diff --git a/dlt_init_openapi/config.py b/dlt_init_openapi/config.py
index f576970..0453fcc 100644
--- a/dlt_init_openapi/config.py
+++ b/dlt_init_openapi/config.py
@@ -49,8 +49,10 @@ class Config(BaseModel):
     """Which class to use for detecting"""
     global_limit: int = 0
     """Set a limit on how many items are emitted from a resource"""
-    parameter_default_value: str = "FILL_ME_IN"
+    required_parameter_default_value: str = "FILL_ME_IN"
     """default to render for required parameters that do not have a default in the spec"""
+    unrequired_parameter_default_value: str = "OPTIONAL_CONFIG"
+    """default to render for unrequired parameters that do not have a default in the spec"""
     allow_openapi_2: bool = False
     """Allow to use OpenAPI 2 specs"""
 
diff --git a/dlt_init_openapi/parser/endpoints.py b/dlt_init_openapi/parser/endpoints.py
index 87b00d2..9a7ba94 100644
--- a/dlt_init_openapi/parser/endpoints.py
+++ b/dlt_init_openapi/parser/endpoints.py
@@ -123,27 +123,36 @@ def unresolvable_path_param_names(self) -> List[str]:
         return [p for p in params if p != transformer_param]
 
     @property
-    def unresolvable_query_param_names(self) -> List[str]:
+    def unresolvable_query_params(self) -> List[Parameter]:
         """returns a list of required query param names with params that are used by the paginator excluded"""
+        print("HERE")
         paginator_params = self.detected_pagination.param_names if self.detected_pagination else []
-        query_param_names = []
+        query_params: List[Parameter] = []
         for param in self.list_all_parameters:
             if param.name not in paginator_params and param.location == "query":
-                query_param_names.append(param.name)
-        return query_param_names
+                query_params.append(param)
+        return query_params
 
-    def is_query_param_required(self, param_name: str) -> bool:
-        for key, p in self.parameters.items():
-            if p.name == param_name and p.location == "query":
-                return p.required
-        return False
+    @property
+    def unresolvable_required_query_param_names(self) -> List[str]:
+        """returns a list of required query param names with params that are used by the paginator excluded"""
+        return [param.name for param in self.unresolvable_query_params if param.required]
+
+    @property
+    def unresolvable_unrequired_query_param_names(self) -> List[str]:
+        return [param.name for param in self.unresolvable_query_params if not param.required]
 
     def default_for_param(self, location: Literal["path", "query"], param_name: str) -> str:
         """get's a default value for the given param, returns"""
+        param: Parameter = None
         for key, p in self.parameters.items():
-            if p.name == param_name and p.location == location and p.default:
-                return p.default
-        return self.context.config.parameter_default_value
+            if p.name == param_name and p.location == location:
+                param = p
+        if param and param.default:
+            return param.default
+        if not param or param.required or location == "path":
+            return self.context.config.required_parameter_default_value
+        return self.context.config.unrequired_parameter_default_value
 
     @property
     def render_description(self) -> Optional[str]:
diff --git a/dlt_init_openapi/renderer/default/templates/source.py.j2 b/dlt_init_openapi/renderer/default/templates/source.py.j2
index 5e85a65..3131835 100644
--- a/dlt_init_openapi/renderer/default/templates/source.py.j2
+++ b/dlt_init_openapi/renderer/default/templates/source.py.j2
@@ -60,7 +60,7 @@ def {{ source_name }}(
                 "data_selector": "{{ endpoint.data_json_path }}",
                 {% endif %}
                 "path": "{{endpoint.path }}",
-                {% if endpoint.transformer or endpoint.unresolvable_path_param_names or endpoint.unresolvable_query_param_names %}
+                {% if endpoint.transformer or endpoint.unresolvable_path_param_names or endpoint.unresolvable_query_params %}
                 "params": {
                     {% if endpoint.transformer %}
                     {% for key, value in endpoint.transformer.path_params_mapping.items()%}
@@ -72,11 +72,18 @@ def {{ source_name }}(
                     {% endfor %}
                     {% endif %}
                     {% for param_name in endpoint.unresolvable_path_param_names %}
-                    "{{param_name}}": "{{ endpoint.default_for_param('path', param_name) }}", # TODO: fill in path parameter
+                    "{{param_name}}": "{{ endpoint.default_for_param('path', param_name) }}", # TODO: fill in required path parameter
                     {% endfor %}
-                    {% for param_name in endpoint.unresolvable_query_param_names %}
-                    {% if not endpoint.is_query_param_required(param_name) %}# {% endif %}"{{param_name}}": "{{ endpoint.default_for_param('query', param_name) }}", # TODO: fill in query parameter
+                    {% for param_name in endpoint.unresolvable_required_query_param_names %}
+                    "{{param_name}}": "{{ endpoint.default_for_param('query', param_name) }}", # TODO: fill in required query parameter
                     {% endfor %}
+                    {% if endpoint.unresolvable_unrequired_query_param_names %}
+                    # the parameters below can optionally be configured
+                    {% for param_name in endpoint.unresolvable_unrequired_query_param_names %}
+                    # "{{param_name}}": "{{ endpoint.default_for_param('query', param_name) }}",
+                    {% endfor %}
+                    {% endif %}
+
                 },
                 {% endif %}
                 {% if endpoint.render_pagination_args %}
diff --git a/tests/integration/basics/test_params.py b/tests/integration/basics/test_params.py
index 650a337..26f9367 100644
--- a/tests/integration/basics/test_params.py
+++ b/tests/integration/basics/test_params.py
@@ -5,7 +5,7 @@
 from dlt_init_openapi.config import Config
 from tests.integration.utils import get_indexed_resources
 
-DEFAULT_VALUE = Config().parameter_default_value
+DEFAULT_VALUE = Config().required_parameter_default_value
 
 
 @pytest.fixture(scope="module")