feat(android): native background poller plugin (no Google) - Cordn pattern

packages/skatespots-background: a local Capacitor Android plugin that polls our
own push-service /pending and raises local notifications. Modes: off / standard
(WorkManager ~15 min) / fast (foreground service ~5 min). Kotlin +
AndroidManifest (POST_NOTIFICATIONS, FOREGROUND_SERVICE_DATA_SYNC, WAKE_LOCK,
battery-exemption) + Gradle module. Client: useBackgroundDelivery (registers a
poll token via NIP-98, seeds the plugin) + a Background delivery (Android)
control in NotificationSettingsCard. The app registers by NAME, not by importing
the package, so the web bundle is unaffected. UNVERIFIED - needs cap sync + a
device.

AGENTS.md

@@ -802,9 +802,17 @@ session with **no other memory of this project**. So:
     `/native/poll/register` (NIP-98 → poll token; the pubkey is added to the relay
     watch), `GET /pending?token&since` → `{ seq, at, changed }` (a content-free
     cursor), and `/native/poll/unregister`; `pushTo()` calls `recordActivity()`.
-    **STILL TODO:** the native `skatespots-background` Capacitor plugin (Kotlin
-    WorkManager + foreground service + local notifications + battery-exemption
-    prompt) — unbuilt, needs a device to verify.
+    **Plugin WRITTEN (2026-10-01):** `packages/skatespots-background/` — a local
+    Capacitor Android plugin (Kotlin: `SkateSpotsBackgroundPlugin`, `PollWorker`
+    [WorkManager], `PollService` [foreground], `Poller`, `Notifier`, `PollPrefs`)
+    plus `src/hooks/useBackgroundDelivery.ts` and a **Background delivery
+    (Android)** control in `NotificationSettingsCard` (Off / Standard / Fast).
+    The app registers it **by NAME** via `@capacitor/core` — it does **not**
+    import the package (no web-bundle dep); only the Android shell does, via the
+    `file:` dep + `cap sync`. ⚠️ **UNVERIFIED — needs `cap sync` + a device.**
+    `android/` is regenerated, so the `file:` dep must stay in `package.json` for
+    `cap sync` to add the module; `build.gradle`/manifest may need tuning per the
+    app's Capacitor version.
     ⚠️ **Android `standard` mode is best-effort** (Doze/OEM battery managers
     defer it); `fast` needs a sticky notification. Never the only path. (Approach
     + tradeoffs came from the Numo/Linky/BTCPay/Cordn review this session.)

eslint.config.js

@@ -26,6 +26,8 @@ export default tseslint.config(
       "ai-proxy",
       // Standalone Bun push service — own tsconfig (`typecheck:push`).
       "push-service",
+      // Local Capacitor plugins (Kotlin + a TS bridge built only for the shell).
+      "packages",
       // Static utility HTML (icon generators, sticker sheets, QR pages) that
       // are intentionally minimal and don't need app-level meta/OG tags.
       "public/**/*.html",

package-lock.json

@@ -99,6 +99,7 @@
         "react-resizable-panels": "^2.1.3",
         "react-router-dom": "^6.26.2",
         "recharts": "^2.12.7",
+        "skatespots-background": "file:packages/skatespots-background",
         "tailwind-merge": "^2.5.2",
         "tailwindcss-animate": "^1.0.7",
         "three": "^0.185.1",
@@ -11295,6 +11296,10 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/skatespots-background": {
+      "resolved": "packages/skatespots-background",
+      "link": true
+    },
     "node_modules/slice-ansi": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/slice-ansi/-/slice-ansi-4.0.0.tgz",
@@ -13618,6 +13623,12 @@
       "peerDependencies": {
         "zod": "^3.25.28 || ^4"
       }
+    },
+    "packages/skatespots-background": {
+      "version": "0.0.1",
+      "dependencies": {
+        "@capacitor/core": "^8.4.2"
+      }
     }
   }
 }

package.json

@@ -117,6 +117,7 @@
     "react-resizable-panels": "^2.1.3",
     "react-router-dom": "^6.26.2",
     "recharts": "^2.12.7",
+    "skatespots-background": "file:packages/skatespots-background",
     "tailwind-merge": "^2.5.2",
     "tailwindcss-animate": "^1.0.7",
     "three": "^0.185.1",

