diff --git a/.gitignore b/.gitignore
index 5d37faf..7a24f86 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,6 +44,7 @@ coverage.xml
 htmlcov/
 .pytest_cache/
 .mypy_cache/
+*,cover
 
 # Mac
 .DS_Store
diff --git a/TODO.md b/TODO.md
index 222ccd8..0cff1f3 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,49 +1,31 @@
 # Project TODO and Notes
 
-## Refactoring TODOs
+## TODOs:
 
-- Typing
+- PyPi deployment
 
-  - Try to get rid of `Optional[Dict[str, Any]]` args
+- For all `create_...`methods, add the ID from the response to logs and maybe
+  something human readable, like the first n characters of the name??. Right
+  now:
+
+```log
+[2025-02-05 06:09:34,828] INFO [fitbit_client.NutritionResource] create_food_log succeeded for foods/log.json (status 201)
+```
 
 - base.py: reorganize and see what we can move out.
 
   - Rename to `_base`? Files it first, makes it clearer that everything in it is
     private
-  - Move the methods for building `curl` commands into a mixin? It's a lot of
-    code for an isolated and tightly scoped feature.
-  - refactor `_make_request`.
-    - do we need both `data` and `json`? Also, could we simplify a lot of typing
-      if we separated GET, POST, and DELETE methods? Maybe even a separate,
-      second non-auth GET? Could use `@overload`
-    - we had to makee a `ParamDict` type in `nutrition.py`. Use this everywhere?
-    - start by looking at how many methods use which params
 
 - client.py:
 
   - Creat and Test that all methods have an alias in `Client` and that the
     signatures match
 
-```python
-if not food_id and not (food_name and calories):
-    raise ClientValidationException(
-        "Must provide either food_id or (food_name and calories)"
-    )
-```
-
-- nutrition.py:
-- It doesn't seem like this should be passing tests when CALORIES is not an int:
+- CI:
 
-```python
-        # Handle both enum and string nutritional values
-       for key, value in nutritional_values.items():
-           if isinstance(key, NutritionalValue):
-               params[key.value] = float(value)
-           else:
-               params[str(key)] = float(value)
-```
-
-see: test_create_food_calories_from_fat_must_be_integer(nutrition_resource)
+* Read and implement:
+  https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/configuring-advanced-setup-for-code-scanning#configuring-advanced-setup-for-code-scanning-with-codeql
 
 - exceptions.py Consider:
   - Add automatic token refresh for ExpiredTokenException
@@ -77,14 +59,6 @@ see: test_create_food_calories_from_fat_must_be_integer(nutrition_resource)
     be reused.
   - We may need a public version of a generic `make_request` method.
 
-- For all `create_...`methods, add the ID from the response to logs and maybe
-  something human readable, like the first n characters of the name??. Right
-  now:
-
-```log
-[2025-02-05 06:09:34,828] INFO [fitbit_client.NutritionResource] create_food_log succeeded for foods/log.json (status 201)
-```
-
 - Form to change scopes are part of OAuth flow? Maybe get rid of the cut and
   paste method altogether? It's less to test...
 
@@ -101,19 +75,4 @@ see: test_create_food_calories_from_fat_must_be_integer(nutrition_resource)
     one. (there might be several of these that make sense--just take an ID and
     then the signature of the "create" method).
 
-- PyPI deployment
-
 - Enum for units? (it'll be big, maybe just common ones?)
-
-## CI/CD/Linting
-
-- GitHub Actions Setup
-
-  - Linting
-    - black
-    - isort
-    - mdformat
-    - mypy
-  - Test running (TBD)
-  - Coverage reporting (TBD)
-  - Automated PyPI deployment
diff --git a/fitbit_client/exceptions.py b/fitbit_client/exceptions.py
index 708df35..721848c 100644
--- a/fitbit_client/exceptions.py
+++ b/fitbit_client/exceptions.py
@@ -6,6 +6,9 @@
 from typing import List
 from typing import Optional
 
