diff --git a/.opencode/plans/server-thresholds.md b/.opencode/plans/server-thresholds.md
new file mode 100644
index 0000000..3c439f5
--- /dev/null
+++ b/.opencode/plans/server-thresholds.md
@@ -0,0 +1,256 @@
+# Plan: Umbrales de notificación por servidor
+
+## Archivos a modificar/crear
+
+### 1. `database/migrations/012_server_thresholds.sql` — CREAR
+
+```sql
+ALTER TABLE `servers`
+  ADD COLUMN `threshold_cpu_warning`  DECIMAL(5,2) DEFAULT 80.00 AFTER `agent_last_seen_at`,
+  ADD COLUMN `threshold_cpu_critical` DECIMAL(5,2) DEFAULT 95.00 AFTER `threshold_cpu_warning`,
+  ADD COLUMN `threshold_ram_warning`  DECIMAL(5,2) DEFAULT 80.00 AFTER `threshold_cpu_critical`,
+  ADD COLUMN `threshold_ram_critical` DECIMAL(5,2) DEFAULT 95.00 AFTER `threshold_ram_warning`,
+  ADD COLUMN `threshold_disk_warning` DECIMAL(5,2) DEFAULT 85.00 AFTER `threshold_disk_warning`,
+  ADD COLUMN `threshold_disk_critical` DECIMAL(5,2) DEFAULT 95.00 AFTER `threshold_disk_critical`;
+```
+
+### 2. `src/Core/Database.php` — MODIFICAR
+
+Agregar método `fetchCol()` después de `fetchAll()`:
+
+```php
+    public function fetchCol(string $sql, array $params = []): array
+    {
+        return $this->query($sql, $params)->fetchAll(\PDO::FETCH_COLUMN);
+    }
+```
+
+### 3. `src/Models/Server.php` — MODIFICAR
+
+Agregar método `getAccessibleUserIds()` antes de `findByAgentKey()`:
+
+```php
+    public function getAccessibleUserIds(int $serverId): array
+    {
+        $direct = $this->db->fetchCol(
+            'SELECT user_id FROM server_user WHERE server_id = ? AND status = \'active\'',
+            [$serverId]
+        );
+
+        $team = $this->db->fetchCol(
+            'SELECT DISTINCT tu.user_id FROM team_user tu
+             JOIN team_server ts ON tu.team_id = ts.team_id
+             WHERE ts.server_id = ? AND tu.status = \'active\' AND ts.status = \'active\'',
+            [$serverId]
+        );
+
+        $owner = $this->db->fetchCol(
+            'SELECT created_by FROM servers WHERE id = ? AND status = \'active\'',
+            [$serverId]
+        );
+
+        return array_unique(array_merge($direct, $team, $owner));
+    }
+```
+
+### 4. `routes/web.php` — MODIFICAR
+
+Agregar después de línea 67 (`/servers/:id/metrics`):
+
+```php
+$router->post('/servers/:id/thresholds', [ServerController::class, 'saveThresholds'], [AuthMiddleware::class, CSRFMiddleware::class]);
+```
+
+### 5. `src/Controllers/ServerController.php` — MODIFICAR
+
+Agregar en `use` imports (si no está ya) + nuevo método después de `metrics()`:
+
+```php
+    public function saveThresholds(int $id): void
+    {
+        $server = $this->requireServerAccess($id, 'manager');
+        $role = $this->serverModel->getUserRole($id, (int) Session::get('user_id'));
+
+        if ($role !== 'owner') {
+            $this->view->json(['success' => false, 'error' => 'Only the server owner can modify notification thresholds.'], 403);
+        }
+
+        $fields = ['cpu_warning', 'cpu_critical', 'ram_warning', 'ram_critical', 'disk_warning', 'disk_critical'];
+        $data = [];
+        foreach ($fields as $f) {
+            $key = 'threshold_' . $f;
+            $data[$key] = isset($_POST[$f]) ? max(0, min(100, (float) $_POST[$f])) : null;
+        }
+
+        $this->serverModel->update($id, $data);
+        $this->auditService->log('thresholds_updated', 'server', $id, $data);
+        $this->view->json(['success' => true, 'message' => 'Notification thresholds updated.']);
+    }
+```
+
+### 6. `src/Controllers/ApiController.php` — MODIFICAR
+
+En `pushMetrics()`, después de `updateAgentLastSeen()` (línea 435) y antes de `$this->view->json(['success' => true])` (línea 437):
+
+```php
+        // --- Verificar umbrales de notificación ---
+        $checks = [
+            'cpu'  => ['val' => $cpu,  'warn' => $server['threshold_cpu_warning'],  'crit' => $server['threshold_cpu_critical']],
+            'ram'  => ['val' => $ram,  'warn' => $server['threshold_ram_warning'],  'crit' => $server['threshold_ram_critical']],
+            'disk' => ['val' => $disk, 'warn' => $server['threshold_disk_warning'], 'crit' => $server['threshold_disk_critical']],
+        ];
+
+        $breaches = [];
+        foreach ($checks as $metric => $c) {
+            if ($c['crit'] !== null && $c['val'] >= (float) $c['crit']) {
+                $breaches[] = ['metric' => $metric, 'level' => 'critical', 'current' => $c['val'], 'threshold' => $c['crit']];
+            } elseif ($c['warn'] !== null && $c['val'] >= (float) $c['warn']) {
+                $breaches[] = ['metric' => $metric, 'level' => 'warning', 'current' => $c['val'], 'threshold' => $c['warn']];
+            }
+        }
+
+        if (!empty($breaches)) {
+            $userIds = $serverModel->getAccessibleUserIds((int) $server['id']);
+            $notificationModel = new \ServerManager\Models\Notification();
+            foreach ($breaches as $b) {
+                $title = strtoupper($b['metric']) . " {$b['level']} on {$server['name']}";
+                $message = "{$server['name']}: {$b['metric']} at {$b['current']}% ({$b['level']} threshold: {$b['threshold']}%)";
+                foreach ($userIds as $uid) {
+                    $notificationModel->create([
+                        'user_id' => (int) $uid,
+                        'title' => $title,
+                        'message' => $message,
+                        'type' => $b['level'],
+                    ]);
+                }
+            }
+        }
+```
+
