release: v1.21 (versionCode 22) — WebView hardening

The WebView holds the claude.ai session cookie; lock down every path a loaded
page could use to reach local files. No effect on the login/SSO flow.

LICENSE

@@ -0,0 +1,45 @@
+Claude Usage Widget Source-Available License
+Copyright (c) 2026 Amir Khodak. All rights reserved.
+
+This is NOT an OSI-approved open-source license. The source code is made
+publicly viewable ("source-available"), but the rights granted are limited as
+described below. Where this license is silent, all rights are reserved.
+
+1. DEFINITIONS
+   "Software" means the Claude Usage Widget source code, assets, and
+   documentation in this repository. "You" means anyone other than the
+   copyright holder.
+
+2. WHAT YOU MAY DO
+   a. View, read, and study the Software.
+   b. Clone or fork the repository for your own private, personal,
+      non-commercial use and experimentation.
+   c. Build the Software from source and run it on devices you personally own.
+   d. Submit contributions (pull requests) back to this repository; by doing so
+      you license your contribution to the copyright holder under these terms.
+
+3. WHAT YOU MAY NOT DO (without the copyright holder's prior written permission)
+   a. Redistribute, publish, or make available the Software or any derivative
+      work — in source or binary/APK form — to any third party or app store
+      (including but not limited to Google Play, F-Droid, Amazon Appstore,
+      Gitea/GitHub releases, or any website).
+   b. Use the Software, in whole or in part, for any commercial purpose.
+   c. Sell, sublicense, rent, or offer the Software as a service.
+   d. Use the names, app identity ("Claude Usage Widget"), package identifier
+      ("me.khodak.claudeusage"), logos, or signing keys of the original work.
+   e. Remove or alter this license or the copyright notice.
+
+4. RESERVED RIGHTS
+   All publishing and distribution rights are reserved exclusively to the
+   copyright holder. Only the copyright holder may publish official builds.
+
+5. TRADEMARK NOTE
+   "Claude" is a trademark of Anthropic. This is an unofficial, independent
+   utility and is not affiliated with or endorsed by Anthropic.
+
+6. NO WARRANTY
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM,
+   DAMAGES, OR OTHER LIABILITY ARISING FROM THE SOFTWARE OR ITS USE.
+
+To request permission for anything in section 3, contact the copyright holder.

README.md

@@ -23,6 +23,12 @@ Android home screen widget that shows your Claude Pro usage at a glance.
 - Responsive: works as 4×1 (compact) or 4×2 (full)
 - Auto-refreshes every 5 minutes in the background
 
+## Screenshots
+
+<p align="center">
+  <img src="docs/screenshots/signin.png" width="240" alt="Sign in">
+</p>
+
 ## Install
 
 1. Download `claude-usage-widget.apk` from the [latest release](../../releases/latest)

app/build.gradle.kts

@@ -24,8 +24,8 @@ android {
         applicationId = "me.khodak.claudeusage"
         minSdk = 26
         targetSdk = 34
-        versionCode = 21
+        versionCode = 22
-        versionName = "1.20"
+        versionName = "1.21"
     }
 
     val releaseStorePassword = signingCred("KEYSTORE_PASSWORD", "storePassword")

app/src/main/java/me/khodak/claudeusage/ClaudeUsageWidget.kt

@@ -102,6 +102,8 @@ class ClaudeUsageWidget : AppWidgetProvider() {
         }
 
         private fun buildSmallViews(context: Context, prefs: PreferencesManager, apiData: UsageData?): RemoteViews {
+            val SESSION_FILL = ThemeColors.sessionFill(context, prefs)
+            val WEEKLY_FILL = ThemeColors.weeklyFill(context, prefs)
             val v = RemoteViews(context.packageName, R.layout.widget_layout_small)
             applyPeak(v, showText = false)
             if (!prefs.isLoggedIn()) {
@@ -174,6 +176,8 @@ class ClaudeUsageWidget : AppWidgetProvider() {
         }
 
         private fun buildViews(context: Context, prefs: PreferencesManager, apiData: UsageData?): RemoteViews {
+            val SESSION_FILL = ThemeColors.sessionFill(context, prefs)
+            val WEEKLY_FILL = ThemeColors.weeklyFill(context, prefs)
             val v = RemoteViews(context.packageName, R.layout.widget_layout)
             applyPeak(v, showText = true)
 