+# Local imports
+from fitbit_client.utils.types import JSONDict
+
 
 class FitbitAPIException(Exception):
     """Base exception for all Fitbit API errors"""
@@ -15,7 +18,7 @@ def __init__(
         message: str,
         error_type: str,
         status_code: Optional[int] = None,
-        raw_response: Optional[Dict[str, Any]] = None,
+        raw_response: Optional[JSONDict] = None,
         field_name: Optional[str] = None,
     ):
         self.message = message
diff --git a/fitbit_client/resources/activity.py b/fitbit_client/resources/activity.py
index 9114cd9..83f9f29 100644
--- a/fitbit_client/resources/activity.py
+++ b/fitbit_client/resources/activity.py
@@ -18,6 +18,7 @@
 from fitbit_client.utils.pagination_validation import validate_pagination_params
 from fitbit_client.utils.types import JSONDict
 from fitbit_client.utils.types import JSONList
+from fitbit_client.utils.types import ParamDict
 
 
 class ActivityResource(BaseResource):
@@ -88,7 +89,7 @@ def create_activity_goals(
                 field_name="value",
             )
 
-        params = {"type": type.value, "value": value}
+        params: ParamDict = {"type": type.value, "value": value}
         result = self._make_request(
             f"activities/goals/{period.value}.json",
             params=params,
@@ -152,24 +153,26 @@ def create_activity_log(
             - Start time should be in 24-hour format (e.g., "14:30" for 2:30 PM)
         """
         if activity_id:
-            params = {
+            activity_params: ParamDict = {
                 "activityId": activity_id,
                 "startTime": start_time,
                 "durationMillis": duration_millis,
                 "date": date,
             }
             if distance is not None:
-                params["distance"] = distance
+                activity_params["distance"] = distance
                 if distance_unit:
-                    params["distanceUnit"] = distance_unit
+                    activity_params["distanceUnit"] = distance_unit
+            params = activity_params
         elif activity_name and manual_calories:
-            params = {
+            name_params: ParamDict = {
                 "activityName": activity_name,
                 "manualCalories": manual_calories,
                 "startTime": start_time,
                 "durationMillis": duration_millis,
                 "date": date,
             }
+            params = name_params
         else:
             raise MissingParameterException(
                 message="Must provide either activity_id or (activity_name and manual_calories)",
@@ -229,7 +232,7 @@ def get_activity_log_list(
             - The source field indicates whether the activity was logged manually by the user
               or automatically by a Fitbit device
         """
-        params = {"sort": sort.value, "limit": limit, "offset": offset}
+        params: ParamDict = {"sort": sort.value, "limit": limit, "offset": offset}
         if before_date:
             params["beforeDate"] = before_date
         if after_date:
@@ -651,7 +654,9 @@ def get_activity_tcx(
             - Not all activities have TCX data available (e.g., manually logged activities)
             - To check if an activity has GPS data, look for hasGps=True in the activity log
         """
-        params = {"includePartialTCX": include_partial_tcx} if include_partial_tcx else None
+        params: Optional[ParamDict] = (
+            {"includePartialTCX": include_partial_tcx} if include_partial_tcx else None
+        )
         result = self._make_request(
             f"activities/{log_id}.tcx", params=params, user_id=user_id, debug=debug
         )
diff --git a/fitbit_client/resources/base.py b/fitbit_client/resources/base.py
index e423e26..4bf1be0 100644
--- a/fitbit_client/resources/base.py
+++ b/fitbit_client/resources/base.py
@@ -11,6 +11,7 @@
 from typing import Optional
 from typing import Set
 from typing import cast
+from typing import overload
 from urllib.parse import urlencode
 
 # Third party imports
@@ -21,7 +22,12 @@
 from fitbit_client.exceptions import ERROR_TYPE_EXCEPTIONS
 from fitbit_client.exceptions import FitbitAPIException
 from fitbit_client.exceptions import STATUS_CODE_EXCEPTIONS
+from fitbit_client.utils.curl_debug_mixin import CurlDebugMixin
+from fitbit_client.utils.types import FormDataDict
+from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import JSONList
 from fitbit_client.utils.types import JSONType
+from fitbit_client.utils.types import ParamDict
 
 # Constants for important fields to track in logging
 IMPORTANT_RESPONSE_FIELDS: Set[str] = {
@@ -41,7 +47,7 @@
 }
 
 
-class BaseResource:
+class BaseResource(CurlDebugMixin):
     """Provides foundational functionality for all Fitbit API resource classes.
 