+Agregar import de Notification en los `use` del ApiController (si no está):
+```php
+use ServerManager\Models\Notification;
+```
+
+### 7. `views/servers/show.php` — MODIFICAR
+
+**a) Botón en Management Actions** (después de línea 272, antes de `<?php endif; ?>`):
+
+```php
+            <?php if ($server_role === 'owner'): ?>
+            <button class="action-card" onclick="showThresholdModal()">
+                <i class="fas fa-bell"></i>
+                <span>Notification Thresholds</span>
+            </button>
+            <?php endif; ?>
+```
+
+**b) Modal** (después del `#agentConfirmModal`, antes de `<form id="csrfForm">`):
+
+```php
+<div id="thresholdModal" class="modal">
+    <div class="modal-dialog">
+        <div class="modal-header">
+            <h3><i class="fas fa-bell"></i> Notification Thresholds</h3>
+            <button type="button" class="modal-close" onclick="closeThresholdModal()">&times;</button>
+        </div>
+        <div class="modal-body">
+            <p class="text-muted" style="margin-bottom:20px">
+                Notifications are sent to all users with access to this server when the agent reports values
+                exceeding these thresholds. Only the server owner can modify them.
+            </p>
+            <form id="thresholdForm" onsubmit="return false">
+                <div class="table-responsive">
+                    <table class="table">
+                        <thead>
+                            <tr>
+                                <th>Resource</th>
+                                <th>Warning (%)</th>
+                                <th>Critical (%)</th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            <?php foreach (['cpu' => 'CPU', 'ram' => 'RAM', 'disk' => 'Disk'] as $key => $label): ?>
+                            <tr>
+                                <td><strong><?= $label ?></strong></td>
+                                <td>
+                                    <input type="number" name="<?= $key ?>_warning"
+                                           value="<?= htmlspecialchars((string)($server["threshold_{$key}_warning"] ?? 80)) ?>"
+                                           min="0" max="100" step="0.01" class="form-control" style="width:120px">
+                                </td>
+                                <td>
+                                    <input type="number" name="<?= $key ?>_critical"
+                                           value="<?= htmlspecialchars((string)($server["threshold_{$key}_critical"] ?? 95)) ?>"
+                                           min="0" max="100" step="0.01" class="form-control" style="width:120px">
+                                </td>
+                            </tr>
+                            <?php endforeach; ?>
+                        </tbody>
+                    </table>
+                </div>
+            </form>
+        </div>
+        <div class="modal-footer">
+            <button class="btn btn-primary" onclick="saveThresholds()"><i class="fas fa-save"></i> Save</button>
+            <button class="btn btn-secondary" onclick="closeThresholdModal()">Cancel</button>
+        </div>
+    </div>
+</div>
+```
+
+**c) JavaScript** (al final del bloque `<script>`, antes de `</script>`):
+
+```javascript
+function showThresholdModal() {
+    document.getElementById('thresholdModal').style.display = 'flex';
+    document.getElementById('thresholdModal').onclick = function(e) {
+        if (e.target === this) closeThresholdModal();
+    };
+}
+
+function closeThresholdModal() {
+    document.getElementById('thresholdModal').style.display = 'none';
+}
+
+function saveThresholds() {
+    const form = document.getElementById('thresholdForm');
+    const data = new URLSearchParams(new FormData(form));
+    data.append('_csrf_token', getCsrfToken());
+
+    document.querySelector('#thresholdModal .btn-primary').disabled = true;
+
+    fetch('/servers/<?= $server['id'] ?>/thresholds', {
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/x-www-form-urlencoded',
+            'X-CSRF-Token': getCsrfToken(),
+        },
+        body: data.toString(),
+    })
+    .then(r => r.json())
+    .then(d => {
+        showToast(d.success ? 'success' : 'error', d.message ?? d.error);
+        if (d.success) closeThresholdModal();
+    })
+    .catch(e => showToast('error', 'Request failed: ' + e.message))
+    .finally(() => {
+        document.querySelector('#thresholdModal .btn-primary').disabled = false;
+    });
+}
+```
+
+### 8. Ejecutar migración
+
+```bash
+mysql -u root -p"servermanager2024" servermanager < /var/www/servermanager/database/migrations/012_server_thresholds.sql
+```
+
+### 9. Commit y push
+
+```bash
+git add -A && git commit -m "feat: per-server notification thresholds with alert on agent metrics push" && git push origin feat/fcm-apk-v1.8.2
+```
+
+## Variables de umbral en la vista
+
+Las columnas nuevas (`threshold_cpu_warning`, etc.) viajan automáticamente en `$server` porque `findById()` hace `SELECT *`. No requiere cambios en `ServerController::show()`.
diff --git a/android/app/build.gradle.kts b/android/app/build.gradle.kts
index d77d34f..e2b756e 100644
--- a/android/app/build.gradle.kts
+++ b/android/app/build.gradle.kts
@@ -13,8 +13,8 @@ android {
         applicationId = "com.devlab.app"
         minSdk = 26
         targetSdk = 37
-        versionCode = 14
-        versionName = "1.8.2"
+        versionCode = 15
+        versionName = "1.8.3"
     }
 
