diff --git a/TODO.md b/TODO.md
new file mode 100644
index 0000000..c82092f
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,16 @@
+# Transaction Notification Center — Implementation Checklist ✓
+
+## Files to Create
+- [x] `src/lib/notifications.ts` — Types, interfaces, and helper functions
+- [x] `src/components/notifications/useNotifications.tsx` — React Context, Provider, and hook
+- [x] `src/components/notifications/NotificationToast.tsx` — Floating toast component
+- [x] `src/components/notifications/NotificationCenter.tsx` — Dropdown panel with notification list
+
+## Files to Edit
+- [x] `src/app/layout.tsx` — Wrap with NotificationProvider
+- [x] `src/components/Navbar.tsx` — Add bell icon with unread count badge
+
+## Verification
+- [x] `npm run lint` — No linting errors
+- [x] `npm run build` — Production build succeeds (17 routes)
+
diff --git a/next-env.d.ts b/next-env.d.ts
index c4b7818..9edff1c 100644
--- a/next-env.d.ts
+++ b/next-env.d.ts
@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index 1bb6064..05a0b4e 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -4,6 +4,8 @@ import "leaflet/dist/leaflet.css";
 import "./globals.css";
 import Navbar from "@/components/Navbar";
 import Footer from "@/components/Footer";
+import { NotificationProvider } from "@/components/notifications/useNotifications";
+import NotificationToast from "@/components/notifications/NotificationToast";
 
 const inter = Inter({
   variable: "--font-inter",
@@ -31,9 +33,12 @@ export default function RootLayout({
         <script dangerouslySetInnerHTML={{ __html: themeScript }} />
       </head>
       <body className="min-h-full flex flex-col bg-sand text-ink">
-        <Navbar />
-        <main className="flex-1">{children}</main>
-        <Footer />
+        <NotificationProvider>
+          <Navbar />
+          <main className="flex-1">{children}</main>
+          <Footer />
+          <NotificationToast />
+        </NotificationProvider>
       </body>
     </html>
   );
diff --git a/src/components/Navbar.tsx b/src/components/Navbar.tsx
index 7bd6668..ef5738f 100644
--- a/src/components/Navbar.tsx
+++ b/src/components/Navbar.tsx
@@ -5,6 +5,7 @@ import Link from "next/link";
 import { HiMenu, HiX } from "react-icons/hi";
 import Logo from "./brand/Logo";
 import ThemeToggle from "./ThemeToggle";
+import NotificationCenter from "./notifications/NotificationCenter";
 import { buttonClasses } from "./ui/Button";
 
 const navLinks = [
@@ -33,6 +34,7 @@ export default function Navbar() {
 
         <div className="ml-auto hidden items-center gap-2 sm:flex">
           <ThemeToggle />
+          <NotificationCenter />
           <Link href="/login" className={buttonClasses("outline", "sm")}>
             Log in
           </Link>
@@ -43,6 +45,7 @@ export default function Navbar() {
 
         <div className="ml-auto flex items-center gap-2 sm:hidden">
           <ThemeToggle />
+          <NotificationCenter />
           <button
             className="text-2xl text-ink"
             aria-label={open ? "Close menu" : "Open menu"}
diff --git a/src/components/notifications/NotificationCenter.tsx b/src/components/notifications/NotificationCenter.tsx
new file mode 100644
index 0000000..27e014c
--- /dev/null
+++ b/src/components/notifications/NotificationCenter.tsx
@@ -0,0 +1,169 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+import Link from "next/link";
+import { HiBell, HiX, HiTrash } from "react-icons/hi";
+import type { TransactionNotification } from "@/lib/notifications";
+import { useNotifications } from "./useNotifications";
+
+// ── Small icon per type ──────────────────────────────────────────
+function TypeDot({ type }: { type: TransactionNotification["type"] }) {
+    const dotColor = {
+        success: "bg-ok",
+        error: "bg-err",
+        pending: "bg-gold",
+        info: "bg-navy-2",
+    }[type];
+    return <span className={`h-2 w-2 shrink-0 rounded-full ${dotColor}`} />;
+}
+
+// ── Relative time helper ──────────────────────────────────────────
+function timeAgo(iso: string): string {
+    const diff = Date.now() - new Date(iso).getTime();
+    const mins = Math.floor(diff / 60_000);
+    if (mins < 1) return "Just now";
+    if (mins < 60) return `${mins}m ago`;
+    const hours = Math.floor(mins / 60);
+    if (hours < 24) return `${hours}h ago`;
+    const days = Math.floor(hours / 24);
+    return `${days}d ago`;
+}
+
+// ── Single notification row ──────────────────────────────────────
+function NotificationRow({
+    notification,
+    onDismiss,
+}: {
+    notification: TransactionNotification;
+    onDismiss: (id: string) => void;
+}) {
+    return (
+        <div className="flex items-start gap-3 border-b border-line px-4 py-3 last:border-b-0">
+            <TypeDot type={notification.type} />
+
+            <div className="min-w-0 flex-1">
+                <p className="text-sm font-semibold text-ink">{notification.title}</p>
+                <p className="mt-0.5 text-xs text-muted">{notification.message}</p>