     The BaseResource class implements core functionality that all specific resource
@@ -61,7 +67,7 @@ class BaseResource:
      - Request handling with comprehensive error management
      - Response parsing with type safety
      - Detailed logging of requests, responses, and errors
-     - Debug capabilities for API troubleshooting
+     - Debug capabilities for API troubleshooting (via CurlDebugMixin)
      - OAuth2 authentication management
 
     Note:
@@ -134,7 +140,7 @@ def _build_url(
             return f"{self.API_BASE}/{api_version}/user/{user_id}/{endpoint}"
         return f"{self.API_BASE}/{api_version}/{endpoint}"
 
-    def _extract_important_fields(self, data: Dict[str, JSONType]) -> Dict[str, int | str]:
+    def _extract_important_fields(self, data: JSONDict) -> Dict[str, JSONType]:
         """
         Extract important fields from response data for logging.
 
@@ -150,7 +156,7 @@ def _extract_important_fields(self, data: Dict[str, JSONType]) -> Dict[str, int
         """
         extracted = {}
 
-        def extract_recursive(d: Dict[str, Any], prefix: str = "") -> None:
+        def extract_recursive(d: JSONDict, prefix: str = "") -> None:
             for key, value in d.items():
                 full_key = f"{prefix}.{key}" if prefix else key
 
@@ -189,69 +195,6 @@ def _get_calling_method(self) -> str:
             frame = frame.f_back
         return "unknown"
 
-    def _build_curl_command(
-        self,
-        url: str,
-        http_method: str,
-        data: Optional[Dict[str, Any]] = None,
-        json: Optional[Dict[str, Any]] = None,
-        params: Optional[Dict[str, Any]] = None,
-    ) -> str:
-        """
-        Build a curl command string for debugging API requests.
-        
-        Args:
-            url: Full API URL
-            http_method: HTTP method (GET, POST, DELETE)
-            data: Optional form data for POST requests
-            json: Optional JSON data for POST requests
-            params: Optional query parameters for GET requests
-            
-        Returns:
-            Complete curl command as a multi-line string
-
-        The generated command includes:
-        - The HTTP method (for non-GET requests)
-        - Authorization header with OAuth token
-        - Request body (if data or json is provided)
-        - Query parameters (if provided)
-        
-        The command is formatted with line continuations for readability and
-        can be copied directly into a terminal for testing.
-
-        Example output:
-            curl \\
-              -X POST \\
-              -H "Authorization: Bearer <token>" \\
-              -H "Content-Type: application/json" \\
-              -d '{"name": "value"}' \\
-              'https://api.fitbit.com/1/user/-/foods/log.json'
-        """
-        # Start with base command
-        cmd_parts = ["curl -v"]
-
-        # Add method
-        if http_method != "GET":
-            cmd_parts.append(f"-X {http_method}")
-
-        # Add auth header
-        cmd_parts.append(f'-H "Authorization: Bearer {self.oauth.token["access_token"]}"')
-
-        # Add data if present
-        if json:
-            cmd_parts.append(f"-d '{dumps(json)}'")
-            cmd_parts.append('-H "Content-Type: application/json"')
-        elif data:
-            cmd_parts.append(f"-d '{urlencode(data)}'")
-            cmd_parts.append('-H "Content-Type: application/x-www-form-urlencoded"')
-
-        # Add URL with parameters if present
-        if params:
-            url = f"{url}?{urlencode(params)}"
-        cmd_parts.append(f"'{url}'")
-
-        return " \\\n  ".join(cmd_parts)
-
     def _log_response(
         self, calling_method: str, endpoint: str, response: Response, content: Optional[Dict] = None
     ) -> None:
@@ -391,10 +334,10 @@ def _handle_error_response(self, response: Response) -> None:
     def _make_request(
         self,
         endpoint: str,
-        data: Optional[Dict[str, Any]] = None,
-        json: Optional[Dict[str, Any]] = None,
-        params: Optional[Dict[str, Any]] = None,
-        headers: Dict[str, Any] = {},
+        data: Optional[FormDataDict] = None,
+        json: Optional[JSONDict] = None,
+        params: Optional[ParamDict] = None,
+        headers: Dict[str, str] = {},
         user_id: str = "-",
         requires_user_id: bool = True,
         http_method: str = "GET",
@@ -421,7 +364,7 @@ def _make_request(
 