@@ -264,6 +268,8 @@ class ClaudeUsageWidget : AppWidgetProvider() {
          * circular [RingRenderer] gauge (percentage drawn in the center) instead of a bar.
          */
         private fun buildRingViews(context: Context, prefs: PreferencesManager, apiData: UsageData?): RemoteViews {
+            val SESSION_FILL = ThemeColors.sessionFill(context, prefs)
+            val WEEKLY_FILL = ThemeColors.weeklyFill(context, prefs)
             val v = RemoteViews(context.packageName, R.layout.widget_layout_rings)
             applyPeak(v, showText = true)
 

app/src/main/java/me/khodak/claudeusage/LoginActivity.kt

@@ -75,6 +75,15 @@ class LoginActivity : AppCompatActivity() {
                 databaseEnabled = false
                 javaScriptCanOpenWindowsAutomatically = false
                 setSupportMultipleWindows(false)
+                // Hardening: this WebView holds the claude.ai session, so lock down every path a
+                // page could use to reach the device. None of these affect the login flow.
+                allowFileAccess = false
+                allowContentAccess = false
+                @Suppress("DEPRECATION")
+                allowFileAccessFromFileURLs = false
+                @Suppress("DEPRECATION")
+                allowUniversalAccessFromFileURLs = false
+                setGeolocationEnabled(false)
                 // Standard Android Chrome UA — less suspicious than desktop
                 userAgentString = "Mozilla/5.0 (Linux; Android 13; Pixel 7) " +
                     "AppleWebKit/537.36 (KHTML, like Gecko) " +

app/src/main/java/me/khodak/claudeusage/MainActivity.kt

@@ -30,6 +30,33 @@ class MainActivity : AppCompatActivity() {
     private val notifPermLauncher =
         registerForActivityResult(ActivityResultContracts.RequestPermission()) { /* result handled silently */ }
 
+    /** SAF: pick a destination file and write the current settings JSON to it. */
+    private val exportLauncher =
+        registerForActivityResult(ActivityResultContracts.CreateDocument("application/json")) { uri ->
+            if (uri == null) return@registerForActivityResult
+            try {
+                contentResolver.openOutputStream(uri)?.use { it.write(prefs.exportSettings().toByteArray()) }
+                toast("Settings exported")
+            } catch (_: Exception) { toast("Export failed") }
+        }
+
+    /** SAF: pick a backup file and apply it. */
+    private val importLauncher =
+        registerForActivityResult(ActivityResultContracts.OpenDocument()) { uri ->
+            if (uri == null) return@registerForActivityResult
+            try {
+                val json = contentResolver.openInputStream(uri)?.bufferedReader()?.use { it.readText() } ?: ""
+                if (prefs.importSettings(json)) {
+                    toast("Settings restored")
+                    // Reflect restored prefs immediately: re-sync switches and redraw any widgets.
+                    binding.switchNotify.isChecked = prefs.isNotifyEnabled()
+                    binding.switchRingStyle.isChecked = prefs.getWidgetStyle() == PreferencesManager.STYLE_RINGS
+                    binding.switchMaterialYou.isChecked = prefs.isMaterialYou()
+                    ClaudeUsageWidget.notifyDataChanged(this)
+                } else toast("Not a valid settings file")
+            } catch (_: Exception) { toast("Import failed") }
+        }
+
     /** Live refresh loop that runs only while the app is in the foreground. */
     private var autoRefreshJob: Job? = null
 
@@ -67,6 +94,8 @@ class MainActivity : AppCompatActivity() {
 
         setupNotificationSettings()
         setupWidgetStyleSetting()
+        setupMaterialYouSetting()
+        setupBackupRestore()
 