+                <p className="mt-1 text-[10px] text-muted">{timeAgo(notification.timestamp)}</p>
+
+                {/* Action buttons */}
+                {(notification.retryAction || notification.deepLink) && (
+                    <div className="mt-2 flex flex-wrap items-center gap-2">
+                        {notification.retryAction && (
+                            <button
+                                type="button"
+                                onClick={() => {
+                                    void notification.retryAction!.handler();
+                                    onDismiss(notification.id);
+                                }}
+                                className="inline-flex items-center gap-1 rounded-md bg-navy-tint px-2.5 py-1 text-[11px] font-semibold text-navy-2 transition-colors hover:bg-navy/15"
+                            >
+                                {notification.retryAction.label}
+                            </button>
+                        )}
+                        {notification.deepLink && (
+                            <Link
+                                href={notification.deepLink.href}
+                                onClick={() => onDismiss(notification.id)}
+                                className="inline-flex items-center gap-1 rounded-md bg-gold/15 px-2.5 py-1 text-[11px] font-semibold text-gold-deep transition-colors hover:bg-gold/25"
+                            >
+                                {notification.deepLink.label}
+                            </Link>
+                        )}
+                    </div>
+                )}
+            </div>
+
+            <button
+                type="button"
+                onClick={() => onDismiss(notification.id)}
+                aria-label="Dismiss"
+                className="shrink-0 rounded-full p-1 text-muted transition-colors hover:bg-line/70"
+            >
+                <HiX aria-hidden className="text-xs" />
+            </button>
+        </div>
+    );
+}
+
+// ── Notification center bell + dropdown ──────────────────────────
+export default function NotificationCenter() {
+    const { notifications, dismissNotification, clearAll } = useNotifications();
+    const [open, setOpen] = useState(false);
+    const rootRef = useRef<HTMLDivElement>(null);
+
+    // Close on outside click (same pattern as WalletButton.tsx)
+    useEffect(() => {
+        function onClickOutside(e: MouseEvent) {
+            if (rootRef.current && !rootRef.current.contains(e.target as Node)) {
+                setOpen(false);
+            }
+        }
+        document.addEventListener("mousedown", onClickOutside);
+        return () => document.removeEventListener("mousedown", onClickOutside);
+    }, []);
+
+    const unread = notifications.length;
+    const hasNotifications = unread > 0;
+
+    return (
+        <div ref={rootRef} className="relative">
+            {/* Bell button */}
+            <button
+                type="button"
+                onClick={() => setOpen((o) => !o)}
+                aria-label={`Notifications${hasNotifications ? ` (${unread} unread)` : ""}`}
+                aria-expanded={open}
+                className="relative rounded-full p-2 text-muted transition-colors hover:bg-line/60"
+            >
+                <HiBell aria-hidden className="text-xl" />
+                {hasNotifications && (
+                    <span className="absolute -right-0.5 -top-0.5 flex h-4 min-w-[16px] items-center justify-center rounded-full bg-err px-1 text-[10px] font-bold leading-none text-white">
+                        {unread > 9 ? "9+" : unread}
+                    </span>
+                )}
+            </button>
+
+            {/* Dropdown panel */}
+            {open && (
+                <div className="absolute right-0 mt-2 w-80 rounded-xl border border-line bg-surface shadow-float z-50 overflow-hidden">
+                    {/* Header */}
+                    <div className="flex items-center justify-between border-b border-line px-4 py-3">
+                        <span className="text-sm font-semibold text-ink">Notifications</span>
+                        {hasNotifications && (
+                            <button
+                                type="button"
+                                onClick={clearAll}
+                                className="inline-flex items-center gap-1 text-xs font-medium text-muted transition-colors hover:text-err"
+                            >
+                                <HiTrash aria-hidden />
+                                Clear all
+                            </button>
+                        )}
+                    </div>
+
+                    {/* List */}
+                    {notifications.length === 0 ? (
+                        <div className="px-4 py-8 text-center">
+                            <p className="text-sm text-muted">No notifications yet</p>
+                            <p className="mt-1 text-xs text-muted">
+                                Transaction updates will appear here.
