.term_resolved)
-        self.assertEqual(response.data['term_resolved'], self.cst1.term_resolved)
-        self.assertEqual(self.cst3.definition_resolved, f'{self.cst1.term_resolved} form1')
-        self.assertEqual(response.data['definition_resolved'], f'{self.cst1.term_resolved} form1')
-
-
-    @decl_endpoint('/api/constituents/{item}', method='patch')
-    def test_readonly_cst_fields(self):
-        data = {'alias': 'X33', 'order': 10}
-        response = self.executeOK(data=data, item=self.cst1.pk)
-        self.assertEqual(response.data['alias'], 'X1')
-        self.assertEqual(response.data['alias'], self.cst1.alias)
-        self.assertEqual(response.data['order'], self.cst1.order)
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py b/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py
deleted file mode 100644
index 8188bcc5..00000000
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py
+++ /dev/null
@@ -1,80 +0,0 @@
-''' Testing API: Operations. '''
-from apps.rsform.models import Constituenta, CstType, RSForm
-from shared.EndpointTester import EndpointTester, decl_endpoint
-
-
-class TestInlineSynthesis(EndpointTester):
-    ''' Testing Operations endpoints. '''
-
-
-    @decl_endpoint('/api/operations/inline-synthesis', method='patch')
-    def setUp(self):
-        super().setUp()
-        self.schema1 = RSForm.create(title='Test1', alias='T1', owner=self.user)
-        self.schema2 = RSForm.create(title='Test2', alias='T2', owner=self.user)
-        self.unowned = RSForm.create(title='Test3', alias='T3')
-
-
-    def test_inline_synthesis_inputs(self):
-        invalid_id = 1338
-        data = {
-            'receiver': self.unowned.model.pk,
-            'source': self.schema1.model.pk,
-            'items': [],
-            'substitutions': []
-        }
-        self.executeForbidden(data=data)
-
-        data['receiver'] = invalid_id
-        self.executeBadData(data=data)
-
-        data['receiver'] = self.schema1.model.pk
-        data['source'] = invalid_id
-        self.executeBadData(data=data)
-
-        data['source'] = self.schema1.model.pk
-        self.executeOK(data=data)
-
-        data['items'] = [invalid_id]
-        self.executeBadData(data=data)
-
-
-    def test_inline_synthesis(self):
-        ks1_x1 = self.schema1.insert_new('X1', term_raw='KS1X1')  # -> delete
-        ks1_x2 = self.schema1.insert_new('X2', term_raw='KS1X2')  # -> X2
-        ks1_s1 = self.schema1.insert_new('S1', definition_formal='X2', term_raw='KS1S1')  # -> S1
-        ks1_d1 = self.schema1.insert_new('D1', definition_formal=r'S1\X1\X2')  # -> D1
-        ks2_x1 = self.schema2.insert_new('X1', term_raw='KS2X1')  # -> delete
-        ks2_x2 = self.schema2.insert_new('X2', term_raw='KS2X2')  # -> X4
-        ks2_s1 = self.schema2.insert_new('S1', definition_formal='X2×X2', term_raw='KS2S1')  # -> S2
-        ks2_d1 = self.schema2.insert_new('D1', definition_formal=r'S1\X1\X2')  # -> D2
-        ks2_a1 = self.schema2.insert_new('A1', definition_formal='1=1')  # -> not included in items
-
-        data = {
-            'receiver': self.schema1.model.pk,
-            'source': self.schema2.model.pk,
-            'items': [ks2_x1.pk, ks2_x2.pk, ks2_s1.pk, ks2_d1.pk],
-            'substitutions': [
-                {
-                    'original': ks1_x1.pk,
-                    'substitution': ks2_s1.pk
-                },
-                {
-                    'original': ks2_x1.pk,
-                    'substitution': ks1_s1.pk
-                }
-            ]
-        }
-        response = self.executeOK(data=data)
-        result = {item['alias']: item for item in response.data['items']}
-        self.assertEqual(len(result), 6)
-        self.assertEqual(result['X2']['term_raw'], ks1_x2.term_raw)
-        self.assertEqual(result['X2']['order'], 1)
-        self.assertEqual(result['X4']['term_raw'], ks2_x2.term_raw)
-        self.assertEqual(result['X4']['order'], 2)
-        self.assertEqual(result['S1']['term_raw'], ks2_x1.term_raw)
-        self.assertEqual(result['S2']['term_raw'], ks2_s1.term_raw)
-        self.assertEqual(result['S1']['definition_formal'], 'X2')
