diff --git a/pyproject.toml b/pyproject.toml
index fdeae87..a134928 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,6 +8,7 @@ requires-python = ">=3.13"
 dependencies = [
     "cryptography>=46.0.3",
     "jmespath>=1.0.1",
+    "jsonpath-ng>=1.7.0",
     "psutil>=7.0.0",
     "requests>=2.32.4",
 ]
@@ -28,6 +29,7 @@ build-backend = "hatchling.build"
 
 [dependency-groups]
 dev = [
+    "deepdiff>=8.6.1",
     "pytest>=8.4.1",
     "pytest-cov>=6.2.1",
 ]
diff --git a/src/corelibs/json_handling/json_helper.py b/src/corelibs/json_handling/json_helper.py
index 8411a53..6a80d82 100644
--- a/src/corelibs/json_handling/json_helper.py
+++ b/src/corelibs/json_handling/json_helper.py
@@ -5,6 +5,8 @@ json encoder for datetime
 from typing import Any
 from json import JSONEncoder, dumps
 from datetime import datetime, date
+import copy
+from jsonpath_ng import parse  # pyright: ignore[reportMissingTypeStubs, reportUnknownVariableType]
 
 
 # subclass JSONEncoder
@@ -41,4 +43,22 @@ def json_dumps(data: Any):
     """
     return dumps(data, ensure_ascii=False, default=str)
 
+
+def modify_with_jsonpath(data: dict[Any, Any], path: str, new_value: Any):
+    """
+    Modify dictionary using JSONPath (more powerful than JMESPath for modifications)
+    """
+    result = copy.deepcopy(data)
+    jsonpath_expr = parse(path)  # pyright: ignore[reportUnknownVariableType]
+
+    # Find and update all matches
+    matches = jsonpath_expr.find(result)  # pyright: ignore[reportUnknownMemberType, reportUnknownVariableType]
+    for match in matches:  # pyright: ignore[reportUnknownVariableType]
+        match.full_path.update(result, new_value)  # pyright: ignore[reportUnknownMemberType]
+
+    return result
+
+# __END__
+
+
 # __END__
diff --git a/test-run/json_handling/json_replace.py b/test-run/json_handling/json_replace.py
new file mode 100644
index 0000000..cb9c3fa
--- /dev/null
+++ b/test-run/json_handling/json_replace.py
@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+
+"""
+JSON content replace tets
+"""
+
+from deepdiff import DeepDiff
+from corelibs.debug_handling.dump_data import dump_data
+from corelibs.json_handling.json_helper import modify_with_jsonpath
+
+
+def main() -> None:
+    """
+    Comment
+    """
+    __data = {
+        'a': 'b',
+        'foobar': [1, 2, 'a'],
+        'bar': {
+            'a': 1,
+            'b': 'c'
+        },
+        'baz': [
+            {
+                'aa': 1,
+                'ab': 'cc'
+            },
+            {
+                'ba': 2,
+                'bb': 'dd'
+            },
+        ],
+        'foo': {
+            'a': [1, 2, 3],
+            'b': ['a', 'b', 'c']
+        }
+    }
+
+    # Modify some values using JSONPath
+    __replace_data = modify_with_jsonpath(__data, 'bar.a', 42)
+    __replace_data = modify_with_jsonpath(__replace_data, 'foo.b[1]', 'modified')
+    __replace_data = modify_with_jsonpath(__replace_data, 'baz[0].ab', 'changed')
+
+    print(f"Original Data:\n{dump_data(__data)}\n")
+    print(f"Modified Data:\n{dump_data(__replace_data)}\n")
+    print(f"Differences:\n{dump_data(DeepDiff(__data, __replace_data, verbose_level=2))}\n")
+
+
+if __name__ == "__main__":
+    main()
+
+# __END__
diff --git a/tests/unit/json_handling/__init__.py b/tests/unit/json_handling/__init__.py
new file mode 100644
index 0000000..796f6f3
--- /dev/null
+++ b/tests/unit/json_handling/__init__.py
@@ -0,0 +1,3 @@
+"""
+tests for json_handling module
+"""
diff --git a/tests/unit/json_handling/test_json_helper.py b/tests/unit/json_handling/test_json_helper.py
new file mode 100644
index 0000000..8df3276
--- /dev/null
+++ b/tests/unit/json_handling/test_json_helper.py
@@ -0,0 +1,698 @@
+"""
+tests for corelibs.json_handling.json_helper
+"""
+
+import json
+from datetime import datetime, date
+from typing import Any
+from corelibs.json_handling.json_helper import (
+    DateTimeEncoder,
+    default,
+    json_dumps,
+    modify_with_jsonpath
+)
+
+
+# MARK: DateTimeEncoder tests
+class TestDateTimeEncoder:
