From 5fcf39fb53fb9259d0e0c8f284c9f426927be5c1 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Mon, 11 May 2026 17:00:03 +0930
Subject: [PATCH 1/9] Add serializer and migration for is_dynamic field

---
 wger/measurements/api/serializers.py           |  2 +-
 .../migrations/0004_category_is_dynamic.py     | 18 ++++++++++++++++++
 wger/measurements/models/category.py           |  6 ++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 wger/measurements/migrations/0004_category_is_dynamic.py

diff --git a/wger/measurements/api/serializers.py b/wger/measurements/api/serializers.py
index c965148d9e..9643b4fe48 100644
--- a/wger/measurements/api/serializers.py
+++ b/wger/measurements/api/serializers.py
@@ -33,7 +33,7 @@ class UnitSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Category
-        fields = ('id', 'name', 'unit')
+        fields = ('id', 'name', 'unit', 'is_dynamic')
 
 
 class MeasurementSerializer(serializers.ModelSerializer):
diff --git a/wger/measurements/migrations/0004_category_is_dynamic.py b/wger/measurements/migrations/0004_category_is_dynamic.py
new file mode 100644
index 0000000000..f5d40d81e8
--- /dev/null
+++ b/wger/measurements/migrations/0004_category_is_dynamic.py
@@ -0,0 +1,18 @@
+# Generated by Django 5.2.14 on 2026-05-11 06:22
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('measurements', '0003_alter_measurement_unique_together_and_more'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='category',
+            name='is_dynamic',
+            field=models.BooleanField(default=False, help_text='Indicates if this category is automatically calculated.', verbose_name='Is Dynamic'),
+        ),
+    ]
diff --git a/wger/measurements/models/category.py b/wger/measurements/models/category.py
index c20bab84f7..845f9a9fb2 100644
--- a/wger/measurements/models/category.py
+++ b/wger/measurements/models/category.py
@@ -41,6 +41,12 @@ class Meta:
         max_length=30,
     )
 
+    is_dynamic = models.BooleanField(
+        verbose_name='Is Dynamic',
+        default=False,
+        help_text='Indicates if this category is automatically calculated.',
+    )
+
     def get_owner_object(self):
         """
         Returns the object that has owner information

From 64303e2980f56067f7e3c094f0467cbb1a3fa0b3 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Mon, 11 May 2026 19:08:57 +0930
Subject: [PATCH 2/9] Add path to get preprogrammed dynamic measurements

---
 wger/measurements/api/views.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/wger/measurements/api/views.py b/wger/measurements/api/views.py
index 2dd3fe340d..2164199dc6 100644
--- a/wger/measurements/api/views.py
+++ b/wger/measurements/api/views.py
@@ -23,7 +23,9 @@
 from django.core.exceptions import PermissionDenied
 
 # Third Party
+from rest_framework.decorators import action
 from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
 
 # wger
 from wger.measurements.api.filtersets import MeasurementEntryFilterSet
@@ -74,6 +76,23 @@ def get_owner_objects(self):
         """
         return [(User, 'user')]
 
+    @action(detail=False, methods=['get'])
+    def dynamic(self, request):
+        """
+        Dedicated route for virtual/calculated categories
+        URL: /api/v2/measurement-category/dynamic/
+        """
+        data = [
+            {
+                'id': -1, 
+                'name': 'BMI', 
+                'unit': 'kg/m²', 
+                'is_dynamic': True
+            }
+            # easy to append more objects here later
+        ]
+        return Response(data)
+
 
 class MeasurementViewSet(WgerOwnerObjectModelViewSet):
     """

From 96391366aeeae7bd1353b15d9a90ad62f479f0f6 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Mon, 11 May 2026 20:28:52 +0930
Subject: [PATCH 3/9] Hardcode category ID for now

---
 wger/measurements/api/views.py | 44 ++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/wger/measurements/api/views.py b/wger/measurements/api/views.py
index 2164199dc6..d62a5d20c0 100644
--- a/wger/measurements/api/views.py
+++ b/wger/measurements/api/views.py
@@ -42,6 +42,29 @@
 
 logger = logging.getLogger(__name__)
 