+                            </p>
+                        </div>
+                    ) : (
+                        <div className="max-h-80 overflow-y-auto">
+                            {[...notifications].reverse().map((n) => (
+                                <NotificationRow
+                                    key={n.id}
+                                    notification={n}
+                                    onDismiss={dismissNotification}
+                                />
+                            ))}
+                        </div>
+                    )}
+                </div>
+            )}
+        </div>
+    );
+}
+
diff --git a/src/components/notifications/NotificationToast.tsx b/src/components/notifications/NotificationToast.tsx
new file mode 100644
index 0000000..3ee72c6
--- /dev/null
+++ b/src/components/notifications/NotificationToast.tsx
@@ -0,0 +1,133 @@
+"use client";
+
+import { useCallback, useEffect, useState } from "react";
+import Link from "next/link";
+import {
+    HiX,
+    HiCheckCircle,
+    HiExclamationCircle,
+    HiClock,
+    HiInformationCircle,
+} from "react-icons/hi";
+import type { TransactionNotification } from "@/lib/notifications";
+import { useNotifications } from "./useNotifications";
+
+// ── Icon per type ─────────────────────────────────────────────────
+function TypeIcon({ type }: { type: TransactionNotification["type"] }) {
+    switch (type) {
+        case "success":
+            return <HiCheckCircle aria-hidden className="text-lg text-ok" />;
+        case "error":
+            return <HiExclamationCircle aria-hidden className="text-lg text-err" />;
+        case "pending":
+            return <HiClock aria-hidden className="text-lg text-gold-deep" />;
+        case "info":
+            return <HiInformationCircle aria-hidden className="text-lg text-navy-2" />;
+    }
+}
+
+// ── Single toast card ──────────────────────────────────────────────
+function ToastCard({
+    notification,
+    onDismiss,
+}: {
+    notification: TransactionNotification;
+    onDismiss: (id: string) => void;
+}) {
+    const [visible, setVisible] = useState(false);
+
+    useEffect(() => {
+        // Trigger entrance animation on mount
+        requestAnimationFrame(() => setVisible(true));
+    }, []);
+
+    const dismiss = useCallback(() => {
+        setVisible(false);
+        setTimeout(() => onDismiss(notification.id), 200);
+    }, [notification.id, onDismiss]);
+
+    const borderColor = {
+        success: "border-l-ok",
+        error: "border-l-err",
+        pending: "border-l-gold",
+        info: "border-l-navy-2",
+    }[notification.type];
+
+    return (
+        <div
+            role="alert"
+            className={`w-full max-w-sm rounded-xl border border-line bg-surface shadow-float backdrop-blur-md transition-all duration-300 ${visible ? "translate-x-0 opacity-100" : "translate-x-8 opacity-0"
+                } ${borderColor} border-l-4`}
+        >
+            <div className="flex items-start gap-3 p-4">
+                <TypeIcon type={notification.type} />
+
+                <div className="min-w-0 flex-1">
+                    <p className="text-sm font-semibold text-ink">{notification.title}</p>
+                    <p className="mt-0.5 text-xs text-muted">{notification.message}</p>
+
+                    {/* Action buttons — shown for error toasts mostly */}
+                    {(notification.retryAction || notification.deepLink) && (
+                        <div className="mt-3 flex flex-wrap items-center gap-2">
+                            {notification.retryAction && (
+                                <button
+                                    type="button"
+                                    onClick={() => {
+                                        void notification.retryAction!.handler();
+                                        dismiss();
+                                    }}
+                                    className="inline-flex items-center gap-1 rounded-lg bg-navy-tint px-3 py-1.5 text-xs font-semibold text-navy-2 transition-colors hover:bg-navy/15"
+                                >
