diff --git a/config_state/config_state.py b/config_state/config_state.py
index 6318266..7645bc8 100644
--- a/config_state/config_state.py
+++ b/config_state/config_state.py
@@ -1167,8 +1167,8 @@ def config_summary(self):
 
     def get_nested_config(object: Any):
       if isinstance(object, ConfigState):
-        config = dict([(k, get_nested_config(getattr(object, k)))
-                       for k in object._config_fields.keys()])
+        config = dict([(k, get_nested_config(v._value_))
+                       for k, v in object._config_fields.items()])
         return config
       else:
         return str(object)
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..13652f1
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,29 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "config-state"
+version = "1.0.2"
+authors = [
+    { name = "Nicolas Pinchaud", email = "nicolas.pinchaud@gmail.com" },
+]
+description = """
+config-state is a Python module that helps implement classes using the ConfigState pattern.
+This pattern enhances classes by:
+  1.Adding structured configuration management
+  2.Providing state handling capabilities
+  3.Enabling object creation from configuration files
+  4.Offering fine-grained control over how objects are serialized and deserialized"""
+readme = "README.md"
+requires-python = ">=3.7"
+dependencies = [
+    "pyyaml",
+]
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "Operating System :: OS Independent",
+]
+
+[tool.setuptools.packages.find]
+exclude = ["tests", "examples"]
\ No newline at end of file
diff --git a/setup.py b/setup.py
deleted file mode 100644
index e81b80b..0000000
--- a/setup.py
+++ /dev/null
@@ -1,26 +0,0 @@
-import setuptools
-
-with open("README.md", "r") as fh:
-  long_description = fh.read()
-
-setuptools.setup(
-    name="config-state",
-    version="1.0.2",
-    author="Nicolas Pinchaud",
-    author_email="nicolas.pinchaud@gmail.com",
-    description="config-state is a Python module for implementing classes with "
-    "the `ConfigState` pattern. The pattern augments classes with  "
-    "configuration and state semantics enabling their "
-    "instantiation through configuration files together with an "
-    "improved control over their (de)serialization logics.",
-    long_description=long_description,
-    long_description_content_type="text/markdown",
-    url="https://github.com/nicolaspi/config-state",
-    packages=setuptools.find_packages(exclude=('tests', 'examples')),
-    classifiers=[
-        "Programming Language :: Python :: 3",
-        "Operating System :: OS Independent",
-    ],
-    python_requires='>=3.7',
-    install_requires=['pyyaml'],
-)