feat: add ServerItem, AsyncServerItem, and EmailDeliveryInfo models

- ServerItem wraps Item with increase/decrease/tryDecrease quantity methods
- AsyncServerItem provides async counterpart for quantity operations
- EmailDeliveryInfo model for delivery statistics (delivered/bounced/complained/total)
- Export new models from models package

sdks/implementations/python/src/stack_auth/models/__init__.py

@@ -10,7 +10,8 @@ from stack_auth.models.api_keys import (
 from stack_auth.models.contact_channels import ContactChannel
 from stack_auth.models.notifications import NotificationCategory
 from stack_auth.models.oauth import OAuthConnection, OAuthProvider
-from stack_auth.models.payments import Item, Product
+from stack_auth.models.email import EmailDeliveryInfo
+from stack_auth.models.payments import AsyncServerItem, Item, Product, ServerItem
 from stack_auth.models.permissions import ProjectPermission, TeamPermission
 from stack_auth.models.projects import OAuthProviderConfig, Project, ProjectConfig
 from stack_auth.models.sessions import ActiveSession, GeoInfo
@@ -41,5 +42,8 @@ __all__ = [
     "OAuthProvider",
     "Product",
     "Item",
+    "ServerItem",
+    "AsyncServerItem",
+    "EmailDeliveryInfo",
     "NotificationCategory",
 ]

sdks/implementations/python/src/stack_auth/models/email.py

@@ -0,0 +1,14 @@
+"""Email models for Stack Auth."""
+
+from __future__ import annotations
+
+from stack_auth.models._base import StackAuthModel
+
+
+class EmailDeliveryInfo(StackAuthModel):
+    """Email delivery statistics."""
+
+    delivered: int = 0
+    bounced: int = 0
+    complained: int = 0
+    total: int = 0

sdks/implementations/python/src/stack_auth/models/payments.py

@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+from typing import Any
+
 from pydantic import Field
 
 from stack_auth.models._base import StackAuthModel
@@ -25,3 +27,135 @@ class Product(StackAuthModel):
     is_server_only: bool = Field(False, alias="isServerOnly")
     stackable: bool = False
     type: str = "one_time"
+
+
+class ServerItem:
+    """Server-side item with methods to modify quantity.
+
+    Wraps an :class:`Item` and provides ``increase_quantity``,
+    ``decrease_quantity``, and ``try_decrease_quantity`` methods that
+    communicate with the Stack Auth API via the HTTP client.
+    """
+
+    def __init__(
+        self,
+        item: Item,
+        *,
+        _client: Any,
+        _customer_path: str,
+        _item_id: str,
+        _customer_id_field: str,
+        _customer_id_value: str,
+    ) -> None:
+        self.display_name = item.display_name
+        self.quantity = item.quantity
+        self.non_negative_quantity = item.non_negative_quantity
+        self._client = _client
+        self._customer_path = _customer_path
+        self._item_id = _item_id
+        self._customer_id_field = _customer_id_field
+        self._customer_id_value = _customer_id_value
+
+    def _quantity_body(self, quantity: int) -> dict[str, Any]:
+        return {
+            self._customer_id_field: self._customer_id_value,
+            "item_id": self._item_id,
+            "quantity": quantity,
+        }
+
+    def increase_quantity(self, amount: int) -> None:
+        """Increase this item's quantity by *amount*."""
+        self._client.request(
+            "POST",
+            "/internal/items/quantity-changes",
+            body=self._quantity_body(amount),
+        )
+
+    def decrease_quantity(self, amount: int) -> None:
+        """Decrease this item's quantity by *amount*."""
+        self._client.request(
+            "POST",
+            "/internal/items/quantity-changes",
+            body=self._quantity_body(-amount),
+        )
+
+    def try_decrease_quantity(self, amount: int) -> bool:
+        """Try to decrease this item's quantity by *amount*.
+
+        Returns ``True`` if the decrease succeeded, ``False`` otherwise.
+        """
+        data = self._client.request(
+            "POST",
+            "/internal/items/try-decrease",
+            body={
+                self._customer_id_field: self._customer_id_value,
+                "item_id": self._item_id,
+                "amount": amount,
+            },
+        )
+        return bool(data.get("success", False)) if data else False
+
+
+class AsyncServerItem:
+    """Async server-side item with methods to modify quantity.
+
+    Async counterpart of :class:`ServerItem`.
+    """
+
+    def __init__(
+        self,
+        item: Item,
+        *,
+        _client: Any,
+        _customer_path: str,
+        _item_id: str,
+        _customer_id_field: str,
+        _customer_id_value: str,
+    ) -> None:
+        self.display_name = item.display_name
+        self.quantity = item.quantity
+        self.non_negative_quantity = item.non_negative_quantity
+        self._client = _client
+        self._customer_path = _customer_path
+        self._item_id = _item_id
+        self._customer_id_field = _customer_id_field
+        self._customer_id_value = _customer_id_value
+
+    def _quantity_body(self, quantity: int) -> dict[str, Any]:
+        return {
+            self._customer_id_field: self._customer_id_value,
+            "item_id": self._item_id,
+            "quantity": quantity,
+        }
+
+    async def increase_quantity(self, amount: int) -> None:
+        """Increase this item's quantity by *amount*."""
+        await self._client.request(
+            "POST",
+            "/internal/items/quantity-changes",
+            body=self._quantity_body(amount),
+        )
+
+    async def decrease_quantity(self, amount: int) -> None:
+        """Decrease this item's quantity by *amount*."""
+        await self._client.request(
+            "POST",
+            "/internal/items/quantity-changes",
+            body=self._quantity_body(-amount),
+        )
+
+    async def try_decrease_quantity(self, amount: int) -> bool:
+        """Try to decrease this item's quantity by *amount*.
+
+        Returns ``True`` if the decrease succeeded, ``False`` otherwise.
+        """
+        data = await self._client.request(
+            "POST",
+            "/internal/items/try-decrease",
+            body={
+                self._customer_id_field: self._customer_id_value,
+                "item_id": self._item_id,
+                "amount": amount,
+            },
+        )
+        return bool(data.get("success", False)) if data else False