+    """Test cases for DateTimeEncoder class"""
+
+    def test_datetime_encoding(self):
+        """Test encoding datetime objects"""
+        dt = datetime(2025, 10, 23, 15, 30, 45, 123456)
+        data = {"timestamp": dt}
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["timestamp"] == "2025-10-23T15:30:45.123456"
+
+    def test_date_encoding(self):
+        """Test encoding date objects"""
+        d = date(2025, 10, 23)
+        data = {"date": d}
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["date"] == "2025-10-23"
+
+    def test_mixed_datetime_date_encoding(self):
+        """Test encoding mixed datetime and date objects"""
+        dt = datetime(2025, 10, 23, 15, 30, 45)
+        d = date(2025, 10, 23)
+        data = {
+            "timestamp": dt,
+            "date": d,
+            "name": "test"
+        }
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["timestamp"] == "2025-10-23T15:30:45"
+        assert decoded["date"] == "2025-10-23"
+        assert decoded["name"] == "test"
+
+    def test_nested_datetime_encoding(self):
+        """Test encoding nested structures with datetime objects"""
+        data = {
+            "event": {
+                "name": "Meeting",
+                "start": datetime(2025, 10, 23, 10, 0, 0),
+                "end": datetime(2025, 10, 23, 11, 0, 0),
+                "participants": [
+                    {"name": "Alice", "joined": datetime(2025, 10, 23, 10, 5, 0)},
+                    {"name": "Bob", "joined": datetime(2025, 10, 23, 10, 10, 0)}
+                ]
+            }
+        }
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["event"]["start"] == "2025-10-23T10:00:00"
+        assert decoded["event"]["end"] == "2025-10-23T11:00:00"
+        assert decoded["event"]["participants"][0]["joined"] == "2025-10-23T10:05:00"
+        assert decoded["event"]["participants"][1]["joined"] == "2025-10-23T10:10:00"
+
+    def test_list_of_datetimes(self):
+        """Test encoding list of datetime objects"""
+        data = {
+            "timestamps": [
+                datetime(2025, 10, 23, 10, 0, 0),
+                datetime(2025, 10, 23, 11, 0, 0),
+                datetime(2025, 10, 23, 12, 0, 0)
+            ]
+        }
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["timestamps"][0] == "2025-10-23T10:00:00"
+        assert decoded["timestamps"][1] == "2025-10-23T11:00:00"
+        assert decoded["timestamps"][2] == "2025-10-23T12:00:00"
+
+    def test_encoder_with_normal_types(self):
+        """Test that encoder works with standard JSON types"""
+        data = {
+            "string": "test",
+            "number": 42,
+            "float": 3.14,
+            "boolean": True,
+            "null": None,
+            "list": [1, 2, 3],
+            "dict": {"key": "value"}
+        }
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded == data
+
+    def test_encoder_returns_none_for_unsupported_types(self):
+        """Test that encoder default method returns None for unsupported types"""
+        encoder = DateTimeEncoder()
+
+        # The default method should return None for non-date/datetime objects
+        result = encoder.default("string")
+        assert result is None
+
+        result = encoder.default(42)
+        assert result is None
+
+        result = encoder.default([1, 2, 3])
+        assert result is None
+
+
+# MARK: default function tests
+class TestDefaultFunction:
+    """Test cases for the default function"""
+
+    def test_default_datetime(self):
+        """Test default function with datetime"""
+        dt = datetime(2025, 10, 23, 15, 30, 45)
+        result = default(dt)
+        assert result == "2025-10-23T15:30:45"
+
+    def test_default_date(self):
+        """Test default function with date"""
+        d = date(2025, 10, 23)
+        result = default(d)
+        assert result == "2025-10-23"
+
+    def test_default_with_microseconds(self):
+        """Test default function with datetime including microseconds"""
+        dt = datetime(2025, 10, 23, 15, 30, 45, 123456)
