diff --git a/CHANGES.md b/CHANGES.md
index 97a4e54..70f289e 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,39 @@
 # Microdot change log
 
+**Release 2.3.2** - 2025-05-08
+
+- Use async error handlers in auth module [#298](https://github.com/miguelgrinberg/microdot/issues/298) ([commit](https://github.com/miguelgrinberg/microdot/commit/d9d7ff0825e4c5fbed6564d3684374bf3937df11))
+
+**Release 2.3.1** - 2025-04-13
+
+- Additional support needed when using `orjson` ([commit](https://github.com/miguelgrinberg/microdot/commit/cd0b3234ddb0c8ff4861d369836ec2aed77494db))
+
+**Release 2.3.0** - 2025-04-12
+
+- Support optional authentication methods ([commit](https://github.com/miguelgrinberg/microdot/commit/f317b15bdbf924007e5e3414e0c626baccc3ede6))
+- Catch SSL exceptions while writing the response [#206](https://github.com/miguelgrinberg/microdot/issues/206) ([commit](https://github.com/miguelgrinberg/microdot/commit/e7ee74d6bba74cfd89b9ddc38f28e02514eb1791))
+- Use `orjson` instead of `json` if available ([commit](https://github.com/miguelgrinberg/microdot/commit/086f2af3deab86d4340f3f1feb9e019de59f351d))
+- Addressed typing warnings from pyright ([commit](https://github.com/miguelgrinberg/microdot/commit/b6f232db1125045d79c444c736a2ae59c5501fdd))
+
+**Release 2.2.0** - 2025-03-22
+
+- Support for `multipart/form-data` requests [#287](https://github.com/miguelgrinberg/microdot/issues/287) ([commit](https://github.com/miguelgrinberg/microdot/commit/11a91a60350518e426b557fae8dffe75912f8823))
+- Support custom path components in URLs ([commit #1](https://github.com/miguelgrinberg/microdot/commit/c92b5ae28222af5a1094f5d2f70a45d4d17653d5) [commit #2](https://github.com/miguelgrinberg/microdot/commit/aa76e6378b37faab52008a8aab8db75f81b29323))
+- Expose the Jinja environment as `Template.jinja_env` ([commit](https://github.com/miguelgrinberg/microdot/commit/953dd9432122defe943f0637bbe7e01f2fc7743f))
+- Simplified urldecode logic ([commit #1](https://github.com/miguelgrinberg/microdot/commit/3bc31f10b2b2d4460c62366013278d87665f0f97) [commit #2](https://github.com/miguelgrinberg/microdot/commit/d203df75fef32c7cc0fe7cc6525e77522b37a289))
+- Additional urldecode tests ([commit](https://github.com/miguelgrinberg/microdot/commit/99f65c0198590c0dfb402c24685b6f8dfba1935d))
+- Documentation improvements ([commit](https://github.com/miguelgrinberg/microdot/commit/c6b99b6d8117d4e40e16d5b953dbf4deb023d24d))
+- Update micropython version used in tests to 1.24.1 ([commit](https://github.com/miguelgrinberg/microdot/commit/4cc2e95338a7de3b03742389004147ee21285621))
+
+**Release 2.1.0** - 2025-02-04
+
+- User login support ([commit](https://github.com/miguelgrinberg/microdot/commit/d807011ad006e53e70c4594d7eac04d03bb08681))
+- Basic and token authentication support ([commit](https://github.com/miguelgrinberg/microdot/commit/675c9787974da926af446974cd96ef224e0ee27f))
+- Added `local` argument to the `app.mount()` method, to define sub-application specific before and after request handlers ([commit](https://github.com/miguelgrinberg/microdot/commit/fd7931e1aec173c60f81dad18c1a102ed8f0e081))
+- Added `Request.url_prefix`, `Request.subapp` and local mounts ([commit](https://github.com/miguelgrinberg/microdot/commit/fd7931e1aec173c60f81dad18c1a102ed8f0e081))
+- Added a front end to the SSE example [#281](https://github.com/miguelgrinberg/microdot/issues/281) ([commit](https://github.com/miguelgrinberg/microdot/commit/d487a73c1ea5b3467e23907618b348ca52e0235c)) (thanks **Maxi**!)
+- Additional ``app.mount()`` unit tests ([commit](https://github.com/miguelgrinberg/microdot/commit/cd87abba30206ec6d3928e0aabacb2fccf7baf70))
+
 **Release 2.0.7** - 2024-11-10
 
 - Accept responses with just a status code [#263](https://github.com/miguelgrinberg/microdot/issues/263) ([commit #1](https://github.com/miguelgrinberg/microdot/commit/4eac013087f807cafa244b8a6b7b0ed4c82ff150) [commit #2](https://github.com/miguelgrinberg/microdot/commit/c46e4291061046f1be13f300dd08645b71c16635))
diff --git a/README.md b/README.md
index 24e1e42..ca0ebe6 100644
--- a/README.md
+++ b/README.md
@@ -43,8 +43,8 @@ describes the backwards incompatible changes that were made.
 The following features are planned for future releases of Microdot, both for
 MicroPython and CPython:
 
-- Support for forms encoded in `multipart/form-data` format
-- Authentication support, similar to [Flask-Login](https://github.com/maxcountryman/flask-login) for Flask
+- Authentication support, similar to [Flask-Login](https://github.com/maxcountryman/flask-login) for Flask (**Added in version 2.1**)
+- Support for forms encoded in `multipart/form-data` format (**Added in version 2.2**)
 - OpenAPI integration, similar to [APIFairy](https://github.com/miguelgrinberg/apifairy) for Flask
 
 In addition to the above, the following extensions are also under consideration,
@@ -53,4 +53,4 @@ but only for CPython:
 - Database integration through [SQLAlchemy](https://github.com/sqlalchemy/sqlalchemy)
 - Socket.IO support through [python-socketio](https://github.com/miguelgrinberg/python-socketio)
 
-Do you have other ideas to propose? Let's [discuss them](https://github.com/miguelgrinberg/microdot/discussions/new?category=ideas)!
+Do you have other ideas to propose? Let's [discuss them](https://github.com/:miguelgrinberg/microdot/discussions/new?category=ideas)!
diff --git a/bin/micropython b/bin/micropython
index 41e162e..6d1c263 100755
Binary files a/bin/micropython and b/bin/micropython differ
diff --git a/docs/api.rst b/docs/api.rst
index f63db86..f8fbea9 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -14,6 +14,12 @@ Core API
    :members:
 
 
+Multipart Forms
+---------------
+
+.. automodule:: microdot.multipart
+   :members:
+
 WebSocket
 ---------
 
@@ -44,6 +50,22 @@ User Sessions
 .. automodule:: microdot.session
    :members:
 
+Authentication
+--------------
+
+.. automodule:: microdot.auth
+   :inherited-members:
+   :special-members: __call__
+   :members:
+
+User Logins
+-----------
+
+.. automodule:: microdot.login
+   :inherited-members:
+   :special-members: __call__
+   :members:
+
 Cross-Origin Resource Sharing (CORS)
 ------------------------------------
 
diff --git a/docs/extensions.rst b/docs/extensions.rst
index 5f2da1e..69904f0 100644
--- a/docs/extensions.rst
+++ b/docs/extensions.rst
@@ -5,8 +5,82 @@ Microdot is a highly extensible web application framework. The extensions
 described in this section are maintained as part of the Microdot project in
 the same source code repository.
 
-WebSocket Support
-~~~~~~~~~~~~~~~~~
+Multipart Forms
+~~~~~~~~~~~~~~~
+
+.. list-table::
+   :align: left
+
+   * - Compatibility
+     - | CPython & MicroPython
+
+   * - Required Microdot source files
+     -  | `multipart.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/multipart.py>`_
+        | `helpers.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/helpers.py>`_
+
+   * - Required external dependencies
+     - | None
+
+   * - Examples
+     - | `formdata.py <https://github.com/miguelgrinberg/microdot/blob/main/examples/uploads/formdata.py>`_
+
+The multipart extension handles multipart forms, including those that have file
+uploads.
+
+The :func:`with_form_data <microdot.multipart.with_form_data>` decorator
+provides the simplest way to work with these forms. With this decorator added
+to the route, whenever the client sends a multipart request the
+:attr:`request.form <microdot.Request.form>` and
+:attr:`request.files <microdot.Request.files>` properties are populated with
+the submitted data. For form fields the field values are always strings. For
+files, they are instances of the
+:class:`FileUpload <microdot.multipart.FileUpload>` class.
+
+Example::
+
+    from microdot.multipart import with_form_data
+
+    @app.post('/upload')
+    @with_form_data
+    async def upload(request):
+        print('form fields:', request.form)
+        print('files:', request.files)
+
+One disadvantage of the ``@with_form_data`` decorator is that it has to copy
+any uploaded files to memory or temporary disk files, depending on their size.
+The :attr:`FileUpload.max_memory_size <microdot.multipart.FileUpload.max_memory_size>`
+attribute can be used to control the cutoff size above which a file upload
+is transferred to a temporary file.
+
+A more performant alternative to the ``@with_form_data`` decorator is the
+:class:`FormDataIter <microdot.multipart.FormDataIter>` class, which iterates
+over the form fields sequentially, giving the application the option to parse
+the form fields on the fly and decide what to copy and what to discard. When
+using ``FormDataIter`` the ``request.form`` and ``request.files`` attributes
+are not used.
+
+Example::
+
+
+    from microdot.multipart import FormDataIter
+
+    @app.post('/upload')
+    async def upload(request):
+        async for name, value in FormDataIter(request):
+            print(name, value)
+
+For fields that contain an uploaded file, the ``value`` returned by the
+iterator is the same ``FileUpload`` instance. The application can choose to
+save the file with the :meth:`save() <microdot.multipart.FileUpload.save>`
+method, or read it with the :meth:`read() <microdot.multipart.FileUpload.read>`
+method, optionally passing a size to read it in chunks. The
+:meth:`copy() <microdot.multipart.FileUpload.copy>` method is also available to
+apply the copying logic used by the ``@with_form_data`` decorator, which is
+inefficient but allows the file to be set aside to be processed later, after
+the remaining form fields.
+
+WebSocket
+~~~~~~~~~
 
 .. list-table::
    :align: left
@@ -16,6 +90,7 @@ WebSocket Support
 
    * - Required Microdot source files
      -  | `websocket.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/websocket.py>`_
+        | `helpers.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/helpers.py>`_
 
    * - Required external dependencies
      - | None
@@ -32,15 +107,17 @@ messages respectively.
 
 Example::
 
-        @app.route('/echo')
-        @with_websocket
-        async def echo(request, ws):
-            while True:
-                message = await ws.receive()
-                await ws.send(message)
+    from microdot.websocket import with_websocket
+
+    @app.route('/echo')
+    @with_websocket
+    async def echo(request, ws):
+        while True:
+            message = await ws.receive()
+            await ws.send(message)
 
-Server-Sent Events Support
-~~~~~~~~~~~~~~~~~~~~~~~~~~
+Server-Sent Events
+~~~~~~~~~~~~~~~~~~
 
 .. list-table::
    :align: left
@@ -50,6 +127,7 @@ Server-Sent Events Support
 
    * - Required Microdot source files
      -  | `sse.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/sse.py>`_
+        | `helpers.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/helpers.py>`_
 
    * - Required external dependencies
      - | None
@@ -65,6 +143,8 @@ asynchronous method to send an event to the client.
 
 Example::
 
+    from microdot.sse import with_sse
+
     @app.route('/events')
     @with_sse
     async def events(request, sse):
@@ -78,8 +158,8 @@ Example::
    the SSE object. For bidirectional communication with the client, use the
    WebSocket extension.
 
-Rendering Templates
-~~~~~~~~~~~~~~~~~~~
+Templates
+~~~~~~~~~
 
 Many web applications use HTML templates for rendering content to clients.
 Microdot includes extensions to render templates with the
@@ -202,8 +282,8 @@ must be used.
 .. note::
     The Jinja extension is not compatible with MicroPython.
 
-Maintaining Secure User Sessions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Secure User Sessions
+~~~~~~~~~~~~~~~~~~~~
 
 .. list-table::
    :align: left
@@ -213,6 +293,7 @@ Maintaining Secure User Sessions
 
    * - Required Microdot source files
      - | `session.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/session.py>`_
+       | `helpers.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/helpers.py>`_
 
    * - Required external dependencies
      - | CPython: `PyJWT <https://pyjwt.readthedocs.io/>`_
@@ -270,6 +351,204 @@ The :func:`save() <microdot.session.SessionDict.save>` and
 :func:`delete() <microdot.session.SessionDict.delete>` methods are used to update
 and destroy the user session respectively.
 