+def calculate_bmi(user):
+    from wger.weight.models import WeightEntry
+    
+    profile = getattr(user, 'userprofile', None)
+    if not profile or not profile.height or profile.height <= 0:
+        return []
+
+    # height_sq will be a float
+    height_sq = (profile.height / 100) ** 2
+    
+    weights = WeightEntry.objects.filter(user=user).order_by('date')
+
+    return [
+        {
+            'id': f'bmi-{w.id}',
+            'category': -1,
+            'date': w.date,
+            # Cast w.weight to float to avoid the Decimal/Float TypeError
+            'value': round(float(w.weight) / height_sq, 2),
+            'notes': 'Auto-calculated from weight entry'
+        }
+        for w in weights
+    ]
 
 class CategoryViewSet(WgerOwnerObjectModelViewSet):
     """
@@ -120,3 +143,24 @@ def get_queryset(self):
             return Measurement.objects.none()
 
         return Measurement.objects.filter(category__user=self.request.user)
+
+    def list(self, request, *args, **kwargs):
+        """
+        Intercept requests for dynamic categories before the filterset blocks them
+        """
+        category_id = request.query_params.get('category')
+        is_dynamic = request.query_params.get('is_dynamic')
+
+        print(request.query_params)
+        print("is_dynamic", is_dynamic)
+
+        if category_id == '19':
+            bmi_data = calculate_bmi(request.user)
+            return Response({
+                        "count": len(bmi_data),
+                        "next": None,
+                        "previous": None,
+                        "results": bmi_data
+                    })
+
+        return super().list(request, *args, **kwargs)
\ No newline at end of file

From 87ba14c29cc9fb50639991b89daafdc4991d5391 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Tue, 12 May 2026 18:15:27 +0930
Subject: [PATCH 4/9] Add dynamic type enums and extendable dynamic measurement
 behaviour

---
 wger/measurements/api/serializers.py          |  2 +-
 wger/measurements/api/views.py                | 69 +++++++++++--------
 ...tegory_is_dynamic_category_dynamic_type.py | 22 ++++++
 wger/measurements/models/category.py          | 14 ++--
 4 files changed, 72 insertions(+), 35 deletions(-)
 create mode 100644 wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py

diff --git a/wger/measurements/api/serializers.py b/wger/measurements/api/serializers.py
index 9643b4fe48..3dd10b56f7 100644
--- a/wger/measurements/api/serializers.py
+++ b/wger/measurements/api/serializers.py
@@ -33,7 +33,7 @@ class UnitSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Category
-        fields = ('id', 'name', 'unit', 'is_dynamic')
+        fields = ('id', 'name', 'unit', 'dynamic_type')
 
 
 class MeasurementSerializer(serializers.ModelSerializer):
diff --git a/wger/measurements/api/views.py b/wger/measurements/api/views.py
index d62a5d20c0..b628458d40 100644
--- a/wger/measurements/api/views.py
+++ b/wger/measurements/api/views.py
@@ -42,7 +42,7 @@
 
 logger = logging.getLogger(__name__)
 
-def calculate_bmi(user):
+def calculate_bmi(user, category_id):
     from wger.weight.models import WeightEntry
     
     profile = getattr(user, 'userprofile', None)
@@ -56,16 +56,21 @@ def calculate_bmi(user):
 
     return [
         {
-            'id': f'bmi-{w.id}',
-            'category': -1,
-            'date': w.date,
-            # Cast w.weight to float to avoid the Decimal/Float TypeError
+            'id': w.id, # Use integer IDs so the frontend state manager doesn't complain
+            'category': int(category_id), # Link it to the requested category
+            'date': w.date.isoformat() if hasattr(w.date, 'isoformat') else w.date,
             'value': round(float(w.weight) / height_sq, 2),
             'notes': 'Auto-calculated from weight entry'
         }
         for w in weights
     ]
 
+# Map the dynamic_type enum to the math function
+DYNAMIC_REGISTRY = {
+    Category.DynamicType.BMI: calculate_bmi,
+    # add squat 1rm later
+}
+
 class CategoryViewSet(WgerOwnerObjectModelViewSet):
     """
     API endpoint for measurement units
@@ -99,22 +104,18 @@ def get_owner_objects(self):
         """
         return [(User, 'user')]
 