+        result = default(dt)
+        assert result == "2025-10-23T15:30:45.123456"
+
+    def test_default_returns_none_for_other_types(self):
+        """Test that default returns None for non-date/datetime objects"""
+        assert default("string") is None
+        assert default(42) is None
+        assert default(3.14) is None
+        assert default(True) is None
+        assert default(None) is None
+        assert default([1, 2, 3]) is None
+        assert default({"key": "value"}) is None
+
+    def test_default_as_json_default_parameter(self):
+        """Test using default function as default parameter in json.dumps"""
+        data = {
+            "timestamp": datetime(2025, 10, 23, 15, 30, 45),
+            "date": date(2025, 10, 23),
+            "name": "test"
+        }
+
+        result = json.dumps(data, default=default)
+        decoded = json.loads(result)
+
+        assert decoded["timestamp"] == "2025-10-23T15:30:45"
+        assert decoded["date"] == "2025-10-23"
+        assert decoded["name"] == "test"
+
+
+# MARK: json_dumps tests
+class TestJsonDumps:
+    """Test cases for json_dumps function"""
+
+    def test_basic_dict(self):
+        """Test json_dumps with basic dictionary"""
+        data = {"name": "test", "value": 42}
+        result = json_dumps(data)
+        decoded = json.loads(result)
+        assert decoded == data
+
+    def test_unicode_characters(self):
+        """Test json_dumps preserves unicode characters (ensure_ascii=False)"""
+        data = {"name": "テスト", "emoji": "🎉", "chinese": "测试"}
+        result = json_dumps(data)
+
+        # ensure_ascii=False means unicode characters should be preserved
+        assert "テスト" in result
+        assert "🎉" in result
+        assert "测试" in result
+
+        decoded = json.loads(result)
+        assert decoded == data
+
+    def test_datetime_objects_as_string(self):
+        """Test json_dumps converts datetime to string (default=str)"""
+        dt = datetime(2025, 10, 23, 15, 30, 45)
+        data = {"timestamp": dt}
+
+        result = json_dumps(data)
+        decoded = json.loads(result)
+
+        # default=str will convert datetime to its string representation
+        assert isinstance(decoded["timestamp"], str)
+        assert "2025-10-23" in decoded["timestamp"]
+
+    def test_date_objects_as_string(self):
+        """Test json_dumps converts date to string"""
+        d = date(2025, 10, 23)
+        data = {"date": d}
+
+        result = json_dumps(data)
+        decoded = json.loads(result)
+
+        assert isinstance(decoded["date"], str)
+        assert "2025-10-23" in decoded["date"]
+
+    def test_complex_nested_structure(self):
+        """Test json_dumps with complex nested structures"""
+        data = {
+            "user": {
+                "name": "John",
+                "age": 30,
+                "active": True,
+                "balance": 100.50,
+                "tags": ["admin", "user"],
+                "metadata": {
+                    "created": datetime(2025, 1, 1, 0, 0, 0),
+                    "updated": date(2025, 10, 23)
+                }
+            },
+            "items": [
+                {"id": 1, "name": "Item 1"},
+                {"id": 2, "name": "Item 2"}
+            ]
+        }
+
+        result = json_dumps(data)
+        decoded = json.loads(result)
+
+        assert decoded["user"]["name"] == "John"
+        assert decoded["user"]["age"] == 30
+        assert decoded["user"]["active"] is True
+        assert decoded["user"]["balance"] == 100.50
+        assert decoded["user"]["tags"] == ["admin", "user"]
+        assert decoded["items"][0]["id"] == 1
+
+    def test_empty_dict(self):
+        """Test json_dumps with empty dictionary"""
+        data: dict[str, Any] = {}
+        result = json_dumps(data)
+        assert result == "{}"
+
+    def test_empty_list(self):
+        """Test json_dumps with empty list"""
+        data: list[Any] = []
+        result = json_dumps(data)
+        assert result == "[]"