-        self.assertEqual(result['S2']['definition_formal'], 'X4×X4')
-        self.assertEqual(result['D1']['definition_formal'], r'S1\S2\X2')
-        self.assertEqual(result['D2']['definition_formal'], r'S2\S1\X4')
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py b/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
index 054e1d43..e8e8ecd5 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
@@ -482,3 +482,172 @@ class TestRSFormViewset(EndpointTester):
         self.assertEqual(len(items), 2)
         self.assertEqual(items[0]['order'], f1.order + 1)
         self.assertEqual(items[0]['definition_formal'], '[α∈X1, β∈X1] Pr1(F10[α,β])')
+
+
+class TestConstituentaAPI(EndpointTester):
+    ''' Testing Constituenta view. '''
+
+    def setUp(self):
+        super().setUp()
+        self.rsform_owned = RSForm.create(title='Test', alias='T1', owner=self.user)
+        self.rsform_unowned = RSForm.create(title='Test2', alias='T2')
+        self.cst1 = Constituenta.objects.create(
+            alias='X1',
+            cst_type=CstType.BASE,
+            schema=self.rsform_owned.model,
+            order=1,
+            convention='Test',
+            term_raw='Test1',
+            term_resolved='Test1R',
+            term_forms=[{'text': 'form1', 'tags': 'sing,datv'}])
+        self.cst2 = Constituenta.objects.create(
+            alias='X2',
+            cst_type=CstType.BASE,
+            schema=self.rsform_unowned.model,
+            order=1,
+            convention='Test1',
+            term_raw='Test2',
+            term_resolved='Test2R'
+        )
+        self.cst3 = Constituenta.objects.create(
+            alias='X3',
+            schema=self.rsform_owned.model,
+            order=2,
+            term_raw='Test3',
+            term_resolved='Test3',
+            definition_raw='Test1',
+            definition_resolved='Test2'
+        )
+        self.invalid_cst = self.cst3.pk + 1337
+
+    @decl_endpoint('/api/rsforms/{schema}/update-cst', method='patch')
+    def test_partial_update(self):
+        data = {'id': self.cst1.pk, 'convention': 'tt'}
+        self.executeForbidden(data=data, schema=self.rsform_unowned.model.pk)
+
+        self.logout()
+        self.executeForbidden(data=data, schema=self.rsform_owned.model.pk)
+
+        self.login()
+        response = self.executeOK(data=data, schema=self.rsform_owned.model.pk)
+        self.cst1.refresh_from_db()
+        self.assertEqual(response.data['convention'], 'tt')
+        self.assertEqual(self.cst1.convention, 'tt')
+
+        self.executeOK(data=data, schema=self.rsform_owned.model.pk)
+
+
+    @decl_endpoint('/api/rsforms/{schema}/update-cst', method='patch')
+    def test_update_resolved_no_refs(self):
+        data = {
+            'id': self.cst3.pk,
+            'term_raw': 'New term',
+            'definition_raw': 'New def'
+        }
+        response = self.executeOK(data=data, schema=self.rsform_owned.model.pk)
+        self.cst3.refresh_from_db()
+        self.assertEqual(response.data['term_resolved'], 'New term')
+        self.assertEqual(self.cst3.term_resolved, 'New term')
+        self.assertEqual(response.data['definition_resolved'], 'New def')
+        self.assertEqual(self.cst3.definition_resolved, 'New def')
+
+
+    @decl_endpoint('/api/rsforms/{schema}/update-cst', method='patch')
+    def test_update_resolved_refs(self):
+        data = {
+            'id': self.cst3.pk,
+            'term_raw': '@{X1|nomn,sing}',
+            'definition_raw': '@{X1|nomn,sing} @{X1|sing,datv}'
+        }
+        response = self.executeOK(data=data, schema=self.rsform_owned.model.pk)
+        self.cst3.refresh_from_db()
+        self.assertEqual(self.cst3.term_resolved, self.cst1.term_resolved)
+        self.assertEqual(response.data['term_resolved'], self.cst1.term_resolved)
+        self.assertEqual(self.cst3.definition_resolved, f'{self.cst1.term_resolved} form1')
+        self.assertEqual(response.data['definition_resolved'], f'{self.cst1.term_resolved} form1')
+
+
+    @decl_endpoint('/api/rsforms/{schema}/update-cst', method='patch')
+    def test_readonly_cst_fields(self):
+        data = {
