diff --git a/packages/repository-json-schema/src/filter-json-schema.ts b/packages/repository-json-schema/src/filter-json-schema.ts
index 9ced979baaa7..14ac016221e1 100644
--- a/packages/repository-json-schema/src/filter-json-schema.ts
+++ b/packages/repository-json-schema/src/filter-json-schema.ts
@@ -93,7 +93,26 @@ export function getFilterJsonSchemaFor(
       minimum: 1,
       examples: [100],
     },
-
+    sum: {
+      type: 'string',
+      examples: ['column1'],
+    },
+    min: {
+      type: 'string',
+      examples: ['column1'],
+    },
+    max: {
+      type: 'string',
+      examples: ['column1'],
+    },
+    avg: {
+      type: 'string',
+      examples: ['column1'],
+    },
+    count: {
+      type: 'string',
+      examples: ['column1'],
+    },
     skip: {
       type: 'integer',
       minimum: 0,
@@ -120,6 +139,9 @@ export function getFilterJsonSchemaFor(
   if (!excluded.includes('fields')) {
     properties.fields = getFieldsJsonSchemaFor(modelCtor, options);
   }
+  if (!excluded.includes('groupBy')) {
+    properties.fields = getGroupByJsonSchemaFor(modelCtor, options);
+  }
 
   // Remove excluded properties
   for (const p of excluded) {
@@ -235,3 +257,37 @@ export function getFieldsJsonSchemaFor(
 
   return schema;
 }
+
+export function getGroupByJsonSchemaFor(
+  modelCtor: typeof Model,
+  options: FilterSchemaOptions = {},
+): JsonSchema {
+  const schema: JsonSchema = {oneOf: []};
+  if (options.setTitle !== false) {
+    schema.title = `${modelCtor.modelName}.GroupBy`;
+  }
+
+  const properties = Object.keys(modelCtor.definition.properties);
+  const additionalProperties = modelCtor.definition.settings.strict === false;
+
+  schema.oneOf?.push({
+    type: 'object',
+    properties: properties.reduce(
+      (prev, crr) => ({...prev, [crr]: {type: 'boolean'}}),
+      {},
+    ),
+    additionalProperties,
+  });
+
+  schema.oneOf?.push({
+    type: 'array',
+    items: {
+      type: 'string',
+      enum: properties.length && !additionalProperties ? properties : undefined,
+      examples: properties,
+    },
+    uniqueItems: true,
+  });
+
+  return schema;
+}
diff --git a/packages/repository/src/repositories/legacy-juggler-bridge.ts b/packages/repository/src/repositories/legacy-juggler-bridge.ts
index 3df52ed95514..2f89a34514a8 100644
--- a/packages/repository/src/repositories/legacy-juggler-bridge.ts
+++ b/packages/repository/src/repositories/legacy-juggler-bridge.ts
@@ -739,7 +739,7 @@ export class DefaultCrudRepository<
   }
 
   protected toEntity<R extends T>(model: juggler.PersistedModel): R {
-    return new this.entityClass(model.toObject()) as R;
+    return new this.entityClass(model.toObject({onlySchema: false})) as R;
   }
 
   protected toEntities<R extends T>(models: juggler.PersistedModel[]): R[] {