         binding.btnDebug.setOnClickListener {
             if (binding.tvDebugInfo.visibility == android.view.View.GONE) {
@@ -122,6 +151,28 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    /** Material You toggle — switches the bars/rings to wallpaper-derived accents (Android 12+). */
+    private fun setupMaterialYouSetting() {
+        binding.switchMaterialYou.isChecked = prefs.isMaterialYou()
+        binding.switchMaterialYou.setOnCheckedChangeListener { _, checked ->
+            prefs.setMaterialYou(checked)
+            ClaudeUsageWidget.notifyDataChanged(this)
+        }
+    }
+
+    /** Export/Import settings via the Storage Access Framework (no extra permissions needed). */
+    private fun setupBackupRestore() {
+        binding.btnExportSettings.setOnClickListener {
+            exportLauncher.launch("claude-usage-settings.json")
+        }
+        binding.btnImportSettings.setOnClickListener {
+            importLauncher.launch(arrayOf("application/json", "text/*", "*/*"))
+        }
+    }
+
+    private fun toast(msg: String) =
+        android.widget.Toast.makeText(this, msg, android.widget.Toast.LENGTH_SHORT).show()
+
     private fun requestNotificationPermission() {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU) return
         if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS)

app/src/main/java/me/khodak/claudeusage/MainActivity.kt.tmp.283970.ad8df417b08b

@@ -0,0 +1,310 @@
+package me.khodak.claudeusage
+
+import android.Manifest
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Build
+import android.os.Bundle
+import android.view.View
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import me.khodak.claudeusage.data.PreferencesManager
+import me.khodak.claudeusage.data.UsageData
+import me.khodak.claudeusage.databinding.ActivityMainBinding
+import java.text.SimpleDateFormat
+import java.util.*
+import java.util.concurrent.TimeUnit
+
+class MainActivity : AppCompatActivity() {
+
+    private lateinit var binding: ActivityMainBinding
+    private lateinit var prefs: PreferencesManager
+    private lateinit var repo: UsageRepository
+
+    private val notifPermLauncher =
+        registerForActivityResult(ActivityResultContracts.RequestPermission()) { /* result handled silently */ }
+
+    /** SAF: pick a destination file and write the current settings JSON to it. */
+    private val exportLauncher =
+        registerForActivityResult(ActivityResultContracts.CreateDocument("application/json")) { uri ->
+            if (uri == null) return@registerForActivityResult
+            try {
+                contentResolver.openOutputStream(uri)?.use { it.write(prefs.exportSettings().toByteArray()) }
+                toast("Settings exported")
+            } catch (_: Exception) { toast("Export failed") }
+        }
+
+    /** SAF: pick a backup file and apply it. */
+    private val importLauncher =
+        registerForActivityResult(ActivityResultContracts.OpenDocument()) { uri ->
+            if (uri == null) return@registerForActivityResult
+            try {
+                val json = contentResolver.openInputStream(uri)?.bufferedReader()?.use { it.readText() } ?: ""
+                if (prefs.importSettings(json)) {
+                    toast("Settings restored")
+                    // Reflect restored prefs immediately: re-sync switches and redraw any widgets.
+                    binding.switchNotify.isChecked = prefs.isNotifyEnabled()
+                    binding.switchRingStyle.isChecked = prefs.getWidgetStyle() == PreferencesManager.STYLE_RINGS
+                    binding.switchMaterialYou.isChecked = prefs.isMaterialYou()
+                    ClaudeUsageWidget.notifyDataChanged(this)
+                } else toast("Not a valid settings file")
+            } catch (_: Exception) { toast("Import failed") }
+        }
+
+    /** Live refresh loop that runs only while the app is in the foreground. */
+    private var autoRefreshJob: Job? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityMainBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        prefs = PreferencesManager(this)
+        repo = UsageRepository(prefs)
+
+        binding.btnLogin.setOnClickListener {
+            startActivity(Intent(this, LoginActivity::class.java))
+        }
+
+        // If already logged in, go straight to logged-in state without re-opening login
+        if (prefs.isLoggedIn()) {
+            updateUI(prefs.getUsageData())
+        }
+
+        binding.btnLogout.setOnClickListener {
+            prefs.clearSession()
+            updateUI(null)
+        }
+
+        binding.btnRefresh.setOnClickListener {
+            refreshUsage()
+        }
+
+        binding.tvWidgetHint.setOnClickListener {
+            startActivity(Intent(Intent.ACTION_MAIN).apply {
+                addCategory(Intent.CATEGORY_HOME)
+            })
+        }
+