         Returns:
             JSONType: The API response in one of these formats:
-                - Dict[str, Any]: For most JSON object responses
+                - JSONDict: For most JSON object responses
                 - List[Any]: For endpoints that return JSON arrays
                 - str: For XML/TCX responses
                 - None: For successful DELETE operations or debug mode
diff --git a/fitbit_client/resources/body.py b/fitbit_client/resources/body.py
index 42cc63b..fceae50 100644
--- a/fitbit_client/resources/body.py
+++ b/fitbit_client/resources/body.py
@@ -9,6 +9,7 @@
 from fitbit_client.resources.constants import BodyGoalType
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class BodyResource(BaseResource):
@@ -101,7 +102,7 @@ def create_bodyfat_log(
             The 'source' field will be set to "API" for entries created through this endpoint.
             Multiple entries can be logged for the same day with different timestamps.
         """
-        params = {"fat": fat, "date": date}
+        params: ParamDict = {"fat": fat, "date": date}
         if time:
             params["time"] = time
         result = self._make_request(
@@ -151,7 +152,7 @@ def create_weight_goal(
             - If target > start: "GAIN"
             - If target = start: "MAINTAIN"
         """
-        params = {"startDate": start_date, "startWeight": start_weight}
+        params: ParamDict = {"startDate": start_date, "startWeight": start_weight}
         if weight is not None:
             params["weight"] = weight
         result = self._make_request(
@@ -208,7 +209,7 @@ def create_weight_log(
             The 'source' field will be set to "API" for entries created through this endpoint.
             Multiple weight entries can be logged for the same day with different timestamps.
         """
-        params = {"weight": weight, "date": date}
+        params: ParamDict = {"weight": weight, "date": date}
         if time:
             params["time"] = time
         result = self._make_request(
diff --git a/fitbit_client/resources/electrocardiogram.py b/fitbit_client/resources/electrocardiogram.py
index dc058d3..df4de3f 100644
--- a/fitbit_client/resources/electrocardiogram.py
+++ b/fitbit_client/resources/electrocardiogram.py
@@ -12,6 +12,7 @@
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.pagination_validation import validate_pagination_params
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class ElectrocardiogramResource(BaseResource):
@@ -56,7 +57,7 @@ def get_ecg_log_list(
         offset: int = 0,
         user_id: str = "-",
         debug: bool = False,
-    ) -> Dict[str, Any]:
+    ) -> JSONDict:
         """Returns a list of user's ECG log entries before or after a given day.
 
         API Reference: https://dev.fitbit.com/build/reference/web-api/electrocardiogram/get-ecg-log-list/
@@ -92,7 +93,7 @@ def get_ecg_log_list(
             - resultClassification indicates the assessment outcome (normal, afib, inconclusive)
             - For research purposes only, not for clinical or diagnostic use
         """
-        params = {"sort": sort.value, "limit": limit, "offset": offset}
+        params: ParamDict = {"sort": sort.value, "limit": limit, "offset": offset}
 
         if before_date:
             params["beforeDate"] = before_date
diff --git a/fitbit_client/resources/heartrate_timeseries.py b/fitbit_client/resources/heartrate_timeseries.py
index aa7d8e7..2d89c48 100644
--- a/fitbit_client/resources/heartrate_timeseries.py
+++ b/fitbit_client/resources/heartrate_timeseries.py
@@ -12,6 +12,7 @@
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.date_validation import validate_date_range_params
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class HeartrateTimeSeriesResource(BaseResource):
@@ -105,7 +106,7 @@ def get_heartrate_timeseries_by_date(
                 message="Only 'UTC' timezone is supported", field_name="timezone"
             )
 
-        params = {"timezone": timezone} if timezone else None
+        params: Optional[ParamDict] = {"timezone": timezone} if timezone else None
         result = self._make_request(
             f"activities/heart/date/{date}/{period.value}.json",
             params=params,
@@ -169,7 +170,7 @@ def get_heartrate_timeseries_by_date_range(
                 message="Only 'UTC' timezone is supported", field_name="timezone"
             )
 
-        params = {"timezone": timezone} if timezone else None
+        params: Optional[ParamDict] = {"timezone": timezone} if timezone else None
         result = self._make_request(
             f"activities/heart/date/{start_date}/{end_date}.json",
             params=params,
diff --git a/fitbit_client/resources/irregular_rhythm_notifications.py b/fitbit_client/resources/irregular_rhythm_notifications.py
index 5b072b8..db2ef9c 100644
--- a/fitbit_client/resources/irregular_rhythm_notifications.py
+++ b/fitbit_client/resources/irregular_rhythm_notifications.py
@@ -10,6 +10,7 @@
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.pagination_validation import validate_pagination_params
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class IrregularRhythmNotificationsResource(BaseResource):
@@ -93,7 +94,7 @@ def get_irn_alerts_list(
             - The alertTime is when the notification was generated, while detectedTime is
               when the irregular rhythm was detected (usually during sleep)
         """
-        params = {"sort": sort.value, "limit": limit, "offset": offset}
+        params: ParamDict = {"sort": sort.value, "limit": limit, "offset": offset}
 