packages/skatespots-background/README.md

@@ -0,0 +1,49 @@
+# skatespots-background
+
+A **local Capacitor Android plugin** that gives the APK closed-app notifications
+**without Google services** — the [Cordn](https://github.com/Cordn-msg/cordn-web)
+pattern, simplified (our payloads are already content-free, so there is **no Rust
+and no decryption** here).
+
+It polls our own `push-service` (`GET /pending?token&since` → `{seq, at, changed}`)
+and, when the cursor advances, raises a **local notification**.
+
+## Modes
+| Mode | Mechanism | Cadence | Notes |
+| --- | --- | --- | --- |
+| `off` | — | — | default |
+| `standard` | **WorkManager** | ~15 min (OS minimum) | best-effort — Doze/OEM battery managers may defer it |
+| `fast` | **foreground service** | ~5 min | near-live; shows a **sticky notification** + battery |
+
+## Files
+- `src/index.ts` — TS↔Kotlin bridge (the app registers the plugin **by name**).
+- `android/src/main/AndroidManifest.xml` — permissions (`POST_NOTIFICATIONS`,
+  `FOREGROUND_SERVICE[_DATA_SYNC]`, `WAKE_LOCK`, `RECEIVE_BOOT_COMPLETED`,
+  `REQUEST_IGNORE_BATTERY_OPTIMIZATIONS`) + the service.
+- `android/src/main/java/org/skatespots/background/`:
+  - `SkateSpotsBackgroundPlugin.kt` — the `@CapacitorPlugin` (`configure`, `seed`,
+    `postNotification`, `clearNotifications`, `consumePendingUrl`,
+    `isBatteryExempted`, `requestBatteryExemption`).
+  - `PollWorker.kt` (WorkManager), `PollService.kt` (foreground), `Poller.kt`,
+    `Notifier.kt`, `PollPrefs.kt`.
+- `android/build.gradle` — the plugin Gradle module.
+
+## Wiring
+1. The root `package.json` depends on it: `"skatespots-background": "file:packages/skatespots-background"`.
+2. `npm run android:init` / `android:sync` (which run `npx cap sync android`) pick
+   it up and add the Android module.
+3. The client enables it from **Settings → Notifications → Background delivery
+   (Android)** via `src/hooks/useBackgroundDelivery.ts`.
+
+## ⚠️ Caveats
+- **Android-only** and **cannot be verified in CI** — needs a device.
+- `standard` is **not** a guarantee (Doze/OEM). `fast` needs the sticky
+  notification and the user must start it while the app is foreground.
+- `build.gradle` mirrors the Capacitor plugin template; align its Gradle/Kotlin
+  versions with the app's Capacitor major if a build complains.
+- The small icon uses `applicationInfo.icon`; swap for a dedicated monochrome
+  status icon if the app's launcher icon renders poorly in the shade.
+
+## Server contract
+`push-service` (see its README): `POST /native/poll/register` (NIP-98 proof →
+poll token), `GET /pending?token&since`, `POST /native/poll/unregister`.

packages/skatespots-background/android/build.gradle

@@ -0,0 +1,51 @@
+// SkateSpots background poller — a local Capacitor Android plugin.
+// Mirrors the official Capacitor plugin template; tune versions to match the
+// app's Capacitor major if a build complains.
+ext {
+    androidxWorkVersion = project.hasProperty('androidxWorkVersion') ? rootProject.ext.androidxWorkVersion : '2.9.1'
+    androidxCoreVersion = project.hasProperty('androidxCoreVersion') ? rootProject.ext.androidxCoreVersion : '1.13.1'
+}
+
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:8.2.1'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.24"
+    }
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    namespace "org.skatespots.background"
+    compileSdk project.hasProperty('compileSdkVersion') ? rootProject.ext.compileSdkVersion : 35
+
+    defaultConfig {
+        minSdk project.hasProperty('minSdkVersion') ? rootProject.ext.minSdkVersion : 23
+        targetSdk project.hasProperty('targetSdkVersion') ? rootProject.ext.targetSdkVersion : 35
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = '17'
+    }
+}
+
+repositories {
+    google()
+    mavenCentral()
+}
+
+dependencies {
+    implementation project(':capacitor-android')
+    implementation "androidx.work:work-runtime-ktx:$androidxWorkVersion"
+    implementation "androidx.core:core-ktx:$androidxCoreVersion"
+}

packages/skatespots-background/android/src/main/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <!-- Android 14+ requires a typed foreground service. -->
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
+    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
+
+    <application>
+        <service
+            android:name=".PollService"
+            android:exported="false"
+            android:foregroundServiceType="dataSync" />
+    </application>
+</manifest>

packages/skatespots-background/android/src/main/java/org/skatespots/background/Notifier.kt