+Authentication
+~~~~~~~~~~~~~~
+
+.. list-table::
+   :align: left
+
+   * - Compatibility
+     - | CPython & MicroPython
+
+   * - Required Microdot source files
+     - | `auth.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/auth.py>`_
+
+   * - Required external dependencies
+     - | None
+
+   * - Examples
+     - | `basic_auth.py <https://github.com/miguelgrinberg/microdot/blob/main/examples/auth/basic_auth.py>`_
+       | `token_auth.py <https://github.com/miguelgrinberg/microdot/blob/main/examples/auth/token_auth.py>`_
+
+The authentication extension provides helper classes for two commonly used
+authentication patterns, described below.
+
+Basic Authentication
+^^^^^^^^^^^^^^^^^^^^
+
+`Basic Authentication <https://en.wikipedia.org/wiki/Basic_access_authentication>`_
+is a method of authentication that is part of the HTTP specification. It allows
+clients to authenticate to a server using a username and a password. Web
+browsers have native support for Basic Authentication and will automatically
+prompt the user for a username and a password when a protected resource is
+accessed.
+
+To use Basic Authentication, create an instance of the :class:`BasicAuth <microdot.auth.BasicAuth>`
+class::
+
+    from microdot.auth import BasicAuth
+
+    auth = BasicAuth(app)
+
+Next, create an authentication function. The function must accept a request
+object and a username and password pair provided by the user. If the
+credentials are valid, the function must return an object that represents the
+user. If the authentication function cannot validate the user provided
+credentials it must return ``None``. Decorate the function with
+``@auth.authenticate``::
+
+    @auth.authenticate
+    async def verify_user(request, username, password):
+        user = await load_user_from_database(username)
+        if user and user.verify_password(password):
+            return user
+
+To protect a route with authentication, add the ``auth`` instance as a
+decorator::
+
+    @app.route('/')
+    @auth
+    async def index(request):
+        return f'Hello, {request.g.current_user}!'
+
+While running an authenticated request, the user object returned by the
+authenticaction function is accessible as ``request.g.current_user``.
+
+If an endpoint is intended to work with or without authentication, then it can
+be protected with the ``auth.optional`` decorator::
+
+    @app.route('/')
+    @auth.optional
+    async def index(request):
+        if g.current_user:
+            return f'Hello, {request.g.current_user}!'
+        else:
+            return 'Hello, anonymous user!'
+
+As shown in the example, a route can check ``g.current_user`` to determine if
+the user is authenticated or not.
+
+Token Authentication
+^^^^^^^^^^^^^^^^^^^^
+
+To set up token authentication, create an instance of
+:class:`TokenAuth <microdot.auth.TokenAuth>`::
+
+    from microdot.auth import TokenAuth
+
+    auth = TokenAuth()
+
+Then add a function that verifies the token and returns the user it belongs to,
+or ``None`` if the token is invalid or expired::
+
+    @auth.authenticate
+    async def verify_token(request, token):
+        return load_user_from_token(token)
+
+As with Basic authentication, the ``auth`` instance is used as a decorator to
+protect your routes::
+
+    @app.route('/')
+    @auth
+    async def index(request):
+        return f'Hello, {request.g.current_user}!'
+
+Optional authentication can also be used with tokens::
+
+    @app.route('/')
+    @auth.optional
+    async def index(request):
+        if g.current_user:
+            return f'Hello, {request.g.current_user}!'
+        else:
+            return 'Hello, anonymous user!'
+
+User Logins
+~~~~~~~~~~~
+
+.. list-table::
+   :align: left
+
+   * - Compatibility
+     - | CPython & MicroPython
+
+   * - Required Microdot source files
+     - | `login.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/auth.py>`_
+       | `session.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/session.py>`_
+       | `helpers.py <https://github.com/miguelgrinberg/microdot/tree/main/src/microdot/helpers.py>`_
+   * - Required external dependencies
+     - | CPython: `PyJWT <https://pyjwt.readthedocs.io/>`_
+       | MicroPython: `jwt.py <https://github.com/micropython/micropython-lib/blob/master/python-ecosys/pyjwt/jwt.py>`_,
+                      `hmac.py <https://github.com/micropython/micropython-lib/blob/master/python-stdlib/hmac/hmac.py>`_
+   * - Examples
+     - | `login.py <https://github.com/miguelgrinberg/microdot/blob/main/examples/login/login.py>`_
+
+The login extension provides user login functionality. The logged in state of
+the user is stored in the user session cookie, and an optional "remember me"
+cookie can also be added to keep the user logged in across browser sessions.
+
+To use this extension, create instances of the
+:class:`Session <microdot.session.Session>` and :class:`Login <microdot.login.Login>`
+class::
+
+    Session(app, secret_key='top-secret!')
+    login = Login()
+
+The ``Login`` class accept an optional argument with the URL of the login page.
+The default for this URL is */login*.
+
+The application must represent users as objects with an ``id`` attribute. A
+function decorated with ``@login.user_loader`` is used to load a user object::
+
+    @login.user_loader
+    async def get_user(user_id):
+        return database.get_user(user_id)
+
+The application must implement the login form. At the point in which the user
+credentials have been received and verified, a call to the
+:func:`login_user() <microdot.login.Login.login_user>` function must be made to
+record the user in the user session::
+
+    @app.route('/login', methods=['GET', 'POST'])
+    async def login(request):
+        # ...
+        if user.check_password(password):
+            return await login.login_user(request, user, remember=remember_me)
+        return redirect('/login')
+
+The optional ``remember`` argument is used to add a remember me cookie that
+will log the user in automatically in future sessions. A value of ``True`` will
+keep the log in active for 30 days. Alternatively, an integer number of days
+can be passed in this argument.
+
+Any routes that require the user to be logged in must be decorated with
+:func:`@login <microdot.login.Login.__call__>`::
+
+    @app.route('/')
+    @login
+    async def index(request):
+        # ...
+
+Routes that are of a sensitive nature can be decorated with
+:func:`@login.fresh <microdot.login.Login.fresh>`
+instead. This decorator requires that the user has logged in during the current
+session, and will ask the user to logged in again if the session was
+authenticated through a remember me cookie::
+
+    @app.get('/fresh')
+    @login.fresh
+    async def fresh(request):
+        # ...
+
+To log out a user, the :func:`logout_user() <microdot.auth.Login.logout_user>`
+is used::
+
+    @app.post('/logout')
+    @login
+    async def logout(request):
+        await login.logout_user(request)
+        return redirect('/')
+
 Cross-Origin Resource Sharing (CORS)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -305,8 +584,8 @@ Example::
     cors = CORS(app, allowed_origins=['https://example.com/'],
                 allow_credentials=True)
 
-Testing with the Test Client
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test Client
+~~~~~~~~~~~
 
 .. list-table::
    :align: left
@@ -342,8 +621,8 @@ Example::
 See the documentation for the :class:`TestClient <microdot.test_client.TestClient>`
 class for more details.
 
-Deploying on a Production Web Server
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Production Deployments
+~~~~~~~~~~~~~~~~~~~~~~
 
 The ``Microdot`` class creates its own simple web server. This is enough for an
 application deployed with MicroPython, but when using CPython it may be useful
diff --git a/docs/freezing.rst b/docs/freezing.rst
index 0a85bc2..ea75eb5 100644
--- a/docs/freezing.rst
+++ b/docs/freezing.rst
@@ -1,5 +1,8 @@
-Cross-Compiling and Freezing Microdot (MicroPython Only)
---------------------------------------------------------
+Cross-Compiling and Freezing Microdot
+-------------------------------------
+
+.. note::
+   This section only applies when using Microdot on MicroPython.
 
 Microdot is a fairly small framework, so its size is not something you need to
 be concerned about unless you are working with MicroPython on hardware with a
@@ -36,7 +39,7 @@ Cross-Compiling
 
 An issue that is common with low-end microcontroller boards is that they do not
 have enough RAM for the MicroPython compiler to compile the source files, but
-once the code is compiled they are able to run it without problems.
+once the code is compiled they are able to run it just fine.
 
 To address this, MicroPython allows you to cross-compile source files on your
 desktop or laptop computer and then upload their compiled versions to the
@@ -82,8 +85,8 @@ imported directly from the device's ROM, leaving more RAM available for
 application use.
 
 The process to create a custom firmware is unfortunately non-trivial and
-different depending on the device, so you will need to consult the MicroPython
-documentation that applies to your device to learn how to do this.
+different for each microcontroller platform, so you will need to consult the
+MicroPython documentation that applies to your device to learn how to do this.
 
 The part of the process that is common to all devices is the creation of a
 `manifest file <https://docs.micropython.org/en/latest/reference/manifest.html>`_
diff --git a/docs/intro.rst b/docs/intro.rst
index aa76f05..3ce4b49 100644
--- a/docs/intro.rst
+++ b/docs/intro.rst
@@ -329,15 +329,52 @@ URL::
     async def get_test(request, path):
         return 'Test: ' + path
 
-For the most control, the ``re`` type allows the application to provide a
-custom regular expression for the dynamic component. The next example defines
-a route that only matches usernames that begin with an upper or lower case
-letter, followed by a sequence of letters or numbers::
+The ``re`` type allows the application to provide a custom regular expression
+for the dynamic component. The next example defines a route that only matches
+usernames that begin with an upper or lower case letter, followed by a sequence
+of letters or numbers::
 
     @app.get('/users/<re:[a-zA-Z][a-zA-Z0-9]*:username>')
     async def get_user(request, username):
         return 'User: ' + username
 
+The ``re`` type returns the URL component as a string, which sometimes may not
+be the most convenient. To convert a path component to something more
+meaningful than a string, the application can register a custom URL component
+type and provide a parser function that performs the conversion. In the
+following example, a ``hex`` custom type is registered to automatically
+convert hex numbers given in the path to numbers::
+
+    from microdot import URLPattern
+
+    URLPattern.register_type('hex', parser=lambda value: int(value, 16))
+
+    @app.get('/users/<hex:user_id>')
+    async def get_user(request, user_id):
+        user = get_user_by_id(user_id)
+        # ...
+
+In addition to the parser, the custom URL component can include a pattern,
+given as a regular expression. When a pattern is provided, the URL component
+will only match if the regular expression matches the value passed in the URL.
+The ``hex`` example above can be expanded with a pattern as follows::
+
+    URLPattern.register_type('hex', pattern='[0-9a-fA-F]+',
+                             parser=lambda value: int(value, 16))
+
+In cases where a pattern isn't provided, or when the pattern is unable to
+filter out all invalid values, the parser function can return ``None`` to
+indicate a failed match. The next example shows how the parser for the ``hex``
+type can be expanded to do that::
+
+    def hex_parser(value):
+        try:
+            return int(value, 16)
+        except ValueError:
+            return None
+
+    URLPattern.register_type('hex', parser=hex_parser)
+
 .. note::
    Dynamic path components are passed to route functions as keyword arguments,
    so the names of the function arguments must match the names declared in the
@@ -445,7 +482,7 @@ Mounting a Sub-Application
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Small Microdot applications can be written as a single source file, but this
-is not the best option for applications that past a certain size. To make it
+is not the best option for applications that pass a certain size. To make it
 simpler to write large applications, Microdot supports the concept of
 sub-applications that can be "mounted" on a larger application, possibly with
 a common URL prefix applied to all of its routes. For developers familiar with
@@ -501,11 +538,25 @@ The resulting application will have the customer endpoints available at
 */customers/* and the order endpoints available at */orders/*.
 
 .. note::
-   Before-request, after-request and error handlers defined in the
-   sub-application are also copied over to the main application at mount time.
-   Once installed in the main application, these handlers will apply to the
-   whole application and not just the sub-application in which they were
-   created.
+   During the handling of a request, the
+   :attr:`Request.url_prefix <microdot.Microdot.url_prefix>` attribute is
+   set to the URL prefix under which the sub-application was mounted, or an
+   empty string if the endpoint did not come from a sub-application or the
+   sub-application was mounted without a URL prefix. It is possible to issue a
+   redirect that is relative to the sub-application as follows::
+
+      return redirect(request.url_prefix + '/relative-url')
+
+When mounting an application as shown above, before-request, after-request and
+error handlers defined in the sub-application are copied over to the main
+application at mount time. Once installed in the main application, these
+handlers will apply to the whole application and not just the sub-application
+in which they were created.
+
+The :func:`mount() <microdot.Microdot.mount>` method has a ``local`` argument
+that defaults to ``False``. When this argument is set to ``True``, the
+before-request, after-request and error handlers defined in the sub-application
+will only apply to the sub-application.
 