     buildTypes {
diff --git a/android/app/src/main/java/com/devlab/app/data/model/Notification.kt b/android/app/src/main/java/com/devlab/app/data/model/Notification.kt
index 1258ee0..2a8a564 100644
--- a/android/app/src/main/java/com/devlab/app/data/model/Notification.kt
+++ b/android/app/src/main/java/com/devlab/app/data/model/Notification.kt
@@ -8,4 +8,5 @@ data class AppNotification(
     val type: String = "info",
     val is_read: Int = 0,
     val created_at: String = "",
+    val created_at_timestamp: Long = 0,
 )
diff --git a/android/app/src/main/java/com/devlab/app/service/NotificationForegroundService.kt b/android/app/src/main/java/com/devlab/app/service/NotificationForegroundService.kt
index d4e02b0..5866e36 100644
--- a/android/app/src/main/java/com/devlab/app/service/NotificationForegroundService.kt
+++ b/android/app/src/main/java/com/devlab/app/service/NotificationForegroundService.kt
@@ -99,7 +99,7 @@ class NotificationForegroundService : android.app.Service() {
         if (!response.success) return
 
         val newNotifications = response.data.filter { note ->
-            val noteTime = parseTime(note.created_at)
+            val noteTime = note.created_at_timestamp * 1000L
             noteTime > lastCheck && note.is_read == 0
         }
 
