From 8cae46ab02ed96145c89a7c7c18ac4f100cc3dd2 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 5 Jun 2026 08:35:42 +0000
Subject: [PATCH 1/2] Initial plan


From 8eaa58a504ffda1e3c38418eed91e50a17e8dd92 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 5 Jun 2026 08:38:01 +0000
Subject: [PATCH 2/2] Add thread safety documentation to JsonSerializer class

---
 xml/System.Text.Json/JsonSerializer.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xml/System.Text.Json/JsonSerializer.xml b/xml/System.Text.Json/JsonSerializer.xml
index a27333c46a6..10b7f954f3f 100644
--- a/xml/System.Text.Json/JsonSerializer.xml
+++ b/xml/System.Text.Json/JsonSerializer.xml
@@ -41,6 +41,7 @@ For more information, see [How to serialize and deserialize JSON](/dotnet/standa
 
  ]]></format>
     </remarks>
+    <threadsafe>All public static members of <see cref="T:System.Text.Json.JsonSerializer" /> are thread-safe and may be used concurrently from multiple threads. The serializer is designed for thread safety; however, <see cref="T:System.Text.Json.JsonSerializerOptions" /> instances are not thread-safe during initial configuration. Once a <see cref="T:System.Text.Json.JsonSerializerOptions" /> instance is passed to a <see cref="T:System.Text.Json.JsonSerializer" /> method or is otherwise made read-only, it can be safely shared across multiple threads. Avoid concurrent modification of a shared <see cref="T:System.Text.Json.JsonSerializerOptions" /> instance while it is still mutable.</threadsafe>
   </Docs>
   <Members>
     <Member MemberName="Deserialize">