+            'id': self.cst1.pk,
+            'alias': 'X33',
+            'order': 10
+        }
+        response = self.executeOK(data=data, schema=self.rsform_owned.model.pk)
+        self.assertEqual(response.data['alias'], 'X1')
+        self.assertEqual(response.data['alias'], self.cst1.alias)
+        self.assertEqual(response.data['order'], self.cst1.order)
+
+
+class TestInlineSynthesis(EndpointTester):
+    ''' Testing Operations endpoints. '''
+
+
+    @decl_endpoint('/api/rsforms/inline-synthesis', method='patch')
+    def setUp(self):
+        super().setUp()
+        self.schema1 = RSForm.create(title='Test1', alias='T1', owner=self.user)
+        self.schema2 = RSForm.create(title='Test2', alias='T2', owner=self.user)
+        self.unowned = RSForm.create(title='Test3', alias='T3')
+
+
+    def test_inline_synthesis_inputs(self):
+        invalid_id = 1338
+        data = {
+            'receiver': self.unowned.model.pk,
+            'source': self.schema1.model.pk,
+            'items': [],
+            'substitutions': []
+        }
+        self.executeForbidden(data=data)
+
+        data['receiver'] = invalid_id
+        self.executeBadData(data=data)
+
+        data['receiver'] = self.schema1.model.pk
+        data['source'] = invalid_id
+        self.executeBadData(data=data)
+
+        data['source'] = self.schema1.model.pk
+        self.executeOK(data=data)
+
+        data['items'] = [invalid_id]
+        self.executeBadData(data=data)
+
+
+    def test_inline_synthesis(self):
+        ks1_x1 = self.schema1.insert_new('X1', term_raw='KS1X1')  # -> delete
+        ks1_x2 = self.schema1.insert_new('X2', term_raw='KS1X2')  # -> X2
+        ks1_s1 = self.schema1.insert_new('S1', definition_formal='X2', term_raw='KS1S1')  # -> S1
+        ks1_d1 = self.schema1.insert_new('D1', definition_formal=r'S1\X1\X2')  # -> D1
+        ks2_x1 = self.schema2.insert_new('X1', term_raw='KS2X1')  # -> delete
+        ks2_x2 = self.schema2.insert_new('X2', term_raw='KS2X2')  # -> X4
+        ks2_s1 = self.schema2.insert_new('S1', definition_formal='X2×X2', term_raw='KS2S1')  # -> S2
+        ks2_d1 = self.schema2.insert_new('D1', definition_formal=r'S1\X1\X2')  # -> D2
+        ks2_a1 = self.schema2.insert_new('A1', definition_formal='1=1')  # -> not included in items
+
+        data = {
+            'receiver': self.schema1.model.pk,
+            'source': self.schema2.model.pk,
+            'items': [ks2_x1.pk, ks2_x2.pk, ks2_s1.pk, ks2_d1.pk],
+            'substitutions': [
+                {
+                    'original': ks1_x1.pk,
+                    'substitution': ks2_s1.pk
+                },
+                {
+                    'original': ks2_x1.pk,
+                    'substitution': ks1_s1.pk
+                }
+            ]
+        }
+        response = self.executeOK(data=data)
+        result = {item['alias']: item for item in response.data['items']}
+        self.assertEqual(len(result), 6)
+        self.assertEqual(result['X2']['order'], 1)
+        self.assertEqual(result['X4']['order'], 2)
+        self.assertEqual(result['S1']['definition_formal'], 'X2')
+        self.assertEqual(result['S2']['definition_formal'], 'X4×X4')
+        self.assertEqual(result['D1']['definition_formal'], r'S1\S2\X2')
+        self.assertEqual(result['D2']['definition_formal'], r'S2\S1\X4')
diff --git a/rsconcept/backend/apps/rsform/urls.py b/rsconcept/backend/apps/rsform/urls.py
index 4cd7e04d..0c417454 100644
--- a/rsconcept/backend/apps/rsform/urls.py
+++ b/rsconcept/backend/apps/rsform/urls.py
@@ -9,11 +9,9 @@ library_router.register('rsforms', views.RSFormViewSet, 'RSForm')
 
 
 urlpatterns = [
-    path('constituents/<int:pk>', views.ConstituentAPIView.as_view(), name='constituenta-detail'),
     path('rsforms/import-trs', views.TrsImportView.as_view()),
     path('rsforms/create-detailed', views.create_rsform),
-
-    path('operations/inline-synthesis', views.inline_synthesis),
+    path('rsforms/inline-synthesis', views.inline_synthesis),
 
     path('rslang/parse-expression', views.parse_expression),
     path('rslang/to-ascii', views.convert_to_ascii),