         if before_date:
             params["beforeDate"] = before_date
diff --git a/fitbit_client/resources/nutrition.py b/fitbit_client/resources/nutrition.py
index 695c432..ed70e09 100644
--- a/fitbit_client/resources/nutrition.py
+++ b/fitbit_client/resources/nutrition.py
@@ -384,10 +384,15 @@ def create_meal(
             Food IDs can be obtained from food search results or the user's custom foods.
         """
         # snakes to camels
-        foods = [{to_camel_case(k): v for k, v in d.items()} for d in foods]
-        data = {"name": name, "description": description, "mealFoods": foods}
+        foods_list = [{to_camel_case(k): v for k, v in d.items()} for d in foods]
+        # Use cast to handle the complex structure
+        data_dict = {"name": name, "description": description, "mealFoods": foods_list}
         result = self._make_request(
-            "meals.json", json=data, user_id=user_id, http_method="POST", debug=debug
+            "meals.json",
+            json=cast(JSONDict, data_dict),
+            user_id=user_id,
+            http_method="POST",
+            debug=debug,
         )
         return cast(JSONDict, result)
 
@@ -1179,10 +1184,15 @@ def update_meal(
             Meal IDs can be obtained from the get_meals method. Updating a meal does not
             affect any food logs that were previously created using this meal.
         """
-        foods = [{to_camel_case(k): v for k, v in d.items()} for d in foods]
-        data = {"name": name, "description": description, "mealFoods": foods}
+        foods_list = [{to_camel_case(k): v for k, v in d.items()} for d in foods]
+        # Use cast to handle the complex structure
+        data_dict = {"name": name, "description": description, "mealFoods": foods_list}
         result = self._make_request(
-            f"meals/{meal_id}.json", json=data, user_id=user_id, http_method="POST", debug=debug
+            f"meals/{meal_id}.json",
+            json=cast(JSONDict, data_dict),
+            user_id=user_id,
+            http_method="POST",
+            debug=debug,
         )
         return cast(JSONDict, result)
 
diff --git a/fitbit_client/resources/sleep.py b/fitbit_client/resources/sleep.py
index 3d4457c..02fe6f2 100644
--- a/fitbit_client/resources/sleep.py
+++ b/fitbit_client/resources/sleep.py
@@ -14,6 +14,7 @@
 from fitbit_client.utils.date_validation import validate_date_range_params
 from fitbit_client.utils.pagination_validation import validate_pagination_params
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class SleepResource(BaseResource):
@@ -124,7 +125,7 @@ def create_sleep_log(
                 message="duration_millis must be positive", field_name="duration_millis"
             )
 
-        params = {"startTime": start_time, "duration": duration_millis, "date": date}
+        params: ParamDict = {"startTime": start_time, "duration": duration_millis, "date": date}
         result = self._make_request(
             "sleep.json",
             params=params,
@@ -355,7 +356,7 @@ def get_sleep_log_list(
 
             This endpoint uses API version 1.2, unlike most other Fitbit API endpoints.
         """
-        params = {"sort": sort.value, "limit": limit, "offset": offset}
+        params: ParamDict = {"sort": sort.value, "limit": limit, "offset": offset}
         if before_date:
             params["beforeDate"] = before_date
         if after_date:
diff --git a/fitbit_client/resources/user.py b/fitbit_client/resources/user.py
index 2a6efaf..cb4b13f 100644
--- a/fitbit_client/resources/user.py
+++ b/fitbit_client/resources/user.py
@@ -11,6 +11,7 @@
 from fitbit_client.resources.constants import StartDayOfWeek
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
 
 
 class UserResource(BaseResource):
@@ -173,7 +174,8 @@ def update_profile(
             "strideLengthRunning": stride_length_running,
         }
 
