feat(clients): Wake-on-LAN in apple/linux/windows/android/decky

Each client learns a host's MAC from the mDNS `mac` TXT while it's awake, persists it on the saved-host record, and — when reconnecting to an offline host — sends a magic packet before connecting, plus an explicit "Wake host" action. Apple wraps the C-ABI; linux/windows call the core fn directly (linux also gains a --wake CLI mode); android via a new nativeWakeOnLan JNI export (the mDNS browse record gains a 7th mac field); decky shells out to the linux client's --wake before launching the stream.

iOS/tvOS need the managed com.apple.developer.networking.multicast entitlement (pending Apple approval), so the wake path + UI are gated off via PunktfunkConnection.wakeOnLANAvailable and the entitlement is commented out — keeping iOS/tvOS releasable. MAC-learning stays active on every platform so it lights up the moment it's ungated. macOS works today.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/decky/main.py

@@ -489,6 +489,40 @@ class Plugin:
         reason = (err.strip().splitlines() or out.strip().splitlines() or ["pairing failed"])[-1]
         return {"ok": False, "error": reason}
 
+    async def wake(self, host: str, port: int = 9777) -> dict:
+        """Send a Wake-on-LAN magic packet to a saved host via the flatpak client's headless
+        ``--wake`` mode, so a sleeping host is up by the time the stream ``--connect`` runs.
+
+        The MAC comes from the flatpak client's OWN known-hosts store (learned from the host's
+        mDNS ``mac`` TXT while it was online) — no MAC handling here — so this is a no-op if none
+        has been learned yet. Fire it just before launching a stream; it's fast and best-effort.
+        Returns ``{ok, error?}`` (``ok: False`` when no MAC is known / flatpak missing).
+        """
+        flatpak = _flatpak()
+        if not flatpak:
+            return {"ok": False, "error": "flatpak-not-found"}
+        argv = [flatpak, "run", "--arch=x86_64", APP_ID, "--wake", f"{host}:{port}"]
+        decky.logger.info("wake: %s:%s", host, port)
+        try:
+            proc = await asyncio.create_subprocess_exec(
+                *argv,
+                stdout=asyncio.subprocess.PIPE,
+                stderr=asyncio.subprocess.PIPE,
+                env=_flatpak_env(),
+            )
+            _, stderr = await asyncio.wait_for(proc.communicate(), timeout=15.0)
+        except asyncio.TimeoutError:
+            return {"ok": False, "error": "wake timed out"}
+        except Exception as exc:  # noqa: BLE001
+            decky.logger.exception("wake failed to launch")
+            return {"ok": False, "error": str(exc)}
+        if proc.returncode == 0:
+            return {"ok": True}
+        reason = (stderr.decode(errors="replace").strip().splitlines() or
+                  ["no MAC known for this host yet"])[-1]
+        decky.logger.info("wake skipped (rc=%s): %s", proc.returncode, reason)
+        return {"ok": False, "error": reason}
+
     async def library(self, host: str, mgmt_port: int = 0, fp: str = "") -> dict:
         """Fetch a paired host's game library via the flatpak client's headless
         ``--library`` mode (the client's own mTLS identity + pinned-fingerprint transport —

clients/decky/src/backend.ts

@@ -122,6 +122,12 @@ export const setSettings = callable<[settings: StreamSettings], { ok: boolean }>
   "set_settings",
 );
 export const killStream = callable<[], { ok: boolean }>("kill_stream");
+// Send a Wake-on-LAN magic packet to a saved host (headless flatpak --wake) so a sleeping host is
+// up by the time the stream connects. The MAC is looked up from the flatpak client's own
+// known-hosts store; `ok: false` (no-op) when none has been learned yet. Fire before launching.
+export const wake = callable<[host: string, port: number], { ok: boolean; error?: string }>(
+  "wake",
+);
 export const checkUpdate = callable<[force: boolean], UpdateInfo>("check_update");
 // Update the flatpak client in the user installation (`flatpak update --user -y io.unom.Punktfunk`).
 export const updateClient = callable<

clients/decky/src/steam.ts

@@ -8,7 +8,7 @@
 // and start it with RunGame. The wrapper then execs
 // `flatpak run io.unom.Punktfunk --connect <host>` as a reaper descendant.
 
-import { runnerInfo, shortcutArt } from "./backend";
+import { runnerInfo, shortcutArt, wake } from "./backend";
 
 // SteamClient is a Steam-internal global injected into the CEF context; it is not fully typed
 // by @decky/ui, so declare the surface we use. Signatures verified against MoonDeck + the
@@ -219,6 +219,11 @@ export async function launchStream(
   port: number,
   opts: LaunchOpts = {},
 ): Promise<void> {
+  // Wake-on-LAN: if this host is asleep, nudge it awake before the stream connects. Kicked off now
+  // so it races with the shortcut setup (near-zero added latency), and awaited just before RunGame.
+  // Best-effort — the flatpak client's --wake looks up the host's learned MAC (a no-op if none is
+  // known), and the connect that follows has its own retry window, so a failure never blocks launch.
+  const waking = wake(host, port).catch(() => ({ ok: false }));
   const { appId, runner } = await ensureShortcut();
   // Best-effort so the Deck's rich controls reach the client; no-op if the API is absent (the user
   // disables Steam Input manually — see the Settings instruction).
@@ -240,6 +245,7 @@ export async function launchStream(
   // KEY=value ... %command% args — %command% expands to the shortcut exe (/bin/sh); the wrapper
   // script rides behind it as an argument and reads PF_* from the environment.
   SteamClient.Apps.SetAppLaunchOptions(appId, `${env.join(" ")} %command% "${runner}"`);
+  await waking; // ensure the magic packet is out before the connect attempt
   SteamClient.Apps.RunGame(gameIdFromAppId(appId), "", -1, 100);
 }