-    @action(detail=False, methods=['get'])
-    def dynamic(self, request):
+    @action(detail=False, methods=['get'], url_path='dynamic-types')
+    def dynamic_types(self, request):
         """
         Dedicated route for virtual/calculated categories
-        URL: /api/v2/measurement-category/dynamic/
+        Returns a list of available dynamic calculation types from the model Enum.
+        URL: /api/v2/measurement-category/dynamic-types/
         """
-        data = [
-            {
-                'id': -1, 
-                'name': 'BMI', 
-                'unit': 'kg/m²', 
-                'is_dynamic': True
-            }
-            # easy to append more objects here later
+        choices = [
+            {"value": choice.value, "label": choice.label}
+            for choice in Category.DynamicType
         ]
-        return Response(data)
+        return Response(choices)
 
 
 class MeasurementViewSet(WgerOwnerObjectModelViewSet):
@@ -149,18 +150,26 @@ def list(self, request, *args, **kwargs):
         Intercept requests for dynamic categories before the filterset blocks them
         """
         category_id = request.query_params.get('category')
-        is_dynamic = request.query_params.get('is_dynamic')
-
-        print(request.query_params)
-        print("is_dynamic", is_dynamic)
-
-        if category_id == '19':
-            bmi_data = calculate_bmi(request.user)
-            return Response({
-                        "count": len(bmi_data),
-                        "next": None,
-                        "previous": None,
-                        "results": bmi_data
-                    })
+
+        if category_id:
+            try:
+                # look up the category and check its enum value
+                category = Category.objects.get(id=category_id, user=request.user)
+                
+                if category.dynamic_type != Category.DynamicType.NONE:
+                    calc_func = DYNAMIC_REGISTRY.get(category.dynamic_type)
+                    
+                    if calc_func:
+                        # execute the math function and wrap it in the DRF pagination envelope
+                        data = calc_func(request.user, category_id)
+                        return Response({
+                            "count": len(data),
+                            "next": None,
+                            "previous": None,
+                            "results": data
+                        })
+            except (Category.DoesNotExist, ValueError):
+                # fallback to standard behavior
+                pass
 
         return super().list(request, *args, **kwargs)
\ No newline at end of file
diff --git a/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py b/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
new file mode 100644
index 0000000000..e0b3c0dd17
--- /dev/null
+++ b/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
@@ -0,0 +1,22 @@
+# Generated by Django 5.2.14 on 2026-05-12 08:37
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('measurements', '0004_category_is_dynamic'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='category',
+            name='is_dynamic',
+        ),
+        migrations.AddField(
+            model_name='category',
+            name='dynamic_type',
+            field=models.CharField(choices=[('NONE', 'None'), ('BMI', 'Bmi'), ('SQUAT_1RM', 'Squat 1Rm')], db_index=True, default='NONE', max_length=20),
+        ),
+    ]
diff --git a/wger/measurements/models/category.py b/wger/measurements/models/category.py
index 845f9a9fb2..dd001788e3 100644
--- a/wger/measurements/models/category.py
+++ b/wger/measurements/models/category.py
@@ -41,10 +41,16 @@ class Meta:
         max_length=30,
     )
 
-    is_dynamic = models.BooleanField(
-        verbose_name='Is Dynamic',
-        default=False,
-        help_text='Indicates if this category is automatically calculated.',
+    class DynamicType(models.TextChoices):
+        NONE = 'NONE',
+        BMI = 'BMI',
+        # SQUAT_1RM = 'SQUAT_1RM', can be added in future
+
+    dynamic_type = models.CharField(
+        max_length=20,
+        choices=DynamicType.choices,
+        default=DynamicType.NONE,
+        db_index=True
     )
 
     def get_owner_object(self):

From ba75480f924f9308827c642e299d166ead5a3aab Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Tue, 12 May 2026 19:59:00 +0930
Subject: [PATCH 5/9] Add bmi tests

---
 wger/measurements/api/views.py                | 42 +++----------
 .../migrations/0004_category_is_dynamic.py    |  7 ++-
 ...tegory_is_dynamic_category_dynamic_type.py |  8 ++-
 wger/measurements/models/category.py          |  9 +--
 .../tests/test_dynamic_measurements.py        | 62 +++++++++++++++++++
 wger/measurements/utils/__init__.py           |  0
 wger/measurements/utils/bmi.py                | 41 ++++++++++++
 7 files changed, 126 insertions(+), 43 deletions(-)
 create mode 100644 wger/measurements/tests/test_dynamic_measurements.py
 create mode 100644 wger/measurements/utils/__init__.py
 create mode 100644 wger/measurements/utils/bmi.py

diff --git a/wger/measurements/api/views.py b/wger/measurements/api/views.py
index b628458d40..4ab4d4f194 100644
--- a/wger/measurements/api/views.py
+++ b/wger/measurements/api/views.py
@@ -37,33 +37,12 @@
     Category,
     Measurement,
 )
+from wger.measurements.utils.bmi import calculate_bmi
 from wger.utils.viewsets import WgerOwnerObjectModelViewSet
 
 
 logger = logging.getLogger(__name__)
 
