From c2ca7d7449fef69f19ac6e210a547e3183ba2e37 Mon Sep 17 00:00:00 2001
From: ronantakizawa <ronantakizawa@gmail.com>
Date: Tue, 12 Aug 2025 11:00:48 -0600
Subject: [PATCH] fix: fix generic 404 errors

---
 .../client/transport/WebClientStreamableHttpTransport.java  | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mcp-spring/mcp-spring-webflux/src/main/java/io/modelcontextprotocol/client/transport/WebClientStreamableHttpTransport.java b/mcp-spring/mcp-spring-webflux/src/main/java/io/modelcontextprotocol/client/transport/WebClientStreamableHttpTransport.java
index 853aed2bf..648e8b3ea 100644
--- a/mcp-spring/mcp-spring-webflux/src/main/java/io/modelcontextprotocol/client/transport/WebClientStreamableHttpTransport.java
+++ b/mcp-spring/mcp-spring-webflux/src/main/java/io/modelcontextprotocol/client/transport/WebClientStreamableHttpTransport.java
@@ -326,8 +326,10 @@ else if (mediaType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
 						}
 					}
 					else {
-						if (isNotFound(response) && !sessionRepresentation.equals(MISSING_SESSION_ID)) {
-							return mcpSessionNotFoundError(sessionRepresentation);
+						if (isNotFound(response)) {
+							if (transportSession.sessionId().isPresent()) {
+								return mcpSessionNotFoundError(sessionRepresentation);
+							}
 						}
 						return this.extractError(response, sessionRepresentation);
 					}