+        setupNotificationSettings()
+        setupWidgetStyleSetting()
+        setupMaterialYouSetting()
+        setupBackupRestore()
+
+        binding.btnDebug.setOnClickListener {
+            if (binding.tvDebugInfo.visibility == android.view.View.GONE) {
+                binding.tvDebugInfo.text = repo.lastDebugInfo.ifBlank { "No debug info yet — tap Refresh first" }
+                binding.tvDebugInfo.visibility = android.view.View.VISIBLE
+                binding.btnDebug.text = "Hide API Debug"
+            } else {
+                binding.tvDebugInfo.visibility = android.view.View.GONE
+                binding.btnDebug.text = "Show API Debug"
+            }
+        }
+    }
+
+    override fun onResume() {
+        super.onResume()
+        updateUI(prefs.getUsageData())  // show cached instantly — never a blank screen
+        if (prefs.isLoggedIn()) startAutoRefresh()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        autoRefreshJob?.cancel()
+    }
+
+    /** Refresh immediately on open, then every [REFRESH_INTERVAL_MS] while foregrounded. */
+    private fun startAutoRefresh() {
+        autoRefreshJob?.cancel()
+        autoRefreshJob = lifecycleScope.launch {
+            while (isActive) {
+                doRefresh(silent = true)
+                delay(REFRESH_INTERVAL_MS)
+            }
+        }
+    }
+
+    private fun setupNotificationSettings() {
+        binding.switchNotify.isChecked = prefs.isNotifyEnabled()
+        binding.switchNotify.setOnCheckedChangeListener { _, checked ->
+            prefs.setNotifyEnabled(checked)
+            if (checked) requestNotificationPermission()
+        }
+        // Alerts default on, so prompt for the runtime permission once on first launch
+        // (a user who never toggles the switch would otherwise never be asked).
+        if (prefs.isNotifyEnabled()) requestNotificationPermission()
+    }
+
+    /** Bars ⇄ Rings switch for the home-screen widget; redraws any placed widgets immediately. */
+    private fun setupWidgetStyleSetting() {
+        binding.switchRingStyle.isChecked = prefs.getWidgetStyle() == PreferencesManager.STYLE_RINGS
+        binding.switchRingStyle.setOnCheckedChangeListener { _, checked ->
+            prefs.setWidgetStyle(if (checked) PreferencesManager.STYLE_RINGS else PreferencesManager.STYLE_BARS)
+            ClaudeUsageWidget.notifyDataChanged(this)
+        }
+    }
+
+    /** Material You toggle — redraws placed widgets so the new accent applies immediately. */
+    private fun setupMaterialYouSetting() {
+        binding.switchMaterialYou.isChecked = prefs.isMaterialYou()
+        binding.switchMaterialYou.setOnCheckedChangeListener { _, checked ->
+            prefs.setMaterialYou(checked)
+            ClaudeUsageWidget.notifyDataChanged(this)
+            updateUI(prefs.getUsageData())   // refresh the in-app bars too
+        }
+    }
+
+    private fun setupBackupRestore() {
+        binding.btnExportSettings.setOnClickListener { exportLauncher.launch("claude-usage-settings.json") }
+        binding.btnImportSettings.setOnClickListener { importLauncher.launch(arrayOf("application/json", "text/plain", "*/*")) }
+    }
+
+    private fun toast(msg: String) =
+        android.widget.Toast.makeText(this, msg, android.widget.Toast.LENGTH_SHORT).show()
+
+    private fun requestNotificationPermission() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU) return
+        if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS)
+            != PackageManager.PERMISSION_GRANTED
+        ) {
+            notifPermLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
+        }
+    }
+
+    /** Manual "Refresh Now" button — shows the spinner. */
+    private fun refreshUsage() {
+        lifecycleScope.launch { doRefresh(silent = false) }
+    }
+
+    private suspend fun doRefresh(silent: Boolean) {
+        if (!silent) {
+            binding.btnRefresh.isEnabled = false
+            binding.progressIndicator.visibility = View.VISIBLE
+        }
+        val fresh = try {
+            repo.fetchUsage()
+        } catch (e: Exception) {
+            if (e is kotlinx.coroutines.CancellationException) throw e
+            UsageData(errorMessage = "Network error")
+        }
+        // Preserve last-good data so a failed/partial fetch never blanks the UI or widget.
+        val merged = fresh.mergedWith(prefs.getUsageData())
+        prefs.saveUsageData(merged)
+        prefs.recordHistory(fresh)
+        // Note: alerts fire only from the background worker, not here — no point pinging you
+        // with a notification while you're already looking at the app.
+        updateUI(merged)
+        ClaudeUsageWidget.notifyDataChanged(this)  // opening the app refreshes the widget too
+        if (binding.tvDebugInfo.visibility == View.VISIBLE) {
+            binding.tvDebugInfo.text = repo.lastDebugInfo
+        }
