diff --git a/fastapi_users/authentication/__init__.py b/fastapi_users/authentication/__init__.py
index 8421596c..a152b145 100644
--- a/fastapi_users/authentication/__init__.py
+++ b/fastapi_users/authentication/__init__.py
@@ -7,6 +7,8 @@ from fastapi_users.models import BaseUserDB
 
 
 class BaseAuthentication:
+    """Base adapter for generating and decoding authentication tokens."""
+
     async def get_login_response(self, user: BaseUserDB, response: Response):
         raise NotImplementedError()
 
diff --git a/fastapi_users/authentication/jwt.py b/fastapi_users/authentication/jwt.py
index 99f9d282..60f1e20f 100644
--- a/fastapi_users/authentication/jwt.py
+++ b/fastapi_users/authentication/jwt.py
@@ -21,6 +21,12 @@ def generate_jwt(data: dict, lifetime_seconds: int, secret: str, algorithm: str)
 
 
 class JWTAuthentication(BaseAuthentication):
+    """
+    Authentication using a JWT.
+
+    :param secret: Secret used to encode the JWT.
+    :param lifetime_seconds: Lifetime duration of the JWT in seconds.
+    """
 
     algorithm: str = "HS256"
     secret: str
diff --git a/fastapi_users/models.py b/fastapi_users/models.py
index e2660a6f..d84e921c 100644
--- a/fastapi_users/models.py
+++ b/fastapi_users/models.py
@@ -7,6 +7,8 @@ from pydantic.types import EmailStr
 
 
 class BaseUser(BaseModel):
+    """Base User model."""
+
     id: Optional[str] = None
     email: Optional[EmailStr] = None
     is_active: Optional[bool] = True
@@ -31,6 +33,8 @@ class BaseUserDB(BaseUser):
 
 
 class Models:
+    """Generate models inheriting from the custom User model."""
+
     def __init__(self, user_model: Type[BaseUser]):
         class UserCreate(user_model, BaseUserCreate):  # type: ignore
             pass
diff --git a/fastapi_users/router.py b/fastapi_users/router.py
index f091bd76..b0db5a2f 100644
--- a/fastapi_users/router.py
+++ b/fastapi_users/router.py
@@ -14,6 +14,7 @@ from fastapi_users.password import get_password_hash
 def get_user_router(
     user_db: BaseUserDatabase, user_model: Type[BaseUser], auth: BaseAuthentication
 ) -> APIRouter:
+    """Generate a router with the authentication routes."""
     router = APIRouter()
     models = Models(user_model)