From dc5e5d3680f4f2fe04c8808c62b1306290d1fc19 Mon Sep 17 00:00:00 2001
From: Eduard Stanculet <eduard.stanculet@uipath.com>
Date: Wed, 26 Mar 2025 18:45:31 +0200
Subject: [PATCH] Configurable messages endpoint for SSE transport

---
 .../Protocol/Transport/SseResponseStreamTransport.cs      | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/ModelContextProtocol/Protocol/Transport/SseResponseStreamTransport.cs b/src/ModelContextProtocol/Protocol/Transport/SseResponseStreamTransport.cs
index db96a53bb..6c016f70b 100644
--- a/src/ModelContextProtocol/Protocol/Transport/SseResponseStreamTransport.cs
+++ b/src/ModelContextProtocol/Protocol/Transport/SseResponseStreamTransport.cs
@@ -1,4 +1,5 @@
-using System.Buffers;
+using System.Text;
+using System.Buffers;
 using System.Net.ServerSentEvents;
 using System.Text.Json;
 using System.Threading.Channels;
@@ -11,7 +12,8 @@ namespace ModelContextProtocol.Protocol.Transport;
 /// Implements the MCP SSE server transport protocol using the SSE response <see cref="Stream"/>.
 /// </summary>
 /// <param name="sseResponseStream">The stream to write the SSE response body to.</param>
-public sealed class SseResponseStreamTransport(Stream sseResponseStream) : ITransport
+/// <param name="messageEndpoint">The endpoint to send JSON-RPC messages to. Defaults to "/message".</param> 
+public sealed class SseResponseStreamTransport(Stream sseResponseStream, string messageEndpoint = "/message") : ITransport
 {
     private readonly Channel<IJsonRpcMessage> _incomingChannel = CreateSingleItemChannel<IJsonRpcMessage>();
     private readonly Channel<SseItem<IJsonRpcMessage?>> _outgoingSseChannel = CreateSingleItemChannel<SseItem<IJsonRpcMessage?>>();
@@ -34,7 +36,7 @@ void WriteJsonRpcMessageToBuffer(SseItem<IJsonRpcMessage?> item, IBufferWriter<b
         {
             if (item.EventType == "endpoint")
             {
-                writer.Write("/message"u8);
+                writer.Write(Encoding.UTF8.GetBytes(messageEndpoint));
                 return;
             }