-def calculate_bmi(user, category_id):
-    from wger.weight.models import WeightEntry
-    
-    profile = getattr(user, 'userprofile', None)
-    if not profile or not profile.height or profile.height <= 0:
-        return []
-
-    # height_sq will be a float
-    height_sq = (profile.height / 100) ** 2
-    
-    weights = WeightEntry.objects.filter(user=user).order_by('date')
-
-    return [
-        {
-            'id': w.id, # Use integer IDs so the frontend state manager doesn't complain
-            'category': int(category_id), # Link it to the requested category
-            'date': w.date.isoformat() if hasattr(w.date, 'isoformat') else w.date,
-            'value': round(float(w.weight) / height_sq, 2),
-            'notes': 'Auto-calculated from weight entry'
-        }
-        for w in weights
-    ]
 
 # Map the dynamic_type enum to the math function
 DYNAMIC_REGISTRY = {
@@ -71,6 +50,7 @@ def calculate_bmi(user, category_id):
     # add squat 1rm later
 }
 
+
 class CategoryViewSet(WgerOwnerObjectModelViewSet):
     """
     API endpoint for measurement units
@@ -112,8 +92,7 @@ def dynamic_types(self, request):
         URL: /api/v2/measurement-category/dynamic-types/
         """
         choices = [
-            {"value": choice.value, "label": choice.label}
-            for choice in Category.DynamicType
+            {'value': choice.value, 'label': choice.label} for choice in Category.DynamicType
         ]
         return Response(choices)
 
@@ -155,21 +134,18 @@ def list(self, request, *args, **kwargs):
             try:
                 # look up the category and check its enum value
                 category = Category.objects.get(id=category_id, user=request.user)
-                
+
                 if category.dynamic_type != Category.DynamicType.NONE:
                     calc_func = DYNAMIC_REGISTRY.get(category.dynamic_type)
-                    
+
                     if calc_func:
                         # execute the math function and wrap it in the DRF pagination envelope
                         data = calc_func(request.user, category_id)
-                        return Response({
-                            "count": len(data),
-                            "next": None,
-                            "previous": None,
-                            "results": data
-                        })
+                        return Response(
+                            {'count': len(data), 'next': None, 'previous': None, 'results': data}
+                        )
             except (Category.DoesNotExist, ValueError):
                 # fallback to standard behavior
                 pass
 
-        return super().list(request, *args, **kwargs)
\ No newline at end of file
+        return super().list(request, *args, **kwargs)
diff --git a/wger/measurements/migrations/0004_category_is_dynamic.py b/wger/measurements/migrations/0004_category_is_dynamic.py
index f5d40d81e8..16f7f3ab8c 100644
--- a/wger/measurements/migrations/0004_category_is_dynamic.py
+++ b/wger/measurements/migrations/0004_category_is_dynamic.py
@@ -4,7 +4,6 @@
 
 
 class Migration(migrations.Migration):
-
     dependencies = [
         ('measurements', '0003_alter_measurement_unique_together_and_more'),
     ]
@@ -13,6 +12,10 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='category',
             name='is_dynamic',
-            field=models.BooleanField(default=False, help_text='Indicates if this category is automatically calculated.', verbose_name='Is Dynamic'),
+            field=models.BooleanField(
+                default=False,
+                help_text='Indicates if this category is automatically calculated.',
+                verbose_name='Is Dynamic',
+            ),
         ),
     ]
diff --git a/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py b/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
index e0b3c0dd17..3a129e59e3 100644
--- a/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
+++ b/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
@@ -4,7 +4,6 @@
 
 
 class Migration(migrations.Migration):
-
     dependencies = [
         ('measurements', '0004_category_is_dynamic'),
     ]
@@ -17,6 +16,11 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='category',
             name='dynamic_type',
-            field=models.CharField(choices=[('NONE', 'None'), ('BMI', 'Bmi'), ('SQUAT_1RM', 'Squat 1Rm')], db_index=True, default='NONE', max_length=20),
+            field=models.CharField(
+                choices=[('NONE', 'None'), ('BMI', 'Bmi'), ('SQUAT_1RM', 'Squat 1Rm')],
+                db_index=True,
+                default='NONE',
+                max_length=20,
+            ),
         ),
     ]
diff --git a/wger/measurements/models/category.py b/wger/measurements/models/category.py
index dd001788e3..bf57f595f3 100644
--- a/wger/measurements/models/category.py
+++ b/wger/measurements/models/category.py
@@ -42,15 +42,12 @@ class Meta:
     )
 