+
+    def test_list_data(self):
+        """Test json_dumps with list as root element"""
+        data = [1, 2, 3, "test", True, None]
+        result = json_dumps(data)
+        decoded = json.loads(result)
+        assert decoded == data
+
+    def test_none_value(self):
+        """Test json_dumps with None"""
+        data = None
+        result = json_dumps(data)
+        assert result == "null"
+
+    def test_boolean_values(self):
+        """Test json_dumps with boolean values"""
+        data = {"true_val": True, "false_val": False}
+        result = json_dumps(data)
+        decoded = json.loads(result)
+        assert decoded["true_val"] is True
+        assert decoded["false_val"] is False
+
+    def test_numeric_values(self):
+        """Test json_dumps with various numeric values"""
+        data = {
+            "int": 42,
+            "float": 3.14,
+            "negative": -10,
+            "zero": 0,
+            "scientific": 1e10
+        }
+        result = json_dumps(data)
+        decoded = json.loads(result)
+        assert decoded == data
+
+    def test_custom_object_conversion(self):
+        """Test json_dumps with custom objects (converted via str)"""
+        class CustomObject:
+            """test class"""
+            def __str__(self):
+                return "custom_value"
+
+        data = {"custom": CustomObject()}
+        result = json_dumps(data)
+        decoded = json.loads(result)
+        assert decoded["custom"] == "custom_value"
+
+    def test_special_float_values(self):
+        """Test json_dumps handles special float values"""
+        data = {
+            "infinity": float('inf'),
+            "neg_infinity": float('-inf'),
+            "nan": float('nan')
+        }
+        result = json_dumps(data)
+        # These should be converted to strings via default=str
+        assert "Infinity" in result or "inf" in result.lower()
+
+
+# MARK: modify_with_jsonpath tests
+class TestModifyWithJsonpath:
+    """Test cases for modify_with_jsonpath function"""
+
+    def test_simple_path_modification(self):
+        """Test modifying a simple path"""
+        data = {"name": "old_name", "age": 30}
+        result = modify_with_jsonpath(data, "$.name", "new_name")
+
+        assert result["name"] == "new_name"
+        assert result["age"] == 30
+        # Original data should not be modified
+        assert data["name"] == "old_name"
+
+    def test_nested_path_modification(self):
+        """Test modifying nested path"""
+        data = {
+            "user": {
+                "profile": {
+                    "name": "John",
+                    "age": 30
+                }
+            }
+        }
+
+        result = modify_with_jsonpath(data, "$.user.profile.name", "Jane")
+
+        assert result["user"]["profile"]["name"] == "Jane"
+        assert result["user"]["profile"]["age"] == 30
+        # Original should be unchanged
+        assert data["user"]["profile"]["name"] == "John"
+
+    def test_array_index_modification(self):
+        """Test modifying array element by index"""
+        data = {
+            "items": [
+                {"id": 1, "name": "Item 1"},
+                {"id": 2, "name": "Item 2"},
+                {"id": 3, "name": "Item 3"}
+            ]
+        }
+
+        result = modify_with_jsonpath(data, "$.items[1].name", "Updated Item 2")
+
+        assert result["items"][1]["name"] == "Updated Item 2"
+        assert result["items"][0]["name"] == "Item 1"
+        assert result["items"][2]["name"] == "Item 3"
+        # Original unchanged
+        assert data["items"][1]["name"] == "Item 2"
+
+    def test_wildcard_modification(self):
+        """Test modifying multiple elements with wildcard"""
+        data = {
+            "users": [
+                {"name": "Alice", "active": True},
+                {"name": "Bob", "active": True},
+                {"name": "Charlie", "active": True}
+            ]
+        }
+
+        result = modify_with_jsonpath(data, "$.users[*].active", False)
