maestro/web/public/sw.js

// maestro service worker.
//
// Goal: make the app installable and let the shell load offline. It is NOT a
// data cache — anything under /api (HTTP and WebSocket upgrades) is always left
// to the network, since a terminal orchestrator is useless without a live
// daemon. Static assets are cached at runtime so we never need to know Vite's
// hashed filenames ahead of time.

const CACHE = "maestro-shell-v1";

self.addEventListener("install", (event) => {
  // Warm the cache with the app entry so a cold offline launch still paints.
  event.waitUntil(
    caches
      .open(CACHE)
      .then((cache) => cache.addAll(["/", "/manifest.webmanifest"]))
      .catch(() => {}),
  );
  self.skipWaiting();
});

self.addEventListener("activate", (event) => {
  // Drop caches from previous versions, then take control immediately.
  event.waitUntil(
    caches
      .keys()
      .then((keys) =>
        Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k))),
      )
      .then(() => self.clients.claim()),
  );
});

self.addEventListener("fetch", (event) => {
  const req = event.request;
  if (req.method !== "GET") return;

  const url = new URL(req.url);
  // Only handle same-origin GETs; never touch the daemon API.
  if (url.origin !== self.location.origin) return;
  if (url.pathname.startsWith("/api/")) return;

  // SPA navigations: network-first, fall back to the cached shell offline.
  if (req.mode === "navigate") {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const copy = res.clone();
          caches.open(CACHE).then((c) => c.put("/", copy)).catch(() => {});
          return res;
        })
        .catch(() => caches.match("/").then((r) => r || caches.match(req))),
    );
    return;
  }

  // Static assets (Vite emits content-hashed names): stale-while-revalidate.
  event.respondWith(
    caches.match(req).then((cached) => {
      const network = fetch(req)
        .then((res) => {
          if (res.ok && res.type === "basic") {
            const copy = res.clone();
            caches.open(CACHE).then((c) => c.put(req, copy)).catch(() => {});
          }
          return res;
        })
        .catch(() => cached);
      return cached || network;
    }),
  );
});