     class DynamicType(models.TextChoices):
-        NONE = 'NONE',
-        BMI = 'BMI',
+        NONE = ('NONE',)
+        BMI = ('BMI',)
         # SQUAT_1RM = 'SQUAT_1RM', can be added in future
 
     dynamic_type = models.CharField(
-        max_length=20,
-        choices=DynamicType.choices,
-        default=DynamicType.NONE,
-        db_index=True
+        max_length=20, choices=DynamicType.choices, default=DynamicType.NONE, db_index=True
     )
 
     def get_owner_object(self):
diff --git a/wger/measurements/tests/test_dynamic_measurements.py b/wger/measurements/tests/test_dynamic_measurements.py
new file mode 100644
index 0000000000..d725f02668
--- /dev/null
+++ b/wger/measurements/tests/test_dynamic_measurements.py
@@ -0,0 +1,62 @@
+# Standard Library
+import unittest
+from unittest.mock import (
+    MagicMock,
+    patch,
+)
+
+# wger
+from wger.measurements.utils.bmi import calculate_bmi
+
+
+class BMILogicTest(unittest.TestCase):
+    """
+    Pure unit test for BMI math logic.
+    Bypasses Django database and wger signals.
+    """
+
+    @patch('wger.weight.models.WeightEntry.objects.filter')
+    def test_calculate_bmi_math(self, mock_filter):
+        user = MagicMock()
+        user.userprofile.height = 180  # 1.8m
+
+        weight_entry = MagicMock()
+        weight_entry.weight = 80.0
+        weight_entry.date = '2026-05-12'
+
+        mock_filter.return_value.order_by.return_value = [weight_entry]
+
+        results = calculate_bmi(user, category_id=99)
+
+        # 80 / (1.8 * 1.8) = 24.69
+        self.assertEqual(len(results), 1)
+        self.assertEqual(results[0]['value'], 24.69)
+        self.assertEqual(results[0]['category'], 99)
+
+    def test_calculate_bmi_missing_height(self):
+        user = MagicMock()
+        user.userprofile.height = None
+
+        results = calculate_bmi(user, category_id=99)
+        self.assertEqual(results, [])
+
+    @patch('wger.weight.models.WeightEntry.objects.filter')
+    def test_calculate_bmi_multiple_entries(self, mock_filter):
+        user = MagicMock()
+        user.userprofile.height = 175  # 1.75m
+
+        w1 = MagicMock(weight=70.0, date='2026-05-01')
+        w2 = MagicMock(weight=75.0, date='2026-05-10')
+
+        mock_filter.return_value.order_by.return_value = [w1, w2]
+
+        results = calculate_bmi(user, category_id=99)
+
+        # 70 / 1.75^2 = 22.86
+        self.assertEqual(results[0]['value'], 22.86)
+        # 75 / 1.75^2 = 24.49
+        self.assertEqual(results[1]['value'], 24.49)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/wger/measurements/utils/__init__.py b/wger/measurements/utils/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wger/measurements/utils/bmi.py b/wger/measurements/utils/bmi.py
new file mode 100644
index 0000000000..8f4e1bc9e0
--- /dev/null
+++ b/wger/measurements/utils/bmi.py
@@ -0,0 +1,41 @@
+# -*- coding: utf-8 -*-
+
+# This file is part of wger Workout Manager.
+#
+# wger Workout Manager is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# wger Workout Manager is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with Workout Manager.  If not, see <http://www.gnu.org/licenses/>.
+
+
+def calculate_bmi(user, category_id):
+    # wger
+    from wger.weight.models import WeightEntry
+
+    profile = getattr(user, 'userprofile', None)
+    if not profile or not profile.height or profile.height <= 0:
+        return []
+
+    # height_sq will be a float
+    height_sq = (profile.height / 100) ** 2
+
+    weights = WeightEntry.objects.filter(user=user).order_by('date')
+
+    return [
+        {
+            'id': w.id,  # Use integer IDs so the frontend state manager doesn't complain
+            'category': int(category_id),  # Link it to the requested category
+            'date': w.date.isoformat() if hasattr(w.date, 'isoformat') else w.date,
+            'value': round(float(w.weight) / height_sq, 2),
+            'notes': 'Auto-calculated from weight entry',
+        }
+        for w in weights
+    ]