 Shutting Down the Server
 ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -881,18 +932,36 @@ Another option is to create a response object directly in the route function::
 Concurrency
 ~~~~~~~~~~~
 
-Microdot implements concurrency through the ``asyncio`` package. Applications
-must ensure their handlers do not block, as this will prevent other concurrent
-requests from being handled.
+Microdot implements concurrency through the ``asyncio`` package, which means
+that applications must be careful to prevent blocking in their handlers.
+
+"async def" handlers
+^^^^^^^^^^^^^^^^^^^^
+
+The recommendation for route handlers in Microdot is to use asynchronous
+functions, declared as ``async def``. Microdot executes these handler
+functions as native asynchronous tasks. The standard considerations for writing
+asynchronous code apply, and in particular blocking calls should be avoided to
+ensure the application runs smoothly and is always responsive.
+
+"def" handlers
+^^^^^^^^^^^^^^
+
+Microdot also supports the use of synchronous route handlers, declared as
+standard ``def`` functions. These handlers are handled differently under
+CPython and MicroPython.
 
-When running under CPython, ``async def`` handler functions run as native 
-asyncio tasks, while ``def`` handler functions are executed in a
-`thread executor <https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.run_in_executor>`_
-to prevent them from blocking the asynchronous loop.
+When running on CPython, Microdot executes synchronous handlers in a
+`thread executor <https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.run_in_executor>`_,
+which uses a thread pool. The use of blocking or CPU intensive code in these
+handlers does not have such a negative effect on the application, because
+handlers do not run on the same thread as the asynchronous loop. On the other
+hand, the application will be affected by threading issues such as those caused
+by the Global Interpreter Lock.
 
 Under MicroPython the situation is different. Most microcontroller boards
-implementing MicroPython do not have threading support or executors, so ``def``
-handler functions in this platform can only run in the main and only thread.
-These functions will block the asynchronous loop when they take too long to
-complete so ``async def`` handlers properly written to allow other handlers to
-run in parallel should be preferred.
+do not have or have very limited threading support, so Microdot executes
+synchronous handlers in the main and often only thread available. This means
+that these functions will block the asynchronous loop when they take too long
+to complete. The use of properly written asynchronous handlers should be
+preferred.
diff --git a/examples/auth/README.md b/examples/auth/README.md
new file mode 100644
index 0000000..46f692a
--- /dev/null
+++ b/examples/auth/README.md
@@ -0,0 +1 @@
+This directory contains examples that demonstrate basic and token authentication.
diff --git a/examples/auth/basic_auth.py b/examples/auth/basic_auth.py
new file mode 100644
index 0000000..0e7de15
--- /dev/null
+++ b/examples/auth/basic_auth.py
@@ -0,0 +1,31 @@
+from microdot import Microdot
+from microdot.auth import BasicAuth
+from pbkdf2 import generate_password_hash, check_password_hash
+
+
+# this example provides an implementation of the generate_password_hash and
+# check_password_hash functions that can be used in MicroPython. On CPython
+# there are many other options for password hashisng so there is no need to use
+# this custom solution.
+USERS = {
+    'susan': generate_password_hash('hello'),
+    'david': generate_password_hash('bye'),
+}
+app = Microdot()
+auth = BasicAuth()
+
+
+@auth.authenticate
+async def check_credentials(request, username, password):
+    if username in USERS and check_password_hash(USERS[username], password):
+        return username
+
+
+@app.route('/')
+@auth
+async def index(request):
+    return f'Hello, {request.g.current_user}!'
+
+
+if __name__ == '__main__':
+    app.run(debug=True)
diff --git a/examples/auth/pbkdf2.py b/examples/auth/pbkdf2.py
new file mode 100644
index 0000000..ccd18b7
--- /dev/null
+++ b/examples/auth/pbkdf2.py
@@ -0,0 +1,47 @@
+import os
+import hashlib
+
+# PBKDF2 secure password hashing algorithm obtained from:
+# https://codeandlife.com/2023/01/06/how-to-calculate-pbkdf2-hmac-sha256-with-
+# python,-example-code/
+
+
+def sha256(b):
+    return hashlib.sha256(b).digest()
+
+
+def ljust(b, n, f):
+    return b + f * (n - len(b))
+
+
+def gethmac(key, content):
+    okeypad = bytes(v ^ 0x5c for v in ljust(key, 64, b'\0'))
+    ikeypad = bytes(v ^ 0x36 for v in ljust(key, 64, b'\0'))
+    return sha256(okeypad + sha256(ikeypad + content))
+
+
+def pbkdf2(pwd, salt, iterations=1000):
+    U = salt + b'\x00\x00\x00\x01'
+    T = bytes(64)
+    for _ in range(iterations):
+        U = gethmac(pwd, U)
+        T = bytes(a ^ b for a, b in zip(U, T))
+    return T
+
+
+# The number of iterations may need to be adjusted depending on the hardware.
+# Lower numbers make the password hashing algorithm faster but less secure, so
+# the largest number that can be tolerated should be used.
+def generate_password_hash(password, salt=None, iterations=100000):
+    salt = salt or os.urandom(16)
+    dk = pbkdf2(password.encode(), salt, iterations)
+    return f'pbkdf2-hmac-sha256:{salt.hex()}:{iterations}:{dk.hex()}'
+
+
+def check_password_hash(password_hash, password):
+    algorithm, salt, iterations, dk = password_hash.split(':')
+    iterations = int(iterations)
+    if algorithm != 'pbkdf2-hmac-sha256':
+        return False
+    return pbkdf2(password.encode(), salt=bytes.fromhex(salt),
+                  iterations=iterations) == bytes.fromhex(dk)
diff --git a/examples/auth/token_auth.py b/examples/auth/token_auth.py
new file mode 100644
index 0000000..ddfce3c
--- /dev/null
+++ b/examples/auth/token_auth.py
@@ -0,0 +1,26 @@
+from microdot import Microdot
+from microdot.auth import TokenAuth
+
+app = Microdot()
+auth = TokenAuth()
+
+TOKENS = {
+    'susan-token': 'susan',
+    'david-token': 'david',
+}
+
+
+@auth.authenticate
+async def check_token(request, token):
+    if token in TOKENS:
+        return TOKENS[token]
+
+
+@app.route('/')
+@auth
+async def index(request):
+    return f'Hello, {request.g.current_user}!'
+
+
+if __name__ == '__main__':
+    app.run(debug=True)
diff --git a/examples/benchmark/requirements.txt b/examples/benchmark/requirements.txt
index e1f2936..1633d26 100644
--- a/examples/benchmark/requirements.txt
+++ b/examples/benchmark/requirements.txt
@@ -32,9 +32,9 @@ flask==3.0.0
     # via
     #   -r requirements.in
     #   quart
-gunicorn==22.0.0
+gunicorn==23.0.0
     # via -r requirements.in
-h11==0.14.0
+h11==0.16.0
     # via
     #   hypercorn
     #   uvicorn
@@ -57,7 +57,7 @@ itsdangerous==2.1.2
     # via
     #   flask
     #   quart
-jinja2==3.1.4
+jinja2==3.1.6
     # via
     #   flask
     #   quart
@@ -82,7 +82,7 @@ pydantic-core==2.14.5
     # via pydantic
 pyproject-hooks==1.0.0
     # via build
-quart==0.19.7
+quart==0.20.0
     # via -r requirements.in
 requests==2.32.0
     # via -r requirements.in
diff --git a/examples/login/README.md b/examples/login/README.md
new file mode 100644
index 0000000..e41c267
--- /dev/null
+++ b/examples/login/README.md
@@ -0,0 +1 @@
+This directory contains examples that demonstrate user logins.
diff --git a/examples/login/login.py b/examples/login/login.py
new file mode 100644
index 0000000..3135e41
--- /dev/null
+++ b/examples/login/login.py
@@ -0,0 +1,123 @@
+from microdot import Microdot, redirect
+from microdot.session import Session
+from microdot.login import Login
+from pbkdf2 import generate_password_hash, check_password_hash
+
+# this example provides an implementation of the generate_password_hash and
+# check_password_hash functions that can be used in MicroPython. On CPython
+# there are many other options for password hashisng so there is no need to use
+# this custom solution.
+
+
+class User:
+    def __init__(self, id, username, password):
+        self.id = id
+        self.username = username
+        self.password_hash = self.create_hash(password)
+
+    def create_hash(self, password):
+        return generate_password_hash(password)
+
+    def check_password(self, password):
+        return check_password_hash(self.password_hash, password)
+
+
+USERS = {
+    'user001': User('user001', 'susan', 'hello'),
+    'user002': User('user002', 'david', 'bye'),
+}
+
+app = Microdot()
+Session(app, secret_key='top-secret!')
+login = Login()
+
+
+@login.user_loader
+async def get_user(user_id):
+    return USERS.get(user_id)
+
+
+@app.route('/login', methods=['GET', 'POST'])
+async def login_page(request):
+    if request.method == 'GET':
+        return '''
+            <!doctype html>
+            <html>
+              <body>
+                <h1>Please Login</h1>
+                <form method="POST">
+                  <p>
+                    Username<br>
+                    <input name="username" autofocus>
+                  </p>
+                  <p>
+                    Password:<br>
+                    <input name="password" type="password">
+                    <br>
+                  </p>
+                  <p>
+                    <input name="remember_me" type="checkbox"> Remember me
+                    <br>
+                  </p>
+                  <p>
+                    <button type="submit">Login</button>
+                  </p>
+                </form>
+              </body>
+            </html>
+        ''', {'Content-Type': 'text/html'}
+    username = request.form['username']
+    password = request.form['password']
+    remember_me = bool(request.form.get('remember_me'))
+
+    for user in USERS.values():
+        if user.username == username:
+            if user.check_password(password):
+                return await login.login_user(request, user,
+                                              remember=remember_me)
+    return redirect('/login')
+
+
+@app.route('/')
+@login
+async def index(request):
+    return f'''
+        <!doctype html>
+        <html>
+          <body>
+            <h1>Hello, {request.g.current_user.username}!</h1>
+            <p>
+              <a href="http://github.com/fresh">Click here</a> to access the fresh login page.
+            </p>
+            <form method="POST" action="http://github.com/logout">
+              <button type="submit">Logout</button>
+            </form>
+          </body>
+        </html>
+    ''', {'Content-Type': 'text/html'}
+
+
+@app.get('/fresh')
+@login.fresh
+async def fresh(request):
+    return f'''
+        <!doctype html>
+        <html>
+          <body>
+            <h1>Hello, {request.g.current_user.username}!</h1>
+            <p>This page requires a fresh login session.</p>
+            <p><a href="http://github.com/">Go back</a> to the main page.</p>
+          </body>
+        </html>
+    ''', {'Content-Type': 'text/html'}
+
+
+@app.post('/logout')
+@login
+async def logout(request):
+    await login.logout_user(request)
+    return redirect('/')
+
+
+if __name__ == '__main__':
+    app.run(debug=True)
diff --git a/examples/login/pbkdf2.py b/examples/login/pbkdf2.py
new file mode 100644
index 0000000..ccd18b7
--- /dev/null
+++ b/examples/login/pbkdf2.py
@@ -0,0 +1,47 @@
+import os
+import hashlib
+
+# PBKDF2 secure password hashing algorithm obtained from:
+# https://codeandlife.com/2023/01/06/how-to-calculate-pbkdf2-hmac-sha256-with-
+# python,-example-code/
+
+
+def sha256(b):
+    return hashlib.sha256(b).digest()
+
+
+def ljust(b, n, f):
+    return b + f * (n - len(b))
+
+
+def gethmac(key, content):
+    okeypad = bytes(v ^ 0x5c for v in ljust(key, 64, b'\0'))
+    ikeypad = bytes(v ^ 0x36 for v in ljust(key, 64, b'\0'))
+    return sha256(okeypad + sha256(ikeypad + content))
+
+
+def pbkdf2(pwd, salt, iterations=1000):
+    U = salt + b'\x00\x00\x00\x01'
+    T = bytes(64)
+    for _ in range(iterations):
+        U = gethmac(pwd, U)
+        T = bytes(a ^ b for a, b in zip(U, T))
+    return T
+
+
+# The number of iterations may need to be adjusted depending on the hardware.
+# Lower numbers make the password hashing algorithm faster but less secure, so
+# the largest number that can be tolerated should be used.
+def generate_password_hash(password, salt=None, iterations=100000):
+    salt = salt or os.urandom(16)
+    dk = pbkdf2(password.encode(), salt, iterations)
+    return f'pbkdf2-hmac-sha256:{salt.hex()}:{iterations}:{dk.hex()}'
+
+
+def check_password_hash(password_hash, password):
+    algorithm, salt, iterations, dk = password_hash.split(':')
+    iterations = int(iterations)
+    if algorithm != 'pbkdf2-hmac-sha256':
+        return False
+    return pbkdf2(password.encode(), salt=bytes.fromhex(salt),
+                  iterations=iterations) == bytes.fromhex(dk)
diff --git a/examples/sessions/login.py b/examples/sessions/login.py
index e7fd2ef..9a042ac 100644
--- a/examples/sessions/login.py
+++ b/examples/sessions/login.py
@@ -1,3 +1,6 @@
+# This is a simple example that demonstrates how to use the user session, but
+# is not intended as a complete login solution. See the login subdirectory for
+# a more complete example.
 from microdot import Microdot, Response, redirect
 from microdot.session import Session, with_session
 
diff --git a/examples/sse/counter.py b/examples/sse/counter.py
index 36f4bec..ee5a536 100644
--- a/examples/sse/counter.py
+++ b/examples/sse/counter.py
@@ -1,16 +1,28 @@
 import asyncio
-from microdot import Microdot
+from microdot import Microdot, send_file
 from microdot.sse import with_sse
 
 app = Microdot()
 
 
+@app.route("/")
+async def main(request):
+    return send_file('index.html')
+
+
 @app.route('/events')
 @with_sse
 async def events(request, sse):
-    for i in range(10):
-        await asyncio.sleep(1)
-        await sse.send({'counter': i})
+    print('Client connected')
+    try:
+        i = 0
+        while True:
+            await asyncio.sleep(1)
+            i += 1
+            await sse.send({'counter': i})
+    except asyncio.CancelledError:
+        pass
+    print('Client disconnected')
 
 
-app.run(debug=True)
+app.run()
diff --git a/examples/sse/index.html b/examples/sse/index.html
new file mode 100644
index 0000000..bc64df2
--- /dev/null
+++ b/examples/sse/index.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Microdot SSE Example</title>
+    <meta charset="UTF-8">
+  </head>
+  <body>
+    <h1>Microdot SSE Example</h1>
+    <div id="log"></div>
+    <script>
+      const log = (text, color) => {
+        document.getElementById('log').innerHTML += `<span style="color: ${color}">${text}</span><br>`;
+      };
+
+      const eventSource = new EventSource('/events');
+
+      eventSource.onopen = () => {
+        log('Connection to server opened.', 'black');
+      };
+
+      eventSource.onmessage = (event) => {
+        log(`Received message: ${event.data}`, 'blue');
+      };
+
+      eventSource.onerror = (event) => {
+        log(`EventSource failed: ${event.type}`, 'red');
+      };
+    </script>
+  </body>
+</html>
diff --git a/examples/uploads/README.md b/examples/uploads/README.md
index 5c61185..62977b1 100644
--- a/examples/uploads/README.md
+++ b/examples/uploads/README.md
@@ -1 +1,4 @@
 This directory contains file upload examples.
+
+- `simple_uploads.py` demonstrates how to upload a single file.
+- `formdata.py` demonstrates how to process a form that includes file uploads.
diff --git a/examples/uploads/formdata.html b/examples/uploads/formdata.html
new file mode 100644
index 0000000..5411811
--- /dev/null
+++ b/examples/uploads/formdata.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<html>
+  <head>
+    <title>Microdot Multipart Form-Data Example</title>
+    <meta charset="UTF-8">
+  </head>
+  <body>
+    <h1>Microdot Multipart Form-Data Example</h1>
+    <form method="POST" action="" enctype="multipart/form-data">
+      <p>Name: <input type="text" name="name" /></p>
+      <p>Age: <input type="text" name="age" /></p>
+      <p>Comments: <textarea name="comments" rows="4"></textarea></p>
+      <p>File: <input type="file" id="file" name="file" /></p>
+      <input type="submit" value="Submit" />
+    </form>
+  </body>
+</html>
diff --git a/examples/uploads/formdata.py b/examples/uploads/formdata.py
new file mode 100644
index 0000000..2efdcfa
--- /dev/null
+++ b/examples/uploads/formdata.py
@@ -0,0 +1,26 @@
+from microdot import Microdot, send_file, Request
+from microdot.multipart import with_form_data
+
+app = Microdot()
+Request.max_content_length = 1024 * 1024  # 1MB (change as needed)
+
+
+@app.get('/')
+async def index(request):
+    return send_file('formdata.html')
+
+
+@app.post('/')
+@with_form_data
+async def upload(request):
+    print('Form fields:')
+    for field, value in request.form.items():
+        print(f'- {field}: {value}')
+    print('\nFile uploads:')
+    for field, value in request.files.items():
+        print(f'- {field}: {value.filename}, {await value.read()}')
+    return 'We have received your data!'
+
+
+if __name__ == '__main__':
+    app.run(debug=True)
diff --git a/examples/uploads/index.html b/examples/uploads/simple_uploads.html
similarity index 100%
rename from examples/uploads/index.html
rename to examples/uploads/simple_uploads.html
diff --git a/examples/uploads/uploads.py b/examples/uploads/simple_uploads.py
similarity index 95%
