First steps into a payment provider API

src/pretix/base/payment.py

@@ -0,0 +1,10 @@
+class BasePaymentProvider:
+    """
+    This is the base class for all payment providers.
+    """
+
+    def get_identifier(self) -> str:
+        """
+        Return a unique identifier for this payment provider
+        """
+        raise NotImplementedError()

src/pretix/base/plugins.py

@@ -8,6 +8,7 @@ from django.apps import apps
 
 class PluginType(Enum):
     RESTRICTION = 1
+    PAYMENT = 2
 
 
 def get_all_plugins() -> "List[class]":

src/pretix/base/signals.py

@@ -51,3 +51,11 @@ return a positive result (see plugin API documentation for details).
 determine_availability = EventPluginSignal(
     providing_args=["item", "variations", "context", "cache"]
 )
+
+"""
+This signal is sent out to get all known payment providers. Receivers should return a
+subclass of pretix.base.payment.BasePaymentProvider
+"""
+register_payment_providers = EventPluginSignal(
+    providing_args=[]
+)