+
+        # All active fields should be updated
+        for user in result["users"]:
+            assert user["active"] is False
+        # Original unchanged
+        for user in data["users"]:
+            assert user["active"] is True
+
+    def test_deep_copy_behavior(self):
+        """Test that modifications don't affect the original data"""
+        original = {
+            "level1": {
+                "level2": {
+                    "level3": {
+                        "value": "original"
+                    }
+                }
+            }
+        }
+
+        result = modify_with_jsonpath(original, "$.level1.level2.level3.value", "modified")
+
+        assert result["level1"]["level2"]["level3"]["value"] == "modified"
+        assert original["level1"]["level2"]["level3"]["value"] == "original"
+
+        # Verify deep copy by modifying nested dict in result
+        result["level1"]["level2"]["new_key"] = "new_value"
+        assert "new_key" not in original["level1"]["level2"]
+
+    def test_modify_to_different_type(self):
+        """Test changing value to different type"""
+        data = {"count": "10"}
+        result = modify_with_jsonpath(data, "$.count", 10)
+
+        assert result["count"] == 10
+        assert isinstance(result["count"], int)
+        assert data["count"] == "10"
+
+    def test_modify_to_complex_object(self):
+        """Test replacing value with complex object"""
+        data = {"simple": "value"}
+        new_value = {"complex": {"nested": "structure"}}
+
+        result = modify_with_jsonpath(data, "$.simple", new_value)
+
+        assert result["simple"] == new_value
+        assert result["simple"]["complex"]["nested"] == "structure"
+
+    def test_modify_to_list(self):
+        """Test replacing value with list"""
+        data = {"items": None}
+        result = modify_with_jsonpath(data, "$.items", [1, 2, 3])
+
+        assert result["items"] == [1, 2, 3]
+        assert data["items"] is None
+
+    def test_modify_to_none(self):
+        """Test setting value to None"""
+        data = {"value": "something"}
+        result = modify_with_jsonpath(data, "$.value", None)
+
+        assert result["value"] is None
+        assert data["value"] == "something"
+
+    def test_recursive_descent(self):
+        """Test using recursive descent operator"""
+        data: dict[str, Any] = {
+            "store": {
+                "book": [
+                    {"title": "Book 1", "price": 10},
+                    {"title": "Book 2", "price": 20}
+                ],
+                "bicycle": {
+                    "price": 100
+                }
+            }
+        }
+
+        # Update all prices
+        result = modify_with_jsonpath(data, "$..price", 0)
+
+        assert result["store"]["book"][0]["price"] == 0
+        assert result["store"]["book"][1]["price"] == 0
+        assert result["store"]["bicycle"]["price"] == 0
+        # Original unchanged
+        assert data["store"]["book"][0]["price"] == 10
+
+    def test_specific_array_elements(self):
+        """Test updating specific array elements by index"""
+        data = {
+            "products": [
+                {"name": "Product 1", "price": 100, "stock": 5},
+                {"name": "Product 2", "price": 200, "stock": 0},
+                {"name": "Product 3", "price": 150, "stock": 10}
+            ]
+        }
+
+        # Update first product's price
+        result = modify_with_jsonpath(data, "$.products[0].price", 0)
+
+        assert result["products"][0]["price"] == 0
+        assert result["products"][1]["price"] == 200  # not modified
+        assert result["products"][2]["price"] == 150  # not modified
+
+    def test_empty_dict(self):
+        """Test modifying empty dictionary"""
+        data: dict[str, Any] = {}
+        result = modify_with_jsonpath(data, "$.nonexistent", "value")
+
+        # Should return the original empty dict since path doesn't exist
+        assert result == {}
+
+    def test_complex_real_world_scenario(self):
