diff --git a/http-api/app/app.py b/http-api/app/app.py
index 15b4375..933fa45 100644
--- a/http-api/app/app.py
+++ b/http-api/app/app.py
@@ -19,7 +19,6 @@ from middlewares import AuthenticationMiddleware
 from routes import (
     courses,
     enrollments,
-    enrollments_,
     lookup,
     orders,
     orgs,
@@ -54,7 +53,6 @@ app = APIGatewayHttpResolver(
 app.use(middlewares=[AuthenticationMiddleware()])
 app.include_router(courses.router, prefix='/courses')
 app.include_router(enrollments.router, prefix='/enrollments')
-app.include_router(enrollments_.router, prefix='/new/enrollments')
 app.include_router(enrollments.vacancies, prefix='/enrollments')
 app.include_router(enrollments.enroll, prefix='/enrollments')
 app.include_router(enrollments.cancel, prefix='/enrollments')
diff --git a/layercake/layercake/dynamodb.py b/layercake/layercake/dynamodb.py
index 1850d17..bc2e334 100644
--- a/layercake/layercake/dynamodb.py
+++ b/layercake/layercake/dynamodb.py
@@ -228,6 +228,7 @@ class KeyPair(Key):
         *,
         rename_key: str | None = None,
         retain_key: bool = False,
+        table_name: str | None = None,
     ) -> None:
         """
         Initializes a composite key using partition and sort key.
@@ -242,11 +243,13 @@ class KeyPair(Key):
             If provided, renames the sort key in the output.
         retain_key : bool, optional
             Use the key itself as value if True; otherwise, use the extracted value.
+        table_name : str, optional
         """
 
         super().__init__(**{PK: pk, SK: sk})
         self._rename_key = rename_key
         self._retain_key = retain_key
+        self._table_name = table_name
 
     @property
     def rename_key(self) -> str | None:
@@ -256,6 +259,10 @@ class KeyPair(Key):
     def retain_key(self) -> bool:
         return self._retain_key
 
+    @property
+    def table_name(self) -> str | None:
+        return self._table_name
+
     def __repr__(self) -> str:
         pk, sk, *_ = self.values()
         return f'KeyPair({pk!r}, {sk!r})'
@@ -297,7 +304,12 @@ class KeyChain:
         if not isinstance(other, KeyPair):
             raise TypeError('Can only add a KeyPair to a KeyChain')
 
-        return KeyChain(pairs=self.pairs + (other,))
+        if other not in self.pairs:
+            pairs = self.pairs + (other,)
+        else:
+            pairs = self.pairs
+
+        return KeyChain(pairs=pairs)
 
 
 @dataclass(frozen=True)
@@ -311,6 +323,7 @@ class TransactKey:
     """
 
     pk: str
+    table_name: str | None = None
     pairs: tuple[KeyPair, ...] = ()
 
     def __add__(self, other: SortKey | KeyPair) -> 'TransactKey':
@@ -318,9 +331,18 @@ class TransactKey:
             raise TypeError('Can only add a SortKey and KeyPair to a TransactKey')
 
         if isinstance(other, SortKey):
-            other = KeyPair(self.pk, other)
+            other = KeyPair(self.pk, other, table_name=self.table_name)
 
-        return TransactKey(pk=self.pk, pairs=self.pairs + (other,))
+        if other not in self.pairs:
+            pairs = self.pairs + (other,)
+        else:
+            pairs = self.pairs
+
+        return TransactKey(
+            pk=self.pk,
+            table_name=self.table_name,
+            pairs=pairs,
+        )
 
 
 class TransactionCanceledReason(TypedDict):
@@ -884,6 +906,7 @@ class DynamoDBCollection:
         key: Key,
         *,
         ttl: int | datetime | None = None,
+        cond_expr: str | None = None,
         **kwargs: Any,
     ) -> bool:
         """Creates a new item, or replaces an old item with a new item.
@@ -895,6 +918,8 @@ class DynamoDBCollection:
         ttl: int or datetime, optional
             Time-to-live for the item, specified as a timestamp integer
             or datetime object.
+        cond_expr: str, optional
+            Conditional expression for deletion.
         **kwargs
             Additional data to be stored with the item.
 