-        params = {key: value for key, value in updates.items() if value is not None}
+        # Create a ParamDict from the non-None values
+        params: ParamDict = {key: value for key, value in updates.items() if value is not None}
         result = self._make_request(
             "profile.json", params=params, user_id=user_id, http_method="POST", debug=debug
         )
diff --git a/fitbit_client/utils/curl_debug_mixin.py b/fitbit_client/utils/curl_debug_mixin.py
new file mode 100644
index 0000000..43855e5
--- /dev/null
+++ b/fitbit_client/utils/curl_debug_mixin.py
@@ -0,0 +1,94 @@
+# fitbit_client/utils/curl_debug_mixin.py
+
+"""
+Mixin for generating curl commands for API debugging.
+"""
+
+# Standard library imports
+from json import dumps
+from typing import Optional
+from urllib.parse import urlencode
+
+# Local imports
+from fitbit_client.utils.types import FormDataDict
+from fitbit_client.utils.types import JSONDict
+from fitbit_client.utils.types import ParamDict
+
+
+class CurlDebugMixin:
+    """Mixin that provides curl command generation for debugging API requests.
+
+    This mixin can be used with API client classes to add the ability to generate
+    equivalent curl commands for debugging purposes. It helps with:
+    - Testing API endpoints directly
+    - Debugging authentication/scope issues
+    - Verifying request structure
+    - Troubleshooting permission problems
+    """
+
+    def _build_curl_command(
+        self,
+        url: str,
+        http_method: str,
+        data: Optional[FormDataDict] = None,
+        json: Optional[JSONDict] = None,
+        params: Optional[ParamDict] = None,
+    ) -> str:
+        """
+        Build a curl command string for debugging API requests.
+        
+        Args:
+            url: Full API URL
+            http_method: HTTP method (GET, POST, DELETE)
+            data: Optional form data for POST requests
+            json: Optional JSON data for POST requests
+            params: Optional query parameters for GET requests
+            
+        Returns:
+            Complete curl command as a multi-line string
+
+        The generated command includes:
+        - The HTTP method (for non-GET requests)
+        - Authorization header with OAuth token
+        - Request body (if data or json is provided)
+        - Query parameters (if provided)
+        
+        The command is formatted with line continuations for readability and
+        can be copied directly into a terminal for testing.
+
+        Example output:
+            curl \\
+              -X POST \\
+              -H "Authorization: Bearer <token>" \\
+              -H "Content-Type: application/json" \\
+              -d '{"name": "value"}' \\
+              'https://api.fitbit.com/1/user/-/foods/log.json'
+        """
+        # Start with base command
+        cmd_parts = ["curl -v"]
+
+        # Add method
+        if http_method != "GET":
+            cmd_parts.append(f"-X {http_method}")
+
+        # Add auth header
+        if hasattr(self, "oauth") and hasattr(self.oauth, "token"):
+            cmd_parts.append(f'-H "Authorization: Bearer {self.oauth.token["access_token"]}"')
+        else:
+            # Fallback for tests or when not properly initialized
+            cmd_parts.append('-H "Authorization: Bearer TOKEN"')
+
+        # Add data if present
+        if json:
+            cmd_parts.append(f"-d '{dumps(json)}'")
+            cmd_parts.append('-H "Content-Type: application/json"')
+        elif data:
+            cmd_parts.append(f"-d '{urlencode(data)}'")
+            cmd_parts.append('-H "Content-Type: application/x-www-form-urlencoded"')
+
+        # Add URL with parameters if present
+        if params:
+            url = f"{url}?{urlencode(params)}"
+        cmd_parts.append(f"'{url}'")
+
+        return " \\\n  ".join(cmd_parts)
diff --git a/fitbit_client/utils/types.py b/fitbit_client/utils/types.py
index 19efd44..bbce1f7 100644
--- a/fitbit_client/utils/types.py
+++ b/fitbit_client/utils/types.py
@@ -18,6 +18,10 @@
 ParamValue = Union[str, int, float, bool, None]
 ParamDict = Dict[str, ParamValue]
 
+# Type for form data (typically used with data parameter in requests)
+FormDataValue = Union[str, int, float, bool, None]
+FormDataDict = Dict[str, FormDataValue]
+
 
 # Type definitions for token structure
 class TokenDict(TypedDict, total=False):
diff --git a/tests/resources/test_base.py b/tests/resources/test_base.py
index 88d517f..37eeb1a 100644
--- a/tests/resources/test_base.py
+++ b/tests/resources/test_base.py
@@ -247,38 +247,10 @@ def test_log_response_for_error_without_content(base_resource, mock_logger):
 
