feat: SSE reconnection state, list virtualization, wallet availability, stream card memoization

frontend/package.json

@@ -15,6 +15,7 @@
     "@stellar/freighter-api": "^6.0.1",
     "@stellar/stellar-sdk": "^15.1.0",
     "@tanstack/react-query": "^5.101.0",
+    "@tanstack/react-virtual": "^3.14.9",
     "lucide-react": "^0.575.0",
     "next": "16.2.9",
     "next-themes": "^0.4.6",

frontend/src/components/dashboard/ActivityHistory.tsx

@@ -1,13 +1,16 @@
 "use client";
 
-import React from "react";
+import React, { useRef } from "react";
 import Link from "next/link";
+import { useVirtualizer } from "@tanstack/react-virtual";
 import { BackendStreamEvent } from "@/lib/api-types";
 import { formatAmount } from "@/lib/amount";
 import TransactionTracker from "@/components/TransactionTracker";
 import { Download, ExternalLink, Clock } from "lucide-react";
 import { Button } from "../ui/Button";
 
+const VIRTUALIZATION_THRESHOLD = 50;
+
 interface ActivityHistoryProps {
   events: BackendStreamEvent[];
   isLoading?: boolean;
@@ -17,6 +20,17 @@ export const ActivityHistory: React.FC<ActivityHistoryProps> = ({
   events,
   isLoading,
 }) => {
+  const parentRef = useRef<HTMLDivElement>(null);
+  const shouldVirtualize = events.length > VIRTUALIZATION_THRESHOLD;
+
+  const virtualizer = useVirtualizer({
+    count: events.length,
+    getScrollElement: () => parentRef.current,
+    estimateSize: () => 120,
+    overscan: 5,
+    enabled: shouldVirtualize,
+  });
+
   const exportToCSV = () => {
     const headers = [
       "Stream ID",
@@ -139,55 +153,128 @@ export const ActivityHistory: React.FC<ActivityHistoryProps> = ({
         </Button>
       </div>
 
