Document Cosmos support for complex types (EF Core 11)

entity-framework/core/providers/cosmos/modeling.md

@@ -2,7 +2,7 @@
 title: Modeling - Azure Cosmos DB Provider - EF Core
 description: Configuring the model with the Azure Cosmos DB EF Core Provider
 author: roji
-ms.date: 09/26/2024
+ms.date: 03/18/2026
 uid: core/providers/cosmos/modeling
 ---
 # Configuring the model with the EF Core Azure Cosmos DB Provider

entity-framework/core/what-is-new/ef-core-11.0/whatsnew.md

@@ -77,6 +77,12 @@ This enhancement removes a significant limitation when modeling complex domain h
 
 For more information on inheritance mapping strategies, see [Inheritance](xref:core/modeling/inheritance).
 
+<a name="complex-types-cosmos"></a>
+
+### Complex types in Azure Cosmos DB
+
+Complex types are now fully supported in the Azure Cosmos DB provider, embedded as nested JSON objects or arrays. For more information, [see the Cosmos DB section below](#cosmos-complex-types).
+
 ## LINQ and SQL translation
 
 <a name="linq-maxby-minby"></a>
@@ -106,6 +112,38 @@ Similarly, `MinByAsync` orders ascending and returns the element with the minimu
 
 ## Cosmos DB
 
+<a name="cosmos-complex-types"></a>
+
+### Complex types
+
+EF Core [complex types](xref:core/what-is-new/ef-core-10.0/whatsnew#complex-types) are now fully supported in the Azure Cosmos DB provider; they are embedded as nested JSON objects (or arrays, for collections) within the owning document, with support for queries, inserts, and updates.
+
+For example, the following configures `ShippingAddress` as a complex type:
+
+### [Fluent API](#tab/fluent-api)
+
+```csharp
+modelBuilder.Entity<Order>()
+    .ComplexProperty(o => o.ShippingAddress);
+```
+
+### [Data Annotations](#tab/data-annotations)
+
+```csharp
+[ComplexType]
+public class ShippingAddress
+{
+    public required string Street { get; set; }
+    public required string City { get; set; }
+}
+```
+
+***
+
+Complex types are generally a better fit than owned types when mapping to JSON documents: unlike owned types, complex types have value semantics and no identity, which means they work better in scenarios such as comparing two embedded objects within the same document, or using them as keys.
+
+This feature was contributed by [@JoasE](https://github.com/JoasE) - many thanks!
+
 <a name="cosmos-transactional-batches"></a>
 
 ### Transactional batches