+        if (!silent) {
+            binding.btnRefresh.isEnabled = true
+            binding.progressIndicator.visibility = View.GONE
+        }
+    }
+
+    private fun updateUI(data: UsageData?) {
+        val loggedIn = prefs.isLoggedIn()
+
+        binding.layoutLoggedOut.visibility = if (loggedIn) View.GONE else View.VISIBLE
+        binding.layoutLoggedIn.visibility = if (loggedIn) View.VISIBLE else View.GONE
+
+        if (!loggedIn || data == null) return
+
+        // ── Peak-hours row ───────────────────────────────────────────────────
+        val peak = PeakHours.state()
+        binding.imgPeak.setColorFilter(if (peak.active) PEAK_ON else PEAK_OFF)
+        binding.tvPeak.setTextColor(if (peak.active) PEAK_ON else 0xFFAAAAAA.toInt())
+        binding.tvPeak.text = if (peak.active)
+            "🔥 Peak hours — ${peak.endsInLabel} · ${peak.windowLabel}"
+        else
+            "Off-peak · ${peak.windowLabel}"
+
+        // ── Session (5-hour) bar — no pace marker ────────────────────────────
+        binding.barSession.setImageBitmap(
+            BarRenderer.render(data.progressPercent, null, SESSION_FILL, null)
+        )
+
+        // ── Weekly (7-day) bar — single-color pace marker ────────────────────
+        if (data.weeklyUtilization >= 0f) {
+            val wPct = data.weeklyUtilization.toInt()
+            val weeklyPace = PaceCalc.compute(data.weeklyUtilization, data.weeklyResetAtEpoch, PaceCalc.WEEKLY_WINDOW_MS)
+            binding.barWeekly.setImageBitmap(
+                BarRenderer.render(wPct, weeklyPace?.markerPct, WEEKLY_FILL, if (weeklyPace != null) MARKER_COLOR else null)
+            )
+            binding.tvWeeklyUsage.text = "$wPct% this week"
+        } else {
+            binding.barWeekly.setImageBitmap(BarRenderer.render(0, null, WEEKLY_FILL, null))
+            binding.tvWeeklyUsage.text = "—"
+        }
+
+        // Pace text removed per design — bars carry the signal.
+        binding.tvSessionPace.visibility = View.GONE
+        binding.tvWeeklyPace.visibility = View.GONE
+
+        binding.tvUsage.text = when {
+            data.fiveHourUtilization >= 0f -> {
+                val pct = data.fiveHourUtilization.toInt()
+                "$pct% of limit used"
+            }
+            data.messagesLimit > 0 && data.effectiveUsed >= 0 ->
+                "${data.effectiveUsed} of ${data.messagesLimit} messages used"
+            data.effectiveRemaining >= 0 && data.messagesLimit > 0 ->
+                "${data.effectiveRemaining} of ${data.messagesLimit} remaining"
+            data.effectiveRemaining >= 0 ->
+                "${data.effectiveRemaining} messages remaining"
+            else -> "Usage data unavailable"
+        }
+
+        binding.tvReset.text = formatReset(data.effectiveResetEpoch)
+        binding.tvWeeklyReset.text = formatResetDay(data.weeklyResetAtEpoch)
+        binding.tvUpdated.text = if (data.lastUpdated > 0)
+            "Last updated: ${SimpleDateFormat("h:mm a, MMM d", Locale.US).format(Date(data.lastUpdated))}"
+        else ""
+
+        binding.tvError.text = data.errorMessage
+        binding.tvError.visibility = if (data.errorMessage.isNotBlank()) View.VISIBLE else View.GONE
+
+        binding.historyChart.setData(prefs.getHistory())
+    }
+
+    private fun formatReset(epochMs: Long): String {
+        if (epochMs <= 0) return ""
+        val now = System.currentTimeMillis()
+        if (epochMs <= now) return "Resets soon"
+        val diffH = TimeUnit.MILLISECONDS.toHours(epochMs - now)
+        val timeStr = SimpleDateFormat("h:mm a", Locale.US).format(Date(epochMs))
+        return when {
+            diffH < 24 -> "Resets at $timeStr"
+            diffH < 48 -> "Resets tomorrow $timeStr"
+            else -> "Resets ${SimpleDateFormat("EEE", Locale.US).format(Date(epochMs))} $timeStr"
+        }
+    }
+
+    /** Weekly reset shown with the weekday name ("Resets Friday 3:00 PM"), never "tomorrow". */
+    private fun formatResetDay(epochMs: Long): String {
+        if (epochMs <= 0) return ""
+        if (epochMs <= System.currentTimeMillis()) return "Resets soon"
+        val day = SimpleDateFormat("EEEE", Locale.US).format(Date(epochMs))
+        val date = SimpleDateFormat("MMM d", Locale.US).format(Date(epochMs))
+        val timeStr = SimpleDateFormat("h:mm a", Locale.US).format(Date(epochMs))
+        return "Resets $day, $date · $timeStr"
+    }
+
+    companion object {
+        private const val REFRESH_INTERVAL_MS = 30_000L   // live refresh cadence while app is open
+        private const val SESSION_FILL = 0xFFCC785C.toInt()
+        private const val WEEKLY_FILL = 0xFF7B8FCC.toInt()
+        private const val MARKER_COLOR = 0xFFFFFFFF.toInt()   // single-color weekly pace marker
+        private const val PEAK_ON = 0xFFCC785C.toInt()
+        private const val PEAK_OFF = 0xFF666666.toInt()
+    }
+}

