diff --git a/src/database/service.py b/src/database/service.py
index baa61e7..9313812 100644
--- a/src/database/service.py
+++ b/src/database/service.py
@@ -18,9 +18,11 @@ QueryStr = constr(pattern=r"^[ -~]+$", min_length=1)
 
 def common_parameters(
     db_session: DbSession,  # type: ignore
-    current_user: QueryStr = Query(None, alias="currentUser"),  # type: ignore
+    current_user: Optional[str] = Query(None, alias="currentUser"),  # type: ignore
+    current_user_snake: Optional[str] = Query(None, alias="current_user"),  # type: ignore
     page: int = Query(1, gt=0, lt=2147483647),
-    items_per_page: int = Query(5, alias="itemsPerPage", gt=-2, lt=2147483647),
+    items_per_page: Optional[int] = Query(None, alias="items_per_page", gt=-2, lt=2147483647),
+    items_per_page_camel: Optional[int] = Query(None, alias="itemsPerPage", gt=-2, lt=2147483647),
     query_str: QueryStr = Query(None, alias="q"),  # type: ignore
     filter_spec: QueryStr = Query(None, alias="filter"),  # type: ignore
     sort_by: List[str] = Query([], alias="sortBy[]"),
@@ -28,15 +30,23 @@ def common_parameters(
     all: int = Query(0),
     # role: QueryStr = Depends(get_current_role),
 ):
+    # Support both snake_case and camelCase for pagination size
+    final_items_per_page = items_per_page_camel if items_per_page_camel is not None else (
+        items_per_page if items_per_page is not None else 5
+    )
+    
+    # Support both snake_case and camelCase for current user
+    final_current_user = current_user or current_user_snake
+
     return {
         "db_session": db_session,
         "page": page,
-        "items_per_page": items_per_page,
+        "items_per_page": final_items_per_page,
         "query_str": query_str,
         "filter_spec": filter_spec,
         "sort_by": sort_by,
         "descending": descending,
-        "current_user": current_user,
+        "current_user": final_current_user,
         # "role": role,
         "all": bool(all),
     }
diff --git a/src/equipment_master/schema.py b/src/equipment_master/schema.py
index ae94d76..54eed2a 100644
--- a/src/equipment_master/schema.py
+++ b/src/equipment_master/schema.py
@@ -46,5 +46,4 @@ class EquipmentMasterPaginated(Pagination):
 
 class EquipmentMasterQuery(CommonParams):
     parent_id : Optional[str] = None
-    items_per_page : Optional[int] = 5
     search : Optional[str] = None
\ No newline at end of file
diff --git a/src/manpower_master/schema.py b/src/manpower_master/schema.py
index c945b86..26f010d 100644
--- a/src/manpower_master/schema.py
+++ b/src/manpower_master/schema.py
@@ -33,5 +33,4 @@ class ManpowerCostPagination(Pagination):
     items: List[ManpowerCostRead] = []
 
 class QueryParams(CommonParams):
-    items_per_page: Optional[int] = Field(5)
     search: Optional[str] = Field(None)
\ No newline at end of file
diff --git a/src/masterdata/schema.py b/src/masterdata/schema.py
index 7a2d57d..3c77dba 100644
--- a/src/masterdata/schema.py
+++ b/src/masterdata/schema.py
@@ -2,7 +2,7 @@ from datetime import datetime
 from typing import List, Optional
 from uuid import UUID
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, model_validator
 from src.models import DefaultBase, Pagination
 from src.auth.service import CurrentUser
 
@@ -53,13 +53,26 @@ class MasterDataPagination(Pagination):
 