 
 # -----------------------------------------------------------------------------
-# 6. Debug Curl Command Generation
+# 6. Debug Mode Testing
 # -----------------------------------------------------------------------------
 
-
-def test_build_curl_command_with_json_data(base_resource):
-    """Test generating curl command with JSON data"""
-    # This tests lines 217-218 in base.py
-    base_resource.oauth.token = {"access_token": "test_token"}
-
-    json_data = {"name": "Test Activity", "type": "run", "duration": 3600}
-    result = base_resource._build_curl_command(
-        url="https://api.fitbit.com/1/user/-/activities.json", http_method="POST", json=json_data
-    )
-
-    # Assert command contains JSON data and correct header
-    assert '-d \'{"name": "Test Activity", "type": "run", "duration": 3600}\'' in result
-    assert '-H "Content-Type: application/json"' in result
-
-
-def test_build_curl_command_with_form_data(base_resource):
-    """Test generating curl command with form data"""
-    # This tests lines 220-221 in base.py
-    base_resource.oauth.token = {"access_token": "test_token"}
-
-    form_data = {"date": "2023-01-01", "foodId": "12345", "amount": "1", "mealTypeId": "1"}
-    result = base_resource._build_curl_command(
-        url="https://api.fitbit.com/1/user/-/foods/log.json", http_method="POST", data=form_data
-    )
-
-    # Assert command contains form data and correct header
-    assert "-d 'date=2023-01-01&foodId=12345&amount=1&mealTypeId=1'" in result
-    assert '-H "Content-Type: application/x-www-form-urlencoded"' in result
+# Debug mode tests are now in tests/utils/test_curl_debug_mixin.py
 
