From 3c6cdc1dac0795b3cca3e8f2ad4f83cb8bbad009 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 13 May 2026 18:28:30 +0000
Subject: [PATCH 1/2] Initial plan


From d1314356abdb3c03f60b6fab31b848b55dce5b0a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 13 May 2026 18:31:42 +0000
Subject: [PATCH 2/2] Split MessageExtensions AttachmentLayout (list|grid) from
 Attachment.Layout (list|carousel)

Agent-Logs-Url: https://github.com/microsoft/teams.net/sessions/10784387-fb02-4ea9-bbe2-70add2826380

Co-authored-by: corinagum <14900841+corinagum@users.noreply.github.com>
---
 .../MessageExtensions/AttachmentLayout.cs     | 24 +++++++++++++++++++
 .../MessageExtensions/Result.cs               |  2 +-
 Samples/Samples.MessageExtensions/Program.cs  | 12 +++++-----
 3 files changed, 31 insertions(+), 7 deletions(-)
 create mode 100644 Libraries/Microsoft.Teams.Api/MessageExtensions/AttachmentLayout.cs

diff --git a/Libraries/Microsoft.Teams.Api/MessageExtensions/AttachmentLayout.cs b/Libraries/Microsoft.Teams.Api/MessageExtensions/AttachmentLayout.cs
new file mode 100644
index 000000000..e09797dd2
--- /dev/null
+++ b/Libraries/Microsoft.Teams.Api/MessageExtensions/AttachmentLayout.cs
@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.Text.Json.Serialization;
+
+using Microsoft.Teams.Common;
+
+namespace Microsoft.Teams.Api.MessageExtensions;
+
+/// <summary>
+/// Hint for how to deal with multiple attachments in a messaging extension result.
+/// Possible values include: 'list', 'grid'.
+/// </summary>
+[JsonConverter(typeof(StringEnum.JsonConverter<AttachmentLayout>))]
+public class AttachmentLayout(string value) : StringEnum(value)
+{
+    public static readonly AttachmentLayout List = new("list");
+    [JsonIgnore]
+    public bool IsList => List.Equals(Value);
+
+    public static readonly AttachmentLayout Grid = new("grid");
+    [JsonIgnore]
+    public bool IsGrid => Grid.Equals(Value);
+}
diff --git a/Libraries/Microsoft.Teams.Api/MessageExtensions/Result.cs b/Libraries/Microsoft.Teams.Api/MessageExtensions/Result.cs
index f7dc401ac..5995c6b96 100644
--- a/Libraries/Microsoft.Teams.Api/MessageExtensions/Result.cs
+++ b/Libraries/Microsoft.Teams.Api/MessageExtensions/Result.cs
@@ -42,7 +42,7 @@ public class Result
     /// </summary>
     [JsonPropertyName("attachmentLayout")]
     [JsonPropertyOrder(0)]
-    public Api.Attachment.Layout? AttachmentLayout { get; set; }
+    public AttachmentLayout? AttachmentLayout { get; set; }
 
     /// <summary>
     /// The type of the result. Possible values include:
diff --git a/Samples/Samples.MessageExtensions/Program.cs b/Samples/Samples.MessageExtensions/Program.cs
index a82cd5592..38048b706 100644
--- a/Samples/Samples.MessageExtensions/Program.cs
+++ b/Samples/Samples.MessageExtensions/Program.cs
@@ -60,7 +60,7 @@
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = new List<Microsoft.Teams.Api.MessageExtensions.Attachment>()
         }
     });
@@ -198,7 +198,7 @@ static Microsoft.Teams.Api.MessageExtensions.Response CreateSearchResults(string
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = attachments
         }
     };
@@ -233,7 +233,7 @@ static Microsoft.Teams.Api.MessageExtensions.Response HandleCreateCard(JsonEleme
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = new List<Microsoft.Teams.Api.MessageExtensions.Attachment> { attachment }
         }
     };
@@ -268,7 +268,7 @@ static Microsoft.Teams.Api.MessageExtensions.Response HandleGetMessageDetails(Mi
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = new List<Microsoft.Teams.Api.MessageExtensions.Attachment> { attachment }
         }
     };
@@ -303,7 +303,7 @@ static Microsoft.Teams.Api.MessageExtensions.Response CreateLinkUnfurlResponse(s
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = new List<Microsoft.Teams.Api.MessageExtensions.Attachment> { attachment }
         }
     };
@@ -335,7 +335,7 @@ static Microsoft.Teams.Api.MessageExtensions.Response CreateItemSelectionRespons
         ComposeExtension = new Microsoft.Teams.Api.MessageExtensions.Result
         {
             Type = Microsoft.Teams.Api.MessageExtensions.ResultType.Result,
-            AttachmentLayout = Microsoft.Teams.Api.Attachment.Layout.List,
+            AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.List,
             Attachments = new List<Microsoft.Teams.Api.MessageExtensions.Attachment> { attachment }
         }
     };