From d95cf3cb24d9f9eea95d373fb9839bd1ec327347 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Tue, 12 May 2026 20:07:21 +0930
Subject: [PATCH 6/9] Update changelog

---
 CHANGELOG.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00659285f0..559c3be29c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,3 +12,10 @@
   this makes refresh tokens single-use and lets a leaked token live only until
   the next refresh call. It's recommended to update your `prod.env` and set
   `REFRESH_TOKEN_LIFETIME` to a value like 3000.
+
+* Add support for dynamic measurement categories. The (`/api/v2/measurement/`) endpoint now
+  intercepts requests for dynamic categories (such as BMI) and auto-calculates the
+  results on-the-fly using existing user data (e.g., profile height and weight entries).
+  A new endpoint at (`/api/v2/measurement-category/dynamic-types/`) has been added to
+  expose the available dynamic options.
+  An enum is used for the different options and can be extended for more dynamic types.
\ No newline at end of file

From bdff4715c2ef786f04d55cc15723e11de6e30175 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Fri, 15 May 2026 18:04:54 +0930
Subject: [PATCH 7/9] Use pagination, add params for dynamic calculations,
 squash migrations

---
 wger/measurements/api/serializers.py          |  2 +-
 wger/measurements/api/views.py                | 15 ++++++---
 ...ry_dynamic_params_category_dynamic_type.py | 31 +++++++++++++++++++
 .../migrations/0004_category_is_dynamic.py    | 21 -------------
 ...tegory_is_dynamic_category_dynamic_type.py | 26 ----------------
 wger/measurements/models/category.py          |  4 +++
 wger/measurements/utils/bmi.py                |  8 ++---
 7 files changed, 50 insertions(+), 57 deletions(-)
 create mode 100644 wger/measurements/migrations/0004_category_dynamic_params_category_dynamic_type.py
 delete mode 100644 wger/measurements/migrations/0004_category_is_dynamic.py
 delete mode 100644 wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py

diff --git a/wger/measurements/api/serializers.py b/wger/measurements/api/serializers.py
index 3dd10b56f7..92d3629583 100644
--- a/wger/measurements/api/serializers.py
+++ b/wger/measurements/api/serializers.py
@@ -33,7 +33,7 @@ class UnitSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Category
-        fields = ('id', 'name', 'unit', 'dynamic_type')
+        fields = ('id', 'name', 'unit', 'dynamic_type', 'dynamic_params')
 
 
 class MeasurementSerializer(serializers.ModelSerializer):
diff --git a/wger/measurements/api/views.py b/wger/measurements/api/views.py
index 4ab4d4f194..09d4dba974 100644
--- a/wger/measurements/api/views.py
+++ b/wger/measurements/api/views.py
@@ -139,11 +139,16 @@ def list(self, request, *args, **kwargs):
                     calc_func = DYNAMIC_REGISTRY.get(category.dynamic_type)
 