@@ -0,0 +1,69 @@
+package org.skatespots.background
+
+import android.Manifest
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationManagerCompat
+import androidx.core.content.ContextCompat
+
+/** Local notifications — no Google. */
+object Notifier {
+    const val CHANNEL_ID = "skatespots_activity"
+    const val MESSAGE_ID = 4201
+    const val SERVICE_ID = 4200
+
+    fun ensureChannel(ctx: Context) {
+        val mgr = ctx.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        if (mgr.getNotificationChannel(CHANNEL_ID) == null) {
+            mgr.createNotificationChannel(
+                NotificationChannel(CHANNEL_ID, "SkateSpots activity", NotificationManager.IMPORTANCE_DEFAULT).apply {
+                    description = "New messages, offers and trade updates"
+                },
+            )
+        }
+    }
+
+    fun show(ctx: Context, title: String, body: String, url: String) {
+        ensureChannel(ctx)
+        // Remember where a tap should land (consumed by the WebView on resume).
+        PollPrefs.setPendingUrl(ctx, url)
+
+        val launch = ctx.packageManager.getLaunchIntentForPackage(ctx.packageName)?.apply {
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_SINGLE_TOP)
+        } ?: return
+        val pending = PendingIntent.getActivity(
+            ctx,
+            0,
+            launch,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+        )
+
+        val notif = NotificationCompat.Builder(ctx, CHANNEL_ID)
+            .setSmallIcon(ctx.applicationInfo.icon)
+            .setContentTitle(title)
+            .setContentText(body)
+            .setAutoCancel(true)
+            .setContentIntent(pending)
+            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+            .build()
+
+        // POST_NOTIFICATIONS is required on Android 13+; the app asks for it.
+        if (ContextCompat.checkSelfPermission(ctx, Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) {
+            return
+        }
+        try {
+            NotificationManagerCompat.from(ctx).notify(MESSAGE_ID, notif)
+        } catch (_: SecurityException) {
+            // permission revoked mid-flight — ignore
+        }
+    }
+
+    fun clear(ctx: Context) {
+        NotificationManagerCompat.from(ctx).cancel(MESSAGE_ID)
+    }
+}

packages/skatespots-background/android/src/main/java/org/skatespots/background/PollPrefs.kt

@@ -0,0 +1,40 @@
+package org.skatespots.background
+
+import android.content.Context
+import androidx.core.content.edit
+
+/** Tiny SharedPreferences store for the poll target + cursor + tap URL. */
+object PollPrefs {
+    private const val NAME = "skatespots_background"
+
+    private fun prefs(ctx: Context) = ctx.getSharedPreferences(NAME, Context.MODE_PRIVATE)
+
+    fun baseUrl(ctx: Context): String? = prefs(ctx).getString("baseUrl", null)
+    fun token(ctx: Context): String? = prefs(ctx).getString("token", null)
+    fun cursor(ctx: Context): Long = prefs(ctx).getLong("cursor", 0L)
+    fun intervalMinutes(ctx: Context): Int = prefs(ctx).getInt("interval", 5)
+    fun mode(ctx: Context): String = prefs(ctx).getString("mode", "off") ?: "off"
+
+    fun seed(ctx: Context, baseUrl: String, token: String, since: Long) = prefs(ctx).edit {
+        putString("baseUrl", baseUrl)
+        putString("token", token)
+        putLong("cursor", since)
+    }
+
+    fun setCursor(ctx: Context, value: Long) = prefs(ctx).edit { putLong("cursor", value) }
+
+    fun configure(ctx: Context, mode: String, interval: Int) = prefs(ctx).edit {
+        putString("mode", mode)
+        putInt("interval", interval)
+    }
+
+    /** A tapped notification's in-app path, consumed once by the WebView. */
+    fun setPendingUrl(ctx: Context, url: String) = prefs(ctx).edit { putString("pendingUrl", url) }
+    fun consumePendingUrl(ctx: Context): String? {
+        val url = prefs(ctx).getString("pendingUrl", null)
+        if (url != null) prefs(ctx).edit { remove("pendingUrl") }
+        return url
+    }
+
+    fun clear(ctx: Context) = prefs(ctx).edit { clear() }
+}

packages/skatespots-background/android/src/main/java/org/skatespots/background/PollService.kt

