Go back to non-root-relative SSE endpoint event

Author: halter73

src/ModelContextProtocol.AspNetCore/SseHandler.cs

@@ -31,9 +31,7 @@ public async Task HandleSseRequestAsync(HttpContext context)
 
         StreamableHttpHandler.InitializeSseResponse(context);
 
-        var requestPath = (context.Request.PathBase + context.Request.Path).ToString();
-        var endpointPattern = requestPath[..(requestPath.LastIndexOf('/') + 1)];
-        await using var transport = new SseResponseStreamTransport(context.Response.Body, $"{endpointPattern}message?sessionId={sessionId}");
+        await using var transport = new SseResponseStreamTransport(context.Response.Body, $"message?sessionId={sessionId}");
         await using var httpMcpSession = new HttpMcpSession<SseResponseStreamTransport>(sessionId, transport, context.User, httpMcpServerOptions.Value.TimeProvider);
         if (!_sessions.TryAdd(sessionId, httpMcpSession))
         {

tests/ModelContextProtocol.AspNetCore.Tests/MapMcpTests.cs

@@ -53,7 +53,7 @@ public async Task Allows_Customizing_Route(string pattern)
         Assert.NotNull(eventLine);
         Assert.Equal("event: endpoint", eventLine);
         Assert.NotNull(dataLine);
-        Assert.Equal($"data: {pattern}/message", dataLine[..dataLine.IndexOf('?')]);
+        Assert.Equal($"data: message", dataLine[..dataLine.IndexOf('?')]);
     }
 
     [Theory]