                     if calc_func:
-                        # execute the math function and wrap it in the DRF pagination envelope
-                        data = calc_func(request.user, category_id)
-                        return Response(
-                            {'count': len(data), 'next': None, 'previous': None, 'results': data}
-                        )
+                        # get the raw list of calculated dictionaries
+                        raw_data = calc_func(request.user, category_id)
+
+                        # paginate the list
+                        page = self.paginate_queryset(raw_data)
+                        if page is not None:
+                            return self.get_paginated_response(page)
+
+                        # fallback
+                        return Response(raw_data)
             except (Category.DoesNotExist, ValueError):
                 # fallback to standard behavior
                 pass
diff --git a/wger/measurements/migrations/0004_category_dynamic_params_category_dynamic_type.py b/wger/measurements/migrations/0004_category_dynamic_params_category_dynamic_type.py
new file mode 100644
index 0000000000..92ecc96790
--- /dev/null
+++ b/wger/measurements/migrations/0004_category_dynamic_params_category_dynamic_type.py
@@ -0,0 +1,31 @@
+# Generated by Django 5.2.14 on 2026-05-15 08:13
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('measurements', '0003_alter_measurement_unique_together_and_more'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='category',
+            name='dynamic_params',
+            field=models.JSONField(
+                blank=True,
+                default=dict,
+                help_text='Configuration parameters for dynamic calculations',
+            ),
+        ),
+        migrations.AddField(
+            model_name='category',
+            name='dynamic_type',
+            field=models.CharField(
+                choices=[('NONE', 'None'), ('BMI', 'Bmi')],
+                db_index=True,
+                default='NONE',
+                max_length=20,
+            ),
+        ),
+    ]
diff --git a/wger/measurements/migrations/0004_category_is_dynamic.py b/wger/measurements/migrations/0004_category_is_dynamic.py
deleted file mode 100644
index 16f7f3ab8c..0000000000
--- a/wger/measurements/migrations/0004_category_is_dynamic.py
+++ /dev/null
@@ -1,21 +0,0 @@
-# Generated by Django 5.2.14 on 2026-05-11 06:22
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-    dependencies = [
-        ('measurements', '0003_alter_measurement_unique_together_and_more'),
-    ]
-
-    operations = [
-        migrations.AddField(
-            model_name='category',
-            name='is_dynamic',
-            field=models.BooleanField(
-                default=False,
-                help_text='Indicates if this category is automatically calculated.',
-                verbose_name='Is Dynamic',
-            ),
-        ),
-    ]
diff --git a/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py b/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
deleted file mode 100644
index 3a129e59e3..0000000000
--- a/wger/measurements/migrations/0005_remove_category_is_dynamic_category_dynamic_type.py
+++ /dev/null
@@ -1,26 +0,0 @@
-# Generated by Django 5.2.14 on 2026-05-12 08:37
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-    dependencies = [
-        ('measurements', '0004_category_is_dynamic'),
-    ]
-
-    operations = [
-        migrations.RemoveField(
-            model_name='category',
-            name='is_dynamic',
-        ),
-        migrations.AddField(
-            model_name='category',
-            name='dynamic_type',
-            field=models.CharField(
-                choices=[('NONE', 'None'), ('BMI', 'Bmi'), ('SQUAT_1RM', 'Squat 1Rm')],
-                db_index=True,
-                default='NONE',
-                max_length=20,
-            ),
-        ),
-    ]
diff --git a/wger/measurements/models/category.py b/wger/measurements/models/category.py
index bf57f595f3..5bb8f5b8f5 100644
--- a/wger/measurements/models/category.py
+++ b/wger/measurements/models/category.py
@@ -50,6 +50,10 @@ class DynamicType(models.TextChoices):
         max_length=20, choices=DynamicType.choices, default=DynamicType.NONE, db_index=True
     )
 
+    dynamic_params = models.JSONField(
+        default=dict, blank=True, help_text='Configuration parameters for dynamic calculations'
+    )
+
     def get_owner_object(self):
         """
         Returns the object that has owner information
diff --git a/wger/measurements/utils/bmi.py b/wger/measurements/utils/bmi.py
index 8f4e1bc9e0..fc32181a41 100644
--- a/wger/measurements/utils/bmi.py
+++ b/wger/measurements/utils/bmi.py
@@ -20,7 +20,7 @@ def calculate_bmi(user, category_id):
     # wger
     from wger.weight.models import WeightEntry
 
-    profile = getattr(user, 'userprofile', None)
+    profile = user.userprofile
     if not profile or not profile.height or profile.height <= 0:
         return []
 
@@ -31,9 +31,9 @@ def calculate_bmi(user, category_id):
 
     return [
         {
-            'id': w.id,  # Use integer IDs so the frontend state manager doesn't complain
-            'category': int(category_id),  # Link it to the requested category
-            'date': w.date.isoformat() if hasattr(w.date, 'isoformat') else w.date,
+            'id': w.id,
+            'category': int(category_id),  # link it to the requested category
+            'date': w.date.isoformat(),
             'value': round(float(w.weight) / height_sq, 2),
             'notes': 'Auto-calculated from weight entry',
         }

From d81ec7c494f62d60957b9f48bef19fb12a7d64c6 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Fri, 15 May 2026 18:31:35 +0930
Subject: [PATCH 8/9] Add validation for jsonschema of dynamic params

---
 wger/measurements/api/serializers.py | 40 ++++++++++++++++++++++++++++
 wger/measurements/models/category.py |  2 +-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/wger/measurements/api/serializers.py b/wger/measurements/api/serializers.py
index 92d3629583..c07c33d71d 100644
--- a/wger/measurements/api/serializers.py
+++ b/wger/measurements/api/serializers.py
@@ -17,6 +17,7 @@
 from decimal import Decimal
 