@@ -0,0 +1,73 @@
+package org.skatespots.background
+
+import android.app.Service
+import android.content.Intent
+import android.content.pm.ServiceInfo
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+
+/**
+ * `fast` mode — a foreground service polling every N minutes. Near-live, but it
+ * shows a **sticky notification** and costs battery; the user opts in.
+ * Started only while the app is in the foreground (Android restriction).
+ */
+class PollService : Service() {
+    private val scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
+    private var loop: Job? = null
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent?.action == ACTION_STOP) {
+            stopSelf()
+            return START_NOT_STICKY
+        }
+        Notifier.ensureChannel(this)
+        val notif = NotificationCompat.Builder(this, Notifier.CHANNEL_ID)
+            .setSmallIcon(applicationInfo.icon)
+            .setContentTitle("SkateSpots")
+            .setContentText("Keeping you up to date")
+            .setOngoing(true)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .build()
+        val type =
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC else 0
+        ServiceCompat.startForeground(this, Notifier.SERVICE_ID, notif, type)
+        startLoop()
+        return START_STICKY
+    }
+
+    private fun startLoop() {
+        if (loop?.isActive == true) return
+        loop = scope.launch {
+            while (isActive) {
+                val res = Poller.poll(applicationContext)
+                if (res?.changed == true) {
+                    Notifier.show(applicationContext, "SkateSpots", "You have new activity", "/#/trades")
+                }
+                val minutes = PollPrefs.intervalMinutes(applicationContext).coerceAtLeast(1)
+                delay(minutes * 60_000L)
+            }
+        }
+    }
+
+    override fun onDestroy() {
+        loop?.cancel()
+        scope.cancel()
+        super.onDestroy()
+    }
+
+    companion object {
+        const val ACTION_STOP = "org.skatespots.background.STOP"
+    }
+}

packages/skatespots-background/android/src/main/java/org/skatespots/background/PollWorker.kt

@@ -0,0 +1,19 @@
+package org.skatespots.background
+
+import android.content.Context
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+
+/**
+ * `standard` mode — WorkManager, ~15 min (the OS minimum). Best-effort: Doze /
+ * OEM battery managers may defer it, so treat it as "eventually", not "instant".
+ */
+class PollWorker(ctx: Context, params: WorkerParameters) : CoroutineWorker(ctx, params) {
+    override suspend fun doWork(): Result {
+        val res = Poller.poll(applicationContext)
+        if (res?.changed == true) {
+            Notifier.show(applicationContext, "SkateSpots", "You have new activity", "/#/trades")
+        }
+        return Result.success()
+    }
+}

packages/skatespots-background/android/src/main/java/org/skatespots/background/Poller.kt

@@ -0,0 +1,42 @@
+package org.skatespots.background
+
+import android.content.Context
+import org.json.JSONObject
+import java.net.HttpURLConnection
+import java.net.URL
+
+/**
+ * One poll of `GET {base}/pending?token&since` → `{ seq, at, changed }`.
+ * Content-free: the server never tells us *what* arrived.
+ */
+object Poller {
+    data class Result(val changed: Boolean, val seq: Long)
+
+    fun poll(ctx: Context): Result? {
+        val base = PollPrefs.baseUrl(ctx) ?: return null
+        val token = PollPrefs.token(ctx) ?: return null
+        val since = PollPrefs.cursor(ctx)
+        val conn = try {
+            (URL("$base/pending?token=$token&since=$since").openConnection() as HttpURLConnection).apply {
+                requestMethod = "GET"
+                connectTimeout = 10_000
+                readTimeout = 10_000
+            }
+        } catch (e: Exception) {
+            return null
+        }
+        return try {
+            if (conn.responseCode != 200) return null
+            val body = conn.inputStream.bufferedReader().use { it.readText() }
+            val json = JSONObject(body)
+            val seq = json.optLong("seq", since)
+            val changed = json.optBoolean("changed", seq > since)
+            if (changed) PollPrefs.setCursor(ctx, seq)
+            Result(changed, seq)
+        } catch (e: Exception) {
+            null
+        } finally {
+            conn.disconnect()
+        }
+    }
+}

packages/skatespots-background/android/src/main/java/org/skatespots/background/SkateSpotsBackgroundPlugin.kt

