austinywang · Sep 15, 2026 · Sep 15, 2026 · Sep 15, 2026 · Sep 15, 2026 · Sep 15, 2026
diff --git a/Resources/Localizable.xcstrings b/Resources/Localizable.xcstrings
diff --git a/Sources/App/AggregateMemoryPressureResponder.swift b/Sources/App/AggregateMemoryPressureResponder.swift
@@ -1,6 +1,6 @@
 import Foundation
 
-/// Warns about complete aggregate metrics and schedules only safe idle-agent
+/// Responds to complete aggregate metrics by scheduling only safe idle-agent
 /// hibernation while that same aggregate pressure remains observable.
 @MainActor
 final class AggregateMemoryPressureResponder: MemoryPressureResponder {
@@ -11,16 +11,13 @@ final class AggregateMemoryPressureResponder: MemoryPressureResponder {
 
     private let controller: AgentHibernationController
     private let isAggregatePressureActive: @MainActor () -> Bool
-    private let onAggregatePressureWarning: @MainActor (MemoryPressureSnapshot) -> Void
 
     init(
         controller: AgentHibernationController,
-        isAggregatePressureActive: @escaping @MainActor () -> Bool,
-        onAggregatePressureWarning: @escaping @MainActor (MemoryPressureSnapshot) -> Void = { _ in }
+        isAggregatePressureActive: @escaping @MainActor () -> Bool
     ) {
         self.controller = controller
         self.isAggregatePressureActive = isAggregatePressureActive
-        self.onAggregatePressureWarning = onAggregatePressureWarning
     }
 
     func shedMemory(for snapshot: MemoryPressureSnapshot) -> MemoryPressureShedResult {
@@ -33,7 +30,6 @@ final class AggregateMemoryPressureResponder: MemoryPressureResponder {
             )
         }
 
-        onAggregatePressureWarning(snapshot)
         let responderID = memoryPressureResponderID
         let severity = aggregate.severity
         let didSchedule = controller.reclaimIdleAgentsForMemoryPressure(

diff --git a/Sources/App/MemoryPressureMonitor.swift b/Sources/App/MemoryPressureMonitor.swift
@@ -21,9 +21,6 @@ final class MemoryPressureMonitor {
     private(set) var physicalFootprintBytes: UInt64?
     private(set) var aggregateMemoryPressure: MemoryPressureAggregateSnapshot?
 
-    @ObservationIgnored
-    var onPersistentCriticalPressure: (@MainActor (MemoryPressureSnapshot) -> Void)?
-
     @ObservationIgnored
     var onAggregatePressureCleared: (@MainActor () -> Void)?
 
@@ -267,7 +264,7 @@ final class MemoryPressureMonitor {
         if let aggregateMemoryPressure,
            aggregateMemoryPressure.isActionable {
             // Aggregate pressure gets its own dispatch lane. This preserves
-            // the visible warning + idle-agent hibernation contract without
+            // the idle-agent hibernation contract without
             // making aggregate thresholds release unrelated hidden resources.
             let aggregateSnapshot = MemoryPressureSnapshot(
                 severity: aggregateMemoryPressure.severity,
@@ -278,7 +275,7 @@ final class MemoryPressureMonitor {
             registry.dispatch(aggregateSnapshot, signal: .aggregate)
         }
         if evaluation.didBecomePersistentCritical {
-            onPersistentCriticalPressure?(evaluation.snapshot)
+            Self.logger.notice("memoryPressure.persistentCritical")
         }
     }
 

diff --git a/Sources/App/MemoryPressureResponderRegistry.swift b/Sources/App/MemoryPressureResponderRegistry.swift
@@ -12,7 +12,7 @@ final class MemoryPressureResponderRegistry {
         category: "MemoryPressure"
     )
 
