From c5b867bf6c92155d002f5b7f8144be05f43c113a Mon Sep 17 00:00:00 2001
From: Lewis Renfrew <lewis.renfrew@linn.co.uk>
Date: Mon, 18 May 2026 15:34:00 +0100
Subject: [PATCH 1/2] template method pattern to make handling json trivial

---
 src/JsonMessageHandler.cs   | 21 +++++++++++++++++++++
 src/JsonMessagePublisher.cs |  5 +++--
 2 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 src/JsonMessageHandler.cs

diff --git a/src/JsonMessageHandler.cs b/src/JsonMessageHandler.cs
new file mode 100644
index 0000000..ecfc6fc
--- /dev/null
+++ b/src/JsonMessageHandler.cs
@@ -0,0 +1,21 @@
+using System.Text.Json;
+
+namespace Linn.Common.Messaging.RabbitMQ;
+
+public abstract class JsonMessageHandler<T>(JsonSerializerOptions? serializerOptions = null) : IMessageHandler
+{
+    public abstract string RoutingKey { get; }
+
+    public async Task HandleAsync(Message message, CancellationToken cancellationToken)
+    {
+        var payload = JsonSerializer.Deserialize<T>(message.Body.Span, serializerOptions)
+            ?? throw new JsonException($"Failed to deserialize message body to {typeof(T).Name}");
+
+        await HandleAsync(payload, message.Headers, cancellationToken);
+    }
+
+    protected abstract Task HandleAsync(
+        T payload,
+        IReadOnlyDictionary<string, object> headers,
+        CancellationToken cancellationToken);
+}
diff --git a/src/JsonMessagePublisher.cs b/src/JsonMessagePublisher.cs
index abe0204..ae8869d 100644
--- a/src/JsonMessagePublisher.cs
+++ b/src/JsonMessagePublisher.cs
@@ -5,7 +5,8 @@ namespace Linn.Common.Messaging.RabbitMQ;
 public class JsonMessagePublisher<T>(
     RabbitPublisher rabbitPublisher,
     string routingKey,
-    IReadOnlyDictionary<string, object>? headers = null)
+    IReadOnlyDictionary<string, object>? headers = null,
+    JsonSerializerOptions? serializerOptions = null)
     : IPublisher<T>
 {
     public async Task PublishAsync(T obj, CancellationToken cancellationToken = default)
@@ -13,7 +14,7 @@ public async Task PublishAsync(T obj, CancellationToken cancellationToken = defa
         var msg = new Message
         {
             RoutingKey = routingKey,
-            Body = JsonSerializer.SerializeToUtf8Bytes(obj),
+            Body = JsonSerializer.SerializeToUtf8Bytes(obj, serializerOptions),
             Headers = headers ?? new Dictionary<string, object>()
         };
 

From e2d2254918d8794711967b603aa4c558a27f03bc Mon Sep 17 00:00:00 2001
From: Lewis Renfrew <lewis.renfrew@linn.co.uk>
Date: Mon, 18 May 2026 15:37:16 +0100
Subject: [PATCH 2/2] chlog

---
 changelog.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/changelog.md b/changelog.md
index 8187dcb..6715320 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,4 +1,10 @@
 # Changelog
+
+## [5.1.0] - 2026-05-18
+### *Changes*
+- Add JsonMessageHandler<T> abstract base class for type-safe message consumption with automatic JSON deserialization
+- Add optional JsonSerializerOptions parameter to JsonMessagePublisher<T>
+
 ## [5.0.0] - 2026-05-12
 ### *Changes (Breaking)*
 - Target .NET 10