@@ -0,0 +1,101 @@
+package org.skatespots.background
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.os.PowerManager
+import android.provider.Settings
+import androidx.core.content.ContextCompat
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import com.getcapacitor.JSObject
+import com.getcapacitor.Plugin
+import com.getcapacitor.PluginCall
+import com.getcapacitor.PluginMethod
+import com.getcapacitor.annotation.CapacitorPlugin
+import java.util.concurrent.TimeUnit
+
+@CapacitorPlugin(name = "SkateSpotsBackground")
+class SkateSpotsBackgroundPlugin : Plugin() {
+
+    @PluginMethod
+    fun configure(call: PluginCall) {
+        val mode = call.getString("mode") ?: "off"
+        val interval = call.getInt("intervalMinutes") ?: 5
+        PollPrefs.configure(context, mode, interval)
+        when (mode) {
+            "standard" -> startStandard(context)
+            "fast" -> startFast(context)
+            else -> stopAll(context)
+        }
+        call.resolve()
+    }
+
+    @PluginMethod
+    fun seed(call: PluginCall) {
+        val baseUrl = call.getString("baseUrl") ?: run { call.reject("baseUrl required"); return }
+        val token = call.getString("token") ?: run { call.reject("token required"); return }
+        val since = call.getLong("since") ?: 0L
+        PollPrefs.seed(context, baseUrl, token, since)
+        call.resolve()
+    }
+
+    @PluginMethod
+    fun postNotification(call: PluginCall) {
+        Notifier.show(
+            context,
+            call.getString("title") ?: "SkateSpots",
+            call.getString("body") ?: "You have new activity",
+            call.getString("url") ?: "/#/trades",
+        )
+        call.resolve()
+    }
+
+    @PluginMethod
+    fun clearNotifications(call: PluginCall) {
+        Notifier.clear(context)
+        call.resolve()
+    }
+
+    /** A tapped notification's in-app path (HashRouter), consumed once. */
+    @PluginMethod
+    fun consumePendingUrl(call: PluginCall) {
+        call.resolve(JSObject().put("url", PollPrefs.consumePendingUrl(context)))
+    }
+
+    @PluginMethod
+    fun isBatteryExempted(call: PluginCall) {
+        val pm = context.getSystemService(Context.POWER_SERVICE) as PowerManager
+        call.resolve(JSObject().put("exempted", pm.isIgnoringBatteryOptimizations(context.packageName)))
+    }
+
+    @PluginMethod
+    fun requestBatteryExemption(call: PluginCall) {
+        val intent = Intent(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS).apply {
+            data = Uri.parse("package:${context.packageName}")
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        }
+        context.startActivity(intent)
+        call.resolve()
+    }
+
+    /** `standard` = WorkManager ~15 min (best-effort). */
+    private fun startStandard(ctx: Context) {
+        val request = PeriodicWorkRequestBuilder<PollWorker>(15, TimeUnit.MINUTES).build()
+        WorkManager.getInstance(ctx)
+            .enqueueUniquePeriodicWork("skatespots-poll", ExistingPeriodicWorkPolicy.UPDATE, request)
+        ctx.stopService(Intent(ctx, PollService::class.java))
+    }
+
+    /** `fast` = foreground service (sticky notification). */
+    private fun startFast(ctx: Context) {
+        WorkManager.getInstance(ctx).cancelUniqueWork("skatespots-poll")
+        ContextCompat.startForegroundService(ctx, Intent(ctx, PollService::class.java))
+    }
+
+    private fun stopAll(ctx: Context) {
+        WorkManager.getInstance(ctx).cancelUniqueWork("skatespots-poll")
+        ctx.stopService(Intent(ctx, PollService::class.java))
+    }
+}

packages/skatespots-background/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "skatespots-background",
+  "version": "0.0.1",
+  "private": true,
+  "description": "SkateSpots native background notification poller (WorkManager + foreground service). No Google services.",
+  "type": "module",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "capacitor": {
+    "android": {
+      "src": "android"
+    }
+  },
+  "files": ["src", "android"],
+  "dependencies": {
+    "@capacitor/core": "^8.4.2"
+  }
+}