-    private var respondersByID: [String: any MemoryPressureResponder] = [:]
+    var respondersByID: [String: any MemoryPressureResponder] = [:]
 
     func register(_ responder: any MemoryPressureResponder) {
         respondersByID[responder.memoryPressureResponderID] = responder

diff --git a/Sources/App/MemoryPressureStateTracker.swift b/Sources/App/MemoryPressureStateTracker.swift
@@ -28,7 +28,7 @@ struct MemoryPressureStateTracker: Sendable {
         )
         // Aggregate pressure is a distinct signal lane. Keep the legacy
         // system/footprint severity here so aggregate pressure cannot trigger
-        // unrelated resource shedding or the persistent-critical callback.
+        // unrelated resource shedding or persistent-critical diagnostics.
         // The monitor dispatches the aggregate snapshot explicitly to the
         // aggregate responder after this evaluation.
         let nextSeverity = max(systemSeverity ?? .normal, footprintSeverity)

diff --git a/Sources/AppDelegate+PaneMemoryGuardrail.swift b/Sources/AppDelegate+PaneMemoryGuardrail.swift
@@ -5,7 +5,8 @@ extension AppDelegate {
     /// memory-pressure monitor. The pane guardrail keeps its existing
     /// process-tree accounting timer; global pressure is handled through
     /// responder registration. Aggregate pressure is intentionally isolated to
-    /// its warning plus idle-agent-hibernation responder.
+    /// its idle-agent-hibernation responder. Resource diagnostics never enter
+    /// the user notification pipeline.
     func startPaneMemoryGuardrailIfNeeded() {
         let guardrail = PaneMemoryGuardrail.shared
         guardrail.paneProvider = { [weak self] in
@@ -23,7 +24,7 @@ extension AppDelegate {
         }
     }
 
-    private func startMemoryPressureMonitorIfNeeded() {
+    func startMemoryPressureMonitorIfNeeded() {
         let monitor = MemoryPressureMonitor.shared
         monitor.registry.register(
             RendererRealizationMemoryPressureResponder(
@@ -41,9 +42,6 @@ extension AppDelegate {
                 isAggregatePressureActive: { [weak monitor] in
                     guard let aggregate = monitor?.aggregateMemoryPressure else { return false }
                     return aggregate.isActionable && aggregate.severity >= .warning
-                },
-                onAggregatePressureWarning: { [weak self] _ in
-                    self?.postAggregateMemoryPressureWarning()
                 }
             )
         )
@@ -60,71 +58,12 @@ extension AppDelegate {
                 NotificationCacheMemoryPressureResponder(store: notificationStore)
             )
         }
-        monitor.onPersistentCriticalPressure = { [weak self] snapshot in
-            self?.postPersistentCriticalMemoryPressureWarning(snapshot: snapshot)
-        }
         monitor.onAggregatePressureCleared = {
             AgentHibernationController.shared.clearAggregateMemoryPressureConfirmations()
         }
         monitor.start()
     }
 
-    private func postAggregateMemoryPressureWarning() {
-        guard let notificationStore else { return }
-        let managers = paneMemoryGuardrailTabManagers()
-        guard let tabId = tabManager?.selectedTabId
-            ?? managers.lazy.compactMap({ $0.selectedTabId }).first
-            ?? managers.lazy.compactMap({ $0.tabs.first?.id }).first
-        else { return }
-
-        notificationStore.addNotification(
-            tabId: tabId,
-            surfaceId: nil,
-            title: String(
-                localized: "memoryPressure.aggregate.title",
-                defaultValue: "cmux is using substantial aggregate memory"
-            ),
-            subtitle: String(
-                localized: "memoryPressure.aggregate.subtitle",
-                defaultValue: "Idle agent surfaces may be hibernated"
-            ),
-            body: String(
-                localized: "memoryPressure.aggregate.body",
-                defaultValue: "macOS reports memory pressure across cmux and its child processes. Only hidden, idle agent surfaces are considered after a confirmation window; active or visible work is left alone."
-            ),
-            cooldownKey: "memory-pressure-aggregate",
-            cooldownInterval: 300
-        )
-    }
-
-    private func postPersistentCriticalMemoryPressureWarning(snapshot: MemoryPressureSnapshot) {
-        guard let notificationStore else { return }
-        let managers = paneMemoryGuardrailTabManagers()
-        guard let tabId = tabManager?.selectedTabId
-            ?? managers.compactMap({ $0.selectedTabId }).first
-            ?? managers.flatMap({ $0.tabs }).first?.id
-        else { return }
-
-        notificationStore.addNotification(
-            tabId: tabId,
-            surfaceId: nil,
-            title: String(
-                localized: "memoryPressure.critical.title",
-                defaultValue: "cmux is under critical memory pressure"
-            ),
-            subtitle: String(
-                localized: "memoryPressure.critical.subtitle",
-                defaultValue: "Hidden renderers and browsers were released"
-            ),
-            body: String(
-                localized: "memoryPressure.critical.body",
-                defaultValue: "macOS is reporting sustained critical memory pressure. cmux has shed hidden resources; close idle workspaces or restart cmux if pressure continues."
-            ),
-            cooldownKey: "memory-pressure-critical",
-            cooldownInterval: 300
-        )
-    }
-
     private func paneMemoryGuardrailTabManagers() -> [TabManager] {
         var managers: [TabManager] = []
         var seen: Set<ObjectIdentifier> = []

