diff --git a/.idea/misc.xml b/.idea/misc.xml
index 31a9dc3..820854d 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -4,7 +4,7 @@
     <option name="sdkName" value="Poetry (sqlalchemy-bind-manager)" />
   </component>
   <component name="BlackConnectSettings" triggerOnEachSave="true" />
-  <component name="ProjectRootManager" version="2" project-jdk-name="Poetry (sqlalchemy-bind-manager)" project-jdk-type="Python SDK" />
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.13 virtualenv at ~/github/febus982/sqlalchemy-bind-manager/.venv" project-jdk-type="Python SDK" />
   <component name="PythonCompatibilityInspectionAdvertiser">
     <option name="version" value="3" />
   </component>
diff --git a/.idea/sqlalchemy-bind-manager.iml b/.idea/sqlalchemy-bind-manager.iml
index 739e159..e89aaa4 100644
--- a/.idea/sqlalchemy-bind-manager.iml
+++ b/.idea/sqlalchemy-bind-manager.iml
@@ -4,8 +4,9 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/.tox" />
+      <excludeFolder url="file://$MODULE_DIR$/.venv" />
     </content>
-    <orderEntry type="jdk" jdkName="Poetry (sqlalchemy-bind-manager)" jdkType="Python SDK" />
+    <orderEntry type="jdk" jdkName="Python 3.13 virtualenv at ~/github/febus982/sqlalchemy-bind-manager/.venv" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
   <component name="PackageRequirementsSettings">
diff --git a/docs/repository/usage.md b/docs/repository/usage.md
index 4d82e10..ab19b2b 100644
--- a/docs/repository/usage.md
+++ b/docs/repository/usage.md
@@ -57,7 +57,25 @@ async def some_async_function(repository: SQLAlchemyAsyncRepositoryInterface[MyM
     ...
 ```
 
-Both repository and related interface are Generic, accepting the model class as a typing argument.
+Both repository and related interface are Protocols, accepting the model class as a typing argument. You can also
+extend the protocols with your custom methods.
+
+```python
+from typing import Protocol
+from sqlalchemy_bind_manager.repository import SQLAlchemyRepositoryInterface, SQLAlchemyRepository
+
+# SQLAlchemy model
+class MyModel:
+    ...
+
+class MyCustomRepositoryInterface(SQLAlchemyRepositoryInterface[MyModel], Protocol):
+    def some_custom_method(self, model: MyModel) -> MyModel:
+        ...
+
+class MyCustomRepository(SQLAlchemyRepository[MyModel]):
+    def some_custom_method(self, model: MyModel) -> MyModel:
+        return model
+```
 ///
 
 ### Maximum query limit
diff --git a/sqlalchemy_bind_manager/_repository/abstract.py b/sqlalchemy_bind_manager/_repository/abstract.py
index 94b5f34..1c1a5b2 100644
--- a/sqlalchemy_bind_manager/_repository/abstract.py
+++ b/sqlalchemy_bind_manager/_repository/abstract.py
@@ -27,14 +27,13 @@
 #  Software is furnished to do so, subject to the following conditions:
 #
 #
-from abc import ABC, abstractmethod
 from typing import (
     Any,
-    Generic,
     Iterable,
     List,
     Literal,
     Mapping,
+    Protocol,
     Tuple,
     Union,
 )
@@ -48,8 +47,7 @@
 )
 
 
-class SQLAlchemyAsyncRepositoryInterface(Generic[MODEL], ABC):
-    @abstractmethod
+class SQLAlchemyAsyncRepositoryInterface(Protocol[MODEL]):
     async def get(self, identifier: PRIMARY_KEY) -> MODEL:
         """Get a model by primary key.
 
@@ -59,7 +57,6 @@ async def get(self, identifier: PRIMARY_KEY) -> MODEL:
         """
         ...
 
-    @abstractmethod
     async def get_many(self, identifiers: Iterable[PRIMARY_KEY]) -> List[MODEL]:
         """Get a list of models by primary keys.
 
@@ -68,7 +65,6 @@ async def get_many(self, identifiers: Iterable[PRIMARY_KEY]) -> List[MODEL]:
         """
         ...
 
-    @abstractmethod
     async def save(self, instance: MODEL) -> MODEL:
         """Persist a model.
 
@@ -77,7 +73,6 @@ async def save(self, instance: MODEL) -> MODEL:
         """
         ...
 
-    @abstractmethod
     async def save_many(self, instances: Iterable[MODEL]) -> Iterable[MODEL]:
         """Persist many models in a single database get_session.
 
@@ -86,7 +81,6 @@ async def save_many(self, instances: Iterable[MODEL]) -> Iterable[MODEL]:
         """
         ...
 
-    @abstractmethod
     async def delete(self, instance: MODEL) -> None:
         """Deletes a model.
 
@@ -94,7 +88,6 @@ async def delete(self, instance: MODEL) -> None:
         """
         ...
 
-    @abstractmethod
     async def delete_many(self, instances: Iterable[MODEL]) -> None:
         """Deletes a collection of models in a single transaction.
