diff --git a/.dotnet.azure/sdk/openai/Azure.AI.OpenAI/tests/VectorStoreTests.cs b/.dotnet.azure/sdk/openai/Azure.AI.OpenAI/tests/VectorStoreTests.cs
index 2365e0f19..b7dfb8e37 100644
--- a/.dotnet.azure/sdk/openai/Azure.AI.OpenAI/tests/VectorStoreTests.cs
+++ b/.dotnet.azure/sdk/openai/Azure.AI.OpenAI/tests/VectorStoreTests.cs
@@ -85,10 +85,12 @@ public async Task CanCreateGetAndDeleteVectorStores()
         deleted = await client.DeleteVectorStoreAsync(vectorStore.Id);
         Assert.That(deleted, Is.True);
 
-        vectorStore = await client.CreateVectorStoreAsync(new VectorStoreCreationOptions()
+        var options = new VectorStoreCreationOptions();
+        foreach (var file in testFiles)
         {
-            FileIds = testFiles.Select(file => file.Id).ToList()
-        });
+            options.FileIds.Add(file.Id);
+        }
+        vectorStore = await client.CreateVectorStoreAsync(options);
         Validate(vectorStore);
         Assert.Multiple(() =>
         {
diff --git a/.dotnet/CHANGELOG.md b/.dotnet/CHANGELOG.md
index 26b286043..ac6341fbf 100644
--- a/.dotnet/CHANGELOG.md
+++ b/.dotnet/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Removed `ChatMessageContentPart`'s `ToString` overload. (commit_hash)
 - Removed the common `ListOrder` enum from the top-level `OpenAI` namespace in favor of individual enums in their corresponding sub-namespace. (commit_hash)
 - Renamed the `PageSize` property to `PageSizeLimit`. (commit_hash)
+- Removed setter from collection properties.
 
 ### Bugs Fixed
 
diff --git a/.dotnet/api/OpenAI.netstandard2.0.cs b/.dotnet/api/OpenAI.netstandard2.0.cs
index 2c34e38e7..4998c5f07 100644
--- a/.dotnet/api/OpenAI.netstandard2.0.cs
+++ b/.dotnet/api/OpenAI.netstandard2.0.cs
@@ -280,7 +280,7 @@ public class AssistantCreationOptions : IJsonModel<AssistantCreationOptions>, IP
         BinaryData IPersistableModel<AssistantCreationOptions>.Write(ModelReaderWriterOptions options);
     }
     public class AssistantModificationOptions : IJsonModel<AssistantModificationOptions>, IPersistableModel<AssistantModificationOptions> {
-        public IList<ToolDefinition> DefaultTools { get; set; }
+        public IList<ToolDefinition> DefaultTools { get; }
         public string Description { get; set; }
         public string Instructions { get; set; }
         public IDictionary<string, string> Metadata { get; set; }
@@ -344,7 +344,7 @@ public class CodeInterpreterToolDefinition : ToolDefinition, IJsonModel<CodeInte
         BinaryData IPersistableModel<CodeInterpreterToolDefinition>.Write(ModelReaderWriterOptions options);
     }
     public class CodeInterpreterToolResources : IJsonModel<CodeInterpreterToolResources>, IPersistableModel<CodeInterpreterToolResources> {
-        public IList<string> FileIds { get; set; }
+        public IList<string> FileIds { get; }
         CodeInterpreterToolResources IJsonModel<CodeInterpreterToolResources>.Create(ref Utf8JsonReader reader, ModelReaderWriterOptions options);
         void IJsonModel<CodeInterpreterToolResources>.Write(Utf8JsonWriter writer, ModelReaderWriterOptions options);
         CodeInterpreterToolResources IPersistableModel<CodeInterpreterToolResources>.Create(BinaryData data, ModelReaderWriterOptions options);
@@ -361,7 +361,7 @@ public class FileSearchToolDefinition : ToolDefinition, IJsonModel<FileSearchToo
     }
     public class FileSearchToolResources : IJsonModel<FileSearchToolResources>, IPersistableModel<FileSearchToolResources> {
         public IList<VectorStoreCreationHelper> NewVectorStores { get; }
-        public IList<string> VectorStoreIds { get; set; }
+        public IList<string> VectorStoreIds { get; }
         FileSearchToolResources IJsonModel<FileSearchToolResources>.Create(ref Utf8JsonReader reader, ModelReaderWriterOptions options);
         void IJsonModel<FileSearchToolResources>.Write(Utf8JsonWriter writer, ModelReaderWriterOptions options);
         FileSearchToolResources IPersistableModel<FileSearchToolResources>.Create(BinaryData data, ModelReaderWriterOptions options);
@@ -2319,7 +2319,7 @@ public class VectorStoreCollectionOptions {
     public class VectorStoreCreationOptions : IJsonModel<VectorStoreCreationOptions>, IPersistableModel<VectorStoreCreationOptions> {
         public FileChunkingStrategy ChunkingStrategy { get; set; }
         public VectorStoreExpirationPolicy ExpirationPolicy { get; set; }
-        public IList<string> FileIds { get; set; }
+        public IList<string> FileIds { get; }
         public IDictionary<string, string> Metadata { get; set; }
         public string Name { get; set; }
         VectorStoreCreationOptions IJsonModel<VectorStoreCreationOptions>.Create(ref Utf8JsonReader reader, ModelReaderWriterOptions options);
diff --git a/.dotnet/src/Custom/Assistants/AssistantModificationOptions.cs b/.dotnet/src/Custom/Assistants/AssistantModificationOptions.cs
index 6d2544983..295559878 100644
--- a/.dotnet/src/Custom/Assistants/AssistantModificationOptions.cs
+++ b/.dotnet/src/Custom/Assistants/AssistantModificationOptions.cs
@@ -22,7 +22,7 @@ public partial class AssistantModificationOptions
     /// There can be a maximum of 128 tools per assistant. Tools can be of types `code_interpreter`, `file_search`, or `function`.
     /// </summary>
     [CodeGenMember("Tools")]
-    public IList<ToolDefinition> DefaultTools { get; set; } = new ChangeTrackingList<ToolDefinition>();
+    public IList<ToolDefinition> DefaultTools { get; } = new ChangeTrackingList<ToolDefinition>();
 