rename from examples/uploads/uploads.py
rename to examples/uploads/simple_uploads.py
index 37648e9..3530bc2 100644
--- a/examples/uploads/uploads.py
+++ b/examples/uploads/simple_uploads.py
@@ -6,7 +6,7 @@
 
 @app.get('/')
 async def index(request):
-    return send_file('index.html')
+    return send_file('simple_uploads.html')
 
 
 @app.post('/upload')
diff --git a/pyproject.toml b/pyproject.toml
index eb71381..14e49f5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "microdot"
-version = "2.0.8.dev0"
+version = "2.3.3.dev0"
 authors = [
     { name = "Miguel Grinberg", email = "miguel.grinberg@gmail.com" },
 ]
diff --git a/src/microdot/__init__.py b/src/microdot/__init__.py
index b619686..2637085 100644
--- a/src/microdot/__init__.py
+++ b/src/microdot/__init__.py
@@ -1,2 +1,2 @@
 from microdot.microdot import Microdot, Request, Response, abort, redirect, \
-    send_file  # noqa: F401
+    send_file, URLPattern, AsyncBytesIO, iscoroutine  # noqa: F401
diff --git a/src/microdot/auth.py b/src/microdot/auth.py
new file mode 100644
index 0000000..71574ee
--- /dev/null
+++ b/src/microdot/auth.py
@@ -0,0 +1,162 @@
+from microdot import abort
+from microdot.microdot import invoke_handler
+
+
+class BaseAuth:
+    def __init__(self):
+        self.auth_callback = None
+        self.error_callback = None
+
+    def __call__(self, f):
+        """Decorator to protect a route with authentication.
+
+        An instance of this class must be used as a decorator on the routes
+        that need to be protected. Example::
+
+           auth = BasicAuth()  # or TokenAuth()
+
+           @app.route('/protected')
+           @auth
+           def protected(request):
+               # ...
+
+        Routes that are decorated in this way will only be invoked if the
+        authentication callback returned a valid user object, otherwise the
+        error callback will be executed.
+        """
+        async def wrapper(request, *args, **kwargs):
+            auth = self._get_auth(request)
+            if not auth:
+                return await invoke_handler(self.error_callback, request)
+            request.g.current_user = await invoke_handler(
+                self.auth_callback, request, *auth)
+            if not request.g.current_user:
+                return await invoke_handler(self.error_callback, request)
+            return await invoke_handler(f, request, *args, **kwargs)
+
+        return wrapper
+
+    def optional(self, f):
+        """Decorator to protect a route with optional authentication.
+
+        This decorator makes authentication for the decorated route optional,
+        meaning that the route is allowed to run with or with
+        authentication given in the request.
+        """
+        async def wrapper(request, *args, **kwargs):
+            auth = self._get_auth(request)
+            if not auth:
+                request.g.current_user = None
+            else:
+                request.g.current_user = await invoke_handler(
+                    self.auth_callback, request, *auth)
+            return await invoke_handler(f, request, *args, **kwargs)
+
+        return wrapper
+
+
+class BasicAuth(BaseAuth):
+    """Basic Authentication.
+
+    :param realm: The realm that is displayed when the user is prompted to
+                  authenticate in the browser.
+    :param charset: The charset that is used to encode the realm.
+    :param scheme: The authentication scheme. Defaults to 'Basic'.
+    :param error_status: The error status code to return when authentication
+                         fails. Defaults to 401.
+    """
+    def __init__(self, realm='Please login', charset='UTF-8', scheme='Basic',
+                 error_status=401):
+        super().__init__()
+        self.realm = realm
+        self.charset = charset
+        self.scheme = scheme
+        self.error_status = error_status
+        self.error_callback = self.authentication_error
+
+    def _get_auth(self, request):
+        auth = request.headers.get('Authorization')
+        if auth and auth.startswith('Basic '):
+            import binascii
+            try:
+                username, password = binascii.a2b_base64(
+                    auth[6:]).decode().split(':', 1)
+            except Exception:  # pragma: no cover
+                return None
+            return username, password
+
+    async def authentication_error(self, request):
+        return '', self.error_status, {
+            'WWW-Authenticate': '{} realm="{}", charset="{}"'.format(
+                self.scheme, self.realm, self.charset)}
+
+    def authenticate(self, f):
+        """Decorator to configure the authentication callback.
+
+        This decorator must be used with a function that accepts the request
+        object, a username and a password and returns a user object if the
+        credentials are valid, or ``None`` if they are not. Example::
+
+           @auth.authenticate
+           async def check_credentials(request, username, password):
+               user = get_user(username)
+               if user and user.check_password(password):
+                   return get_user(username)
+        """
+        self.auth_callback = f
+
+
+class TokenAuth(BaseAuth):
+    """Token based authentication.
+
+    :param header: The name of the header that will contain the token. Defaults
+                   to 'Authorization'.
+    :param scheme: The authentication scheme. Defaults to 'Bearer'.
+    :param error_status: The error status code to return when authentication
+                         fails. Defaults to 401.
+    """
+    def __init__(self, header='Authorization', scheme='Bearer',
+                 error_status=401):
+        super().__init__()
+        self.header = header
+        self.scheme = scheme.lower()
+        self.error_status = error_status
+        self.error_callback = self.authentication_error
+
+    def _get_auth(self, request):
+        auth = request.headers.get(self.header)
+        if auth:
+            if self.header == 'Authorization':
+                try:
+                    scheme, token = auth.split(' ', 1)
+                except Exception:
+                    return None
+                if scheme.lower() == self.scheme:
+                    return (token.strip(),)
+            else:
+                return (auth,)
+
+    def authenticate(self, f):
+        """Decorator to configure the authentication callback.
+
+        This decorator must be used with a function that accepts the request
+        object, a username and a password and returns a user object if the
+        credentials are valid, or ``None`` if they are not. Example::
+
+           @auth.authenticate
+           async def check_credentials(request, token):
+               return get_user(token)
+        """
+        self.auth_callback = f
+
+    def errorhandler(self, f):
+        """Decorator to configure the error callback.
+
+        Microdot calls the error callback to allow the application to generate
+        a custom error response. The default error response is to call
+        ``abort(401)``.
+        """
+        self.error_callback = f
+
+    async def authentication_error(self, request):
+        abort(self.error_status)
diff --git a/src/microdot/jinja.py b/src/microdot/jinja.py
index 0e1a976..0c6ac61 100644
--- a/src/microdot/jinja.py
+++ b/src/microdot/jinja.py
@@ -1,19 +1,27 @@
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 
-_jinja_env = None
-
 
 class Template:
     """A template object.
 
     :param template: The filename of the template to render, relative to the
                      configured template directory.
+    :param kwargs: any additional options to be passed to the Jinja
+                   environment's ``get_template()`` method.
     """
+    #: The Jinja environment. The ``initialize()`` method must be called before
+    #: this attribute is accessed.
+    jinja_env = None
+
     @classmethod
     def initialize(cls, template_dir='templates', enable_async=False,
                    **kwargs):
         """Initialize the templating subsystem.
 
+        This method is automatically invoked when the first template is
+        created. The application can call it explicitly if custom options need
+        to be provided.
+
         :param template_dir: the directory where templates are stored. This
                              argument is optional. The default is to load
                              templates from a *templates* subdirectory.
@@ -23,20 +31,19 @@ def initialize(cls, template_dir='templates', enable_async=False,
         :param kwargs: any additional options to be passed to Jinja's
                        ``Environment`` class.
         """
-        global _jinja_env
-        _jinja_env = Environment(
+        cls.jinja_env = Environment(
             loader=FileSystemLoader(template_dir),
             autoescape=select_autoescape(),
             enable_async=enable_async,
             **kwargs
         )
 
-    def __init__(self, template):
-        if _jinja_env is None:  # pragma: no cover
+    def __init__(self, template, **kwargs):
+        if self.jinja_env is None:  # pragma: no cover
             self.initialize()
-        #: The name of the template
+        #: The name of the template.
         self.name = template
-        self.template = _jinja_env.get_template(template)
+        self.template = self.jinja_env.get_template(template, **kwargs)
 
     def generate(self, *args, **kwargs):
         """Return a generator that renders the template in chunks, with the
diff --git a/src/microdot/login.py b/src/microdot/login.py
new file mode 100644
index 0000000..aa894e9
--- /dev/null
+++ b/src/microdot/login.py
@@ -0,0 +1,163 @@
+from time import time
+from microdot import redirect
+from microdot.microdot import urlencode, invoke_handler
+
+
+class Login:
+    """User login support for Microdot.
+
+    :param login_url: the URL to redirect to when a login is required. The
+                      default is '/login'.
+    """
+    def __init__(self, login_url='/login'):
+        self.login_url = login_url
+        self.user_loader_callback = None
+
+    def user_loader(self, f):
+        """Decorator to configure the user callback.
+
+        The decorated function receives the user ID as an argument and must
+        return the corresponding user object, or ``None`` if the user ID is
+        invalid.
+        """
+        self.user_loader_callback = f
+
+    def _get_session(self, request):
+        return request.app._session.get(request)
+
+    def _update_remember_cookie(self, request, days, user_id=None):
+        remember_payload = request.app._session.encode({
+            'user_id': user_id,
+            'days': days,
+            'exp': time() + days * 24 * 60 * 60
+        })
+
+        @request.after_request
+        async def _set_remember_cookie(request, response):
+            response.set_cookie('_remember', remember_payload,
+                                max_age=days * 24 * 60 * 60)
+            return response
+
+    def _get_user_id_from_session(self, request):
+        session = self._get_session(request)
+        if session and '_user_id' in session:
+            return session['_user_id']
+        if '_remember' in request.cookies:
+            remember_payload = request.app._session.decode(
+                request.cookies['_remember'])
+            user_id = remember_payload.get('user_id')
+            if user_id:  # pragma: no branch
+                self._update_remember_cookie(
+                    request, remember_payload.get('_days', 30), user_id)
+                session['_user_id'] = user_id
+                session['_fresh'] = False
+                session.save()
+                return user_id
+
+    async def _redirect_to_login(self, request):
+        return '', 302, {'Location': self.login_url + '?next=' + urlencode(
+            request.url)}
+
+    async def login_user(self, request, user, remember=False,
+                         redirect_url='/'):
+        """Log a user in.
+
+        :param request: the request object
+        :param user: the user object
+        :param remember: if the user's logged in state should be remembered
+                         with a cookie after the session ends. Set to the
+                         number of days the remember cookie should last, or to
+                         ``True`` to use a default duration of 30 days.
+        :param redirect_url: the URL to redirect to after login
+
+        This call marks the user as logged in by storing their user ID in the
+        user session. The application must call this method to log a user in
+        after their credentials have been validated.
+
+        The method returns a redirect response, either to the URL the user
+        originally intended to visit, or if there is no original URL to the URL
+        specified by the `redirect_url`.
+        """
+        session = self._get_session(request)
+        session['_user_id'] = user.id
+        session['_fresh'] = True
+        session.save()
+
+        if remember:
+            days = 30 if remember is True else int(remember)
+            self._update_remember_cookie(request, days, session['_user_id'])
+
+        next_url = request.args.get('next', redirect_url)
+        if not next_url.startswith('/'):
+            next_url = redirect_url
+        return redirect(next_url)
+
+    async def logout_user(self, request):
+        """Log a user out.
+
+        :param request: the request object
+
+        This call removes information about the user's log in from the user
+        session. If a remember cookie exists, it is removed as well.
+        """
+        session = self._get_session(request)
+        session.pop('_user_id', None)
+        session.pop('_fresh', None)
+        session.save()
+        if '_remember' in request.cookies:
+            self._update_remember_cookie(request, 0)
+
+    def __call__(self, f):
+        """Decorator to protect a route with authentication.
+
+        If the user is not logged in, Microdot will redirect to the login page
+        first. The decorated route will only run after successful login by the
+        user. If the user is already logged in, the route will run immediately.
+        Example::
+
+            login = Login()
+
+            @app.route('/secret')
+            @login
+            async def secret(request):
+                # only accessible to authenticated users
+
+        """
+        async def wrapper(request, *args, **kwargs):
+            user_id = self._get_user_id_from_session(request)
+            if not user_id:
+                return await self._redirect_to_login(request)
+            request.g.current_user = await invoke_handler(
+                self.user_loader_callback, user_id)
+            if not request.g.current_user:
+                return await self._redirect_to_login(request)
+            return await invoke_handler(f, request, *args, **kwargs)
+
+        return wrapper
+
+    def fresh(self, f):
+        """Decorator to protect a route with "fresh" authentication.
+
+        This decorator prevents the route from running when the login session
+        is not fresh. A fresh session is a session that has been created from
+        direct user interaction with the login page, while a non-fresh session
+        occurs when a login is restored from a "remember me" cookie. Example::
+
+            login = Login()
+
+            @app.route('/secret')
+            @auth.fresh
+            async def secret(request):
+                # only accessible to authenticated users
+                # users logged in via remember me cookie will need to
+                # re-authenticate
+        """
+        base_wrapper = self.__call__(f)
+
+        async def wrapper(request, *args, **kwargs):
+            session = self._get_session(request)
+            if session.get('_fresh'):
+                return await base_wrapper(request, *args, **kwargs)
+            return await self._redirect_to_login(request)
+
+        return wrapper
diff --git a/src/microdot/microdot.py b/src/microdot/microdot.py
index 541aeaf..ba2bae0 100644
--- a/src/microdot/microdot.py
+++ b/src/microdot/microdot.py
@@ -7,9 +7,14 @@
 """
 import asyncio
 import io
-import json
+import re
 import time
 
+try:
+    import orjson as json
+except ImportError:
+    import json
+
 try:
     from inspect import iscoroutinefunction, iscoroutine
     from functools import partial
@@ -56,23 +61,9 @@ def print_exception(exc):
 ]
 
 
-def urldecode_str(s):
-    s = s.replace('+', ' ')
-    parts = s.split('%')
-    if len(parts) == 1:
-        return s
-    result = [parts[0]]
-    for item in parts[1:]:
-        if item == '':
-            result.append('%')
-        else:
-            code = item[:2]
-            result.append(chr(int(code, 16)))
-            result.append(item[2:])
-    return ''.join(result)
-
-
-def urldecode_bytes(s):
+def urldecode(s):
+    if isinstance(s, str):
+        s = s.encode()
     s = s.replace(b'+', b' ')
     parts = s.split(b'%')
     if len(parts) == 1:
@@ -329,7 +320,8 @@ class G:
         pass
 
     def __init__(self, app, client_addr, method, url, http_version, headers,
-                 body=None, stream=None, sock=None):
+                 body=None, stream=None, sock=None, url_prefix='',
+                 subapp=None):
         #: The application instance to which this request belongs.
         self.app = app