 # Third Party
+import jsonschema
 from rest_framework import serializers
 
 # wger
@@ -35,6 +36,45 @@ class Meta:
         model = Category
         fields = ('id', 'name', 'unit', 'dynamic_type', 'dynamic_params')
 
+    def validate(self, data):
+        """
+        Validate the dynamic_params JSON matches the required schema for the selected dynamic_type.
+        """
+        # get type and params
+        dynamic_type = data.get(
+            'dynamic_type', getattr(self.instance, 'dynamic_type', Category.DynamicType.NONE)
+        )
+        dynamic_params = data.get('dynamic_params', getattr(self.instance, 'dynamic_params', {}))
+
+        # if dynamic type is none, just clear params to avoid excessive validation
+        if dynamic_type == Category.DynamicType.NONE:
+            data['dynamic_params'] = {}
+            return super().validate(data)
+
+        # define the allowed JSON structures
+        schemas = {
+            Category.DynamicType.BMI: {
+                'type': 'object',
+                'additionalProperties': False,
+            },
+            # when one rep max is added it can go here
+            # Category.DynamicType.ONE_REP_MAX: {
+            #     "type": "object",
+            #     "properties": {"exercise_id": {"type": "integer"}, "max_reps": {"type": "integer"}},
+            #     "required": ["exercise_id"],
+            #     "additionalProperties": False
+            # }
+        }
+
+        schema = schemas.get(dynamic_type)
+        if schema:
+            try:
+                jsonschema.validate(instance=dynamic_params, schema=schema)
+            except jsonschema.exceptions.ValidationError as e:
+                raise serializers.ValidationError({'dynamic_params': e.message})
+
+        return super().validate(data)
+
 
 class MeasurementSerializer(serializers.ModelSerializer):
     """
diff --git a/wger/measurements/models/category.py b/wger/measurements/models/category.py
index 5bb8f5b8f5..cc6a064814 100644
--- a/wger/measurements/models/category.py
+++ b/wger/measurements/models/category.py
@@ -44,7 +44,7 @@ class Meta:
     class DynamicType(models.TextChoices):
         NONE = ('NONE',)
         BMI = ('BMI',)
-        # SQUAT_1RM = 'SQUAT_1RM', can be added in future
+        # ONE_REP_MAX = ('ONE_REP_MAX'), can be added in future
 
     dynamic_type = models.CharField(
         max_length=20, choices=DynamicType.choices, default=DynamicType.NONE, db_index=True

From e978f141b62ec0abe95821e403433c03ad9e2855 Mon Sep 17 00:00:00 2001
From: Dylan Smith <dylan.npsmith@gmail.com>
Date: Mon, 18 May 2026 19:40:27 +0930
Subject: [PATCH 9/9] Repair tests for previous changes

---
 .../tests/test_dynamic_measurements.py        | 24 +++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/wger/measurements/tests/test_dynamic_measurements.py b/wger/measurements/tests/test_dynamic_measurements.py
index d725f02668..b2556e81fa 100644
--- a/wger/measurements/tests/test_dynamic_measurements.py
+++ b/wger/measurements/tests/test_dynamic_measurements.py
@@ -1,4 +1,20 @@
+# This file is part of wger Workout Manager.
+#
+# wger Workout Manager is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# wger Workout Manager is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with Workout Manager.  If not, see <http://www.gnu.org/licenses/>.
+
 # Standard Library
+import datetime
 import unittest
 from unittest.mock import (
     MagicMock,
@@ -22,7 +38,7 @@ def test_calculate_bmi_math(self, mock_filter):
 
         weight_entry = MagicMock()
         weight_entry.weight = 80.0
-        weight_entry.date = '2026-05-12'
+        weight_entry.date = datetime.date(2026, 5, 12)
 
         mock_filter.return_value.order_by.return_value = [weight_entry]
 
@@ -45,8 +61,8 @@ def test_calculate_bmi_multiple_entries(self, mock_filter):
         user = MagicMock()
         user.userprofile.height = 175  # 1.75m
 
-        w1 = MagicMock(weight=70.0, date='2026-05-01')
-        w2 = MagicMock(weight=75.0, date='2026-05-10')
+        w1 = MagicMock(weight=70.0, date=datetime.date(2026, 5, 1))
+        w2 = MagicMock(weight=75.0, date=datetime.date(2026, 5, 10))
 
         mock_filter.return_value.order_by.return_value = [w1, w2]
 
@@ -59,4 +75,4 @@ def test_calculate_bmi_multiple_entries(self, mock_filter):
 
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main()
\ No newline at end of file