diff --git a/rsconcept/backend/apps/rsform/views/__init__.py b/rsconcept/backend/apps/rsform/views/__init__.py
index df6a6b85..3daa0c4f 100644
--- a/rsconcept/backend/apps/rsform/views/__init__.py
+++ b/rsconcept/backend/apps/rsform/views/__init__.py
@@ -1,6 +1,4 @@
 ''' REST API: Endpoint processors. '''
 from .cctext import generate_lexeme, inflect, parse_text
-from .constituents import ConstituentAPIView
-from .operations import inline_synthesis
-from .rsforms import RSFormViewSet, TrsImportView, create_rsform
+from .rsforms import RSFormViewSet, TrsImportView, create_rsform, inline_synthesis
 from .rslang import convert_to_ascii, convert_to_math, parse_expression
diff --git a/rsconcept/backend/apps/rsform/views/constituents.py b/rsconcept/backend/apps/rsform/views/constituents.py
deleted file mode 100644
index 195a099c..00000000
--- a/rsconcept/backend/apps/rsform/views/constituents.py
+++ /dev/null
@@ -1,16 +0,0 @@
-''' Endpoints for Constituenta. '''
-from drf_spectacular.utils import extend_schema, extend_schema_view
-from rest_framework import generics
-
-from shared import permissions
-
-from .. import models as m
-from .. import serializers as s
-
-
-@extend_schema(tags=['Constituenta'])
-@extend_schema_view()
-class ConstituentAPIView(generics.RetrieveUpdateAPIView, permissions.EditorMixin):
-    ''' Endpoint: Get / Update Constituenta. '''
-    queryset = m.Constituenta.objects.all()
-    serializer_class = s.CstSerializer
diff --git a/rsconcept/backend/apps/rsform/views/operations.py b/rsconcept/backend/apps/rsform/views/operations.py
deleted file mode 100644
index 6fa68d8a..00000000
--- a/rsconcept/backend/apps/rsform/views/operations.py
+++ /dev/null
@@ -1,50 +0,0 @@
-''' Endpoints for RSForm. '''
-from typing import cast
-
-from django.db import transaction
-from drf_spectacular.utils import extend_schema
-from rest_framework import status as c
-from rest_framework.decorators import api_view
-from rest_framework.request import Request
-from rest_framework.response import Response
-
-from .. import models as m
-from .. import serializers as s
-
-
-@extend_schema(
-    summary='Inline synthesis: merge one schema into another',
-    tags=['Operations'],
-    request=s.InlineSynthesisSerializer,
-    responses={c.HTTP_200_OK: s.RSFormParseSerializer}
-)
-@api_view(['PATCH'])
-def inline_synthesis(request: Request):
-    ''' Endpoint: Inline synthesis. '''
-    serializer = s.InlineSynthesisSerializer(
-        data=request.data,
-        context={'user': request.user}
-    )
-    serializer.is_valid(raise_exception=True)
-
-    receiver = m.RSForm(serializer.validated_data['receiver'])
-    items = cast(list[m.Constituenta], serializer.validated_data['items'])
-
-    with transaction.atomic():
-        new_items = receiver.insert_copy(items)
-        for substitution in serializer.validated_data['substitutions']:
-            original = cast(m.Constituenta, substitution['original'])
-            replacement = cast(m.Constituenta, substitution['substitution'])
-            if original in items:
-                index = next(i for (i, cst) in enumerate(items) if cst == original)
-                original = new_items[index]
-            else:
-                index = next(i for (i, cst) in enumerate(items) if cst == replacement)
-                replacement = new_items[index]
-            receiver.substitute(original, replacement)
-        receiver.restore_order()
-
-    return Response(
-        status=c.HTTP_200_OK,
-        data=s.RSFormParseSerializer(receiver.model).data
-    )
diff --git a/rsconcept/backend/apps/rsform/views/rsforms.py b/rsconcept/backend/apps/rsform/views/rsforms.py
index 0666256a..85abd124 100644
--- a/rsconcept/backend/apps/rsform/views/rsforms.py
+++ b/rsconcept/backend/apps/rsform/views/rsforms.py
@@ -12,6 +12,7 @@ from rest_framework import views, viewsets
 from rest_framework.decorators import action, api_view
 from rest_framework.request import Request
 from rest_framework.response import Response
+from rest_framework.serializers import ValidationError
 
 from apps.library.models import AccessPolicy, LibraryItem, LibraryItemType, LocationHead
 from apps.library.serializers import LibraryItemSerializer