         #: The address of the client, as a tuple (host, port).
@@ -338,6 +330,12 @@ def __init__(self, app, client_addr, method, url, http_version, headers,
         self.method = method
         #: The request URL, including the path and query string.
         self.url = url
+        #: The URL prefix, if the endpoint comes from a mounted
+        #: sub-application, or else ''.
+        self.url_prefix = url_prefix
+        #: The sub-application instance, or `None` if this isn't a mounted
+        #: endpoint.
+        self.subapp = subapp
         #: The path portion of the URL.
         self.path = url
         #: The query string portion of the URL.
@@ -377,6 +375,7 @@ def __init__(self, app, client_addr, method, url, http_version, headers,
         self.sock = sock
         self._json = None
         self._form = None
+        self._files = None
         self.after_request_handlers = []
 
     @staticmethod
@@ -433,12 +432,12 @@ def _parse_urlencoded(self, urlencoded):
             if isinstance(urlencoded, str):
                 for kv in [pair.split('=', 1)
                            for pair in urlencoded.split('&') if pair]:
-                    data[urldecode_str(kv[0])] = urldecode_str(kv[1]) \
+                    data[urldecode(kv[0])] = urldecode(kv[1]) \
                         if len(kv) > 1 else ''
             elif isinstance(urlencoded, bytes):  # pragma: no branch
                 for kv in [pair.split(b'=', 1)
                            for pair in urlencoded.split(b'&') if pair]:
-                    data[urldecode_bytes(kv[0])] = urldecode_bytes(kv[1]) \
+                    data[urldecode(kv[0])] = urldecode(kv[1]) \
                         if len(kv) > 1 else b''
         return data
 
@@ -471,7 +470,13 @@ def json(self):
     def form(self):
         """The parsed form submission body, as a
         :class:`MultiDict <microdot.MultiDict>` object, or ``None`` if the
-        request does not have a form submission."""
+        request does not have a form submission.
+
+        Forms that are URL encoded are processed by default. For multipart
+        forms to be processed, the
+        :func:`with_form_data <microdot.multipart.with_form_data>`
+        decorator must be added to the route.
+        """
         if self._form is None:
             if self.content_type is None:
                 return None
@@ -481,6 +486,17 @@ def form(self):
             self._form = self._parse_urlencoded(self.body)
         return self._form
 
+    @property
+    def files(self):
+        """The files uploaded in the request as a dictionary, or ``None`` if
+        the request does not have any files.
+
+        The :func:`with_form_data <microdot.multipart.with_form_data>`
+        decorator must be added to the route that receives file uploads for
+        this property to be set.
+        """
+        return self._files
+
     def after_request(self, f):
         """Register a request-specific function to run after the request is
         handled. Request-specific after request handlers run at the very end,
@@ -562,9 +578,9 @@ def __init__(self, body='', status_code=200, headers=None, reason=None):
         self.headers = NoCaseDict(headers or {})
         self.reason = reason
         if isinstance(body, (dict, list)):
-            self.body = json.dumps(body).encode()
+            body = json.dumps(body)
             self.headers['Content-Type'] = 'application/json; charset=UTF-8'
-        elif isinstance(body, str):
+        if isinstance(body, str):
             self.body = body.encode()
         else:
             # this applies to bytes, file-like objects or generators
@@ -798,13 +814,23 @@ def send_file(cls, filename, status_code=200, content_type=None,
 
 
 class URLPattern():
+    segment_patterns = {
+        'string': '/([^/]+)',
+        'int': '/(-?\\d+)',
+        'path': '/(.+)',
+    }
+    segment_parsers = {
+        'int': lambda value: int(value),
+    }
+
     def __init__(self, url_pattern):
         self.url_pattern = url_pattern
         self.segments = []
         self.regex = None
+
+    def compile(self):
         pattern = ''
-        use_regex = False
-        for segment in url_pattern.lstrip('/').split('/'):
+        for segment in self.url_pattern.lstrip('/').split('/'):
             if segment and segment[0] == '<':
                 if segment[-1] != '>':
                     raise ValueError('invalid URL pattern')
@@ -815,81 +841,46 @@ def __init__(self, url_pattern):
                     type_ = 'string'
                     name = segment
                 parser = None
-                if type_ == 'string':
-                    parser = self._string_segment
-                    pattern += '/([^/]+)'
-                elif type_ == 'int':
-                    parser = self._int_segment
-                    pattern += '/(-?\\d+)'
-                elif type_ == 'path':
-                    use_regex = True
-                    pattern += '/(.+)'
-                elif type_.startswith('re:'):
-                    use_regex = True
+                if type_.startswith('re:'):
                     pattern += '/({pattern})'.format(pattern=type_[3:])
                 else:
-                    raise ValueError('invalid URL segment type')
+                    if type_ not in self.segment_patterns:
+                        raise ValueError('invalid URL segment type')
+                    pattern += self.segment_patterns[type_]
+                    parser = self.segment_parsers.get(type_)
                 self.segments.append({'parser': parser, 'name': name,
                                       'type': type_})
             else:
                 pattern += '/' + segment
-                self.segments.append({'parser': self._static_segment(segment)})
-        if use_regex:
-            import re
-            self.regex = re.compile('^' + pattern + '$')
+                self.segments.append({'parser': None})
+        self.regex = re.compile('^' + pattern + '$')
+        return self.regex
+
+    @classmethod
+    def register_type(cls, type_name, pattern='[^/]+', parser=None):
+        cls.segment_patterns[type_name] = '/({})'.format(pattern)
+        cls.segment_parsers[type_name] = parser
 
     def match(self, path):
         args = {}
-        if self.regex:
-            g = self.regex.match(path)
-            if not g:
-                return
-            i = 1
-            for segment in self.segments:
-                if 'name' not in segment:
-                    continue
-                value = g.group(i)
-                if segment['type'] == 'int':
-                    value = int(value)
-                args[segment['name']] = value
-                i += 1
-        else:
-            if len(path) == 0 or path[0] != '/':
-                return
-            path = path[1:]
-            args = {}
-            for segment in self.segments:
-                if path is None:
-                    return
-                arg, path = segment['parser'](path)
+        g = (self.regex or self.compile()).match(path)
+        if not g:
+            return
+        i = 1
+        for segment in self.segments:
+            if 'name' not in segment:
+                continue
+            arg = g.group(i)
+            if segment['parser']:
+                arg = self.segment_parsers[segment['type']](arg)
                 if arg is None:
                     return
-                if 'name' in segment:
-                    args[segment['name']] = arg
-            if path is not None:
-                return
+            args[segment['name']] = arg
+            i += 1
         return args
 
-    def _static_segment(self, segment):
-        def _static(value):
-            s = value.split('/', 1)
-            if s[0] == segment:
-                return '', s[1] if len(s) > 1 else None
-            return None, None
-        return _static
-
-    def _string_segment(self, value):
-        s = value.split('/', 1)
-        if len(s[0]) == 0:
-            return None, None
-        return s[0], s[1] if len(s) > 1 else None
-
-    def _int_segment(self, value):
-        s = value.split('/', 1)
-        try:
-            return int(s[0]), s[1] if len(s) > 1 else None
-        except ValueError:
-            return None, None
+    def __repr__(self):  # pragma: no cover
+        return 'URLPattern: {}'.format(self.url_pattern)
 
 
 class HTTPException(Exception):
@@ -959,7 +950,7 @@ def index(request):
         def decorated(f):
             self.url_map.append(
                 ([m.upper() for m in (methods or ['GET'])],
-                 URLPattern(url_pattern), f))
+                 URLPattern(url_pattern), f, '', None))
             return f
         return decorated
 
@@ -1127,24 +1118,33 @@ def decorated(f):
             return f
         return decorated
 
-    def mount(self, subapp, url_prefix=''):
+    def mount(self, subapp, url_prefix='', local=False):
         """Mount a sub-application, optionally under the given URL prefix.
 
         :param subapp: The sub-application to mount.
         :param url_prefix: The URL prefix to mount the application under.
+        :param local: When set to ``True``, the before, after and error request
+                      handlers only apply to endpoints defined in the
+                      sub-application. When ``False``, they apply to the entire
+                      application. The default is ``False``.
         """
-        for methods, pattern, handler in subapp.url_map:
+        for methods, pattern, handler, _prefix, _subapp in subapp.url_map:
             self.url_map.append(
                 (methods, URLPattern(url_prefix + pattern.url_pattern),
-                 handler))
-        for handler in subapp.before_request_handlers:
-            self.before_request_handlers.append(handler)
-        for handler in subapp.after_request_handlers:
-            self.after_request_handlers.append(handler)
-        for handler in subapp.after_error_request_handlers:
-            self.after_error_request_handlers.append(handler)
-        for status_code, handler in subapp.error_handlers.items():
-            self.error_handlers[status_code] = handler
+                 handler, url_prefix + _prefix, _subapp or subapp))
+        if not local:
+            for handler in subapp.before_request_handlers:
+                self.before_request_handlers.append(handler)
+            subapp.before_request_handlers = []
+            for handler in subapp.after_request_handlers:
+                self.after_request_handlers.append(handler)
+            subapp.after_request_handlers = []
+            for handler in subapp.after_error_request_handlers:
+                self.after_error_request_handlers.append(handler)
+            subapp.after_error_request_handlers = []
+            for status_code, handler in subapp.error_handlers.items():
+                self.error_handlers[status_code] = handler
+            subapp.error_handlers = {}
 
     @staticmethod
     def abort(status_code, reason=None):
@@ -1302,23 +1302,28 @@ def shutdown(request):
     def find_route(self, req):
         method = req.method.upper()
         if method == 'OPTIONS' and self.options_handler:
-            return self.options_handler(req)
+            return self.options_handler(req), '', None
         if method == 'HEAD':
             method = 'GET'
         f = 404
-        for route_methods, route_pattern, route_handler in self.url_map:
+        p = ''
+        s = None
+        for route_methods, route_pattern, route_handler, url_prefix, subapp \
+                in self.url_map:
             req.url_args = route_pattern.match(req.path)
             if req.url_args is not None:
+                p = url_prefix
+                s = subapp
                 if method in route_methods:
                     f = route_handler
                     break
                 else:
                     f = 405
-        return f
+        return f, p, s
 
     def default_options_handler(self, req):
         allow = []
-        for route_methods, route_pattern, route_handler in self.url_map:
+        for route_methods, route_pattern, _, _, _ in self.url_map:
             if route_pattern.match(req.path) is not None:
                 allow.extend(route_methods)
         if 'GET' in allow:
@@ -1335,9 +1340,9 @@ async def handle_request(self, reader, writer):
             print_exception(exc)
 
         res = await self.dispatch_request(req)
-        if res != Response.already_handled:  # pragma: no branch
-            await res.write(writer)
         try:
+            if res != Response.already_handled:  # pragma: no branch
+                await res.write(writer)
             await writer.aclose()
         except OSError as exc:  # pragma: no cover
             if exc.errno in MUTED_SOCKET_ERRORS:
@@ -1349,43 +1354,76 @@ async def handle_request(self, reader, writer):
                 method=req.method, path=req.path,
                 status_code=res.status_code))
 
+    def get_request_handlers(self, req, attr, local_first=True):
+        handlers = getattr(self, attr + '_handlers')
+        local_handlers = getattr(req.subapp, attr + '_handlers') \
+            if req and req.subapp else []
+        return local_handlers + handlers if local_first \
+            else handlers + local_handlers
+
+    async def error_response(self, req, status_code, reason=None):
+        if req and req.subapp and status_code in req.subapp.error_handlers:
+            return await invoke_handler(
+                req.subapp.error_handlers[status_code], req)
+        elif status_code in self.error_handlers:
+            return await invoke_handler(self.error_handlers[status_code], req)
+        return reason or 'N/A', status_code
+
     async def dispatch_request(self, req):
         after_request_handled = False
         if req:
             if req.content_length > req.max_content_length:
-                if 413 in self.error_handlers:
-                    res = await invoke_handler(self.error_handlers[413], req)
-                else:
-                    res = 'Payload too large', 413
+                # the request body is larger than allowed
+                res = await self.error_response(req, 413, 'Payload too large')
             else:
-                f = self.find_route(req)
+                # find the route in the app's URL map
+                f, req.url_prefix, req.subapp = self.find_route(req)
+
                 try:
                     res = None
                     if callable(f):
-                        for handler in self.before_request_handlers:
+                        # invoke the before request handlers
+                        for handler in self.get_request_handlers(
+                                req, 'before_request', False):
                             res = await invoke_handler(handler, req)
                             if res:
                                 break
+
+                        # invoke the endpoint handler
                         if res is None:
-                            res = await invoke_handler(
-                                f, req, **req.url_args)
+                            res = await invoke_handler(f, req, **req.url_args)
+
+                        # process the response
                         if isinstance(res, int):
+                            # an integer response is taken as a status code
+                            # with an empty body
                             res = '', res
                         if isinstance(res, tuple):
+                            # handle a tuple response
                             if isinstance(res[0], int):
+                                # a tuple that starts with an int has an empty
+                                # body
                                 res = ('', res[0],
                                        res[1] if len(res) > 1 else {})
                             body = res[0]
                             if isinstance(res[1], int):
+                                # extract the status code and headers (if
+                                # available)
                                 status_code = res[1]
                                 headers = res[2] if len(res) > 2 else {}
                             else:
+                                # if the status code is missing, assume 200
                                 status_code = 200
                                 headers = res[1]
                             res = Response(body, status_code, headers)
                         elif not isinstance(res, Response):
+                            # any other response types are wrapped in a
+                            # Response object
                             res = Response(res)
-                        for handler in self.after_request_handlers:
+
+                        # invoke the after request handlers
+                        for handler in self.get_request_handlers(
+                                req, 'after_request', True):
                             res = await invoke_handler(
                                 handler, req, res) or res
                         for handler in req.after_request_handlers:
@@ -1393,50 +1431,62 @@ async def dispatch_request(self, req):
                                 handler, req, res) or res
                         after_request_handled = True
                     elif isinstance(f, dict):