diff --git a/cmux.xcodeproj/project.pbxproj b/cmux.xcodeproj/project.pbxproj
@@ -2045,6 +2045,7 @@
 		7490C0037490C0037490C003 /* MemoryPressureFootprintThresholds.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490D0037490D0037490D003 /* MemoryPressureFootprintThresholds.swift */; };
 		7490C0047490C0047490C004 /* MemoryPressureMonitor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490D0047490D0047490D004 /* MemoryPressureMonitor.swift */; };
 		7490A0017490A0017490A001 /* MemoryPressureMonitorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490A0027490A0027490A002 /* MemoryPressureMonitorTests.swift */; };
+		126510000000000000000001 /* MemoryPressureNotificationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 126510000000000000000002 /* MemoryPressureNotificationTests.swift */; };
 		7490C0057490C0057490C005 /* MemoryPressureResponder.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490D0057490D0057490D005 /* MemoryPressureResponder.swift */; };
 		7490C0067490C0067490C006 /* MemoryPressureResponderRegistry.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490D0067490D0067490D006 /* MemoryPressureResponderRegistry.swift */; };
 		7490C0097490C0097490C009 /* MemoryPressureSeverity.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7490D0097490D0097490D009 /* MemoryPressureSeverity.swift */; };
@@ -5791,6 +5792,7 @@
 		7490D0037490D0037490D003 /* MemoryPressureFootprintThresholds.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App/MemoryPressureFootprintThresholds.swift; sourceTree = "<group>"; };
 		7490D0047490D0047490D004 /* MemoryPressureMonitor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App/MemoryPressureMonitor.swift; sourceTree = "<group>"; };
 		7490A0027490A0027490A002 /* MemoryPressureMonitorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryPressureMonitorTests.swift; sourceTree = "<group>"; };
+		126510000000000000000002 /* MemoryPressureNotificationTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryPressureNotificationTests.swift; sourceTree = "<group>"; };
 		7490D0057490D0057490D005 /* MemoryPressureResponder.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App/MemoryPressureResponder.swift; sourceTree = "<group>"; };
 		7490D0067490D0067490D006 /* MemoryPressureResponderRegistry.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App/MemoryPressureResponderRegistry.swift; sourceTree = "<group>"; };
 		7490D0097490D0097490D009 /* MemoryPressureSeverity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = App/MemoryPressureSeverity.swift; sourceTree = "<group>"; };
@@ -10918,6 +10920,7 @@
 					A7206B020000000000000001 /* SystemAppearanceObserverTests.swift */,
 					6313FACE0000000000000001 /* PaneMemoryGuardrailTests.swift */,
 					7490A0027490A0027490A002 /* MemoryPressureMonitorTests.swift */,
+					126510000000000000000002 /* MemoryPressureNotificationTests.swift */,
 					C0DE10510000000000000002 /* MobileHostServiceSettingsTests.swift */,
 				46438523E2764A18B697CC4B /* ManagedPolicySettingsImportTests.swift */,
 				F0128D58A0B34955A144D263 /* ManagedPolicyRemoteControlTests.swift */,
@@ -15258,6 +15261,7 @@
 				D6069002D6069002D6069002 /* MarkdownMermaidZoomTests.swift in Sources */,
 				D3664002D3664002D3664002 /* MarkdownPanelTests.swift in Sources */,
 					7490A0017490A0017490A001 /* MemoryPressureMonitorTests.swift in Sources */,
+					126510000000000000000001 /* MemoryPressureNotificationTests.swift in Sources */,
 				606500010000000000000001 /* MenuBarOnlyActivationPolicyTests.swift in Sources */,
 					C0DE70520000000000000002 /* MenuBarProfilingLauncherTests.swift in Sources */,
 				6AA2F2E8BEB19ED6B8E125DB /* MobileHostAuthorizationTests.swift in Sources */,