app/src/main/java/me/khodak/claudeusage/Notifier.kt

@@ -23,8 +23,42 @@ import me.khodak.claudeusage.data.UsageData
 object Notifier {
 
     private const val CHANNEL_ID = "usage_alerts"
+    private const val AUTH_CHANNEL_ID = "session_alerts"
+    private const val AUTH_NOTIF_ID = 3000
     private val LEVELS = intArrayOf(90, 100)
 
+    /**
+     * Fired once when the saved claude.ai session is cleared after repeated 401/403s — without
+     * this the widget would just silently go stale and the user would have to notice the dead
+     * data themselves. Tapping opens LoginActivity straight to the cookie re-paste flow. Posts on
+     * its own channel so it can be muted independently of usage alerts, and is not gated on the
+     * usage-alert toggle: a dead widget is a functional failure the user needs to know about.
+     */
+    fun notifySessionExpired(context: Context) {
+        val mgr = NotificationManagerCompat.from(context)
+        if (!mgr.areNotificationsEnabled()) return
+        ensureAuthChannel(context)
+        val intent = Intent(context, LoginActivity::class.java)
+            .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP)
+        val pi = PendingIntent.getActivity(
+            context, 1, intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+        val notif = NotificationCompat.Builder(context, AUTH_CHANNEL_ID)
+            .setSmallIcon(R.drawable.ic_claude_burst)
+            .setContentTitle("Claude sign-in expired")
+            .setContentText("Tap to sign in again — the widget can't update until you do.")
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+            .setAutoCancel(true)
+            .setContentIntent(pi)
+            .build()
+        try {
+            mgr.notify(AUTH_NOTIF_ID, notif)
+        } catch (_: SecurityException) {
+            // Notifications revoked between the check and post — nothing to do.
+        }
+    }
+
     fun checkAndNotify(context: Context, prefs: PreferencesManager, data: UsageData) {
         if (!prefs.isNotifyEnabled()) return
         val mgr = NotificationManagerCompat.from(context)
@@ -94,6 +128,17 @@ object Notifier {
     private fun notifId(metric: String, levelIndex: Int) =
         2000 + (if (metric == "weekly") 10 else 0) + levelIndex
 
