fix: merge same-key operator dicts in AND metadata filters (#4853)

mem0/memory/main.py

@@ -1271,6 +1271,14 @@ class Memory(MemoryBase):
                     raise ValueError(f"Unsupported metadata filter operator: {operator}")
             return result
 
+        def merge_filters(target: Dict[str, Any], source: Dict[str, Any]) -> None:
+            """Merge source into target, deep-merging nested operator dicts for the same key."""
+            for key, value in source.items():
+                if key in target and isinstance(target[key], dict) and isinstance(value, dict):
+                    target[key].update(value)
+                else:
+                    target[key] = value
+
         for key, value in metadata_filters.items():
             if key == "AND":
                 # Logical AND: combine multiple conditions
@@ -1278,7 +1286,7 @@ class Memory(MemoryBase):
                     raise ValueError("AND operator requires a list of conditions")
                 for condition in value:
                     for sub_key, sub_value in condition.items():
-                        processed_filters.update(process_condition(sub_key, sub_value))
+                        merge_filters(processed_filters, process_condition(sub_key, sub_value))
             elif key == "OR":
                 # Logical OR: Pass through to vector store for implementation-specific handling
                 if not isinstance(value, list) or not value:
@@ -1288,7 +1296,7 @@ class Memory(MemoryBase):
                 for condition in value:
                     or_condition = {}
                     for sub_key, sub_value in condition.items():
-                        or_condition.update(process_condition(sub_key, sub_value))
+                        merge_filters(or_condition, process_condition(sub_key, sub_value))
                     processed_filters["$or"].append(or_condition)
             elif key == "NOT":
                 # Logical NOT: Pass through to vector store for implementation-specific handling
@@ -1298,10 +1306,10 @@ class Memory(MemoryBase):
                 for condition in value:
                     not_condition = {}
                     for sub_key, sub_value in condition.items():
-                        not_condition.update(process_condition(sub_key, sub_value))
+                        merge_filters(not_condition, process_condition(sub_key, sub_value))
                     processed_filters["$not"].append(not_condition)
             else:
-                processed_filters.update(process_condition(key, value))
+                merge_filters(processed_filters, process_condition(key, value))
 
         return processed_filters
 
@@ -2682,6 +2690,14 @@ class AsyncMemory(MemoryBase):
                     raise ValueError(f"Unsupported metadata filter operator: {operator}")
             return result
 
+        def merge_filters(target: Dict[str, Any], source: Dict[str, Any]) -> None:
+            """Merge source into target, deep-merging nested operator dicts for the same key."""
+            for key, value in source.items():
+                if key in target and isinstance(target[key], dict) and isinstance(value, dict):
+                    target[key].update(value)
+                else:
+                    target[key] = value
+
         for key, value in metadata_filters.items():
             if key == "AND":
                 # Logical AND: combine multiple conditions
@@ -2689,7 +2705,7 @@ class AsyncMemory(MemoryBase):
                     raise ValueError("AND operator requires a list of conditions")
                 for condition in value:
                     for sub_key, sub_value in condition.items():
-                        processed_filters.update(process_condition(sub_key, sub_value))
+                        merge_filters(processed_filters, process_condition(sub_key, sub_value))
             elif key == "OR":
                 # Logical OR: Pass through to vector store for implementation-specific handling
                 if not isinstance(value, list) or not value:
@@ -2699,7 +2715,7 @@ class AsyncMemory(MemoryBase):
                 for condition in value:
                     or_condition = {}
                     for sub_key, sub_value in condition.items():
-                        or_condition.update(process_condition(sub_key, sub_value))
+                        merge_filters(or_condition, process_condition(sub_key, sub_value))
                     processed_filters["$or"].append(or_condition)
             elif key == "NOT":
                 # Logical NOT: Pass through to vector store for implementation-specific handling
@@ -2709,10 +2725,10 @@ class AsyncMemory(MemoryBase):
                 for condition in value:
                     not_condition = {}
                     for sub_key, sub_value in condition.items():
-                        not_condition.update(process_condition(sub_key, sub_value))
+                        merge_filters(not_condition, process_condition(sub_key, sub_value))
                     processed_filters["$not"].append(not_condition)
             else:
-                processed_filters.update(process_condition(key, value))
+                merge_filters(processed_filters, process_condition(key, value))
 
         return processed_filters
 

tests/test_memory.py

@@ -760,6 +760,38 @@ class TestProcessMetadataFiltersMerge:
             "score": {"gt": 0.5, "lt": 0.9},
         }
 
+    def test_and_same_key_different_operators_merged(self, mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory):
+        """AND with same key in separate conditions must merge operators (issue #4850)."""
+        memory = self._make_memory(mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory)
+        result = memory._process_metadata_filters({
+            "AND": [{"price": {"gt": 10}}, {"price": {"lt": 20}}]
+        })
+        assert result == {"price": {"gt": 10, "lt": 20}}
+
+    def test_and_same_key_three_operators_merged(self, mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory):
+        """AND with three conditions on the same key must merge all operators."""
+        memory = self._make_memory(mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory)
+        result = memory._process_metadata_filters({
+            "AND": [{"price": {"gte": 5}}, {"price": {"lte": 100}}, {"price": {"ne": 50}}]
+        })
+        assert result == {"price": {"gte": 5, "lte": 100, "ne": 50}}
+
+    def test_and_mixed_keys_with_same_key_overlap(self, mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory):
+        """AND with a mix of same-key and different-key conditions."""
+        memory = self._make_memory(mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory)
+        result = memory._process_metadata_filters({
+            "AND": [{"price": {"gt": 10}}, {"category": "electronics"}, {"price": {"lt": 20}}]
+        })
+        assert result == {"price": {"gt": 10, "lt": 20}, "category": "electronics"}
+
+    def test_and_simple_equality_no_merge(self, mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory):
+        """AND with simple equality values on the same key — last value wins."""
+        memory = self._make_memory(mock_sqlite, mock_llm_factory, mock_vector_factory, mock_embedder_factory)
+        result = memory._process_metadata_filters({
+            "AND": [{"status": "active"}, {"status": "pending"}]
+        })
+        assert result == {"status": "pending"}
+
 
 # --- Issue #3040: reset() should clean up graph database ---