From 26b47438c60a673bf500728e7236d0dcd5173438 Mon Sep 17 00:00:00 2001
From: Jerome <jerome@anthropic.com>
Date: Mon, 24 Feb 2025 10:39:38 +0000
Subject: [PATCH] Tidy up CORS error catching

---
 src/client/auth.ts | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/client/auth.ts b/src/client/auth.ts
index 5f5c860e..c7799429 100644
--- a/src/client/auth.ts
+++ b/src/client/auth.ts
@@ -170,11 +170,12 @@ export async function discoverOAuthMetadata(
         "MCP-Protocol-Version": opts?.protocolVersion ?? LATEST_PROTOCOL_VERSION
       }
     });
-  } catch {
-    try {
+  } catch (error) {
+    // CORS errors come back as TypeError
+    if (error instanceof TypeError) {
       response = await fetch(url);
-    } catch {
-      return undefined;
+    } else {
+      throw error;
     }
   }