-      <div className="relative space-y-4 before:absolute before:inset-0 before:ml-5 before:-translate-x-px md:before:mx-auto md:before:translate-x-0 before:h-full before:w-0.5 before:bg-gradient-to-b before:from-transparent before:via-slate-700 before:to-transparent">
-        {events.map((event, index) => (
+      {shouldVirtualize ? (
+        <div
+          ref={parentRef}
+          className="relative h-[600px] overflow-auto before:absolute before:inset-0 before:ml-5 before:-translate-x-px md:before:mx-auto md:before:translate-x-0 before:h-full before:w-0.5 before:bg-gradient-to-b before:from-transparent before:via-slate-700 before:to-transparent"
+        >
           <div
-            key={`${event.id}-${index}`}
-            className="relative flex items-center justify-between md:justify-normal md:odd:flex-row-reverse group"
+            style={{ height: virtualizer.getTotalSize() }}
+            className="relative w-full"
           >
-            {/* Dot */}
-            <div className="flex items-center justify-center w-10 h-10 rounded-full border border-slate-700 bg-slate-900 text-accent shadow shrink-0 md:order-1 md:group-odd:-translate-x-1/2 md:group-even:translate-x-1/2">
-              <Clock className="h-5 w-5" />
-            </div>
-            {/* Content Card */}
-            <div className="w-[calc(100%-4rem)] md:w-[calc(50%-2.5rem)] p-4 bg-white/5 border border-glass-border rounded-xl hover:bg-white/10 transition-colors shadow-xl">
-              <div className="flex flex-col sm:flex-row justify-between items-start mb-2 gap-2">
-                <div>
-                  <p className="text-white font-medium text-sm sm:text-base">
-                    {renderEventMessage(event)}
-                  </p>
-                  <time className="text-xs text-slate-400 flex items-center gap-1 mt-1">
-                    {new Date(event.timestamp * 1000).toLocaleString()}
-                  </time>
+            {virtualizer.getVirtualItems().map((virtualRow) => {
+              const event = events[virtualRow.index];
+              if (!event) return null;
+              return (
+                <div
+                  key={`${event.id}-${virtualRow.index}`}
+                  ref={virtualizer.measureElement}
+                  data-index={virtualRow.index}
+                  style={{
+                    position: "absolute",
+                    top: 0,
+                    left: 0,
+                    width: "100%",
+                    transform: `translateY(${virtualRow.start}px)`,
+                  }}
+                  className="relative flex items-center justify-between md:justify-normal md:odd:flex-row-reverse group mb-4"
+                >
+                  {/* Dot */}
+                  <div className="flex items-center justify-center w-10 h-10 rounded-full border border-slate-700 bg-slate-900 text-accent shadow shrink-0 md:order-1 md:group-odd:-translate-x-1/2 md:group-even:translate-x-1/2">
+                    <Clock className="h-5 w-5" />
+                  </div>
+                  {/* Content Card */}
+                  <div className="w-[calc(100%-4rem)] md:w-[calc(50%-2.5rem)] p-4 bg-white/5 border border-glass-border rounded-xl hover:bg-white/10 transition-colors shadow-xl">
+                    <div className="flex flex-col sm:flex-row justify-between items-start mb-2 gap-2">
+                      <div>
+                        <p className="text-white font-medium text-sm sm:text-base">
+                          {renderEventMessage(event)}
+                        </p>
+                        <time className="text-xs text-slate-400 flex items-center gap-1 mt-1">
+                          {new Date(event.timestamp * 1000).toLocaleString()}
+                        </time>
+                      </div>
+                      <span className="text-[10px] uppercase tracking-wider px-2 py-1 rounded bg-accent/10 text-accent font-bold border border-accent/20">
+                        {event.eventType}
+                      </span>
+                    </div>
+
+                    {event.transactionHash && (
+                      <div className="mt-4 pt-4 border-t border-white/5 flex items-center justify-between">
+                        <TransactionTracker
+                          status="confirmed"
+                          action="withdraw"
+                          txHash={event.transactionHash}
+                          streamId={event.streamId.toString()}
+                        />
+                        <a
+                          href={`https://stellar.expert/explorer/testnet/tx/${event.transactionHash}`}
+                          target="_blank"
+                          rel="noopener noreferrer"
+                          className="text-slate-500 hover:text-white transition-colors"
+                          title="View on Explorer"
+                        >
+                          <ExternalLink className="h-4 w-4" />
+                        </a>
+                      </div>
+                    )}
+                  </div>
                 </div>
-                <span className="text-[10px] uppercase tracking-wider px-2 py-1 rounded bg-accent/10 text-accent font-bold border border-accent/20">
-                  {event.eventType}
-                </span>
+              );
+            })}
+          </div>
+        </div>
+      ) : (
+        <div className="relative space-y-4 before:absolute before:inset-0 before:ml-5 before:-translate-x-px md:before:mx-auto md:before:translate-x-0 before:h-full before:w-0.5 before:bg-gradient-to-b before:from-transparent before:via-slate-700 before:to-transparent">
+          {events.map((event, index) => (
+            <div
+              key={`${event.id}-${index}`}
+              className="relative flex items-center justify-between md:justify-normal md:odd:flex-row-reverse group"
+            >
+              {/* Dot */}
+              <div className="flex items-center justify-center w-10 h-10 rounded-full border border-slate-700 bg-slate-900 text-accent shadow shrink-0 md:order-1 md:group-odd:-translate-x-1/2 md:group-even:translate-x-1/2">
+                <Clock className="h-5 w-5" />
               </div>
-
-              {event.transactionHash && (
-                <div className="mt-4 pt-4 border-t border-white/5 flex items-center justify-between">
-                  <TransactionTracker
-                    status="confirmed"
-                    action="withdraw"
-                    txHash={event.transactionHash}
-                    streamId={event.streamId.toString()}
-                  />
-                  <a
-                    href={`https://stellar.expert/explorer/testnet/tx/${event.transactionHash}`}
-                    target="_blank"
-                    rel="noopener noreferrer"
-                    className="text-slate-500 hover:text-white transition-colors"
-                    title="View on Explorer"
-                  >
-                    <ExternalLink className="h-4 w-4" />
-                  </a>
+              {/* Content Card */}
+              <div className="w-[calc(100%-4rem)] md:w-[calc(50%-2.5rem)] p-4 bg-white/5 border border-glass-border rounded-xl hover:bg-white/10 transition-colors shadow-xl">
+                <div className="flex flex-col sm:flex-row justify-between items-start mb-2 gap-2">
+                  <div>
+                    <p className="text-white font-medium text-sm sm:text-base">
+                      {renderEventMessage(event)}
+                    </p>
+                    <time className="text-xs text-slate-400 flex items-center gap-1 mt-1">
+                      {new Date(event.timestamp * 1000).toLocaleString()}
+                    </time>
+                  </div>
+                  <span className="text-[10px] uppercase tracking-wider px-2 py-1 rounded bg-accent/10 text-accent font-bold border border-accent/20">
+                    {event.eventType}
+                  </span>
                 </div>
-              )}
+
+                {event.transactionHash && (
+                  <div className="mt-4 pt-4 border-t border-white/5 flex items-center justify-between">
+                    <TransactionTracker
+                      status="confirmed"
+                      action="withdraw"
+                      txHash={event.transactionHash}
+                      streamId={event.streamId.toString()}
+                    />
+                    <a
+                      href={`https://stellar.expert/explorer/testnet/tx/${event.transactionHash}`}
+                      target="_blank"
+                      rel="noopener noreferrer"
+                      className="text-slate-500 hover:text-white transition-colors"
+                      title="View on Explorer"
+                    >
+                      <ExternalLink className="h-4 w-4" />
+                    </a>
+                  </div>
+                )}
+              </div>
             </div>
-          </div>
-        ))}
-      </div>
+          ))}
+        </div>
+      )}
 
