From 418b5e90707797dd1fed2ec0ead8d21749b636b2 Mon Sep 17 00:00:00 2001
From: Danny Avila <danny@librechat.ai>
Date: Tue, 15 Jul 2025 18:20:11 -0400
Subject: [PATCH] =?UTF-8?q?=E2=99=BB=EF=B8=8F=20fix:=20Resolve=20MCP=20Con?=
 =?UTF-8?q?nection=20if=20Ping=20is=20Unsupported=20(#8483)?=
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---
 packages/api/src/mcp/connection.ts | 51 ++++++++++++++++++++++++++++--
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/packages/api/src/mcp/connection.ts b/packages/api/src/mcp/connection.ts
index e46d59a3e2..99e59b5467 100644
--- a/packages/api/src/mcp/connection.ts
+++ b/packages/api/src/mcp/connection.ts
@@ -590,12 +590,59 @@ export class MCPConnection extends EventEmitter {
   }
 
   public async isConnected(): Promise<boolean> {
+    // First check if we're in a connected state
+    if (this.connectionState !== 'connected') {
+      return false;
+    }
+
     try {
+      // Try ping first as it's the lightest check
       await this.client.ping();
       return this.connectionState === 'connected';
     } catch (error) {
-      logger.error(`${this.getLogPrefix()} Ping failed:`, error);
-      return false;
+      // Check if the error is because ping is not supported (method not found)
+      const pingUnsupported =
+        error instanceof Error &&
+        ((error as Error)?.message.includes('-32601') ||
+          (error as Error)?.message.includes('invalid method ping') ||
+          (error as Error)?.message.includes('method not found'));
+
+      if (!pingUnsupported) {
+        logger.error(`${this.getLogPrefix()} Ping failed:`, error);
+        return false;
+      }
+
+      // Ping is not supported by this server, try an alternative verification
+      logger.debug(
+        `${this.getLogPrefix()} Server does not support ping method, verifying connection with capabilities`,
+      );
+
+      try {
+        // Get server capabilities to verify connection is truly active
+        const capabilities = this.client.getServerCapabilities();
+
+        // If we have capabilities, try calling a supported method to verify connection
+        if (capabilities?.tools) {
+          await this.client.listTools();
+          return this.connectionState === 'connected';
+        } else if (capabilities?.resources) {
+          await this.client.listResources();
+          return this.connectionState === 'connected';
+        } else if (capabilities?.prompts) {
+          await this.client.listPrompts();
+          return this.connectionState === 'connected';
+        } else {
+          // No capabilities to test, but we're in connected state and initialization succeeded
+          logger.debug(
+            `${this.getLogPrefix()} No capabilities to test, assuming connected based on state`,
+          );
+          return this.connectionState === 'connected';
+        }
+      } catch (capabilityError) {
+        // If capability check fails, the connection is likely broken
+        logger.error(`${this.getLogPrefix()} Connection verification failed:`, capabilityError);
+        return false;
+      }
     }
   }