 
 # -----------------------------------------------------------------------------
diff --git a/tests/utils/test_curl_debug_mixin.py b/tests/utils/test_curl_debug_mixin.py
new file mode 100644
index 0000000..d93d5d3
--- /dev/null
+++ b/tests/utils/test_curl_debug_mixin.py
@@ -0,0 +1,134 @@
+# tests/utils/test_curl_debug_mixin.py
+
+"""Tests for CurlDebugMixin"""
+
+# Standard library imports
+from unittest.mock import Mock
+from unittest.mock import patch
+
+# Third party imports
+from pytest import fixture
+
+# Local imports
+from fitbit_client.utils.curl_debug_mixin import CurlDebugMixin
+
+
+# Create a test class that uses the mixin for debug testing
+class TestResource(CurlDebugMixin):
+    """Test class that uses CurlDebugMixin"""
+
+    def __init__(self):
+        self.oauth = Mock()
+        self.oauth.token = {"access_token": "test_token"}
+
+    def make_debug_request(self, debug=False):
+        """Test method that simulates _make_request with debug mode"""
+        url = "https://api.fitbit.com/1/user/-/test/endpoint"
+
+        if debug:
+            curl_command = self._build_curl_command(
+                url=url, http_method="GET", params={"param1": "value1"}
+            )
+            print(f"\n# Debug curl command:")
+            print(curl_command)
+            print()
+            return None
+
+        return {"success": True}
+
+
+@fixture
+def curl_debug_mixin():
+    """Fixture for CurlDebugMixin with mocked OAuth session"""
+    mixin = CurlDebugMixin()
+    mixin.oauth = Mock()
+    mixin.oauth.token = {"access_token": "test_token"}
+    return mixin
+
+
+def test_build_curl_command_with_json_data(curl_debug_mixin):
+    """Test generating curl command with JSON data"""
+    json_data = {"name": "Test Activity", "type": "run", "duration": 3600}
+    result = curl_debug_mixin._build_curl_command(
+        url="https://api.fitbit.com/1/user/-/activities.json", http_method="POST", json=json_data
+    )
+
+    # Assert command contains JSON data and correct header
+    assert '-d \'{"name": "Test Activity", "type": "run", "duration": 3600}\'' in result
+    assert '-H "Content-Type: application/json"' in result
+    assert "-X POST" in result
+    assert "curl -v" in result
+    assert '-H "Authorization: Bearer test_token"' in result
+    assert "'https://api.fitbit.com/1/user/-/activities.json'" in result
+
+
+def test_build_curl_command_with_form_data(curl_debug_mixin):
+    """Test generating curl command with form data"""
+    form_data = {"date": "2023-01-01", "foodId": "12345", "amount": "1", "mealTypeId": "1"}
+    result = curl_debug_mixin._build_curl_command(
+        url="https://api.fitbit.com/1/user/-/foods/log.json", http_method="POST", data=form_data
+    )
+
+    # Assert command contains form data and correct header
+    assert "-d 'date=2023-01-01&foodId=12345&amount=1&mealTypeId=1'" in result
+    assert '-H "Content-Type: application/x-www-form-urlencoded"' in result
+    assert "-X POST" in result
+
+
+def test_build_curl_command_with_get_params(curl_debug_mixin):
+    """Test generating curl command with GET parameters"""
+    params = {"date": "2023-01-01", "offset": "0", "limit": "10"}
+    result = curl_debug_mixin._build_curl_command(
+        url="https://api.fitbit.com/1/user/-/activities/list.json", http_method="GET", params=params
+    )
+
+    # Assert command doesn't have -X GET but has parameters in URL
+    assert "-X GET" not in result
+    assert "?date=2023-01-01&offset=0&limit=10" in result
+
+
+def test_build_curl_command_with_delete(curl_debug_mixin):
+    """Test generating curl command for DELETE request"""
+    result = curl_debug_mixin._build_curl_command(
+        url="https://api.fitbit.com/1/user/-/foods/log/123456.json", http_method="DELETE"
+    )
+
+    # Assert command has DELETE method
+    assert "-X DELETE" in result
+    assert "curl -v" in result
+    assert '-H "Authorization: Bearer test_token"' in result
+
+
+def test_debug_mode_integration(capsys):
+    """Test debug mode integration with a resource class"""
+    # Create test resource
+    resource = TestResource()
+
+    # Call make_debug_request with debug=True
+    result = resource.make_debug_request(debug=True)
+
+    # Capture stdout
+    captured = capsys.readouterr()
+
+    # Verify results
+    assert result is None
+    assert "curl" in captured.out
+    assert "test/endpoint" in captured.out
+    assert "param1=value1" in captured.out
+    assert "test_token" in captured.out
+
+
+def test_build_curl_command_without_oauth():
+    """Test curl command generation when oauth is not available"""
+    # Create a bare mixin instance without oauth
+    mixin = CurlDebugMixin()
+
+    # Generate a curl command
+    result = mixin._build_curl_command(
+        url="https://api.fitbit.com/1/user/-/test.json", http_method="GET"
+    )
+
+    # Verify that the fallback auth header is used
+    assert '-H "Authorization: Bearer TOKEN"' in result
+    assert "curl -v" in result
+    assert "'https://api.fitbit.com/1/user/-/test.json'" in result
diff --git a/tests/utils/test_date_validation.py b/tests/utils/test_date_validation.py
index 232b548..18c036b 100644
--- a/tests/utils/test_date_validation.py
+++ b/tests/utils/test_date_validation.py
@@ -15,6 +15,7 @@
 from fitbit_client.utils.date_validation import validate_date_param
 from fitbit_client.utils.date_validation import validate_date_range
 from fitbit_client.utils.date_validation import validate_date_range_params
+from fitbit_client.utils.types import JSONDict
 
 
 class TestDateValidation:
@@ -106,7 +107,7 @@ def test_validate_date_range_params_decorator(self):
         """Test the validate_date_range_params decorator"""
 
         @validate_date_range_params(max_days=30)
-        def dummy_func(start_date: str, end_date: str) -> Dict[str, Any]:
+        def dummy_func(start_date: str, end_date: str) -> JSONDict:
             return {"start": start_date, "end": end_date}
 
         result = dummy_func("2024-02-01", "2024-02-13")
@@ -148,7 +149,7 @@ def test_validate_date_range_params_decorator_with_optional(self):
         @validate_date_range_params(max_days=30)
         def dummy_func(
             start_date: Optional[str] = None, end_date: Optional[str] = None
-        ) -> Dict[str, Any]:
+        ) -> JSONDict:
             return {"start": start_date, "end": end_date}
 
         # Should work with no parameters
@@ -169,7 +170,7 @@ def test_validate_date_range_params_custom_field_names(self):
         """Test that validate_date_range_params respects custom field names"""
 
         @validate_date_range_params(start_field="begin_date", end_field="finish_date", max_days=30)
-        def dummy_func(begin_date: str, finish_date: str) -> Dict[str, Any]:
+        def dummy_func(begin_date: str, finish_date: str) -> JSONDict:
             return {"start": begin_date, "end": finish_date}
 
         # Test valid dates