       {events.length === 0 && !isLoading && (
         <div className="text-center py-12 text-slate-400 bg-white/5 rounded-xl border border-dashed border-slate-700">

frontend/src/components/dashboard/SSEStatusIndicator.tsx

@@ -58,7 +58,11 @@ export function SSEStatusIndicator({
       {/* Disconnect Banner */}
       {showDisconnectBanner && isDisconnected && (
         <div
-          className="fixed top-0 left-0 right-0 z-50 bg-red-500/90 text-white p-4 flex items-center justify-between gap-4 animate-in slide-in-from-top"
+          className={`fixed top-0 left-0 right-0 z-50 ${
+            isReconnecting
+              ? "bg-yellow-500/90"
+              : "bg-red-500/90"
+          } text-white p-4 flex items-center justify-between gap-4 animate-in slide-in-from-top`}
           role="alert"
         >
           <div className="flex items-center gap-3 max-w-2xl">

frontend/src/components/dashboard/dashboard-view.tsx

@@ -18,7 +18,6 @@ import toast from "react-hot-toast";
 import {
   getDashboardAnalytics,
   fetchDashboardData,
-  useDashboard,
   dashboardQueryKey,
   type DashboardSnapshot,
   type Stream,
@@ -48,6 +47,7 @@ import {
   type StreamFormData,
 } from "../stream-creation/StreamCreationWizard";
 import { TopUpModal } from "../stream-creation/TopUpModal";
+import { useQueryClient } from "@tanstack/react-query";
 import { CancelConfirmModal } from "../stream-creation/CancelConfirmModal";
 import { StreamDetailsModal } from "./StreamDetailsModal";
 import { Button } from "../ui/Button";

frontend/src/components/streams/IncomingStreamCard.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import React from "react";
 import { Button } from "@/components/ui/Button";
 import { useStreamingAmount } from "@/hooks/useStreamingAmount";
 import type {
@@ -32,7 +33,7 @@ function badgeClassName(status: IncomingStreamStatus): string {
   }
 }
 