+                        # the response from an OPTIONS request is a dict with
+                        # headers
                         res = Response(headers=f)
-                    elif f in self.error_handlers:
-                        res = await invoke_handler(self.error_handlers[f], req)
                     else:
-                        res = 'Not found', f
+                        # if the route is not found, return a 404 or 405
+                        # response as appropriate
+                        res = await self.error_response(req, f, 'Not found')
                 except HTTPException as exc:
-                    if exc.status_code in self.error_handlers:
-                        res = self.error_handlers[exc.status_code](req)
-                    else:
-                        res = exc.reason, exc.status_code
+                    # an HTTP exception was raised while handling this request
+                    res = await self.error_response(req, exc.status_code,
+                                                    exc.reason)
                 except Exception as exc:
+                    # an unexpected exception was raised while handling this
+                    # request
                     print_exception(exc)
-                    exc_class = None
+
+                    # invoke the error handler for the exception class if one
+                    # exists
+                    handler = None
                     res = None
-                    if exc.__class__ in self.error_handlers:
-                        exc_class = exc.__class__
+                    if req.subapp and exc.__class__ in \
+                            req.subapp.error_handlers:
+                        handler = req.subapp.error_handlers[exc.__class__]
+                    elif exc.__class__ in self.error_handlers:
+                        handler = self.error_handlers[exc.__class__]
                     else:
+                        # walk up the exception class hierarchy to try to find
+                        # a handler
                         for c in mro(exc.__class__)[1:]:
-                            if c in self.error_handlers:
-                                exc_class = c
+                            if req.subapp and c in req.subapp.error_handlers:
+                                handler = req.subapp.error_handlers[c]
+                                break
+                            elif c in self.error_handlers:
+                                handler = self.error_handlers[c]
                                 break
-                    if exc_class:
+                    if handler:
                         try:
-                            res = await invoke_handler(
-                                self.error_handlers[exc_class], req, exc)
+                            res = await invoke_handler(handler, req, exc)
                         except Exception as exc2:  # pragma: no cover
                             print_exception(exc2)
                     if res is None:
-                        if 500 in self.error_handlers:
-                            res = await invoke_handler(
-                                self.error_handlers[500], req)
-                        else:
-                            res = 'Internal server error', 500
+                        # if there is still no response, issue a 500 error
+                        res = await self.error_response(
+                            req, 500, 'Internal server error')
         else:
-            if 400 in self.error_handlers:
-                res = await invoke_handler(self.error_handlers[400], req)
-            else:
-                res = 'Bad request', 400
+            # if the request could not be parsed, issue a 400 error
+            res = await self.error_response(req, 400, 'Bad request')
         if isinstance(res, tuple):
             res = Response(*res)
         elif not isinstance(res, Response):
             res = Response(res)
         if not after_request_handled:
-            for handler in self.after_error_request_handlers:
+            # if the request did not finish due to an error, invoke the after
+            # error request handler
+            for handler in self.get_request_handlers(
+                    req, 'after_error_request', True):
                 res = await invoke_handler(
                     handler, req, res) or res
         res.is_head = (req and req.method == 'HEAD')
diff --git a/src/microdot/multipart.py b/src/microdot/multipart.py
new file mode 100644
index 0000000..62acc70
--- /dev/null
+++ b/src/microdot/multipart.py
@@ -0,0 +1,291 @@
+import os
+from random import choice
+from microdot import abort, iscoroutine, AsyncBytesIO
+from microdot.helpers import wraps
+
+
+class FormDataIter:
+    """Asynchronous iterator that parses a ``multipart/form-data`` body and
+    returns form fields and files as they are parsed.
+
+    :param request: the request object to parse.
+
+    Example usage::
+
+        from microdot.multipart import FormDataIter
+
+        @app.post('/upload')
+        async def upload(request):
+            async for name, value in FormDataIter(request):
+                print(name, value)
+
+    The iterator returns no values when the request has a content type other
+    than ``multipart/form-data``. For a file field, the returned value is of
+    type :class:`FileUpload`, which supports the
+    :meth:`read() <FileUpload.read>` and :meth:`save() <FileUpload.save>`
+    methods. Values for regular fields are provided as strings.
+
+    The request body is read efficiently in chunks of size
+    :attr:`buffer_size <FormDataIter.buffer_size>`. On iterations in which a
+    file field is encountered, the file must be consumed before moving on to
+    the next iteration, as the internal stream stored in ``FileUpload``
+    instances is invalidated at the end of the iteration.
+    """
+    #: The size of the buffer used to read chunks of the request body.
+    buffer_size = 256
+
+    def __init__(self, request):
+        self.request = request
+        self.buffer = None
+        try:
+            mimetype, boundary = request.content_type.rsplit('; boundary=', 1)
+        except ValueError:
+            return  # not a multipart request
+        if mimetype.split(';', 1)[0] == \
+                'multipart/form-data':  # pragma: no branch
+            self.boundary = b'--' + boundary.encode()
+            self.extra_size = len(boundary) + 4
+            self.buffer = b''
+
+    def __aiter__(self):
+        return self
+
+    async def __anext__(self):
+        if self.buffer is None:
+            raise StopAsyncIteration
+
+        # make sure we have consumed the previous entry
+        while await self._read_buffer(self.buffer_size) != b'':
+            pass
+
+        # make sure we are at a boundary
+        s = self.buffer.split(self.boundary, 1)
+        if len(s) != 2 or s[0] != b'':
+            abort(400)  # pragma: no cover
+        self.buffer = s[1]
+        if self.buffer[:2] == b'--':
+            # we have reached the end
+            raise StopAsyncIteration
+        elif self.buffer[:2] != b'\r\n':
+            abort(400)  # pragma: no cover
+        self.buffer = self.buffer[2:]
+
+        # parse the headers of this part
+        name = ''
+        filename = None
+        content_type = None
+        while True:
+            await self._fill_buffer()
+            lines = self.buffer.split(b'\r\n', 1)
+            if len(lines) != 2:
+                abort(400)  # pragma: no cover
+            line, self.buffer = lines
+            if line == b'':
+                # we reached the end of the headers
+                break
+            header, value = line.decode().split(':', 1)
+            header = header.lower()
+            value = value.strip()
+            if header == 'content-disposition':
+                parts = value.split(';')
+                if len(parts) < 2 or parts[0] != 'form-data':
+                    abort(400)  # pragma: no cover
+                for part in parts[1:]:
+                    part = part.strip()
+                    if part.startswith('name="'):
+                        name = part[6:-1]
+                    elif part.startswith('filename="'):  # pragma: no branch
+                        filename = part[10:-1]
+            elif header == 'content-type':  # pragma: no branch
+                content_type = value
+
+        if filename is None:
+            # this is a regular form field, so we read the value
+            value = b''
+            while True:
+                v = await self._read_buffer(self.buffer_size)
+                value += v
+                if len(v) < self.buffer_size:  # pragma: no branch
+                    break
+            return name, value.decode()
+        return name, FileUpload(filename, content_type, self._read_buffer)
+
+    async def _fill_buffer(self):
+        self.buffer += await self.request.stream.read(
+            self.buffer_size + self.extra_size - len(self.buffer))
+
+    async def _read_buffer(self, n=-1):
+        data = b''
+        while n == -1 or len(data) < n:
+            await self._fill_buffer()
+            s = self.buffer.split(self.boundary, 1)
+            data += s[0][:n] if n != -1 else s[0]
+            self.buffer = s[0][n:] if n != -1 else b''
+            if len(s) == 2:  # pragma: no branch
+                # the end of this part is in the buffer
+                if len(self.buffer) < 2:
+                    # we have read all the way to the end of this part
+                    data = data[:-(2 - len(self.buffer))]  # remove last "\r\n"
+                self.buffer += self.boundary + s[1]
+                return data
+        return data
+
+
+class FileUpload:
+    """Class that represents an uploaded file.
+
+    :param filename: the name of the uploaded file.
+    :param content_type: the content type of the uploaded file.
+    :param read: a coroutine that reads from the uploaded file's stream.
+
+    An uploaded file can be read from the stream using the :meth:`read()`
+    method or saved to a file using the :meth:`save()` method.
+
+    Instances of this class do not normally need to be created directly.
+    """
+    #: The size at which the file is copied to a temporary file.
+    max_memory_size = 1024
+
+    def __init__(self, filename, content_type, read):
+        self.filename = filename
+        self.content_type = content_type
+        self._read = read
+        self._close = None
+
+    async def read(self, n=-1):
+        """Read up to ``n`` bytes from the uploaded file's stream.
+
+        :param n: the maximum number of bytes to read. If ``n`` is -1 or not
+                  given, the entire file is read.
+        """
+        return await self._read(n)
+
+    async def save(self, path_or_file):
+        """Save the uploaded file to the given path or file object.
+
+        :param path_or_file: the path to save the file to, or a file object
+                             to which the file is to be written.
+
+        The file is read and written in chunks of size
+        :attr:`FormDataIter.buffer_size`.
+        """
+        if isinstance(path_or_file, str):
+            f = open(path_or_file, 'wb')
+        else:
+            f = path_or_file
+        while True:
+            data = await self.read(FormDataIter.buffer_size)
+            if not data:
+                break
+            f.write(data)
+        if f != path_or_file:
+            f.close()
+
+    async def copy(self, max_memory_size=None):
+        """Copy the uploaded file to a temporary file, to allow the parsing of
+        the multipart form to continue.
+
+        :param max_memory_size: the maximum size of the file to keep in memory.
+                                If not given, then the class attribute of the
+                                same name is used.
+        """
+        max_memory_size = max_memory_size or FileUpload.max_memory_size
+        buffer = await self.read(max_memory_size)
+        if len(buffer) < max_memory_size:
+            f = AsyncBytesIO(buffer)
+            self._read = f.read
+            return self
+
+        # create a temporary file
+        while True:
+            tmpname = "".join([
+                choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
+                for _ in range(12)
+            ])
+            try:
+                f = open(tmpname, 'x+b')
+            except OSError as e:  # pragma: no cover
+                if e.errno == 17:
+                    # EEXIST
+                    continue
+                elif e.errno == 2:
+                    # ENOENT
+                    # some MicroPython platforms do not support mode "x"
+                    f = open(tmpname, 'w+b')
+                    if f.read(1) != b'':
+                        f.close()
+                        continue
+                else:
+                    raise
+            break
+        f.write(buffer)
+        await self.save(f)
+        f.seek(0)
+
+        async def read(n=-1):
+            return f.read(n)
+
+        async def close():
+            f.close()
+            os.remove(tmpname)
+
+        self._read = read
+        self._close = close
+        return self
+
+    async def close(self):
+        """Close an open file.
+
+        This method must be called to free memory or temporary files created by
+        the ``copy()`` method.
+
+        Note that when using the ``@with_form_data`` decorator this method is
+        called automatically when the request ends.
+        """
+        if self._close:
+            await self._close()
+            self._close = None
+
+
+def with_form_data(f):
+    """Decorator that parses a ``multipart/form-data`` body and updates the
+    request object with the parsed form fields and files.
+
+    Example usage::
+
+        from microdot.multipart import with_form_data
+
+        @app.post('/upload')
+        @with_form_data
+        async def upload(request):
+            print('form fields:', request.form)
+            print('files:', request.files)
+
+    Note: this decorator calls the :meth:`FileUpload.copy()
+    <microdot.multipart.FileUpload.copy>` method on all uploaded files, so that
+    the request can be parsed in its entirety. The files are either copied to
+    memory or a temporary file, depending on their size. The temporary files
+    are automatically deleted when the request ends.
+    """
+    @wraps(f)
+    async def wrapper(request, *args, **kwargs):
+        form = {}
+        files = {}
+        async for name, value in FormDataIter(request):
+            if isinstance(value, FileUpload):
+                files[name] = await value.copy()
+            else:
+                form[name] = value
+        if form or files:
+            request._form = form
+            request._files = files
+        try:
+            ret = f(request, *args, **kwargs)
+            if iscoroutine(ret):
+                ret = await ret
+        finally:
+            if request.files:
+                for file in request.files.values():
+                    await file.close()
+        return ret
+    return wrapper
diff --git a/src/microdot/sse.py b/src/microdot/sse.py
index 01143c8..6376ee0 100644
--- a/src/microdot/sse.py
+++ b/src/microdot/sse.py
@@ -1,7 +1,11 @@
 import asyncio
-import json
 from microdot.helpers import wraps
 
+try:
+    import orjson as json
+except ImportError:
+    import json
+
 
 class SSE:
     """Server-Sent Events object.
@@ -25,8 +29,8 @@ async def send(self, data, event=None, event_id=None):
                       given, it must be a string.
         """
         if isinstance(data, (dict, list)):
-            data = json.dumps(data).encode()
-        elif isinstance(data, str):
+            data = json.dumps(data)
+        if isinstance(data, str):
             data = data.encode()
         elif not isinstance(data, bytes):
             data = str(data).encode()
@@ -57,7 +61,14 @@ def sse_response(request, event_function, *args, **kwargs):
     sse = SSE()
 
     async def sse_task_wrapper():
-        await event_function(request, sse, *args, **kwargs)
+        try:
+            await event_function(request, sse, *args, **kwargs)
+        except asyncio.CancelledError:  # pragma: no cover
+            pass
+        except Exception as exc:
+            # the SSE task raised an exception so we need to pass it to the
+            # main route so that it is re-raised there
+            sse.queue.append(exc)
         sse.event.set()
 
     task = asyncio.create_task(sse_task_wrapper())
@@ -75,7 +86,11 @@ async def __anext__(self):
                 except IndexError:
                     await sse.event.wait()
                     sse.event.clear()
-            if event is None:
+            if isinstance(event, Exception):
+                # if the event is an exception we re-raise it here so that it
+                # can be handled appropriately
+                raise event
+            elif event is None:
                 raise StopAsyncIteration
             return event
 
diff --git a/src/microdot/test_client.py b/src/microdot/test_client.py
index 1018f84..909bd55 100644
--- a/src/microdot/test_client.py
+++ b/src/microdot/test_client.py
@@ -1,4 +1,4 @@
-import json
+import asyncio
 from microdot.microdot import Request, Response, AsyncBytesIO
 
 try:
@@ -6,6 +6,11 @@
 except:  # pragma: no cover  # noqa: E722
     WebSocket = None
 
+try:
+    import orjson as json
