diff --git a/backend/api/main.py b/backend/api/main.py
index 6fdf1c8..e90faba 100644
--- a/backend/api/main.py
+++ b/backend/api/main.py
@@ -12,6 +12,8 @@ from backend.repository.tribe_sqlite_repository import (
     TribeRepositoryError,
     TribeSQLiteRepository,
 )
+from backend.service import services
+from backend.service.services import StudentDoesExist, TribeDoesNotExist, TribeExists
 
 # from sqlalchemy import create_engine
 # from sqlalchemy.orm import clear_mappers, sessionmaker
@@ -38,13 +40,14 @@ async def post_tribe(item: TribeModel):
     tribe = Tribe(**item.dict())
 
     try:
-        tribe_repo.add(tribe)
-    except TribeRepositoryError:
+        services.add_tribe(
+            name=item.name, level=item.level, tribe_repo=tribe_repo, conn=conn
+        )
+    except TribeExists:
         return JSONResponse(
             status_code=status.HTTP_409_CONFLICT,
             content=f"The tribe {tribe.name} already exists",
         )
-    conn.commit()
 
     return tribe.to_dict()
 
@@ -71,20 +74,20 @@ async def post_student(item: StudentModel):
             content=f"You can't post a student with an id. It is already registrered. Use PUT to modify it.",
         )
 
-    tribe_name = item.tribe_name
     try:
-        tribe = tribe_repo.get(tribe_name)
-    except TribeRepositoryError:
+        student = services.add_student(
+            name=item.name,
+            tribe=item.tribe_name,
+            tribe_repo=tribe_repo,
+            student_repo=student_repo,
+            conn=conn,
+        )
+    except TribeDoesNotExist:
         return JSONResponse(
             status_code=status.HTTP_409_CONFLICT,
-            content=f"The tribe {tribe_name} does not exists. You can't add a student in it.",
+            content=f"The tribe {item.tribe_name} does not exists. You can't add a student in it.",
         )
 
-    student = Student(item.name, tribe)
-
-    student_repo.add(student)
-    conn.commit()
-
     return student.to_dict()
 
 
@@ -94,18 +97,30 @@ async def post_student(item: StudentModel):
     response_model=StudentModel,
 )
 async def put_student(student_id, item: StudentModel):
-    tribe_name = item.tribe_name
+    if student_id != item.id:
+        return JSONResponse(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            content=f"Url and student id are the same",
+        )
+
     try:
-        tribe = tribe_repo.get(tribe_name)
-    except TribeRepositoryError:
+        student = services.update_student(
+            id=item.id,
+            name=item.name,
+            tribe=item.tribe_name,
+            tribe_repo=tribe_repo,
+            student_repo=student_repo,
+            conn=conn,
+        )
+    except TribeDoesNotExist:
         return JSONResponse(
             status_code=status.HTTP_409_CONFLICT,
             content=f"The tribe {tribe_name} does not exists. You can't add a student in it.",
         )
-
-    student = Student(name=item.name, tribe=tribe, id=student_id)
-
-    student_repo.update(student)
-    conn.commit()
+    except StudentDoesExist:
+        return JSONResponse(
+            status_code=status.HTTP_409_CONFLICT,
+            content=f"The student {item.name} ({item.id=}) does not exists. You can't modify it.",
+        )
 
     return student.to_dict()