+        """Test complex real-world modification scenario"""
+        data: dict[str, Any] = {
+            "api_version": "1.0",
+            "config": {
+                "database": {
+                    "host": "localhost",
+                    "port": 5432,
+                    "credentials": {
+                        "username": "admin",
+                        "password": "secret"
+                    }
+                },
+                "services": [
+                    {"name": "auth", "enabled": True, "port": 8001},
+                    {"name": "api", "enabled": True, "port": 8002},
+                    {"name": "cache", "enabled": False, "port": 8003}
+                ]
+            }
+        }
+
+        # Update database port
+        result = modify_with_jsonpath(data, "$.config.database.port", 5433)
+        assert result["config"]["database"]["port"] == 5433
+
+        # Update all service ports
+        result2 = modify_with_jsonpath(result, "$.config.services[*].enabled", True)
+        assert all(service["enabled"] for service in result2["config"]["services"])
+
+        # Original unchanged
+        assert data["config"]["database"]["port"] == 5432
+        assert data["config"]["services"][2]["enabled"] is False
+
+    def test_list_slice_modification(self):
+        """Test modifying list slice"""
+        data = {"numbers": [1, 2, 3, 4, 5]}
+
+        # Modify first three elements
+        result = modify_with_jsonpath(data, "$.numbers[0:3]", 0)
+
+        assert result["numbers"][0] == 0
+        assert result["numbers"][1] == 0
+        assert result["numbers"][2] == 0
+        assert result["numbers"][3] == 4
+        assert result["numbers"][4] == 5
+
+    def test_modify_with_datetime_value(self):
+        """Test modifying with datetime value"""
+        data = {"timestamp": "2025-01-01T00:00:00"}
+        new_datetime = datetime(2025, 10, 23, 15, 30, 45)
+
+        result = modify_with_jsonpath(data, "$.timestamp", new_datetime)
+
+        assert result["timestamp"] == new_datetime
+        assert isinstance(result["timestamp"], datetime)
+
+
+# MARK: Integration tests
+class TestIntegration:
+    """Integration tests combining multiple functions"""
+
+    def test_encoder_and_json_dumps_comparison(self):
+        """Test that DateTimeEncoder and json_dumps handle datetimes differently"""
+        dt = datetime(2025, 10, 23, 15, 30, 45)
+        data = {"timestamp": dt}
+
+        # Using DateTimeEncoder produces ISO format
+        with_encoder = json.dumps(data, cls=DateTimeEncoder)
+        decoded_encoder = json.loads(with_encoder)
+        assert decoded_encoder["timestamp"] == "2025-10-23T15:30:45"
+
+        # Using json_dumps (default=str) produces string representation
+        with_dumps = json_dumps(data)
+        decoded_dumps = json.loads(with_dumps)
+        assert isinstance(decoded_dumps["timestamp"], str)
+        assert "2025-10-23" in decoded_dumps["timestamp"]
+
+    def test_modify_and_serialize(self):
+        """Test modifying data and then serializing it"""
+        data = {
+            "event": {
+                "name": "Meeting",
+                "date": date(2025, 10, 23),
+                "attendees": [
+                    {"name": "Alice", "confirmed": False},
+                    {"name": "Bob", "confirmed": False}
+                ]
+            }
+        }
+
+        # Modify confirmation status
+        modified = modify_with_jsonpath(data, "$.event.attendees[*].confirmed", True)
+
+        # Serialize with datetime handling
+        serialized = json.dumps(modified, cls=DateTimeEncoder)
+        decoded = json.loads(serialized)
+
+        assert decoded["event"]["date"] == "2025-10-23"
+        assert decoded["event"]["attendees"][0]["confirmed"] is True
+        assert decoded["event"]["attendees"][1]["confirmed"] is True
+
+    def test_round_trip_with_modification(self):
+        """Test full round trip: serialize -> modify -> serialize"""
+        original = {
+            "config": {
