diff --git a/open-sse/handlers/chatCore.js b/open-sse/handlers/chatCore.js
index 7fe4605f..2bc2a0e1 100644
--- a/open-sse/handlers/chatCore.js
+++ b/open-sse/handlers/chatCore.js
@@ -115,7 +115,7 @@ export async function handleChatCore({ body, modelInfo, credentials, log, onCred
       streamController.handleError(error);
       return createErrorResult(499, "Request aborted");
     }
-    const errMsg = formatProviderError(error, provider, model);
+    const errMsg = formatProviderError(error, provider, model, 502);
     console.log(`${COLORS.red}[ERROR] ${errMsg}${COLORS.reset}`);
     return createErrorResult(502, errMsg);
   }
@@ -205,7 +205,7 @@ export async function handleChatCore({ body, modelInfo, credentials, log, onCred
   // Check provider response - return error info for fallback handling
   if (!providerResponse.ok) {
     const { statusCode, message } = await parseUpstreamError(providerResponse);
-    const errMsg = formatProviderError(new Error(message), provider, model);
+    const errMsg = formatProviderError(new Error(message), provider, model, statusCode);
     console.log(`${COLORS.red}[ERROR] ${errMsg}${COLORS.reset}`);
     
     // Log error with full request body for debugging
diff --git a/open-sse/utils/error.js b/open-sse/utils/error.js
index 17670bbd..75b7f858 100644
--- a/open-sse/utils/error.js
+++ b/open-sse/utils/error.js
@@ -126,8 +126,11 @@ export function createErrorResult(statusCode, message) {
  * @param {Error} error - Original error
  * @param {string} provider - Provider name
  * @param {string} model - Model name
+ * @param {number|string} statusCode - HTTP status code or error code
  * @returns {string} Formatted error message
  */
-export function formatProviderError(error, provider, model) {
-  return error.message || "Unknown error";
+export function formatProviderError(error, provider, model, statusCode) {
+  const code = statusCode || error.code || 'FETCH_FAILED';
+  const message = error.message || "Unknown error";
+  return `[${code}]: ${message}`;
 }