diff --git a/.gitignore b/.gitignore
index 8035d84..893ddbe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@
 *.db
 
 .env
+env/
 
 .cache
 .coverage
@@ -18,4 +19,6 @@ build/
 dist/
 _build/
 
-tags
\ No newline at end of file
+tags
+
+.idea/
diff --git a/README.rst b/README.rst
index ebdd401..e36cd84 100644
--- a/README.rst
+++ b/README.rst
@@ -47,6 +47,17 @@ Now you can install the djangosaml2idp package using pip. This will also install
     pip install djangosaml2idp
 
 
+Running the test suite
+======================
+Install the dev dependencies in ``requirements-dev.txt``::
+
+  pip install -r requirements-dev.txt
+
+Run ``py.test`` from the project root::
+
+  py.test
+
+
 Configuration & Usage
 =====================
 
diff --git a/djangosaml2idp/error_views.py b/djangosaml2idp/error_views.py
index 737418d..a50485b 100644
--- a/djangosaml2idp/error_views.py
+++ b/djangosaml2idp/error_views.py
@@ -9,8 +9,9 @@ class SamlIDPErrorView(TemplateView):
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
         exception = kwargs.get("exception")
+
         context.update({
-            "exception_type": ".".join([exception.__module__, exception.__class__.__name__]) if exception else None,
+            "exception_type": exception.__class__.__name__ if exception else None,
             "exception_msg": str(exception) if exception else None,
             "extra_message": kwargs.get("extra_message"),
         })
diff --git a/djangosaml2idp/processors.py b/djangosaml2idp/processors.py
index cc99834..b138413 100644
--- a/djangosaml2idp/processors.py
+++ b/djangosaml2idp/processors.py
@@ -1,9 +1,15 @@
+from django.conf import settings
+
+
 class BaseProcessor:
     """ Processor class is used to determine if a user has access to a client service of this IDP
         and to construct the identity dictionary which is sent to the SP
     """
 
-    def has_access(self, user):
+    def __init__(self, entity_id):
+        self._entity_id = entity_id
+
+    def has_access(self, request):
         """ Check if this user is allowed to use this IDP
         """
         return True
@@ -13,9 +19,15 @@ def enable_multifactor(self, user):
         """
         return False
 
-    def create_identity(self, user, sp_mapping):
+    def get_user_id(self, user):
+        user_field = getattr(settings, 'SAML_IDP_DJANGO_USERNAME_FIELD', None) or \
+                     getattr(user, 'USERNAME_FIELD', 'username')
+        return str(getattr(user, user_field))
+
+    def create_identity(self, user, sp_mapping, **extra_config):
         """ Generate an identity dictionary of the user based on the given mapping of desired user attributes by the SP
         """
+
         return {
             out_attr: getattr(user, user_attr)
             for user_attr, out_attr in sp_mapping.items()
diff --git a/djangosaml2idp/views.py b/djangosaml2idp/views.py
index 8307201..5eb3493 100644
--- a/djangosaml2idp/views.py
+++ b/djangosaml2idp/views.py
@@ -15,7 +15,7 @@
 from django.views.decorators.cache import never_cache
 from django.views.decorators.csrf import csrf_exempt
 from django.views.decorators.http import require_http_methods
-from saml2 import BINDING_HTTP_POST
+from saml2 import BINDING_HTTP_POST, BINDING_HTTP_REDIRECT
 from saml2.authn_context import PASSWORD, AuthnBroker, authn_context_class_ref
 from saml2.config import IdPConfig
 from saml2.ident import NameID
@@ -42,7 +42,15 @@ def sso_entry(request):
     """ Entrypoint view for SSO. Gathers the parameters from the HTTP request, stores them in the session
         and redirects the requester to the login_process view.
     """
-    passed_data = request.POST if request.method == 'POST' else request.GET
+    if request.method == 'POST':
+        passed_data = request.POST
+        binding = BINDING_HTTP_POST
+    else:
+        passed_data = request.GET
+        binding = BINDING_HTTP_REDIRECT
+
+    request.session['Binding'] = binding
+
     try:
         request.session['SAMLRequest'] = passed_data['SAMLRequest']
     except (KeyError, MultiValueDictKeyError) as e:
@@ -74,22 +82,23 @@ def dispatch(self, request, *args, **kwargs):
             return self.handle_error(request, exception=e)
         return super(IdPHandlerViewMixin, self).dispatch(request, *args, **kwargs)
 
-    def get_processor(self, sp_config):
+    def get_processor(self, entity_id, sp_config):
         """ "Instantiate user-specified processor or fallback to all-access base processor
         """
         processor_string = sp_config.get('processor', None)
         if processor_string:
             try:
-                return import_string(processor_string)()
+                return import_string(processor_string)(entity_id)
             except Exception as e:
                 logger.error("Failed to instantiate processor: {} - {}".format(processor_string, e), exc_info=True)
-        return BaseProcessor
+                raise
+        return BaseProcessor(entity_id)
 
     def get_identity(self, processor, user, sp_config):
         """ Create Identity dict (using SP-specific mapping)
         """
         sp_mapping = sp_config.get('attribute_mapping', {'username': 'username'})
-        return processor.create_identity(user, sp_mapping)
+        return processor.create_identity(user, sp_mapping, **sp_config.get('extra_config', {}))
 