+                "updated": datetime(2025, 10, 23, 15, 30, 45),
+                "version": "1.0"
+            }
+        }
+
+        # Serialize
+        json_str = json.dumps(original, cls=DateTimeEncoder)
+
+        # Deserialize
+        deserialized = json.loads(json_str)
+
+        # Modify
+        modified = modify_with_jsonpath(deserialized, "$.config.version", "2.0")
+
+        # Serialize again
+        final_json = json_dumps(modified)
+        final_data = json.loads(final_json)
+
+        assert final_data["config"]["version"] == "2.0"
+        assert final_data["config"]["updated"] == "2025-10-23T15:30:45"
+
+
+# MARK: Edge cases
+class TestEdgeCases:
+    """Test edge cases and error scenarios"""
+
+    def test_circular_reference_in_modify(self):
+        """Test that modify_with_jsonpath handles data without circular references"""
+        # Note: JSON doesn't support circular references, so we test normal nested data
+        data = {
+            "a": {
+                "b": {
+                    "c": "value"
+                }
+            }
+        }
+
+        result = modify_with_jsonpath(data, "$.a.b.c", "new_value")
+        assert result["a"]["b"]["c"] == "new_value"
+
+    def test_unicode_in_keys_and_values(self):
+        """Test handling unicode in both keys and values"""
+        data = {
+            "日本語": "テスト",
+            "emoji_🎉": "🚀",
+            "normal": "value"
+        }
+
+        result = json_dumps(data)
+        decoded = json.loads(result)
+
+        assert decoded["日本語"] == "テスト"
+        assert decoded["emoji_🎉"] == "🚀"
+        assert decoded["normal"] == "value"
+
+    def test_very_nested_structure(self):
+        """Test deeply nested structure"""
+        # Create a 10-level deep nested structure
+        data: dict[str, Any] = {"level0": {}}
+        current = data["level0"]
+        for i in range(1, 10):
+            current[f"level{i}"] = {}
+            current = current[f"level{i}"]
+        current["value"] = "deep_value"
+
+        result = modify_with_jsonpath(data, "$..value", "modified_deep_value")
+
+        # Navigate to the deep value
+        current = result["level0"]
+        for i in range(1, 10):
+            current = current[f"level{i}"]
+        assert current["value"] == "modified_deep_value"
+
+    def test_large_list_modification(self):
+        """Test modifying large list"""
+        data = {"items": [{"id": i, "value": i * 10} for i in range(100)]}
+
+        result = modify_with_jsonpath(data, "$.items[*].value", 0)
+
+        assert all(item["value"] == 0 for item in result["items"])
+        assert len(result["items"]) == 100
+
+    def test_mixed_date_types_encoding(self):
+        """Test encoding with both date and datetime in same structure"""
+        data = {
+            "created_date": date(2025, 10, 23),
+            "created_datetime": datetime(2025, 10, 23, 15, 30, 45),
+            "updated_date": date(2025, 10, 24),
+            "updated_datetime": datetime(2025, 10, 24, 16, 45, 30)
+        }
+
+        result = json.dumps(data, cls=DateTimeEncoder)
+        decoded = json.loads(result)
+
+        assert decoded["created_date"] == "2025-10-23"
+        assert decoded["created_datetime"] == "2025-10-23T15:30:45"
+        assert decoded["updated_date"] == "2025-10-24"
+        assert decoded["updated_datetime"] == "2025-10-24T16:45:30"
diff --git a/uv.lock b/uv.lock
index fc5c34f..74e2521 100644
--- a/uv.lock
+++ b/uv.lock
@@ -113,12 +113,14 @@ source = { editable = "." }
 dependencies = [
     { name = "cryptography" },
     { name = "jmespath" },
+    { name = "jsonpath-ng" },
     { name = "psutil" },
     { name = "requests" },
 ]
 
 [package.dev-dependencies]
 dev = [
+    { name = "deepdiff" },
     { name = "pytest" },
     { name = "pytest-cov" },
 ]
@@ -127,12 +129,14 @@ dev = [
 requires-dist = [
     { name = "cryptography", specifier = ">=46.0.3" },
     { name = "jmespath", specifier = ">=1.0.1" },
+    { name = "jsonpath-ng", specifier = ">=1.7.0" },