 
@@ -102,7 +95,6 @@ async def delete_many(self, instances: Iterable[MODEL]) -> None:
         """
         ...
 
-    @abstractmethod
     async def find(
         self,
         search_params: Union[None, Mapping[str, Any]] = None,
@@ -130,7 +122,6 @@ async def find(
         """
         ...
 
-    @abstractmethod
     async def paginated_find(
         self,
         items_per_page: int,
@@ -169,7 +160,6 @@ async def paginated_find(
         """
         ...
 
-    @abstractmethod
     async def cursor_paginated_find(
         self,
         items_per_page: int,
@@ -205,8 +195,7 @@ async def cursor_paginated_find(
         ...
 
 
-class SQLAlchemyRepositoryInterface(Generic[MODEL], ABC):
-    @abstractmethod
+class SQLAlchemyRepositoryInterface(Protocol[MODEL]):
     def get(self, identifier: PRIMARY_KEY) -> MODEL:
         """Get a model by primary key.
 
@@ -216,7 +205,6 @@ def get(self, identifier: PRIMARY_KEY) -> MODEL:
         """
         ...
 
-    @abstractmethod
     def get_many(self, identifiers: Iterable[PRIMARY_KEY]) -> List[MODEL]:
         """Get a list of models by primary keys.
 
@@ -225,7 +213,6 @@ def get_many(self, identifiers: Iterable[PRIMARY_KEY]) -> List[MODEL]:
         """
         ...
 
-    @abstractmethod
     def save(self, instance: MODEL) -> MODEL:
         """Persist a model.
 
@@ -234,7 +221,6 @@ def save(self, instance: MODEL) -> MODEL:
         """
         ...
 
-    @abstractmethod
     def save_many(self, instances: Iterable[MODEL]) -> Iterable[MODEL]:
         """Persist many models in a single database get_session.
 
@@ -243,7 +229,6 @@ def save_many(self, instances: Iterable[MODEL]) -> Iterable[MODEL]:
         """
         ...
 
-    @abstractmethod
     def delete(self, instance: MODEL) -> None:
         """Deletes a model.
 
@@ -251,7 +236,6 @@ def delete(self, instance: MODEL) -> None:
         """
         ...
 
-    @abstractmethod
     def delete_many(self, instances: Iterable[MODEL]) -> None:
         """Deletes a collection of models in a single transaction.
 
@@ -259,7 +243,6 @@ def delete_many(self, instances: Iterable[MODEL]) -> None:
         """
         ...
 
-    @abstractmethod
     def find(
         self,
         search_params: Union[None, Mapping[str, Any]] = None,
@@ -287,7 +270,6 @@ def find(
         """
         ...
 
-    @abstractmethod
     def paginated_find(
         self,
         items_per_page: int,
@@ -326,7 +308,6 @@ def paginated_find(
         """
         ...
 
-    @abstractmethod
     def cursor_paginated_find(
         self,
         items_per_page: int,
diff --git a/tests/test_interfaces.py b/tests/test_interfaces.py
index b05509b..07f35fe 100644
--- a/tests/test_interfaces.py
+++ b/tests/test_interfaces.py
@@ -1,4 +1,5 @@
 from inspect import signature
+from typing import Protocol, runtime_checkable
 
 from sqlalchemy_bind_manager.repository import (
     SQLAlchemyAsyncRepository,
@@ -8,9 +9,17 @@
 )
 
 
+@runtime_checkable
+class RuntimeRepoProtocol(SQLAlchemyRepositoryInterface, Protocol): ...
+
+
+@runtime_checkable
+class RuntimeAsyncRepoProtocol(SQLAlchemyAsyncRepositoryInterface, Protocol): ...
+
+
 def test_interfaces():
-    assert issubclass(SQLAlchemyRepository, SQLAlchemyRepositoryInterface)
-    assert issubclass(SQLAlchemyAsyncRepository, SQLAlchemyAsyncRepositoryInterface)
+    assert issubclass(SQLAlchemyRepository, RuntimeRepoProtocol)
+    assert issubclass(SQLAlchemyAsyncRepository, RuntimeAsyncRepoProtocol)
 
     sync_methods = [
         method
@@ -26,15 +35,15 @@ def test_interfaces():
     assert sync_methods == async_methods
 
     for method in sync_methods:
-        # Sync signature is the same as sync protocol
+        # Concrete sync signature is the same as sync protocol signature
         assert signature(getattr(SQLAlchemyRepository, method)) == signature(
             getattr(SQLAlchemyRepositoryInterface, method)
         )
-        # Async signature is the same as async protocol
+        # Concrete async signature is the same as async protocol signature
         assert signature(getattr(SQLAlchemyAsyncRepository, method)) == signature(
             getattr(SQLAlchemyAsyncRepositoryInterface, method)
         )
-        # Sync signature is the same as async signature
+        # Sync protocol signature is the same as async protocol signature
         assert signature(
             getattr(SQLAlchemyAsyncRepositoryInterface, method)
         ) == signature(getattr(SQLAlchemyRepositoryInterface, method))