@@ -108,19 +108,7 @@ class NotificationForegroundService : android.app.Service() {
             for (notification in newNotifications) {
                 NotificationHelper.showNotification(this, notification)
             }
-            lastCheck = newNotifications.maxOf { parseTime(it.created_at) }
-        }
-    }
-
-    private fun parseTime(time: String?): Long {
-        if (time == null) return 0L
-        return try {
-            val sdf = java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss", java.util.Locale.US).apply {
-                timeZone = java.util.TimeZone.getTimeZone("UTC")
-            }
-            sdf.parse(time)?.time ?: 0L
-        } catch (_: Exception) {
-            0L
+            lastCheck = newNotifications.maxOf { it.created_at_timestamp * 1000L }
         }
     }
 
diff --git a/android/app/src/main/java/com/devlab/app/ui/notifications/NotificationsScreen.kt b/android/app/src/main/java/com/devlab/app/ui/notifications/NotificationsScreen.kt
index fe743e1..725d03d 100644
--- a/android/app/src/main/java/com/devlab/app/ui/notifications/NotificationsScreen.kt
+++ b/android/app/src/main/java/com/devlab/app/ui/notifications/NotificationsScreen.kt
@@ -219,7 +219,7 @@ private fun NotificationItem(
 
                 Row(verticalAlignment = Alignment.CenterVertically) {
                     Text(
-                        text = formatTime(notification.created_at),
+                        text = formatTime(notification.created_at_timestamp * 1000L),
                         style = MaterialTheme.typography.labelSmall,
                         color = Grey500
                     )
@@ -240,27 +240,17 @@ private fun NotificationItem(
     }
 }
 
-private fun formatTime(timestamp: String?): String {
-    if (timestamp == null) return ""
-    return try {
-        val sdf = SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US).apply {
-            timeZone = TimeZone.getTimeZone("UTC")
+private fun formatTime(millis: Long): String {
+    if (millis <= 0) return ""
+    val now = System.currentTimeMillis()
+    val diff = now - millis
+    return when {
+        diff < 60_000 -> "Just now"
+        diff < 3600_000 -> "${diff / 60_000}m ago"
+        diff < 86400_000 -> "${diff / 3600_000}h ago"
+        else -> {
+            val sdf = SimpleDateFormat("MMM d, HH:mm", Locale.US)
+            sdf.format(Date(millis))
         }
-        val date = sdf.parse(timestamp) ?: return timestamp
-        val now = Calendar.getInstance()
-        val then = Calendar.getInstance().apply {
-            this.time = date
-        }
-
-        val diff = now.timeInMillis - then.timeInMillis
-        when {
-            diff < 60_000 -> "Just now"
-            diff < 3600_000 -> "${diff / 60_000}m ago"
-            diff < 86400_000 -> "${diff / 3600_000}h ago"
-            else -> {
-                val out = SimpleDateFormat("MMM d, HH:mm", Locale.US)
-                out.format(date)
-            }
-        }
-    } catch (_: Exception) { timestamp }
+    }
 }
diff --git a/android/app/src/main/java/com/devlab/app/util/NotificationHelper.kt b/android/app/src/main/java/com/devlab/app/util/NotificationHelper.kt
index ae44543..95cecf0 100644
--- a/android/app/src/main/java/com/devlab/app/util/NotificationHelper.kt
+++ b/android/app/src/main/java/com/devlab/app/util/NotificationHelper.kt
@@ -113,19 +113,8 @@ object NotificationHelper {
                 markReadPendingIntent
             )
             .setAutoCancel(true)
-            .setWhen(parseTime(notification.created_at))
+            .setWhen(if (notification.created_at_timestamp > 0) notification.created_at_timestamp * 1000L else System.currentTimeMillis())
 
         NotificationManagerCompat.from(context).notify(notification.id, built.build())
     }
-
-    private fun parseTime(time: String?): Long {
-        if (time == null) return System.currentTimeMillis()
-        return try {
-            java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss", java.util.Locale.US).apply {
-                timeZone = java.util.TimeZone.getTimeZone("UTC")
-            }.parse(time)?.time ?: System.currentTimeMillis()
-        } catch (_: Exception) {
-            System.currentTimeMillis()
-        }
-    }
 }
diff --git a/android/app/src/main/java/com/devlab/app/util/NotificationPoller.kt b/android/app/src/main/java/com/devlab/app/util/NotificationPoller.kt
index d76bf0b..82e6e6c 100644
--- a/android/app/src/main/java/com/devlab/app/util/NotificationPoller.kt
+++ b/android/app/src/main/java/com/devlab/app/util/NotificationPoller.kt
@@ -3,7 +3,6 @@ package com.devlab.app.util
 import android.content.Context
 import android.util.Log
 import com.devlab.app.data.api.RetrofitClient
-import com.devlab.app.data.model.AppNotification
 import kotlinx.coroutines.*
 
