diff --git a/convex/machines.ts b/convex/machines.ts
index 03dc52c..237af94 100644
--- a/convex/machines.ts
+++ b/convex/machines.ts
@@ -10,6 +10,7 @@ import type { MutationCtx } from "./_generated/server"
 const DEFAULT_TENANT_ID = "tenant-atlas"
 const DEFAULT_TOKEN_TTL_MS = 1000 * 60 * 60 * 24 * 30 // 30 dias
 const ALLOWED_MACHINE_PERSONAS = new Set(["collaborator", "manager"])
+const DEFAULT_OFFLINE_THRESHOLD_MS = 10 * 60 * 1000
 
 type NormalizedIdentifiers = {
   macs: string[]
@@ -48,6 +49,26 @@ function getTokenTtlMs(): number {
   return parsed
 }
 
+function getOfflineThresholdMs(): number {
+  const raw = process.env["MACHINE_OFFLINE_THRESHOLD_MS"]
+  if (!raw) return DEFAULT_OFFLINE_THRESHOLD_MS
+  const parsed = Number(raw)
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    return DEFAULT_OFFLINE_THRESHOLD_MS
+  }
+  return parsed
+}
+
+function getStaleThresholdMs(offlineMs: number): number {
+  const raw = process.env["MACHINE_STALE_THRESHOLD_MS"]
+  if (!raw) return offlineMs * 12
+  const parsed = Number(raw)
+  if (!Number.isFinite(parsed) || parsed <= offlineMs) {
+    return offlineMs * 12
+  }
+  return parsed
+}
+
 function normalizeIdentifiers(macAddresses: string[], serialNumbers: string[]): NormalizedIdentifiers {
   const normalizeMac = (value: string) => value.replace(/[^a-f0-9]/gi, "").toLowerCase()
   const normalizeSerial = (value: string) => value.trim().toLowerCase()
@@ -681,9 +702,24 @@ export const listByTenant = query({
           .collect()
 
         const activeToken = tokens.find((token) => !token.revoked && token.expiresAt > now) ?? null
-        const derivedStatus =
-          machine.status ??
-          (machine.lastHeartbeatAt && now - machine.lastHeartbeatAt <= 5 * 60 * 1000 ? "online" : machine.lastHeartbeatAt ? "offline" : "unknown")
+        const offlineThresholdMs = getOfflineThresholdMs()
+        const staleThresholdMs = getStaleThresholdMs(offlineThresholdMs)
+        const manualStatus = (machine.status ?? "").toLowerCase()
+        let derivedStatus: string
+        if (["maintenance", "blocked"].includes(manualStatus)) {
+          derivedStatus = manualStatus
+        } else if (machine.lastHeartbeatAt) {
+          const age = now - machine.lastHeartbeatAt
+          if (age <= offlineThresholdMs) {
+            derivedStatus = "online"
+          } else if (age <= staleThresholdMs) {
+            derivedStatus = "offline"
+          } else {
+            derivedStatus = "stale"
+          }
+        } else {
+          derivedStatus = machine.status ?? "unknown"
+        }
 
         const metadata = includeMetadata ? (machine.metadata ?? null) : null
 
diff --git a/src/components/admin/machines/admin-machines-overview.tsx b/src/components/admin/machines/admin-machines-overview.tsx
index c0859d2..c1e9442 100644
--- a/src/components/admin/machines/admin-machines-overview.tsx
+++ b/src/components/admin/machines/admin-machines-overview.tsx
@@ -441,9 +441,23 @@ function useMachinesQuery(tenantId: string): MachinesQueryItem[] {
   )
 }
 
+const DEFAULT_OFFLINE_THRESHOLD_MS = 10 * 60 * 1000
+const DEFAULT_STALE_THRESHOLD_MS = DEFAULT_OFFLINE_THRESHOLD_MS * 12
+
+function parseThreshold(raw: string | undefined, fallback: number) {
+  if (!raw) return fallback
+  const parsed = Number(raw)
+  if (!Number.isFinite(parsed) || parsed <= 0) return fallback
+  return parsed
+}
+
+const MACHINE_OFFLINE_THRESHOLD_MS = parseThreshold(process.env.NEXT_PUBLIC_MACHINE_OFFLINE_THRESHOLD_MS, DEFAULT_OFFLINE_THRESHOLD_MS)
+const MACHINE_STALE_THRESHOLD_MS = parseThreshold(process.env.NEXT_PUBLIC_MACHINE_STALE_THRESHOLD_MS, DEFAULT_STALE_THRESHOLD_MS)
+
 const statusLabels: Record<string, string> = {
   online: "Online",
   offline: "Offline",
+  stale: "Sem sinal",
   maintenance: "Manutenção",
   blocked: "Bloqueada",
   unknown: "Desconhecida",
@@ -452,6 +466,7 @@ const statusLabels: Record<string, string> = {
 const statusClasses: Record<string, string> = {
   online: "border-emerald-500/20 bg-emerald-500/15 text-emerald-600",
   offline: "border-rose-500/20 bg-rose-500/15 text-rose-600",
+  stale: "border-slate-400/30 bg-slate-200 text-slate-700",
   maintenance: "border-amber-500/20 bg-amber-500/15 text-amber-600",
   blocked: "border-orange-500/20 bg-orange-500/15 text-orange-600",
   unknown: "border-slate-300 bg-slate-200 text-slate-700",
@@ -512,6 +527,21 @@ function getStatusVariant(status?: string | null) {
   }
 }
 