packages/skatespots-background/src/index.ts

@@ -0,0 +1,55 @@
+/**
+ * SkateSpots background delivery — TS↔Kotlin bridge.
+ *
+ * A native poller that asks our OWN `push-service` "anything new since N?" and
+ * raises a **local notification** when it moves — the Cordn pattern, with **no
+ * Google**. `/pending` returns only a content-free cursor, so the worker never
+ * decrypts anything.
+ *
+ * Every method rejects on web; callers guard with `isNativePlatform()`.
+ */
+import { registerPlugin } from '@capacitor/core';
+
+/** `off` | `standard` (WorkManager ~15 min) | `fast` (foreground service ~5 min). */
+export type DeliveryMode = 'off' | 'standard' | 'fast';
+
+export interface ConfigureOptions {
+  mode: DeliveryMode;
+  /** Minutes between foreground-service polls. Only used by `fast`. Default 5. */
+  intervalMinutes?: number;
+}
+
+export interface SeedOptions {
+  /** Base URL of the push service, e.g. https://push.skate-spots.org */
+  baseUrl: string;
+  /** The poll token from `/native/poll/register`. */
+  token: string;
+  /** The cursor we already know — the worker only notifies when it advances. */
+  since: number;
+}
+
+export interface PostNotificationOptions {
+  title?: string;
+  body?: string;
+  /** In-app path to open on tap (HashRouter), e.g. /#/trades */
+  url?: string;
+}
+
+export interface SkateSpotsBackgroundPlugin {
+  /** Set the delivery mode; starts/stops the foreground service accordingly. */
+  configure(options: ConfigureOptions): Promise<void>;
+  /** Store the poll target (base URL + token + cursor). Call on enable/login. */
+  seed(options: SeedOptions): Promise<void>;
+  /** Post a local notification (used by the live in-app path for consistency). */
+  postNotification(options?: PostNotificationOptions): Promise<void>;
+  /** Cancel all message notifications. */
+  clearNotifications(): Promise<void>;
+  /** A tapped notification's in-app path (HashRouter), consumed once. */
+  consumePendingUrl(): Promise<{ url: string | null }>;
+  /** Whether the app is exempt from Doze/battery optimization. */
+  isBatteryExempted(): Promise<{ exempted: boolean }>;
+  /** Open the system "disable battery optimization" prompt. */
+  requestBatteryExemption(): Promise<void>;
+}
+
+export const SkateSpotsBackground = registerPlugin<SkateSpotsBackgroundPlugin>('SkateSpotsBackground');

src/components/NotificationSettingsCard.tsx

@@ -4,6 +4,8 @@ import { Switch } from '@/components/ui/switch';
 import { Button } from '@/components/ui/button';
 import { useNotificationPrefs } from '@/hooks/useNotificationPrefs';
 import { usePushNotifications } from '@/hooks/usePushNotifications';
+import { useBackgroundDelivery } from '@/hooks/useBackgroundDelivery';
+import { useToast } from '@/hooks/useToast';
 import { NOTIFICATION_CATEGORIES } from '@/lib/notificationPrefs';
 import {
   getNotificationPermission,
@@ -25,6 +27,8 @@ export function NotificationSettingsCard() {
   const [permission, setPermission] = useState<OsPermission | 'loading'>('loading');
   const [busy, setBusy] = useState(false);
   const push = usePushNotifications();
+  const background = useBackgroundDelivery();
+  const { toast } = useToast();
 
   useEffect(() => {
     let cancelled = false;
@@ -173,6 +177,49 @@ export function NotificationSettingsCard() {
         </p>
       </div>
 