@@ -45,7 +46,8 @@ class RSFormViewSet(viewsets.GenericViewSet, generics.ListAPIView, generics.Retr
             'substitute',
             'restore_order',
             'reset_aliases',
-            'produce_structure'
+            'produce_structure',
+            'update_cst'
         ]:
             permission_list = [permissions.ItemEditor]
         elif self.action in [
@@ -88,15 +90,43 @@ class RSFormViewSet(viewsets.GenericViewSet, generics.ListAPIView, generics.Retr
         new_cst = m.RSForm(schema).create_cst(data, insert_after)
 
         schema.refresh_from_db()
-        response = Response(
+        return Response(
             status=c.HTTP_201_CREATED,
             data={
                 'new_cst': s.CstSerializer(new_cst).data,
                 'schema': s.RSFormParseSerializer(schema).data
             }
         )
-        response['Location'] = new_cst.get_absolute_url()
-        return response
+
+    @extend_schema(
+        summary='update persistent attributes of a given constituenta',
+        tags=['RSForm'],
+        request=s.CstSerializer,
+        responses={
+            c.HTTP_200_OK: s.CstSerializer,
+            c.HTTP_400_BAD_REQUEST: None,
+            c.HTTP_403_FORBIDDEN: None,
+            c.HTTP_404_NOT_FOUND: None
+        }
+    )
+    @action(detail=True, methods=['patch'], url_path='update-cst')
+    def update_cst(self, request: Request, pk):
+        ''' Update persistent attributes of a given constituenta. '''
+        schema = self._get_item()
+        serializer = s.CstSerializer(data=request.data, partial=True)
+        serializer.is_valid(raise_exception=True)
+
+        cst = m.Constituenta.objects.get(pk=request.data['id'])
+        if cst.schema != schema:
+            raise ValidationError({
+                f'schema': msg.constituentaNotInRSform(schema.title)
+            })
+        serializer.update(instance=cst, validated_data=serializer.validated_data)
+
+        return Response(
+            status=c.HTTP_200_OK,
+            data=s.CstSerializer(cst).data
+        )
 
     @extend_schema(
         summary='produce the structure of a given constituenta',
@@ -521,3 +551,41 @@ def _prepare_rsform_data(data: dict, request: Request, owner: Union[User, None])
 
     data['access_policy'] = request.data.get('access_policy', AccessPolicy.PUBLIC)
     data['location'] = request.data.get('location', LocationHead.USER)
+
+
+@extend_schema(
+    summary='Inline synthesis: merge one schema into another',
+    tags=['Operations'],
+    request=s.InlineSynthesisSerializer,
+    responses={c.HTTP_200_OK: s.RSFormParseSerializer}
+)
+@api_view(['PATCH'])
+def inline_synthesis(request: Request):
+    ''' Endpoint: Inline synthesis. '''
+    serializer = s.InlineSynthesisSerializer(
+        data=request.data,
+        context={'user': request.user}
+    )
+    serializer.is_valid(raise_exception=True)
+
+    receiver = m.RSForm(serializer.validated_data['receiver'])
+    items = cast(list[m.Constituenta], serializer.validated_data['items'])
+
+    with transaction.atomic():
+        new_items = receiver.insert_copy(items)
+        for substitution in serializer.validated_data['substitutions']:
+            original = cast(m.Constituenta, substitution['original'])
+            replacement = cast(m.Constituenta, substitution['substitution'])
+            if original in items:
+                index = next(i for (i, cst) in enumerate(items) if cst == original)
+                original = new_items[index]
+            else:
+                index = next(i for (i, cst) in enumerate(items) if cst == replacement)
+                replacement = new_items[index]
+            receiver.substitute(original, replacement)
+        receiver.restore_order()
+
+    return Response(
+        status=c.HTTP_200_OK,
+        data=s.RSFormParseSerializer(receiver.model).data
+    )
diff --git a/rsconcept/frontend/src/backend/constituents.ts b/rsconcept/frontend/src/backend/constituents.ts
deleted file mode 100644
index 576e9e05..00000000
--- a/rsconcept/frontend/src/backend/constituents.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Endpoints: constituents.