     { name = "psutil", specifier = ">=7.0.0" },
     { name = "requests", specifier = ">=2.32.4" },
 ]
 
 [package.metadata.requires-dev]
 dev = [
+    { name = "deepdiff", specifier = ">=8.6.1" },
     { name = "pytest", specifier = ">=8.4.1" },
     { name = "pytest-cov", specifier = ">=6.2.1" },
 ]
@@ -254,6 +258,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e8/cb/2da4cc83f5edb9c3257d09e1e7ab7b23f049c7962cae8d842bbef0a9cec9/cryptography-46.0.3-cp38-abi3-win_arm64.whl", hash = "sha256:d89c3468de4cdc4f08a57e214384d0471911a3830fcdaf7a8cc587e42a866372", size = 2918740, upload-time = "2025-10-15T23:18:12.277Z" },
 ]
 
+[[package]]
+name = "deepdiff"
+version = "8.6.1"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "orderly-set" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/19/76/36c9aab3d5c19a94091f7c6c6e784efca50d87b124bf026c36e94719f33c/deepdiff-8.6.1.tar.gz", hash = "sha256:ec56d7a769ca80891b5200ec7bd41eec300ced91ebcc7797b41eb2b3f3ff643a", size = 634054, upload-time = "2025-09-03T19:40:41.461Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/f7/e6/efe534ef0952b531b630780e19cabd416e2032697019d5295defc6ef9bd9/deepdiff-8.6.1-py3-none-any.whl", hash = "sha256:ee8708a7f7d37fb273a541fa24ad010ed484192cd0c4ffc0fa0ed5e2d4b9e78b", size = 91378, upload-time = "2025-09-03T19:40:39.679Z" },
+]
+
 [[package]]
 name = "idna"
 version = "3.11"
@@ -281,6 +297,27 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/31/b4/b9b800c45527aadd64d5b442f9b932b00648617eb5d63d2c7a6587b7cafc/jmespath-1.0.1-py3-none-any.whl", hash = "sha256:02e2e4cc71b5bcab88332eebf907519190dd9e6e82107fa7f83b1003a6252980", size = 20256, upload-time = "2022-06-17T18:00:10.251Z" },
 ]
 
+[[package]]
+name = "jsonpath-ng"
+version = "1.7.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "ply" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/6d/86/08646239a313f895186ff0a4573452038eed8c86f54380b3ebac34d32fb2/jsonpath-ng-1.7.0.tar.gz", hash = "sha256:f6f5f7fd4e5ff79c785f1573b394043b39849fb2bb47bcead935d12b00beab3c", size = 37838, upload-time = "2024-10-11T15:41:42.404Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/35/5a/73ecb3d82f8615f32ccdadeb9356726d6cae3a4bbc840b437ceb95708063/jsonpath_ng-1.7.0-py3-none-any.whl", hash = "sha256:f3d7f9e848cba1b6da28c55b1c26ff915dc9e0b1ba7e752a53d6da8d5cbd00b6", size = 30105, upload-time = "2024-11-20T17:58:30.418Z" },
+]
+
+[[package]]
+name = "orderly-set"
+version = "5.5.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/4a/88/39c83c35d5e97cc203e9e77a4f93bf87ec89cf6a22ac4818fdcc65d66584/orderly_set-5.5.0.tar.gz", hash = "sha256:e87185c8e4d8afa64e7f8160ee2c542a475b738bc891dc3f58102e654125e6ce", size = 27414, upload-time = "2025-07-10T20:10:55.885Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/12/27/fb8d7338b4d551900fa3e580acbe7a0cf655d940e164cb5c00ec31961094/orderly_set-5.5.0-py3-none-any.whl", hash = "sha256:46f0b801948e98f427b412fcabb831677194c05c3b699b80de260374baa0b1e7", size = 13068, upload-time = "2025-07-10T20:10:54.377Z" },
+]
+
 [[package]]
 name = "packaging"
 version = "25.0"
@@ -299,6 +336,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/54/20/4d324d65cc6d9205fabedc306948156824eb9f0ee1633355a8f7ec5c66bf/pluggy-1.6.0-py3-none-any.whl", hash = "sha256:e920276dd6813095e9377c0bc5566d94c932c33b27a3e3945d8389c374dd4746", size = 20538, upload-time = "2025-05-15T12:30:06.134Z" },
 ]
 
+[[package]]
+name = "ply"
+version = "3.11"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/e5/69/882ee5c9d017149285cab114ebeab373308ef0f874fcdac9beb90e0ac4da/ply-3.11.tar.gz", hash = "sha256:00c7c1aaa88358b9c765b6d3000c6eec0ba42abca5351b095321aef446081da3", size = 159130, upload-time = "2018-02-15T19:01:31.097Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/a3/58/35da89ee790598a0700ea49b2a66594140f44dec458c07e8e3d4979137fc/ply-3.11-py2.py3-none-any.whl", hash = "sha256:096f9b8350b65ebd2fd1346b12452efe5b9607f7482813ffca50c22722a807ce", size = 49567, upload-time = "2018-02-15T19:01:27.172Z" },
+]
+
 [[package]]
 name = "psutil"
 version = "7.1.1"