+                                    {notification.retryAction.label}
+                                </button>
+                            )}
+                            {notification.deepLink && (
+                                <Link
+                                    href={notification.deepLink.href}
+                                    onClick={dismiss}
+                                    className="inline-flex items-center gap-1 rounded-lg bg-gold/15 px-3 py-1.5 text-xs font-semibold text-gold-deep transition-colors hover:bg-gold/25"
+                                >
+                                    {notification.deepLink.label}
+                                </Link>
+                            )}
+                        </div>
+                    )}
+                </div>
+
+                <button
+                    type="button"
+                    onClick={dismiss}
+                    aria-label="Dismiss notification"
+                    className="shrink-0 rounded-full p-1 text-muted transition-colors hover:bg-line/70"
+                >
+                    <HiX aria-hidden className="text-sm" />
+                </button>
+            </div>
+        </div>
+    );
+}
+
+// ── Toast stack (floating container) ───────────────────────────────
+export default function NotificationToast() {
+    const { notifications, dismissNotification } = useNotifications();
+
+    // Only show the 3 most recent notifications to avoid clutter
+    const visible = notifications.slice(-3);
+
+    if (visible.length === 0) return null;
+
+    return (
+        <div
+            aria-live="polite"
+            aria-label="Notifications"
+            className="pointer-events-none fixed bottom-6 right-6 z-[100] flex flex-col-reverse items-end gap-3"
+        >
+            {visible.map((n) => (
+                <div key={n.id} className="pointer-events-auto">
+                    <ToastCard notification={n} onDismiss={dismissNotification} />
+                </div>
+            ))}
+        </div>
+    );
+}
+
diff --git a/src/components/notifications/index.ts b/src/components/notifications/index.ts
new file mode 100644
index 0000000..a93eb94
--- /dev/null
+++ b/src/components/notifications/index.ts
@@ -0,0 +1,4 @@
+export { NotificationProvider, useNotifications } from "./useNotifications";
+export { default as NotificationToast } from "./NotificationToast";
+export { default as NotificationCenter } from "./NotificationCenter";
+
diff --git a/src/components/notifications/useNotifications.tsx b/src/components/notifications/useNotifications.tsx
new file mode 100644
index 0000000..70813de
--- /dev/null
+++ b/src/components/notifications/useNotifications.tsx
@@ -0,0 +1,100 @@
+"use client";
+
+import {
+    createContext,
+    useCallback,
+    useContext,
+    useEffect,
+    useRef,
+    useState,
+    type ReactNode,
+} from "react";
+import type { TransactionNotification } from "@/lib/notifications";
+
+// ── Auto-dismiss durations ────────────────────────────────────────
+const DISMISS_MS: Record<string, number> = {
+    success: 5_000,
+    info: 5_000,
+    pending: 10_000, // give pending a bit longer before disappearing
+    error: 10_000, // errors stay longer so the user can retry
+};
+
+// ── Context shape ─────────────────────────────────────────────────
+interface NotificationContextValue {
+    notifications: TransactionNotification[];
+    addNotification: (n: TransactionNotification) => void;
+    dismissNotification: (id: string) => void;
+    clearAll: () => void;
+}
+
+const NotificationContext = createContext<NotificationContextValue | null>(null);
+
+// ── Provider ───────────────────────────────────────────────────────
+export function NotificationProvider({ children }: { children: ReactNode }) {
+    const [notifications, setNotifications] = useState<TransactionNotification[]>([]);
+    const timersRef = useRef<Map<string, ReturnType<typeof setTimeout>>>(new Map());
+
+    // Auto‑dismiss logic — set a timer per notification based on its type.
+    // Clears the timer if the notification is manually dismissed before expiry.