+    private fun ensureAuthChannel(context: Context) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+        val mgr = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        if (mgr.getNotificationChannel(AUTH_CHANNEL_ID) != null) return
+        mgr.createNotificationChannel(
+            NotificationChannel(
+                AUTH_CHANNEL_ID, "Sign-in alerts", NotificationManager.IMPORTANCE_HIGH
+            ).apply { description = "Tells you when your claude.ai session expires and needs re-auth" }
+        )
+    }
+
     private fun ensureChannel(context: Context) {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
         val mgr = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

app/src/main/java/me/khodak/claudeusage/ThemeColors.kt

@@ -0,0 +1,30 @@
+package me.khodak.claudeusage
+
+import android.content.Context
+import android.os.Build
+import me.khodak.claudeusage.data.PreferencesManager
+
+/**
+ * Central source of the two accent colors used by the bars/rings (session + weekly).
+ *
+ * Default = the Claude brand palette. When the user enables Material You *and* the device is
+ * Android 12+ (where the wallpaper-derived `system_accent*` palette exists), the fills switch to
+ * the dynamic system accents so the widget matches the rest of the home screen. On older devices
+ * the toggle is a no-op and the brand colors are always used.
+ */
+object ThemeColors {
+
+    const val SESSION_DEFAULT = 0xFFCC785C.toInt()   // Claude orange
+    const val WEEKLY_DEFAULT = 0xFF7B8FCC.toInt()    // Claude periwinkle
+
+    private fun dynamicAvailable(prefs: PreferencesManager): Boolean =
+        prefs.isMaterialYou() && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S
+
+    fun sessionFill(context: Context, prefs: PreferencesManager): Int =
+        if (dynamicAvailable(prefs)) context.getColor(android.R.color.system_accent1_300)
+        else SESSION_DEFAULT
+
+    fun weeklyFill(context: Context, prefs: PreferencesManager): Int =
+        if (dynamicAvailable(prefs)) context.getColor(android.R.color.system_accent2_300)
+        else WEEKLY_DEFAULT
+}

app/src/main/java/me/khodak/claudeusage/UsageUpdateWorker.kt

@@ -31,10 +31,16 @@ class UsageUpdateWorker(
             val animJob = launch { rotateRefreshIcon() }
             try {
                 val data = UsageRepository(prefs).fetchUsage()
+                // We passed the isLoggedIn() guard above, so if the session is gone now the
+                // cookie just expired this cycle — tell the user once (next cycle returns early).
+                if (!prefs.isLoggedIn()) {
+                    Notifier.notifySessionExpired(context)
+                } else {
                     // Preserve last-good data so a failed/partial fetch never blanks the widget.
                     prefs.saveUsageData(data.mergedWith(prefs.getUsageData()))
                     prefs.recordHistory(data)       // history records only fresh readings
                     Notifier.checkAndNotify(context, prefs, data)
+                }
             } catch (_: Exception) {}
             animJob.cancel()
             animJob.join()

app/src/main/java/me/khodak/claudeusage/data/PreferencesManager.kt

@@ -143,6 +143,42 @@ class PreferencesManager(context: Context) {
     fun isNotifyEnabled(): Boolean = prefs.getBoolean(KEY_NOTIFY_ENABLED, true)
     fun setNotifyEnabled(v: Boolean) = prefs.edit().putBoolean(KEY_NOTIFY_ENABLED, v).apply()
 