 
 class QueryParams(DefaultBase):
-    items_per_page: Optional[int] = Field(
+    items_per_page: int = Field(
         5,
         ge=1,
-        alias="itemsPerPage",
+        alias="items_per_page",
         description="Items per page"
     )
+    itemsPerPage: Optional[int] = Field(
+        None,
+        ge=1,
+        description="Alias for items_per_page"
+    )
     search: Optional[str] = Field(
         None,
         description="Search keyword"
     )
+
+    @model_validator(mode="before")
+    @classmethod
+    def resolve_aliases(cls, data: any) -> any:
+        if isinstance(data, dict):
+            if "itemsPerPage" in data and data["itemsPerPage"] is not None:
+                data.setdefault("items_per_page", data["itemsPerPage"])
+        return data
diff --git a/src/models.py b/src/models.py
index 9fdaee8..b03adf8 100644
--- a/src/models.py
+++ b/src/models.py
@@ -2,7 +2,7 @@
 from datetime import datetime
 from typing import Generic, List, Optional, TypeVar
 import uuid
-from pydantic import BaseModel, Field, SecretStr, ConfigDict
+from pydantic import BaseModel, Field, SecretStr, ConfigDict, model_validator
 from sqlalchemy import Column, DateTime, String, func, event
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
@@ -100,9 +100,11 @@ class StandardResponse(BaseModel, Generic[T]):
 
 class CommonParams(DefaultBase):
     # This ensures no extra query params are allowed
-    current_user: Optional[str] = Field(None, alias="currentUser")
+    current_user: Optional[str] = Field(None, alias="current_user")
+    currentUser: Optional[str] = Field(None, description="Alias for current_user")
     page: int = Field(1, gt=0, lt=2147483647)
-    items_per_page: int = Field(5, gt=-2, lt=2147483647, alias="itemsPerPage")
+    items_per_page: int = Field(5, gt=-2, lt=2147483647, alias="items_per_page")
+    itemsPerPage: Optional[int] = Field(None, description="Alias for items_per_page")
     query_str: Optional[str] = Field(None, alias="q")
     filter_spec: Optional[str] = Field(None, alias="filter")
     sort_by: List[str] = Field(default_factory=list, alias="sortBy[]")
@@ -110,6 +112,16 @@ class CommonParams(DefaultBase):
     exclude: List[str] = Field(default_factory=list, alias="exclude[]")
     all_params: int = Field(0, alias="all")
 
+    @model_validator(mode="before")
+    @classmethod
+    def resolve_aliases(cls, data: any) -> any:
+        if isinstance(data, dict):
+            if "itemsPerPage" in data and data["itemsPerPage"] is not None:
+                data.setdefault("items_per_page", data["itemsPerPage"])
+            if "currentUser" in data and data["currentUser"] is not None:
+                data.setdefault("current_user", data["currentUser"])
+        return data
+
     # Property to mirror your original return dict's bool conversion
     @property
     def is_all(self) -> bool:
diff --git a/src/plant_fs_transaction_data/schema.py b/src/plant_fs_transaction_data/schema.py
index d2497e4..2341a18 100644
--- a/src/plant_fs_transaction_data/schema.py
+++ b/src/plant_fs_transaction_data/schema.py
@@ -102,13 +102,6 @@ class PlantFSChartData(DefaultBase):
 
 
 class ListQueryParams(CommonParams):
-    items_per_page: Optional[int] = Field(
-        default=5,
-        ge=1,
-        le=1000,
-        description="Number of items per page",
-        alias="itemsPerPage",
-    )
     search: Optional[str] = Field(
         default=None,
         description="Search keyword",
diff --git a/src/plant_masterdata/schema.py b/src/plant_masterdata/schema.py
index c938a6b..58c22d4 100644
--- a/src/plant_masterdata/schema.py
+++ b/src/plant_masterdata/schema.py
@@ -88,13 +88,6 @@ class PlantMasterDataPagination(Pagination):
 
 
 class ListQueryParams(CommonParams):
-    items_per_page: Optional[int] = Field(
-        default=5,
-        ge=1,
-        le=1000,
-        description="Number of items per page",
-        alias="itemsPerPage",
-    )
     search: Optional[str] = Field(
         default=None,
         description="Search keyword",
diff --git a/src/simulations/schema.py b/src/simulations/schema.py
index c4780bf..fe09cd0 100644
--- a/src/simulations/schema.py
+++ b/src/simulations/schema.py
@@ -54,13 +54,6 @@ class SimulationRunPayload(DefaultBase):
 
 
 class ListQueryParams(CommonParams):
-    items_per_page: Optional[int] = Field(
-        default=5,
-        ge=1,
-        le=1000,
-        description="Number of items per page",
-        alias="itemsPerPage",
-    )
     search: Optional[str] = Field(
         default=None,
         description="Search keyword",