- */
-
-import { IConstituentaMeta, ICstUpdateData } from '@/models/rsform';
-
-import { AxiosPatch, FrontExchange } from './apiTransport';
-
-export function patchConstituenta(target: string, request: FrontExchange<ICstUpdateData, IConstituentaMeta>) {
-  AxiosPatch({
-    endpoint: `/api/constituents/${target}`,
-    request: request
-  });
-}
diff --git a/rsconcept/frontend/src/backend/operations.ts b/rsconcept/frontend/src/backend/operations.ts
deleted file mode 100644
index 5fce8876..00000000
--- a/rsconcept/frontend/src/backend/operations.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Endpoints: operations.
- */
-
-import { IInlineSynthesisData, IRSFormData } from '@/models/rsform';
-
-import { AxiosPatch, FrontExchange } from './apiTransport';
-
-export function patchInlineSynthesis(request: FrontExchange<IInlineSynthesisData, IRSFormData>) {
-  AxiosPatch({
-    endpoint: `/api/operations/inline-synthesis`,
-    request: request
-  });
-}
diff --git a/rsconcept/frontend/src/backend/rsforms.ts b/rsconcept/frontend/src/backend/rsforms.ts
index 51e198d6..c9f3f0eb 100644
--- a/rsconcept/frontend/src/backend/rsforms.ts
+++ b/rsconcept/frontend/src/backend/rsforms.ts
@@ -6,10 +6,13 @@ import { ILibraryCreateData, ILibraryItem } from '@/models/library';
 import { ICstSubstituteData } from '@/models/oss';
 import {
   IConstituentaList,
+  IConstituentaMeta,
   ICstCreateData,
   ICstCreatedResponse,
   ICstMovetoData,
   ICstRenameData,
+  ICstUpdateData,
+  IInlineSynthesisData,
   IProduceStructureResponse,
   IRSFormData,
   IRSFormUploadData,
@@ -68,6 +71,13 @@ export function postCreateConstituenta(schema: string, request: FrontExchange<IC
   });
 }
 
+export function patchUpdateConstituenta(schema: string, request: FrontExchange<ICstUpdateData, IConstituentaMeta>) {
+  AxiosPatch({
+    endpoint: `/api/rsforms/${schema}/update-cst`,
+    request: request
+  });
+}
+
 export function patchDeleteConstituenta(schema: string, request: FrontExchange<IConstituentaList, IRSFormData>) {
   AxiosPatch({
     endpoint: `/api/rsforms/${schema}/delete-multiple-cst`,
@@ -135,3 +145,10 @@ export function patchUploadTRS(target: string, request: FrontExchange<IRSFormUpl
     }
   });
 }
+
+export function patchInlineSynthesis(request: FrontExchange<IInlineSynthesisData, IRSFormData>) {
+  AxiosPatch({
+    endpoint: `/api/rsforms/inline-synthesis`,
+    request: request
+  });
+}
diff --git a/rsconcept/frontend/src/context/RSFormContext.tsx b/rsconcept/frontend/src/context/RSFormContext.tsx
index c13f54a1..db985e23 100644
--- a/rsconcept/frontend/src/context/RSFormContext.tsx
+++ b/rsconcept/frontend/src/context/RSFormContext.tsx
@@ -3,7 +3,6 @@
 import { createContext, useCallback, useContext, useMemo, useState } from 'react';
 
 import { DataCallback } from '@/backend/apiTransport';
-import { patchConstituenta } from '@/backend/constituents';
 import {
   deleteUnsubscribe,
   patchLibraryItem,
@@ -14,16 +13,17 @@ import {
   postCreateVersion,
   postSubscribe
 } from '@/backend/library';
-import { patchInlineSynthesis } from '@/backend/operations';
 import {
   getTRSFile,
   patchDeleteConstituenta,
+  patchInlineSynthesis,
   patchMoveConstituenta,
   patchProduceStructure,
   patchRenameConstituenta,
   patchResetAliases,
   patchRestoreOrder,
   patchSubstituteConstituents,
+  patchUpdateConstituenta,
   patchUploadTRS,
   postCreateConstituenta
 } from '@/backend/rsforms';
@@ -439,7 +439,7 @@ export const RSFormState = ({ itemID, versionID, children }: RSFormStateProps) =
   const cstUpdate = useCallback(
     (data: ICstUpdateData, callback?: DataCallback<IConstituentaMeta>) => {
       setProcessingError(undefined);
-      patchConstituenta(String(data.id), {
+      patchUpdateConstituenta(itemID, {
         data: data,
         showError: true,
         setLoading: setProcessing,