+      {/* Background delivery (Android only — no Google services). */}
+      {background.supported && (
+        <div className="overflow-hidden rounded-2xl border border-white/8 bg-white/2">
+          <div className="px-4 py-3.5">
+            <p className="text-sm font-bold text-white">Background delivery (Android)</p>
+            <p className="mt-0.5 text-xs leading-tight text-muted-foreground">
+              Check for new messages, offers and trades while the app is closed — no Google services.
+            </p>
+            <div className="mt-3 flex flex-wrap gap-2">
+              <Button size="sm" variant={background.mode === 'off' ? 'default' : 'outline'} onClick={() => void background.disable()}>
+                Off
+              </Button>
+              <Button
+                size="sm"
+                variant={background.mode === 'standard' ? 'default' : 'outline'}
+                onClick={() => {
+                  void background.enable('standard').catch((e) => {
+                    toast({ title: 'Could not enable', description: e instanceof Error ? e.message : 'Try again.', variant: 'destructive' });
+                  });
+                }}
+              >
+                Standard (~15 min)
+              </Button>
+              <Button
+                size="sm"
+                variant={background.mode === 'fast' ? 'default' : 'outline'}
+                onClick={() => {
+                  void background.enable('fast').catch((e) => {
+                    toast({ title: 'Could not enable', description: e instanceof Error ? e.message : 'Try again.', variant: 'destructive' });
+                  });
+                }}
+              >
+                Fast (~5 min)
+              </Button>
+            </div>
+            <p className="mt-2 text-[10px] leading-relaxed text-gray-600">
+              Standard is best-effort — Android may defer it under Doze. Fast shows a persistent
+              notification and uses more battery. Nothing is decrypted on our server.
+            </p>
+          </div>
+        </div>
+      )}
+
       {/* Per-category toggles */}
       <div className="overflow-hidden rounded-2xl border border-white/8 bg-white/2">
         <p className="border-b border-white/5 px-4 py-2.5 text-[10px] font-black uppercase tracking-widest text-muted-foreground/60">

src/hooks/useBackgroundDelivery.ts

@@ -0,0 +1,72 @@
+/**
+ * useBackgroundDelivery — Android-only closed-app notifications, **without
+ * Google**. Registers a poll token with our `push-service` and hands the native
+ * `skatespots-background` plugin the base URL + token so its worker can ask
+ * "anything new since N?" and raise a local notification.
+ *
+ * Two modes (chosen in Settings): `standard` = WorkManager ~15 min (best-effort),
+ * `fast` = a foreground service ~5 min (sticky notification).
+ */
+import { useCallback, useState } from 'react';
+import { registerPlugin } from '@capacitor/core';
+
+import { useCurrentUser } from '@/hooks/useCurrentUser';
+import { isNativePlatform, getPlatform } from '@/lib/platform';
+import { pushServiceBase, requestPushChallenge } from '@/lib/pushService';
+
+type DeliveryMode = 'off' | 'standard' | 'fast';
+
+/**
+ * Registered by NAME (`@capacitor/core`), not imported from the package — the
+ * plugin's TS source lives in `packages/skatespots-background` and is only a
+ * build-time dependency of the Android shell (Capacitor finds it via package.json).
+ */
+interface SkateSpotsBackgroundPlugin {
+  configure(options: { mode: DeliveryMode; intervalMinutes?: number }): Promise<void>;
+  seed(options: { baseUrl: string; token: string; since: number }): Promise<void>;
+  clearNotifications(): Promise<void>;
+}
+const SkateSpotsBackground = registerPlugin<SkateSpotsBackgroundPlugin>('SkateSpotsBackground');
+
+export function useBackgroundDelivery() {
+  const { user } = useCurrentUser();
+  const supported = isNativePlatform() && getPlatform() === 'android';
+  const [mode, setMode] = useState<DeliveryMode>('off');
+
+  const enable = useCallback(
+    async (nextMode: Exclude<DeliveryMode, 'off'>, intervalMinutes = 5) => {
+      if (!supported) throw new Error('Background delivery is Android-only.');
+      if (!user?.pubkey || !user.signer) throw new Error('Log in first.');
+
+      const challenge = await requestPushChallenge(user.pubkey);
+      const proof = await user.signer.signEvent({
+        kind: 27235,
+        content: '',
+        created_at: Math.floor(Date.now() / 1000),
+        tags: [['challenge', challenge]],
+      });
+
+      const res = await fetch(`${pushServiceBase()}/native/poll/register`, {
+        method: 'POST',
+        headers: { 'content-type': 'application/json' },
+        body: JSON.stringify({ pubkey: user.pubkey, proof }),
+      });
+      if (!res.ok) throw new Error('Could not register for background delivery.');
+      const { token, seq } = (await res.json()) as { token: string; seq: number };
+
+      await SkateSpotsBackground.seed({ baseUrl: pushServiceBase(), token, since: seq ?? 0 });
+      await SkateSpotsBackground.configure({ mode: nextMode, intervalMinutes });
+      setMode(nextMode);
+    },
+    [supported, user],
+  );
+
+  const disable = useCallback(async () => {
+    if (!supported) return;
+    await SkateSpotsBackground.configure({ mode: 'off' });
+    await SkateSpotsBackground.clearNotifications();
+    setMode('off');
+  }, [supported]);
+
+  return { supported, mode, enable, disable };
+}