+    // ── Material You (dynamic color) ─────────────────────────────────────────
+
+    /** When on (and Android 12+), bars/rings use the wallpaper-derived system accents. */
+    fun isMaterialYou(): Boolean = prefs.getBoolean(KEY_MATERIAL_YOU, false)
+    fun setMaterialYou(v: Boolean) = prefs.edit().putBoolean(KEY_MATERIAL_YOU, v).apply()
+
+    // ── Settings backup / restore ────────────────────────────────────────────
+
+    /**
+     * Serialize the user-tunable settings (NOT the session cookie or usage data) to JSON, so a
+     * reinstall doesn't lose preferences. Cookies are deliberately excluded — they're sensitive and
+     * device-bound, so a backup file stays safe to store anywhere.
+     */
+    fun exportSettings(): String = gson.toJson(
+        mapOf(
+            "version" to 1,
+            KEY_NOTIFY_ENABLED to isNotifyEnabled(),
+            KEY_WIDGET_STYLE to getWidgetStyle(),
+            KEY_MATERIAL_YOU to isMaterialYou()
+        )
+    )
+
+    /** Apply a settings JSON produced by [exportSettings]. Returns true if it parsed and applied. */
+    fun importSettings(json: String): Boolean = try {
+        @Suppress("UNCHECKED_CAST")
+        val map = gson.fromJson(json, Map::class.java) as Map<String, Any?>
+        val e = prefs.edit()
+        (map[KEY_NOTIFY_ENABLED] as? Boolean)?.let { e.putBoolean(KEY_NOTIFY_ENABLED, it) }
+        (map[KEY_MATERIAL_YOU] as? Boolean)?.let { e.putBoolean(KEY_MATERIAL_YOU, it) }
+        (map[KEY_WIDGET_STYLE] as? String)?.let {
+            if (it == STYLE_BARS || it == STYLE_RINGS) e.putString(KEY_WIDGET_STYLE, it)
+        }
+        e.apply()
+        true
+    } catch (_: Exception) { false }
+
     /**
      * Per-level "already alerted" flag (e.g. "session_90"). Set when the level is crossed,
      * cleared when usage drops back below it — so each level fires once per window.
@@ -162,6 +198,7 @@ class PreferencesManager(context: Context) {
         private const val KEY_NOTIFY_ENABLED = "notify_enabled"
         private const val KEY_AUTH_FAILS = "auth_fail_count"
         private const val KEY_WIDGET_STYLE = "widget_style"
+        private const val KEY_MATERIAL_YOU = "material_you"
 
         const val STYLE_BARS = "bars"
         const val STYLE_RINGS = "rings"

app/src/main/res/layout/activity_main.xml

@@ -333,6 +333,48 @@
 
             </LinearLayout>
 
+            <!-- Material You card -->
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical"
+                android:background="@drawable/widget_background"
+                android:padding="20dp"
+                android:layout_marginTop="16dp">
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:orientation="horizontal"
+                    android:gravity="center_vertical">
+
+                    <TextView
+                        android:layout_width="0dp"
+                        android:layout_height="wrap_content"
+                        android:layout_weight="1"
+                        android:text="MATERIAL YOU COLORS"
+                        android:textColor="#888888"
+                        android:textSize="11sp"
+                        android:letterSpacing="0.1" />
+
+                    <com.google.android.material.switchmaterial.SwitchMaterial
+                        android:id="@+id/switchMaterialYou"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content" />
+
+                </LinearLayout>
+
+                <TextView
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:text="Use your wallpaper-derived system accent colors for the bars/rings (Android 12+). Off = Claude brand colors."
+                    android:textColor="#AAAAAA"
+                    android:textSize="13sp"
+                    android:lineSpacingExtra="3dp" />
+
+            </LinearLayout>
+
             <!-- Notifications card -->
             <LinearLayout
                 android:layout_width="match_parent"
@@ -375,6 +417,60 @@
 
             </LinearLayout>
 
+            <!-- Backup & Restore card -->
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical"
+                android:background="@drawable/widget_background"
+                android:padding="20dp"
+                android:layout_marginTop="16dp">
+
+                <TextView
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:text="BACKUP &amp; RESTORE"
+                    android:textColor="#888888"
+                    android:textSize="11sp"
+                    android:letterSpacing="0.1" />
+
+                <TextView
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:text="Save your settings (widget style, Material You, alerts) to a file so a reinstall doesn't lose them. The Claude session cookie is never included."
+                    android:textColor="#AAAAAA"
+                    android:textSize="13sp"
+                    android:lineSpacingExtra="3dp" />
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:orientation="horizontal"
+                    android:layout_marginTop="14dp">
+
+                    <Button
+                        android:id="@+id/btnExportSettings"
+                        android:layout_width="0dp"
+                        android:layout_weight="1"
+                        android:layout_height="wrap_content"
+                        android:layout_marginEnd="6dp"
+                        android:text="Export"
+                        style="?attr/materialButtonOutlinedStyle" />
+
+                    <Button
+                        android:id="@+id/btnImportSettings"
+                        android:layout_width="0dp"
+                        android:layout_weight="1"
+                        android:layout_height="wrap_content"
+                        android:layout_marginStart="6dp"
+                        android:text="Import"
+                        style="?attr/materialButtonOutlinedStyle" />
+
+                </LinearLayout>
+
+            </LinearLayout>
+
             <Button
                 android:id="@+id/btnRefresh"
                 android:layout_width="match_parent"