-export function IncomingStreamCard({
+export const IncomingStreamCard = React.memo(function IncomingStreamCard({
   stream,
   withdrawing,
   onWithdraw,
@@ -124,4 +125,17 @@ export function IncomingStreamCard({
       </div>
     </article>
   );
-}
+}, (prevProps, nextProps) => {
+  return (
+    prevProps.stream.deposited === nextProps.stream.deposited &&
+    prevProps.stream.withdrawn === nextProps.stream.withdrawn &&
+    prevProps.stream.ratePerSecond === nextProps.stream.ratePerSecond &&
+    prevProps.stream.lastUpdateTime === nextProps.stream.lastUpdateTime &&
+    prevProps.stream.isActive === nextProps.stream.isActive &&
+    prevProps.stream.isPaused === nextProps.stream.isPaused &&
+    prevProps.stream.pausedAt === nextProps.stream.pausedAt &&
+    prevProps.stream.totalPausedDuration === nextProps.stream.totalPausedDuration &&
+    prevProps.stream.status === nextProps.stream.status &&
+    prevProps.withdrawing === nextProps.withdrawing
+  );
+});

frontend/src/components/wallet/WalletButton.tsx

@@ -13,7 +13,7 @@
  *     - "Disconnect" button
  */
 
-import { useState, useRef, useEffect } from "react";
+import { useState, useRef, useEffect, useCallback } from "react";
 import { useWallet } from "@/context/wallet-context";
 import {
   shortenPublicKey,
@@ -27,8 +27,29 @@ export function WalletButton() {
   const [modalOpen, setModalOpen] = useState(false);
   const [dropdownOpen, setDropdownOpen] = useState(false);
   const [copied, setCopied] = useState(false);
+  const [walletUnavailable, setWalletUnavailable] = useState(false);
   const dropdownRef = useRef<HTMLDivElement>(null);
 
+  const checkWalletAvailability = useCallback(() => {
+    if (typeof window === "undefined") return true;
+    const freighterAvailable =
+      "freighter" in window || "stellar" in window;
+    return freighterAvailable;
+  }, []);
+
+  useEffect(() => {
+    if (status !== "connected") return;
+
+    const interval = setInterval(() => {
+      if (!checkWalletAvailability()) {
+        setWalletUnavailable(true);
+        disconnect();
+      }
+    }, 5000);
+
+    return () => clearInterval(interval);
+  }, [status, checkWalletAvailability, disconnect]);
+
   // Close dropdown when clicking outside
   useEffect(() => {
     function handleClickOutside(e: MouseEvent) {
@@ -59,7 +80,11 @@ export function WalletButton() {
   const handleDisconnect = () => {
     setDropdownOpen(false);
     setModalOpen(false);
-    disconnect();
+    try {
+      disconnect();
+    } catch {
+      setWalletUnavailable(true);
+    }
   };
 
   // Close modal when connection is successful
@@ -78,6 +103,26 @@ export function WalletButton() {
     );
   }
 
+  if (walletUnavailable) {
+    return (
+      <div className="flex items-center gap-2">
+        <span className="text-xs text-amber-600 dark:text-amber-400">
+          Wallet extension unavailable
+        </span>
+        <button
+          type="button"
+          className="wallet-connect-btn"
+          onClick={() => {
+            setWalletUnavailable(false);
+            setModalOpen(true);
+          }}
+        >
+          Reconnect
+        </button>
+      </div>
+    );
+  }
+
   if (status === "connected" && session) {
 
     const networkOk = isExpectedNetwork(session.network);

frontend/src/lib/dashboard.ts

@@ -88,21 +88,19 @@ async function fetchStreams(
   for (const endpoint of endpoints) {
     try {
       const response = await fetch(`${endpoint}?${params.toString()}`, { signal });
-    if (response.ok) {
-      const payload = (await response.json()) as
-        | BackendStream[]
-        | { data?: BackendStream[] };
-      return Array.isArray(payload) ? payload : payload.data ?? [];
-    }
-
-    if (response.status === 404) {
-      lastError = new Error(`Endpoint not found: ${endpoint}`);
-      continue;
-    }
+      if (response.ok) {
+        const payload = (await response.json()) as
+          | BackendStream[]
+          | { data?: BackendStream[] };
+        return Array.isArray(payload) ? payload : payload.data ?? [];
+      }
 
-    lastError = new Error(`Failed to fetch streams (${response.status}) from ${endpoint}`);
-  }
+      if (response.status === 404) {
+        lastError = new Error(`Endpoint not found: ${endpoint}`);
+        continue;
+      }
 
+      lastError = new Error(`Failed to fetch streams (${response.status}) from ${endpoint}`);
     } catch (err) {
       if (err instanceof Error && err.name === "AbortError") {
         throw err;