+except ImportError:
+    import json
+
 __all__ = ['TestClient', 'TestResponse']
 
 
@@ -19,7 +24,7 @@ def __init__(self):
         #: explicitly sets it on the response object.
         self.reason = None
         #: A dictionary with the response headers.
-        self.headers = None
+        self.headers = {}
         #: The body of the response, as a bytes object.
         self.body = None
         #: The body of the response, decoded to a UTF-8 string. Set to
@@ -28,6 +33,11 @@ def __init__(self):
         #: The body of the JSON response, decoded to a dictionary or list. Set
         #: ``Note`` if the response does not have a JSON payload.
         self.json = None
+        #: The body of the SSE response, decoded to a list of events, each
+        #: given as a dictionary with a ``data`` key and optionally also
+        #: ``event`` and ``id`` keys. Set to ``None`` if the response does not
+        #: have an SSE payload.
+        self.events = None
 
     def _initialize_response(self, res):
         self.status_code = res.status_code
@@ -37,10 +47,13 @@ def _initialize_response(self, res):
     async def _initialize_body(self, res):
         self.body = b''
         iter = res.body_iter()
-        async for body in iter:  # pragma: no branch
-            if isinstance(body, str):
-                body = body.encode()
-            self.body += body
+        try:
+            async for body in iter:  # pragma: no branch
+                if isinstance(body, str):
+                    body = body.encode()
+                self.body += body
+        except asyncio.CancelledError:  # pragma: no cover
+            pass
         if hasattr(iter, 'aclose'):  # pragma: no branch
             await iter.aclose()
 
@@ -56,6 +69,32 @@ def _process_json_body(self):
             if content_type.split(';')[0] == 'application/json':
                 self.json = json.loads(self.text)
 
+    def _process_sse_body(self):
+        if 'Content-Type' in self.headers:  # pragma: no branch
+            content_type = self.headers['Content-Type']
+            if content_type.split(';')[0] == 'text/event-stream':
+                self.events = []
+                for sse_event in self.body.split(b'\n\n'):
+                    data = None
+                    event = None
+                    event_id = None
+                    for line in sse_event.split(b'\n'):
+                        if line.startswith(b'data:'):
+                            data = line[5:].strip()
+                        elif line.startswith(b'event:'):
+                            event = line[6:].strip().decode()
+                        elif line.startswith(b'id:'):
+                            event_id = line[3:].strip().decode()
+                    if data:
+                        data_json = None
+                        try:
+                            data_json = json.loads(data)
+                        except ValueError:
+                            pass
+                        self.events.append({
+                            "data": data, "data_json": data_json,
+                            "event": event, "event_id": event_id})
+
     @classmethod
     async def create(cls, res):
         test_res = cls()
@@ -64,6 +103,7 @@ async def create(cls, res):
             await test_res._initialize_body(res)
             test_res._process_text_body()
             test_res._process_json_body()
+            test_res._process_sse_body()
         return test_res
 
 
@@ -101,10 +141,10 @@ def _process_body(self, body, headers):
         if body is None:
             body = b''
         elif isinstance(body, (dict, list)):
-            body = json.dumps(body).encode()
+            body = json.dumps(body)
             if 'Content-Type' not in headers:  # pragma: no cover
                 headers['Content-Type'] = 'application/json'
-        elif isinstance(body, str):
+        if isinstance(body, str):
             body = body.encode()
         if body and 'Content-Length' not in headers:
             headers['Content-Length'] = str(len(body))
@@ -195,7 +235,7 @@ async def request(self, method, path, headers=None, body=None, sock=None):
                                    ('127.0.0.1', 1234))
         res = await self.app.dispatch_request(req)
         if res == Response.already_handled:
-            return None
+            return TestResponse()
         res.complete()
 
         self._update_cookies(res)
diff --git a/tests/__init__.py b/tests/__init__.py
index 4f40481..f1ead3f 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -4,8 +4,11 @@
 from tests.test_response import *  # noqa: F401, F403
 from tests.test_urlencode import *  # noqa: F401, F403
 from tests.test_url_pattern import *  # noqa: F401, F403
+from tests.test_multipart import *  # noqa: F401, F403
 from tests.test_websocket import *  # noqa: F401, F403
 from tests.test_sse import *  # noqa: F401, F403
 from tests.test_cors import *  # noqa: F401, F403
 from tests.test_utemplate import *  # noqa: F401, F403
 from tests.test_session import *  # noqa: F401, F403
+from tests.test_auth import *  # noqa: F401, F403
+from tests.test_login import *  # noqa: F401, F403
diff --git a/tests/test_auth.py b/tests/test_auth.py
new file mode 100644
index 0000000..b8b397f
--- /dev/null
+++ b/tests/test_auth.py
@@ -0,0 +1,190 @@
+import asyncio
+import binascii
+import unittest
+from microdot import Microdot
+from microdot.auth import BasicAuth, TokenAuth
+from microdot.test_client import TestClient
+
+
+class TestAuth(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        if hasattr(asyncio, 'set_event_loop'):
+            asyncio.set_event_loop(asyncio.new_event_loop())
+        cls.loop = asyncio.get_event_loop()
+
+    def _run(self, coro):
+        return self.loop.run_until_complete(coro)
+
+    def test_basic_auth(self):
+        app = Microdot()
+        basic_auth = BasicAuth()
+
+        @basic_auth.authenticate
+        def authenticate(request, username, password):
+            if username == 'foo' and password == 'bar':
+                return {'username': username}
+
+        @app.route('/')
+        @basic_auth
+        def index(request):
+            return request.g.current_user['username']
+
+        client = TestClient(app)
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic ' + binascii.b2a_base64(
+                b'foo:bar').decode()}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'foo')
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic ' + binascii.b2a_base64(
+                b'foo:baz').decode()}))
+        self.assertEqual(res.status_code, 401)
+
+    def test_basic_optional_auth(self):
+        app = Microdot()
+        basic_auth = BasicAuth()
+
+        @basic_auth.authenticate
+        def authenticate(request, username, password):
+            if username == 'foo' and password == 'bar':
+                return {'username': username}
+
+        @app.route('/')
+        @basic_auth.optional
+        def index(request):
+            return request.g.current_user['username'] \
+                if request.g.current_user else ''
+
+        client = TestClient(app)
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '')
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic ' + binascii.b2a_base64(
+                b'foo:bar').decode()}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'foo')
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic ' + binascii.b2a_base64(
+                b'foo:baz').decode()}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '')
+
+    def test_token_auth(self):
+        app = Microdot()
+        token_auth = TokenAuth()
+
+        @token_auth.authenticate
+        def authenticate(request, token):
+            if token == 'foo':
+                return 'user'
+
+        @app.route('/')
+        @token_auth
+        def index(request):
+            return request.g.current_user
+
+        client = TestClient(app)
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic foo'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={'Authorization': 'invalid'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Bearer foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'user')
+
+    def test_token_optional_auth(self):
+        app = Microdot()
+        token_auth = TokenAuth()
+
+        @token_auth.authenticate
+        def authenticate(request, token):
+            if token == 'foo':
+                return 'user'
+
+        @app.route('/')
+        @token_auth.optional
+        def index(request):
+            return request.g.current_user or ''
+
+        client = TestClient(app)
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '')
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '')
+
+        res = self._run(client.get('/', headers={'Authorization': 'foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '')
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Bearer foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'user')
+
+    def test_token_auth_custom_header(self):
+        app = Microdot()
+        token_auth = TokenAuth(header='X-Auth-Token')
+
+        @token_auth.authenticate
+        def authenticate(request, token):
+            if token == 'foo':
+                return 'user'
+
+        @app.route('/')
+        @token_auth
+        def index(request):
+            return request.g.current_user
+
+        client = TestClient(app)
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Basic foo'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={'Authorization': 'foo'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'Authorization': 'Bearer foo'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={
+            'X-Token-Auth': 'Bearer foo'}))
+        self.assertEqual(res.status_code, 401)
+
+        res = self._run(client.get('/', headers={'X-Auth-Token': 'foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'user')
+
+        res = self._run(client.get('/', headers={'x-auth-token': 'foo'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'user')
+
+        @token_auth.errorhandler
+        def error_handler(request):
+            return {'status_code': 403}, 403
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 403)
+        self.assertEqual(res.json, {'status_code': 403})
diff --git a/tests/test_login.py b/tests/test_login.py
new file mode 100644
index 0000000..3199b76
--- /dev/null
+++ b/tests/test_login.py
@@ -0,0 +1,188 @@
+import asyncio
+import unittest
+from microdot import Microdot
+from microdot.login import Login
+from microdot.session import Session
+from microdot.test_client import TestClient
+
+
+class TestLogin(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        if hasattr(asyncio, 'set_event_loop'):
+            asyncio.set_event_loop(asyncio.new_event_loop())
+        cls.loop = asyncio.get_event_loop()
+
+    def _run(self, coro):
+        return self.loop.run_until_complete(coro)
+
+    def test_login(self):
+        app = Microdot()
+        Session(app, secret_key='secret')
+        login = Login()
+
+        class User:
+            def __init__(self, id, name):
+                self.id = id
+                self.name = name
+
+        @login.user_loader
+        def load_user(user_id):
+            return User(user_id, f'user{user_id}')
+
+        @app.get('/')
+        @login
+        def index(request):
+            return request.g.current_user.name
+
+        @app.post('/login')
+        async def login_route(request):
+            return await login.login_user(request, User(123, 'user123'))
+
+        @app.post('/logout')
+        async def logout_route(request):
+            await login.logout_user(request)
+            return 'ok'
+
+        client = TestClient(app)
+        res = self._run(client.get('/?foo=bar'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/login?next=/%3Ffoo%3Dbar')
+
+        res = self._run(client.post('/login?next=/%3Ffoo=bar'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/?foo=bar')
+        self.assertEqual(len(res.headers['Set-Cookie']), 1)
+        self.assertIn('session', client.cookies)
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'user123')
+
+        res = self._run(client.post('/logout'))
+        self.assertEqual(res.status_code, 200)
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 302)
+
+    def test_login_bad_user_id(self):
+        class User:
+            def __init__(self, id, name):
+                self.id = id
+                self.name = name
+
+        app = Microdot()
+        Session(app, secret_key='secret')
+        login = Login()
+
+        @login.user_loader
+        def load_user(user_id):
+            return None
+
+        @app.get('/foo')
+        @login
+        async def index(request):
+            return 'ok'
+
+        @app.post('/login')
+        async def login_route(request):
+            return await login.login_user(request, User(1, 'user'))
+
+        client = TestClient(app)
+        res = self._run(client.post('/login?next=/'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/')
+        res = self._run(client.get('/foo'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/login?next=/foo')
+
+    def test_login_bad_redirect(self):
+        class User:
+            def __init__(self, id, name):
+                self.id = id
+                self.name = name
+
+        app = Microdot()
+        Session(app, secret_key='secret')
+        login = Login()
+
+        @login.user_loader
+        def load_user(user_id):
+            return user_id
+
+        @app.get('/')
+        @login
+        async def index(request):
+            return 'ok'
+
+        @app.post('/login')
+        async def login_route(request):
+            return await login.login_user(request, User(1, 'user'))
+
+        client = TestClient(app)
+        res = self._run(client.post('/login?next=http://example.com'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/')
+
+    def test_login_remember(self):
+        class User:
+            def __init__(self, id, name):
+                self.id = id
+                self.name = name
+
+        app = Microdot()
+        Session(app, secret_key='secret')
+        login = Login()
+
+        @login.user_loader
+        def load_user(user_id):
+            return User(user_id, f'user{user_id}')
+
+        @app.get('/')
+        @login
+        def index(request):
+            return {'user': request.g.current_user.id}
+
+        @app.post('/login')
+        async def login_route(request):
+            return await login.login_user(request, User(1, 'user1'),
+                                          remember=True)
+
+        @app.post('/logout')
+        async def logout(request):
+            await login.logout_user(request)
+            return 'ok'
+
+        @app.get('/fresh')
+        @login.fresh
+        async def fresh(request):
+            return f'fresh {request.g.current_user.id}'
+
+        client = TestClient(app)
+        res = self._run(client.post('/login?next=/%3Ffoo=bar'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/?foo=bar')
+        self.assertEqual(len(res.headers['Set-Cookie']), 2)
+        self.assertIn('session', client.cookies)
+        self.assertIn('_remember', client.cookies)
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, '{"user": 1}')
+        res = self._run(client.get('/fresh'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'fresh 1')
+
+        del client.cookies['session']
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        res = self._run(client.get('/fresh'))
+        self.assertEqual(res.status_code, 302)
+        self.assertEqual(res.headers['Location'], '/login?next=/fresh')
+
+        res = self._run(client.post('/logout'))
+        self.assertEqual(res.status_code, 200)
+        self.assertFalse('_remember' in client.cookies)
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 302)
diff --git a/tests/test_microdot.py b/tests/test_microdot.py
index ebd4d58..71e0d26 100644
--- a/tests/test_microdot.py
+++ b/tests/test_microdot.py
@@ -771,7 +771,7 @@ def index(req):
 
         client = TestClient(app)
         res = self._run(client.get('/'))
-        self.assertEqual(res, None)
+        self.assertEqual(res.body, None)
 
     def test_mount(self):
         subapp = Microdot()
@@ -794,7 +794,7 @@ def not_found(req):
 
         @subapp.route('/app')
         def index(req):
-            return req.g.before + ':foo'
+            return req.g.before + ':' + req.url_prefix
 
         app = Microdot()
         app.mount(subapp, url_prefix='/sub')
@@ -811,4 +811,203 @@ def index(req):
         self.assertEqual(res.status_code, 200)
         self.assertEqual(res.headers['Content-Type'],
                          'text/plain; charset=UTF-8')
-        self.assertEqual(res.text, 'before:foo:after')
+        self.assertEqual(res.text, 'before:/sub:after')
+
+    def test_mount_local(self):
+        subapp1 = Microdot()
+        subapp2 = Microdot()
+
+        @subapp1.before_request
+        def before1(req):
+            req.g.before += ':before1'
+
+        @subapp1.after_error_request
+        def after_error1(req, res):
+            res.body += b':errorafter'
+
+        @subapp1.errorhandler(ValueError)
+        def value_error(req, exc):
+            return str(exc), 400
+
+        @subapp1.route('/')
+        def index1(req):
+            raise ZeroDivisionError()
+
+        @subapp1.route('/foo')
+        def foo(req):
