diff --git a/index.html b/index.html
index c85cf4b..5b5cf95 100644
--- a/index.html
+++ b/index.html
@@ -6,6 +6,8 @@
     <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png" />
     <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png" />
     <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+    <link rel="manifest" href="/site.webmanifest" />
+    <meta name="theme-color" content="#b366ff" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
diff --git a/public/favicon-192x192.png b/public/favicon-192x192.png
new file mode 100644
index 0000000..3887e80
Binary files /dev/null and b/public/favicon-192x192.png differ
diff --git a/public/site.webmanifest b/public/site.webmanifest
new file mode 100644
index 0000000..3231cf2
--- /dev/null
+++ b/public/site.webmanifest
@@ -0,0 +1,49 @@
+{
+  "name": "Grimoire - A Nostr Client for Magicians",
+  "short_name": "Grimoire",
+  "description": "A tiling window manager interface for exploring the Nostr protocol. Each window is a Nostr app (profile viewer, event feed, NIP documentation, etc.). Commands are launched Unix-style via Cmd+K palette.",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#020817",
+  "theme_color": "#b366ff",
+  "orientation": "any",
+  "icons": [
+    {
+      "src": "/favicon-16x16.png",
+      "sizes": "16x16",
+      "type": "image/png"
+    },
+    {
+      "src": "/favicon-32x32.png",
+      "sizes": "32x32",
+      "type": "image/png"
+    },
+    {
+      "src": "/apple-touch-icon.png",
+      "sizes": "180x180",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/favicon-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/favicon-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }
+  ],
+  "categories": ["social", "utilities", "productivity"],
+  "shortcuts": [
+    {
+      "name": "Command Palette",
+      "short_name": "Commands",
+      "description": "Open the command palette to launch Nostr apps",
+      "url": "/?action=command-palette"
+    }
+  ]
+}
diff --git a/public/sw.js b/public/sw.js
new file mode 100644
index 0000000..8824bde
--- /dev/null
+++ b/public/sw.js
@@ -0,0 +1,84 @@
+// Grimoire Service Worker - v1.0.0
+const CACHE_NAME = "grimoire-v1";
+const RUNTIME_CACHE = "grimoire-runtime";
+
+// Core assets to cache on install
+const PRECACHE_URLS = [
+  "/",
+  "/index.html",
+  "/favicon.ico",
+  "/favicon-192x192.png",
+  "/favicon-512x512.png",
+];
+
+// Install event - precache core assets
+self.addEventListener("install", (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => {
+      return cache.addAll(PRECACHE_URLS);
+    }),
+  );
+  // Activate immediately
+  self.skipWaiting();
+});
+
+// Activate event - clean up old caches
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    caches.keys().then((cacheNames) => {
+      return Promise.all(
+        cacheNames
+          .filter((name) => name !== CACHE_NAME && name !== RUNTIME_CACHE)
+          .map((name) => caches.delete(name)),
+      );
+    }),
+  );
+  // Take control immediately
+  self.clients.claim();
+});
+
+// Fetch event - network first, fallback to cache
+self.addEventListener("fetch", (event) => {
+  // Skip non-GET requests
+  if (event.request.method !== "GET") return;
+
+  // Skip cross-origin requests
+  if (!event.request.url.startsWith(self.location.origin)) return;
+
+  // Network first strategy for app shell and assets
+  event.respondWith(
+    fetch(event.request)
+      .then((response) => {
+        // Clone the response before caching
+        const responseClone = response.clone();
+
+        // Cache successful responses
+        if (response.status === 200) {
+          caches.open(RUNTIME_CACHE).then((cache) => {
+            cache.put(event.request, responseClone);
+          });
+        }
+
+        return response;
+      })
+      .catch(() => {
+        // Fallback to cache if network fails
+        return caches.match(event.request).then((cachedResponse) => {
+          if (cachedResponse) {
+            return cachedResponse;
+          }
+
+          // If no cache, return offline page for navigation requests
+          if (event.request.mode === "navigate") {
+            return caches.match("/index.html");
+          }
+
+          // For other requests, just fail
+          return new Response("Offline", {
+            status: 503,
+            statusText: "Service Unavailable",
+          });
+        });
+      }),
+  );
+});
diff --git a/src/main.tsx b/src/main.tsx
index dd08235..3959323 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -35,3 +35,17 @@ createRoot(document.getElementById("root")!).render(
     </ThemeProvider>
   </ErrorBoundary>,
 );
+
+// Register service worker for PWA functionality
+if ("serviceWorker" in navigator) {
+  window.addEventListener("load", () => {
+    navigator.serviceWorker
+      .register("/sw.js")
+      .then((registration) => {
+        console.log("SW registered:", registration);
+      })
+      .catch((error) => {
+        console.log("SW registration failed:", error);
+      });
+  });
+}