From 426f3bbda7bb5a3f4c2cb0bc54bb9a7652e0990c Mon Sep 17 00:00:00 2001
From: rUv <ruv@ruv.net>
Date: Sat, 21 Mar 2026 22:54:39 +0000
Subject: [PATCH] fix(ruvocal): MCP SSE auto-reconnect on stale session
 (404/connection errors)

- Widen isConnectionClosedError to catch 404, fetch failed, ECONNRESET
- Add transport readyState check in clientPool for dead connections
- Retry logic now triggers reconnection on stale SSE sessions

Co-Authored-By: claude-flow <ruv@ruv.net>
---
 ui/ruvocal/src/lib/server/mcp/clientPool.ts | 14 +++++++++++++-
 ui/ruvocal/src/lib/server/mcp/httpClient.ts | 12 +++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/ui/ruvocal/src/lib/server/mcp/clientPool.ts b/ui/ruvocal/src/lib/server/mcp/clientPool.ts
index 2f78ddd9..becb2a32 100644
--- a/ui/ruvocal/src/lib/server/mcp/clientPool.ts
+++ b/ui/ruvocal/src/lib/server/mcp/clientPool.ts
@@ -16,7 +16,19 @@ function keyOf(server: McpServerConfig) {
 export async function getClient(server: McpServerConfig, signal?: AbortSignal): Promise<Client> {
 	const key = keyOf(server);
 	const existing = pool.get(key);
-	if (existing) return existing;
+	if (existing) {
+		// Verify the cached client is still alive by checking transport state
+		try {
+			// If the transport is closed/errored, evict and reconnect
+			if ((existing as unknown as { _transport?: { readyState?: number } })._transport?.readyState === 2) {
+				pool.delete(key);
+			} else {
+				return existing;
+			}
+		} catch {
+			return existing;
+		}
+	}
 
 	let firstError: unknown;
 	const client = new Client({ name: "chat-ui-mcp", version: "0.1.0" });
diff --git a/ui/ruvocal/src/lib/server/mcp/httpClient.ts b/ui/ruvocal/src/lib/server/mcp/httpClient.ts
index eb862157..de629c69 100644
--- a/ui/ruvocal/src/lib/server/mcp/httpClient.ts
+++ b/ui/ruvocal/src/lib/server/mcp/httpClient.ts
@@ -4,7 +4,17 @@ import { config } from "$lib/server/config";
 
 function isConnectionClosedError(err: unknown): boolean {
 	const message = err instanceof Error ? err.message : String(err);
-	return message.includes("-32000") || message.toLowerCase().includes("connection closed");
+	const lower = message.toLowerCase();
+	return (
+		message.includes("-32000") ||
+		lower.includes("connection closed") ||
+		lower.includes("404") ||
+		lower.includes("not found") ||
+		lower.includes("session") ||
+		lower.includes("fetch failed") ||
+		lower.includes("econnreset") ||
+		lower.includes("econnrefused")
+	);
 }
 
 export interface McpServerConfig {