 
 @method_decorator(never_cache, name='dispatch')
@@ -99,9 +108,11 @@ class LoginProcessView(LoginRequiredMixin, IdPHandlerViewMixin, View):
     """
 
     def get(self, request, *args, **kwargs):
+        binding = request.session.get('Binding', BINDING_HTTP_POST)
+
         # Parse incoming request
         try:
-            req_info = self.IDP.parse_authn_request(request.session['SAMLRequest'], BINDING_HTTP_POST)
+            req_info = self.IDP.parse_authn_request(request.session['SAMLRequest'], binding)
         except Exception as excp:
             return self.handle_error(request, exception=excp)
         # TODO this is taken from example, but no idea how this works or whats it does. Check SAML2 specification?
@@ -129,10 +140,10 @@ def get(self, request, *args, **kwargs):
         except Exception:
             return self.handle_error(request, exception=ImproperlyConfigured("No config for SP %s defined in SAML_IDP_SPCONFIG" % resp_args['sp_entity_id']), status=400)
 
-        processor = self.get_processor(sp_config)
+        processor = self.get_processor(resp_args['sp_entity_id'], sp_config)
 
         # Check if user has access to the service of this SP
-        if not processor.has_access(request.user):
+        if not processor.has_access(request):
             return self.handle_error(request, exception=PermissionDenied("You do not have access to this resource"), status=403)
 
         identity = self.get_identity(processor, request.user, sp_config)
@@ -142,11 +153,13 @@ def get(self, request, *args, **kwargs):
         AUTHN_BROKER = AuthnBroker()
         AUTHN_BROKER.add(authn_context_class_ref(req_authn_context), "")
 
+        user_id = processor.get_user_id(request.user)
+
         # Construct SamlResponse message
         try:
             authn_resp = self.IDP.create_authn_response(
-                identity=identity, userid=request.user.username,
-                name_id=NameID(format=resp_args['name_id_policy'].format, sp_name_qualifier=resp_args['sp_entity_id'], text=request.user.username),
+                identity=identity, userid=user_id,
+                name_id=NameID(format=resp_args['name_id_policy'].format, sp_name_qualifier=resp_args['sp_entity_id'], text=user_id),
                 authn=AUTHN_BROKER.get_authn_by_accr(req_authn_context),
                 sign_response=self.IDP.config.getattr("sign_response", "idp") or False,
                 sign_assertion=self.IDP.config.getattr("sign_assertion", "idp") or False,
@@ -201,10 +214,10 @@ def get(self, request, *args, **kwargs):
             service="assertion_consumer_service",
             entity_id=sp_entity_id)
 
-        processor = self.get_processor(sp_config)
+        processor = self.get_processor(sp_entity_id, sp_config)
 
         # Check if user has access to the service of this SP
-        if not processor.has_access(request.user):
+        if not processor.has_access(request):
             return self.handle_error(request, exception=PermissionDenied("You do not have access to this resource"), status=403)
 
         identity = self.get_identity(processor, request.user, sp_config)
@@ -213,10 +226,12 @@ def get(self, request, *args, **kwargs):
         AUTHN_BROKER = AuthnBroker()
         AUTHN_BROKER.add(authn_context_class_ref(req_authn_context), "")
 
+        user_id = processor.get_user_id(request.user)
+
         # Construct SamlResponse messages
         try:
             name_id_formats = self.IDP.config.getattr("name_id_format", "idp") or [NAMEID_FORMAT_UNSPECIFIED]
-            name_id = NameID(format=name_id_formats[0], text=request.user.username)
+            name_id = NameID(format=name_id_formats[0], text=user_id)
             authn = AUTHN_BROKER.get_authn_by_accr(req_authn_context)
             sign_response = self.IDP.config.getattr("sign_response", "idp") or False
             sign_assertion = self.IDP.config.getattr("sign_assertion", "idp") or False
@@ -225,7 +240,7 @@ def get(self, request, *args, **kwargs):
                 in_response_to="IdP_Initiated_Login",
                 destination=destination,
                 sp_entity_id=sp_entity_id,
-                userid=request.user.username,
+                userid=user_id,
                 name_id=name_id,
                 authn=authn,
                 sign_response=sign_response,
diff --git a/pytest.ini b/pytest.ini
index 7dffe55..9b6f225 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -5,3 +5,8 @@ skip = build/*,dist/*,docs/*,*/manage.py
 