     // CUSTOM: reuse common request/response models for tool resources. Note that modification operations use the
     //          response models (which do not contain resource initialization helpers).
diff --git a/.dotnet/src/Custom/Assistants/CodeInterpreterToolResources.cs b/.dotnet/src/Custom/Assistants/CodeInterpreterToolResources.cs
index 6b763dc67..5f80800f4 100644
--- a/.dotnet/src/Custom/Assistants/CodeInterpreterToolResources.cs
+++ b/.dotnet/src/Custom/Assistants/CodeInterpreterToolResources.cs
@@ -14,7 +14,7 @@ public partial class CodeInterpreterToolResources
     public IList<string> FileIds
     {
         get => _fileIds;
-        set
+        internal set
         {
             _fileIds = new ChangeTrackingList<string>();
             foreach (string fileId in value)
diff --git a/.dotnet/src/Custom/Assistants/FileSearchToolResources.cs b/.dotnet/src/Custom/Assistants/FileSearchToolResources.cs
index 8c199b06d..f85e5cf48 100644
--- a/.dotnet/src/Custom/Assistants/FileSearchToolResources.cs
+++ b/.dotnet/src/Custom/Assistants/FileSearchToolResources.cs
@@ -16,7 +16,7 @@ public partial class FileSearchToolResources
     public IList<string> VectorStoreIds
     {
         get => _vectorStoreIds;
-        set
+        internal set
         {
             _vectorStoreIds = new ChangeTrackingList<string>();
             foreach (string item in value)
diff --git a/.dotnet/src/Custom/VectorStores/VectorStoreCreationOptions.cs b/.dotnet/src/Custom/VectorStores/VectorStoreCreationOptions.cs
index 066fb6194..a421d5901 100644
--- a/.dotnet/src/Custom/VectorStores/VectorStoreCreationOptions.cs
+++ b/.dotnet/src/Custom/VectorStores/VectorStoreCreationOptions.cs
@@ -7,9 +7,6 @@ namespace OpenAI.VectorStores;
 [CodeGenModel("CreateVectorStoreRequest")]
 public partial class VectorStoreCreationOptions
 {
-    /// <summary> A list of [File](/docs/api-reference/files) IDs that the vector store should use. Useful for tools like `file_search` that can access files. </summary>
-    public IList<string> FileIds { get; set; }
-
     /// <summary> Gets or sets the policy that controls when the new vector store will be automatically deleted. </summary>
     [CodeGenMember("ExpiresAfter")]
     public VectorStoreExpirationPolicy ExpirationPolicy { get; set; }
diff --git a/.dotnet/src/Generated/Models/VectorStoreCreationOptions.cs b/.dotnet/src/Generated/Models/VectorStoreCreationOptions.cs
index 6c26058e0..6d5f31216 100644
--- a/.dotnet/src/Generated/Models/VectorStoreCreationOptions.cs
+++ b/.dotnet/src/Generated/Models/VectorStoreCreationOptions.cs
@@ -25,6 +25,8 @@ internal VectorStoreCreationOptions(IList<string> fileIds, string name, VectorSt
             Metadata = metadata;
             SerializedAdditionalRawData = serializedAdditionalRawData;
         }
+
+        public IList<string> FileIds { get; }
         public string Name { get; set; }
         public IDictionary<string, string> Metadata { get; set; }
     }
diff --git a/.dotnet/tests/Assistants/VectorStoreTests.cs b/.dotnet/tests/Assistants/VectorStoreTests.cs
index 5f210ce48..ba11cb321 100644
--- a/.dotnet/tests/Assistants/VectorStoreTests.cs
+++ b/.dotnet/tests/Assistants/VectorStoreTests.cs
@@ -73,10 +73,13 @@ public void CanCreateGetAndDeleteVectorStores()
         Assert.That(deleted, Is.True);
         _vectorStoresToDelete.RemoveAt(_vectorStoresToDelete.Count - 1);
 
-        vectorStore = client.CreateVectorStore(new VectorStoreCreationOptions()
+        var options = new VectorStoreCreationOptions();
+        foreach (var file in testFiles)
         {
-            FileIds = testFiles.Select(file => file.Id).ToList()
-        });
+            options.FileIds.Add(file.Id);
+        }
+        vectorStore = client.CreateVectorStore(options);
+
         Validate(vectorStore);
         Assert.Multiple(() =>
         {
@@ -324,11 +327,16 @@ public async Task CanApplyChunkingStrategy(ChunkingStrategyKind strategyKind)
             Assert.That(inputStaticStrategy.OverlappingTokenCount, Is.EqualTo(250));
         }
 
-        VectorStore vectorStore = await client.CreateVectorStoreAsync(new VectorStoreCreationOptions()
+        var options = new VectorStoreCreationOptions()
         {
-            FileIds = testFiles.Select(file => file.Id).ToList(),
             ChunkingStrategy = chunkingStrategy,
-        });
+        };
+        foreach (var file in testFiles)
+        {
+            options.FileIds.Add(file.Id);
+        }
+        VectorStore vectorStore = client.CreateVectorStore(options);
+
         Validate(vectorStore);
         Assert.That(vectorStore.FileCounts.Total, Is.EqualTo(5));