@@ -909,7 +934,10 @@ class DynamoDBCollection:
         if isinstance(ttl, datetime):
             kwargs.update({'ttl': timestamp(ttl)})
 
-        return self.persistence_layer.put_item(item=key | kwargs)
+        return self.persistence_layer.put_item(
+            item=key | kwargs,
+            cond_expr=cond_expr,
+        )
 
     def delete_item(
         self,
@@ -1013,7 +1041,7 @@ class DynamoDBCollection:
         transact_items = [
             {
                 'Get': {
-                    'TableName': getattr(pair, 'table_name', table_name),
+                    'TableName': pair.table_name or table_name,
                     'Key': serialize(pair),
                 }
             }
diff --git a/layercake/pyproject.toml b/layercake/pyproject.toml
index 27dcb73..1aad35e 100644
--- a/layercake/pyproject.toml
+++ b/layercake/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "layercake"
-version = "0.6.5"
+version = "0.6.11"
 description = "Packages shared dependencies to optimize deployment and ensure consistency across functions."
 readme = "README.md"
 authors = [
@@ -23,6 +23,7 @@ dependencies = [
     "arnparse>=0.0.2",
     "weasyprint>=65.0",
     "smart-open[s3]>=7.1.0",
+    "sqlite-utils>=3.38",
 ]
 
 [dependency-groups]
@@ -50,4 +51,4 @@ select = ["E", "F", "I"]
 
 [build-system]
 requires = ["hatchling"]
-build-backend = "hatchling.build"
+build-backend = "hatchling.build"
\ No newline at end of file
diff --git a/layercake/tests/seeds.jsonl b/layercake/tests/seeds.jsonl
index 030a1e4..edd4d55 100644
--- a/layercake/tests/seeds.jsonl
+++ b/layercake/tests/seeds.jsonl
@@ -6,4 +6,4 @@
 {"id": {"S": "logs#5OxmMjL-ujoR5IMGegQz"}, "sk": {"S": "2019-03-25T00:00:00-03:00"}, "action": {"S": "CLICK_EMAIL"}}
 {"id": {"S": "cJtK9SsnJhKPyxESe7g3DG"}, "sk": {"S": "0"}, "name": {"S": "EDUSEG"}, "cnpj": {"S": "15608435000190"}, "email": {"S": "org+15608435000190@users.noreply.betaeducacao.com.br"}}
 {"id": {"S": "cJtK9SsnJhKPyxESe7g3DG"}, "sk": {"S": "metadata#payment_policy"}, "due_days": {"N": "90"}}
-{"id": {"S": "cJtK9SsnJhKPyxESe7g3DG"}, "sk": {"S": "metadata#billing_policy"}, "billing_day": {"N": "1"}, "payment_method": {"S": "PIX"}}
+{"id": {"S": "cJtK9SsnJhKPyxESe7g3DG"}, "sk": {"S": "metadata#billing_policy"}, "billing_day": {"N": "1"}, "payment_method": {"S": "PIX"}}
\ No newline at end of file
diff --git a/layercake/tests/test_dynamodb.py b/layercake/tests/test_dynamodb.py
index 026b0ab..76c6d4d 100644
--- a/layercake/tests/test_dynamodb.py
+++ b/layercake/tests/test_dynamodb.py
@@ -269,7 +269,10 @@ def test_collection_get_items(
 ):
     collect = DynamoDBCollection(dynamodb_persistence_layer)
     doc = collect.get_items(
-        TransactKey('cJtK9SsnJhKPyxESe7g3DG')
+        TransactKey(
+            'cJtK9SsnJhKPyxESe7g3DG', table_name=dynamodb_persistence_layer.table_name
+        )
+        + SortKey('0')
         + SortKey('0')
         + SortKey('metadata#billing_policy', path_spec='payment_method')
         + SortKey('metadata#payment_policy', remove_prefix='metadata#'),
diff --git a/layercake/uv.lock b/layercake/uv.lock
index cd6a0a3..6ace092 100644
--- a/layercake/uv.lock
+++ b/layercake/uv.lock
@@ -589,7 +589,7 @@ wheels = [
 
 [[package]]
 name = "layercake"
-version = "0.6.4"
+version = "0.6.5"
 source = { editable = "." }
 dependencies = [
     { name = "arnparse" },