+    useEffect(() => {
+        const timers = timersRef.current;
+
+        for (const n of notifications) {
+            if (!timers.has(n.id)) {
+                const ms = DISMISS_MS[n.type] ?? 5_000;
+                const timer = setTimeout(() => {
+                    setNotifications((prev) => prev.filter((x) => x.id !== n.id));
+                    timers.delete(n.id);
+                }, ms);
+                timers.set(n.id, timer);
+            }
+        }
+
+        // Clean up timers for notifications that have been removed
+        return () => {
+            for (const [id, timer] of timers) {
+                clearTimeout(timer);
+                timers.delete(id);
+            }
+        };
+    }, [notifications]);
+
+    const addNotification = useCallback((n: TransactionNotification) => {
+        setNotifications((prev) => [...prev, n]);
+    }, []);
+
+    const dismissNotification = useCallback((id: string) => {
+        setNotifications((prev) => prev.filter((x) => x.id !== id));
+        const timer = timersRef.current.get(id);
+        if (timer) {
+            clearTimeout(timer);
+            timersRef.current.delete(id);
+        }
+    }, []);
+
+    const clearAll = useCallback(() => {
+        for (const [, timer] of timersRef.current) clearTimeout(timer);
+        timersRef.current.clear();
+        setNotifications([]);
+    }, []);
+
+    return (
+        <NotificationContext.Provider
+            value={{ notifications, addNotification, dismissNotification, clearAll }}
+        >
+            {children}
+        </NotificationContext.Provider>
+    );
+}
+
+// ── Hook ───────────────────────────────────────────────────────────
+export function useNotifications(): NotificationContextValue {
+    const ctx = useContext(NotificationContext);
+    if (!ctx) {
+        throw new Error(
+            "useNotifications must be used within a <NotificationProvider>"
+        );
+    }
+    return ctx;
+}
+
diff --git a/src/lib/notifications.ts b/src/lib/notifications.ts
new file mode 100644
index 0000000..c9d23e8
--- /dev/null
+++ b/src/lib/notifications.ts
@@ -0,0 +1,99 @@
+/** Deep-link target attached to a notification. */
+export interface DeepLink {
+    label: string;
+    href: string;
+}
+
+/** Retry action attached to a notification. */
+export interface RetryAction {
+    label: string;
+    handler: () => Promise<void> | void;
+}
+
+export type NotificationType = "pending" | "success" | "error" | "info";
+
+export interface TransactionNotification {
+    id: string;
+    type: NotificationType;
+    title: string;
+    message: string;
+    /** ISO timestamp of when the notification was created. */
+    timestamp: string;
+    /** Optional deep-link rendered as a button inside the toast / center. */
+    deepLink?: DeepLink;
+    /** Optional retry action, shown as a button for failed transactions. */
+    retryAction?: RetryAction;
+}
+
+let _counter = 0;
+
+/** Create a unique, human‑readable notification ID. */
+export function createNotificationId(): string {
+    _counter += 1;
+    return `notif-${Date.now()}-${_counter}`;
+}
+
+/** Helper to build a success notification. */
+export function successNotification(
+    title: string,
+    message: string,
+    deepLink?: DeepLink
+): TransactionNotification {
+    return {
+        id: createNotificationId(),
+        type: "success",
+        title,
+        message,
+        timestamp: new Date().toISOString(),
+        deepLink,
+    };
+}
+
+/** Helper to build an error notification with an optional retry action. */
+export function errorNotification(
+    title: string,
+    message: string,
+    retryAction?: RetryAction,
+    deepLink?: DeepLink
+): TransactionNotification {
+    return {
+        id: createNotificationId(),
+        type: "error",
+        title,
+        message,
+        timestamp: new Date().toISOString(),
+        retryAction,
+        deepLink,
+    };
+}
+
+/** Helper to build a pending notification. */
+export function pendingNotification(
+    title: string,
+    message: string
+): TransactionNotification {
+    return {
+        id: createNotificationId(),
+        type: "pending",
+        title,
+        message,
+        timestamp: new Date().toISOString(),
+    };
+}
+
+/** Helper to build an info notification. */
+export function infoNotification(
+    title: string,
+    message: string,
+    deepLink?: DeepLink
+): TransactionNotification {
+    return {
+        id: createNotificationId(),
+        type: "info",
+        title,
+        message,
+        timestamp: new Date().toISOString(),
+        deepLink,
+    };
+}
+