 [pep8]
 ignore = C0111,C0301,E122,E127,E128,E131,E501,E502,E722,E731,W605
+
+[pytest]
+django_find_project = false
+norecursedirs = env
+DJANGO_SETTINGS_MODULE=tests.settings
diff --git a/requirements-dev.txt b/requirements-dev.txt
index d29b092..9abf3a9 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,2 +1,7 @@
 django>2.0,<2.1
 pysaml2>=4.4.0
+
+pytest==4.0.1
+pytest-django==3.4.4
+pytest-pythonpath==0.7.3
+python-dateutil==2.7.5
diff --git a/runtests.py b/runtests.py
deleted file mode 100644
index 0c2ef30..0000000
--- a/runtests.py
+++ /dev/null
@@ -1,15 +0,0 @@
-#!/usr/bin/env python
-import os
-import sys
-
-import django
-from django.conf import settings
-from django.test.utils import get_runner
-
-if __name__ == "__main__":
-    os.environ['DJANGO_SETTINGS_MODULE'] = 'tests.settings'
-    django.setup()
-    TestRunner = get_runner(settings)
-    test_runner = TestRunner()
-    failures = test_runner.run_tests(["tests"])
-    sys.exit(bool(failures))
diff --git a/tests/settings.py b/tests/settings.py
index 8d8fe7f..e48bcc3 100644
--- a/tests/settings.py
+++ b/tests/settings.py
@@ -6,12 +6,12 @@
 
 DATABASES = {
     'default': {
-        'ENGINE': 'django.db.backends.sqlite3',  # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
-        'NAME': './idptest.sqlite',                      # Or path to database file if using sqlite3.
-        'USER': '',                      # Not used with sqlite3.
-        'PASSWORD': '',                  # Not used with sqlite3.
-        'HOST': '',                      # Set to empty string for localhost. Not used with sqlite3.
-        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': './idptest.sqlite',
+        'USER': '',
+        'PASSWORD': '',
+        'HOST': '',
+        'PORT': '',
     }
 }
 
@@ -42,3 +42,11 @@
 )
 
 ROOT_URLCONF = 'tests.urls'
+
+# ---
+
+SAML_IDP_SPCONFIG = {
+    'test_idp_1': {
+        'attribute_mapping': {}
+    }
+}
diff --git a/tests/test_processor.py b/tests/test_processor.py
new file mode 100644
index 0000000..5b440df
--- /dev/null
+++ b/tests/test_processor.py
@@ -0,0 +1,29 @@
+import pytest
+
+from django.contrib.auth import get_user_model
+
+from djangosaml2idp.processors import BaseProcessor
+
+
+User = get_user_model()
+
+
+class TestBaseProcessor:
+
+    def test_extract_user_id_configure_by_user_class(self):
+
+        user = User()
+        user.USERNAME_FIELD = 'email'
+        user.email = 'test_email'
+
+        assert BaseProcessor('entity-id').get_user_id(user) == 'test_email'
+
+    def test_extract_user_id_configure_by_settings(self, settings):
+        """Should use `settings.SAML_IDP_DJANGO_USERNAME_FIELD` to determine the user id field"""
+
+        settings.SAML_IDP_DJANGO_USERNAME_FIELD = 'first_name'
+
+        user = User()
+        user.first_name = 'test_first_name'
+
+        assert BaseProcessor('entity-id').get_user_id(user) == 'test_first_name'
diff --git a/tests/test_views.py b/tests/test_views.py
new file mode 100644
index 0000000..9170495
--- /dev/null
+++ b/tests/test_views.py
@@ -0,0 +1,54 @@
+import pytest
+
+from django.contrib.auth import get_user_model
+
+from djangosaml2idp.views import IdPHandlerViewMixin
+
+from djangosaml2idp.processors import BaseProcessor
+
+
+User = get_user_model()
+
+
+class CustomProcessor(BaseProcessor):
+    pass
+
+
+class TestIdPHandlerViewMixin:
+    def test_get_identity_provides_extra_config(self):
+        obj = IdPHandlerViewMixin()
+
+    def test_get_processor_errors_if_processor_cannot_be_loaded(self):
+        sp_config = {
+            'processor': 'this.does.not.exist'
+        }
+
+        with pytest.raises(Exception):
+            IdPHandlerViewMixin().get_processor('entity_id', sp_config)
+
+    def test_get_processor_defaults_to_base_processor(self):
+        sp_config = {
+        }
+
+        assert isinstance(IdPHandlerViewMixin().get_processor('entity_id', sp_config), BaseProcessor)
+
+    def test_get_processor_loads_custom_processor(self):
+        sp_config = {
+            'processor': 'tests.test_views.CustomProcessor'
+        }
+
+        assert isinstance(IdPHandlerViewMixin().get_processor('entity_id', sp_config), CustomProcessor)
+
+
+class TestIdpInitiatedFlow:
+    pass
+
+
+class TestMetadata:
+    pass
+
+
+class LoginFlow:
+    def test_requires_authentication(self):
+        """test redriect to settings.LOGIN_VIEW"""
+        pass