 class NotificationPoller(private val context: Context) {
@@ -56,7 +55,7 @@ class NotificationPoller(private val context: Context) {
                     onCountChanged?.invoke(_unreadCount)
 
                     val newNotes = response.data.filter { note ->
-                        val noteTime = parseTime(note.created_at)
+                        val noteTime = note.created_at_timestamp * 1000L
                         noteTime > lastCheck && note.is_read == 0
                     }
 
@@ -65,20 +64,10 @@ class NotificationPoller(private val context: Context) {
                     }
 
                     if (newNotes.isNotEmpty()) {
-                        lastCheck = newNotes.maxOf { parseTime(it.created_at) }
+                        lastCheck = newNotes.maxOf { it.created_at_timestamp * 1000L }
                     }
                 }
             } catch (_: Exception) { }
         }
     }
-
-    private fun parseTime(time: String?): Long {
-        if (time == null) return 0L
-        return try {
-            val sdf = java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss", java.util.Locale.US).apply {
-                timeZone = java.util.TimeZone.getTimeZone("UTC")
-            }
-            sdf.parse(time)?.time ?: 0L
-        } catch (_: Exception) { 0L }
-    }
 }
diff --git a/android/app/src/main/java/com/devlab/app/worker/NotificationWorker.kt b/android/app/src/main/java/com/devlab/app/worker/NotificationWorker.kt
index 1780a79..8450817 100644
--- a/android/app/src/main/java/com/devlab/app/worker/NotificationWorker.kt
+++ b/android/app/src/main/java/com/devlab/app/worker/NotificationWorker.kt
@@ -4,7 +4,6 @@ import android.content.Context
 import android.util.Log
 import androidx.work.*
 import com.devlab.app.data.api.RetrofitClient
-import com.devlab.app.data.model.AppNotification
 import com.devlab.app.util.NotificationHelper
 import com.devlab.app.util.PreferencesManager
 import kotlinx.coroutines.Dispatchers
@@ -40,7 +39,7 @@ class NotificationWorker(
                     Log.d("NotificationWorker", "Got ${response.data.size} notifications, unread: ${response.unread_count}")
 
                     val newNotifications = response.data.filter { note ->
-                        val noteTime = parseTime(note.created_at)
+                        val noteTime = note.created_at_timestamp * 1000L
                         noteTime > lastCheck && note.is_read == 0
                     }
 
@@ -51,7 +50,7 @@ class NotificationWorker(
                     }
 
                     val maxTime = newNotifications.maxOfOrNull {
-                        parseTime(it.created_at)
+                        it.created_at_timestamp * 1000L
                     } ?: now
 
                     prefs.setLastNotificationCheck(
@@ -71,18 +70,6 @@ class NotificationWorker(
         }
     }
 
-    private fun parseTime(time: String?): Long {
-        if (time == null) return 0L
-        return try {
-            val sdf = java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss", java.util.Locale.US).apply {
-                timeZone = java.util.TimeZone.getTimeZone("UTC")
-            }
-            sdf.parse(time)?.time ?: 0L
-        } catch (_: Exception) {
-            0L
-        }
-    }
-
     companion object {
         private const val WORK_NAME = "notification_check"
 
diff --git a/public/sysadmin.apk b/public/sysadmin.apk
index f7ee935..490a157 100644
Binary files a/public/sysadmin.apk and b/public/sysadmin.apk differ
diff --git a/src/Controllers/ApiController.php b/src/Controllers/ApiController.php
index 71a2579..0121573 100755
--- a/src/Controllers/ApiController.php
+++ b/src/Controllers/ApiController.php
@@ -701,6 +701,7 @@ class ApiController
 
         $data = array_map(function ($n) {
             $n['time_ago'] = time_ago($n['created_at'] ?? '');
+            $n['created_at_timestamp'] = $n['created_at'] ? strtotime($n['created_at']) : 0;
             return $n;
         }, $result['data']);