+            return req.g.before + ':foo:' + req.url_prefix
+
+        @subapp1.route('/err')
+        def err(req):
+            raise ValueError('err')
+
+        @subapp1.route('/err2')
+        def err2(req):
+            class MyErr(ValueError):
+                pass
+
+            raise MyErr('err')
+
+        @subapp2.before_request
+        def before2(req):
+            req.g.before += ':before2'
+
+        @subapp2.after_request
+        def after2(req, res):
+            res.body += b':after'
+
+        @subapp2.errorhandler(405)
+        def method_not_found2(req):
+            return '405', 405
+
+        @subapp2.route('/bar')
+        def bar(req):
+            return req.g.before + ':bar:' + req.url_prefix
+
+        @subapp2.route('/baz')
+        def baz(req):
+            abort(405)
+
+        app = Microdot()
+
+        @app.before_request
+        def before(req):
+            req.g.before = 'before-app'
+
+        @app.after_request
+        def after(req, res):
+            res.body += b':after-app'
+
+        app.mount(subapp1, local=True)
+        app.mount(subapp2, url_prefix='/sub', local=True)
+
+        client = TestClient(app)
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 500)
+        self.assertEqual(res.text, 'Internal server error:errorafter')
+
+        res = self._run(client.get('/foo'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.headers['Content-Type'],
+                         'text/plain; charset=UTF-8')
+        self.assertEqual(res.text, 'before-app:before1:foo::after-app')
+
+        res = self._run(client.get('/err'))
+        self.assertEqual(res.status_code, 400)
+        self.assertEqual(res.text, 'err:errorafter')
+
+        res = self._run(client.get('/err2'))
+        self.assertEqual(res.status_code, 400)
+        self.assertEqual(res.text, 'err:errorafter')
+
+        res = self._run(client.get('/sub/bar'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.headers['Content-Type'],
+                         'text/plain; charset=UTF-8')
+        self.assertEqual(res.text,
+                         'before-app:before2:bar:/sub:after:after-app')
+
+        res = self._run(client.post('/sub/bar'))
+        self.assertEqual(res.status_code, 405)
+        self.assertEqual(res.text, '405')
+
+        res = self._run(client.get('/sub/baz'))
+        self.assertEqual(res.status_code, 405)
+        self.assertEqual(res.text, '405')
+
+    def test_many_mounts(self):
+        subsubapp = Microdot()
+
+        @subsubapp.before_request
+        def subsubapp_before(req):
+            req.g.before = 'subsubapp'
+
+        @subsubapp.route('/')
+        def subsubapp_index(req):
+            return f'{req.g.before}:{req.subapp == subsubapp}:{req.url_prefix}'
+
+        subapp = Microdot()
+
+        @subapp.before_request
+        def subapp_before(req):
+            req.g.before = 'subapp'
+
+        @subapp.route('/')
+        def subapp_index(req):
+            return f'{req.g.before}:{req.subapp == subapp}:{req.url_prefix}'
+
+        app = Microdot()
+
+        @app.before_request
+        def app_before(req):
+            req.g.before = 'app'
+
+        @app.route('/')
+        def app_index(req):
+            return f'{req.g.before}:{req.subapp is None}:{req.url_prefix}'
+
+        subapp.mount(subsubapp, url_prefix='/subsub')
+        app.mount(subapp, url_prefix='/sub')
+
+        client = TestClient(app)
+
+        res = self._run(client.get('/sub/subsub/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'subsubapp:True:/sub/subsub')
+
+        res = self._run(client.get('/sub/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'subsubapp:True:/sub')
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'subsubapp:True:')
+
+    def test_many_local_mounts(self):
+        subsubapp = Microdot()
+
+        @subsubapp.before_request
+        def subsubapp_before(req):
+            req.g.before = 'subsubapp'
+
+        @subsubapp.route('/')
+        def subsubapp_index(req):
+            return f'{req.g.before}:{req.subapp == subsubapp}:{req.url_prefix}'
+
+        subapp = Microdot()
+
+        @subapp.before_request
+        def subapp_before(req):
+            req.g.before = 'subapp'
+
+        @subapp.route('/')
+        def subapp_index(req):
+            return f'{req.g.before}:{req.subapp == subapp}:{req.url_prefix}'
+
+        app = Microdot()
+
+        @app.before_request
+        def app_before(req):
+            req.g.before = 'app'
+
+        @app.route('/')
+        def app_index(req):
+            return f'{req.g.before}:{req.subapp is None}:{req.url_prefix}'
+
+        subapp.mount(subsubapp, url_prefix='/subsub', local=True)
+        app.mount(subapp, url_prefix='/sub', local=True)
+
+        client = TestClient(app)
+
+        res = self._run(client.get('/sub/subsub/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'subsubapp:True:/sub/subsub')
+
+        res = self._run(client.get('/sub/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'subapp:True:/sub')
+
+        res = self._run(client.get('/'))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'app:True:')
diff --git a/tests/test_multipart.py b/tests/test_multipart.py
new file mode 100644
index 0000000..f5db84a
--- /dev/null
+++ b/tests/test_multipart.py
@@ -0,0 +1,192 @@
+import asyncio
+import os
+import unittest
+from microdot import Microdot
+from microdot.multipart import with_form_data, FileUpload, FormDataIter
+from microdot.test_client import TestClient
+
+
+class TestMultipart(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        if hasattr(asyncio, 'set_event_loop'):
+            asyncio.set_event_loop(asyncio.new_event_loop())
+        cls.loop = asyncio.get_event_loop()
+
+    def _run(self, coro):
+        return self.loop.run_until_complete(coro)
+
+    def test_simple_form(self):
+        app = Microdot()
+
+        @app.post('/sync')
+        @with_form_data
+        def sync_route(req):
+            return dict(req.form)
+
+        @app.post('/async')
+        @with_form_data
+        async def async_route(req):
+            return dict(req.form)
+
+        client = TestClient(app)
+
+        res = self._run(client.post(
+            '/sync', headers={
+                'Content-Type': 'multipart/form-data; boundary=boundary',
+            },
+            body=(
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="foo"\r\n\r\nbar\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="baz"\r\n\r\nbaz\r\n'
+                b'--boundary--\r\n')
+        ))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json, {'foo': 'bar', 'baz': 'baz'})
+
+        res = self._run(client.post(
+            '/async', headers={
+                'Content-Type': 'multipart/form-data; boundary=boundary',
+            },
+            body=(
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="foo"\r\n\r\nbar\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="baz"\r\n\r\nbaz\r\n'
+                b'--boundary--\r\n')
+        ))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json, {'foo': 'bar', 'baz': 'baz'})
+
+    def test_form_with_files(self):
+        saved_max_memory_size = FileUpload.max_memory_size
+        FileUpload.max_memory_size = 5
+
+        app = Microdot()
+
+        @app.post('/async')
+        @with_form_data
+        async def async_route(req):
+            d = dict(req.form)
+            for name, file in req.files.items():
+                d[name] = '{}|{}|{}'.format(file.filename, file.content_type,
+                                            (await file.read()).decode())
+            return d
+
+        client = TestClient(app)
+
+        res = self._run(client.post(
+            '/async', headers={
+                'Content-Type': 'multipart/form-data; boundary=boundary',
+            },
+            body=(
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="foo"\r\n\r\nbar\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="f"; filename="f"\r\n'
+                b'Content-Type: text/plain\r\n\r\nbaz\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="g"; filename="g"\r\n'
+                b'Content-Type: text/html\r\n\r\n<p>hello</p>\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="x"\r\n\r\ny\r\n'
+                b'--boundary--\r\n')
+        ))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json, {'foo': 'bar', 'x': 'y',
+                                    'f': 'f|text/plain|baz',
+                                    'g': 'g|text/html|<p>hello</p>'})
+        FileUpload.max_memory_size = saved_max_memory_size
+
+    def test_file_save(self):
+        app = Microdot()
+
+        @app.post('/async')
+        @with_form_data
+        async def async_route(req):
+            for _, file in req.files.items():
+                await file.save('_x.txt')
+
+        client = TestClient(app)
+
+        res = self._run(client.post(
+            '/async', headers={
+                'Content-Type': 'multipart/form-data; boundary=boundary',
+            },
+            body=(
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="foo"\r\n\r\nbar\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="f"; filename="f"\r\n'
+                b'Content-Type: text/plain\r\n\r\nbaz\r\n'
+                b'--boundary--\r\n')
+        ))
+        self.assertEqual(res.status_code, 204)
+        with open('_x.txt', 'rb') as f:
+            self.assertEqual(f.read(), b'baz')
+        os.unlink('_x.txt')
+
+    def test_no_form(self):
+        app = Microdot()
+
+        @app.post('/async')
+        @with_form_data
+        async def async_route(req):
+            return str(req.form)
+
+        client = TestClient(app)
+
+        res = self._run(client.post('/async', body={'foo': 'bar'}))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.text, 'None')
+
+    def test_upload_iterator(self):
+        app = Microdot()
+
+        @app.post('/async')
+        async def async_route(req):
+            d = {}
+            async for name, value in FormDataIter(req):
+                if isinstance(value, FileUpload):
+                    d[name] = '{}|{}|{}'.format(value.filename,
+                                                value.content_type,
+                                                (await value.read(4)).decode())
+                else:
+                    d[name] = value
+            return d
+
+        client = TestClient(app)
+
+        res = self._run(client.post(
+            '/async', headers={
+                'Content-Type': 'multipart/form-data; boundary=boundary',
+            },
+            body=(
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="foo"\r\n\r\nbar\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="f"; filename="f"\r\n'
+                b'Content-Type: text/plain\r\n\r\nbaz\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="g"; filename="g.h"\r\n'
+                b'Content-Type: text/html\r\n\r\n<p>hello</p>\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="x"\r\n\r\ny\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="h"; filename="hh"\r\n'
+                b'Content-Type: text/plain\r\n\r\nyy' + (b'z' * 500) + b'\r\n'
+                b'--boundary\r\n'
+                b'Content-Disposition: form-data; name="i"; filename="i.1"\r\n'
+                b'Content-Type: text/plain\r\n\r\n1234\r\n'
+                b'--boundary--\r\n')
+        ))
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json, {
+            'foo': 'bar',
+            'f': 'f|text/plain|baz',
+            'g': 'g.h|text/html|<p>h',
+            'x': 'y',
+            'h': 'hh|text/plain|yyzz',
+            'i': 'i.1|text/plain|1234',
+        })
diff --git a/tests/test_session.py b/tests/test_session.py
index 0359ed9..43d8e2a 100644
--- a/tests/test_session.py
+++ b/tests/test_session.py
@@ -37,7 +37,7 @@ async def session_context_manager(req, session):
 
         @app.post('/set')
         @with_session
-        async def save_session(req, session):
+        def save_session(req, session):
             session['name'] = 'joe'
             session.save()
             return 'OK'
diff --git a/tests/test_sse.py b/tests/test_sse.py
index 0fcb6c2..0586b72 100644
--- a/tests/test_sse.py
+++ b/tests/test_sse.py
@@ -42,3 +42,40 @@ async def handle_sse(request, sse):
                                          'data: [42, "foo", "bar"]\n\n'
                                          'data: foo\n\n'
                                          'data: foo\n\n'))
+        self.assertEqual(len(response.events), 8)
+        self.assertEqual(response.events[0], {
+            'data': b'foo', 'data_json': None, 'event': None,
+            'event_id': None})
+        self.assertEqual(response.events[1], {
+            'data': b'bar', 'data_json': None, 'event': 'test',
+            'event_id': None})
+        self.assertEqual(response.events[2], {
+            'data': b'bar', 'data_json': None, 'event': 'test',
+            'event_id': 'id42'})
+        self.assertEqual(response.events[3], {
+            'data': b'bar', 'data_json': None, 'event': None,
+            'event_id': 'id42'})
+        self.assertEqual(response.events[4], {
+            'data': b'{"foo": "bar"}', 'data_json': {'foo': 'bar'},
+            'event': None, 'event_id': None})
+        self.assertEqual(response.events[5], {
+            'data': b'[42, "foo", "bar"]', 'data_json': [42, 'foo', 'bar'],
+            'event': None, 'event_id': None})
+        self.assertEqual(response.events[6], {
+            'data': b'foo', 'data_json': None, 'event': None,
+            'event_id': None})
+        self.assertEqual(response.events[7], {
+            'data': b'foo', 'data_json': None, 'event': None,
+            'event_id': None})
+
+    def test_sse_exception(self):
+        app = Microdot()
+
+        @app.route('/sse')
+        @with_sse
+        async def handle_sse(request, sse):
+            await sse.send('foo')
+            await sse.send(1 / 0)
+
+        client = TestClient(app)
+        self.assertRaises(ZeroDivisionError, self._run, client.get('/sse'))
diff --git a/tests/test_url_pattern.py b/tests/test_url_pattern.py
index e9b4a43..48ebde4 100644
--- a/tests/test_url_pattern.py
+++ b/tests/test_url_pattern.py
@@ -119,5 +119,30 @@ def test_many_arguments(self):
         self.assertIsNone(p.match('/foo/abc/def/123/test'))
 
     def test_invalid_url_patterns(self):
-        self.assertRaises(ValueError, URLPattern, '/users/<foo/bar')
-        self.assertRaises(ValueError, URLPattern, '/users/<badtype:id>')
+        p = URLPattern('/users/<foo/bar')
+        self.assertRaises(ValueError, p.compile)
+        p = URLPattern('/users/<badtype:id>')
+        self.assertRaises(ValueError, p.compile)
+
+    def test_custom_url_pattern(self):
+        URLPattern.register_type('hex', '[0-9a-f]+')
+        p = URLPattern('/users/<hex:id>')
+        self.assertEqual(p.match('/users/a1'), {'id': 'a1'})
+        self.assertIsNone(p.match('/users/ab12z'))
+
+        URLPattern.register_type('hex', '[0-9a-f]+',
+                                 parser=lambda value: int(value, 16))
+        p = URLPattern('/users/<hex:id>')
+        self.assertEqual(p.match('/users/a1'), {'id': 161})
+        self.assertIsNone(p.match('/users/ab12z'))
+
+        def hex_parser(value):
+            try:
+                return int(value, 16)
+            except ValueError:
+                return None
+
+        URLPattern.register_type('hex', parser=hex_parser)
+        p = URLPattern('/users/<hex:id>')
+        self.assertEqual(p.match('/users/a1'), {'id': 161})
+        self.assertIsNone(p.match('/users/ab12z'))
diff --git a/tests/test_urlencode.py b/tests/test_urlencode.py
index db21d85..2a9a1d4 100644
--- a/tests/test_urlencode.py
+++ b/tests/test_urlencode.py
@@ -1,5 +1,5 @@
 import unittest
-from microdot.microdot import urlencode, urldecode_str, urldecode_bytes
+from microdot.microdot import urlencode, urldecode
 
 
 class TestURLEncode(unittest.TestCase):
@@ -7,5 +7,7 @@ def test_urlencode(self):
         self.assertEqual(urlencode('?foo=bar&x'), '%3Ffoo%3Dbar%26x')
 
     def test_urldecode(self):
-        self.assertEqual(urldecode_str('%3Ffoo%3Dbar%26x'), '?foo=bar&x')
-        self.assertEqual(urldecode_bytes(b'%3Ffoo%3Dbar%26x'), '?foo=bar&x')
+        self.assertEqual(urldecode('%3Ffoo%3Dbar%26x'), '?foo=bar&x')
+        self.assertEqual(urldecode(b'%3Ffoo%3Dbar%26x'), '?foo=bar&x')
+        self.assertEqual(urldecode('dot%e2%80%a2dot'), 'dot•dot')
+        self.assertEqual(urldecode(b'dot%e2%80%a2dot'), 'dot•dot')
diff --git a/tests/test_websocket.py b/tests/test_websocket.py
index 9c20682..92d3605 100644
--- a/tests/test_websocket.py
+++ b/tests/test_websocket.py
@@ -46,11 +46,11 @@ async def ws():
 
         client = TestClient(app)
         res = self._run(client.websocket('/echo', ws))
-        self.assertIsNone(res)
+        self.assertIsNone(res.body)
         self.assertEqual(results, ['hello', b'bye', b'*' * 300, b'+' * 65537])
 
         res = self._run(client.websocket('/divzero', ws))
-        self.assertIsNone(res)
+        self.assertIsNone(res.body)
         WebSocket.max_message_length = -1
 
     @unittest.skipIf(sys.implementation.name == 'micropython',
@@ -74,7 +74,7 @@ async def ws():
 
         client = TestClient(app)
         res = self._run(client.websocket('/echo', ws))
-        self.assertIsNone(res)
+        self.assertIsNone(res.body)
         self.assertEqual(results, [])
         Request.max_body_length = saved_max_body_length