+function resolveMachineStatus(machine: { status?: string | null; lastHeartbeatAt?: number | null }): string {
+  const manualStatus = (machine.status ?? "").toLowerCase()
+  if (["maintenance", "blocked"].includes(manualStatus)) {
+    return manualStatus
+  }
+  const heartbeat = machine.lastHeartbeatAt
+  if (typeof heartbeat === "number" && Number.isFinite(heartbeat) && heartbeat > 0) {
+    const age = Date.now() - heartbeat
+    if (age <= MACHINE_OFFLINE_THRESHOLD_MS) return "online"
+    if (age <= MACHINE_STALE_THRESHOLD_MS) return "offline"
+    return "stale"
+  }
+  return machine.status ?? "unknown"
+}
+
 function OsIcon({ osName }: { osName?: string | null }) {
   const name = (osName ?? "").toLowerCase()
   if (name.includes("mac") || name.includes("darwin") || name.includes("macos")) return <Apple className="size-4 text-black" />
@@ -546,12 +576,12 @@ export function AdminMachinesOverview({ tenantId }: { tenantId: string }) {
 
   const companyNameOptions = useMemo(() => (companies ?? []).map((c) => c.name).sort((a,b)=>a.localeCompare(b,"pt-BR")), [companies])
 
-  const filteredMachines = useMemo(() => {
+const filteredMachines = useMemo(() => {
     const text = q.trim().toLowerCase()
     return machines.filter((m) => {
       if (onlyAlerts && !(Array.isArray(m.postureAlerts) && m.postureAlerts.length > 0)) return false
       if (statusFilter !== "all") {
-        const s = (m.status ?? "unknown").toLowerCase()
+        const s = resolveMachineStatus(m).toLowerCase()
         if (s !== statusFilter) return false
       }
       if (osFilter !== "all" && (m.osName ?? "").toLowerCase() !== osFilter.toLowerCase()) return false
@@ -592,6 +622,7 @@ export function AdminMachinesOverview({ tenantId }: { tenantId: string }) {
                 <SelectItem value="all">Todos status</SelectItem>
                 <SelectItem value="online">Online</SelectItem>
                 <SelectItem value="offline">Offline</SelectItem>
+                <SelectItem value="stale">Sem sinal</SelectItem>
                 <SelectItem value="unknown">Desconhecido</SelectItem>
               </SelectContent>
             </Select>
@@ -707,6 +738,7 @@ type MachineDetailsProps = {
 export function MachineDetails({ machine }: MachineDetailsProps) {
   const { convexUserId } = useAuth()
   const router = useRouter()
+  const effectiveStatus = machine ? resolveMachineStatus(machine) : "unknown"
   // Company name lookup (by slug)
   const companyQueryArgs = convexUserId && machine ? { tenantId: machine.tenantId, viewerId: convexUserId as Id<"users"> } : undefined
   const companies = useQuery(
@@ -972,7 +1004,7 @@ export function MachineDetails({ machine }: MachineDetailsProps) {
                     </p>
                   ) : null}
                 </div>
-                <MachineStatusBadge status={machine.status} />
+                <MachineStatusBadge status={effectiveStatus} />
               </div>
               {/* ping integrado na badge de status */}
               <div className="flex flex-wrap items-center gap-2">
@@ -1908,7 +1940,8 @@ function MachinesGrid({ machines, companyNameBySlug }: { machines: MachinesQuery
 }
 
 function MachineCard({ machine, companyName }: { machine: MachinesQueryItem; companyName?: string | null }) {
-  const { className } = getStatusVariant(machine.status)
+  const effectiveStatus = resolveMachineStatus(machine)
+  const { className } = getStatusVariant(effectiveStatus)
   const lastHeartbeat = machine.lastHeartbeatAt ? new Date(machine.lastHeartbeatAt) : null
   type AgentMetrics = {
     memoryUsedBytes?: number
@@ -1962,7 +1995,7 @@ function MachineCard({ machine, companyName }: { machine: MachinesQueryItem; com
                     : "bg-slate-400"
             )}
           />
-          {String(machine.status ?? "").toLowerCase() === "online" ? (
+          {effectiveStatus === "online" ? (
             <span className="absolute left-1/2 top-1/2 -z-10 size-4 -translate-x-1/2 -translate-y-1/2 rounded-full bg-emerald-400/30 animate-ping" />
           ) : null}
         </div>