diff --git a/AeroSpace.xcodeproj/project.pbxproj b/AeroSpace.xcodeproj/project.pbxproj
index 2143856f..bf49d3f6 100644
--- a/AeroSpace.xcodeproj/project.pbxproj
+++ b/AeroSpace.xcodeproj/project.pbxproj
@@ -15,6 +15,7 @@
 		1311398A83B998908773C54D /* FocusCommandTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0EAADE8D2FB5D05FA5456B0 /* FocusCommandTest.swift */; };
 		1C46EBB55D401C0D1AFD50F0 /* CollectionEx.swift in Sources */ = {isa = PBXBuildFile; fileRef = 51CE37C1B8D858C81A396F40 /* CollectionEx.swift */; };
 		1FD8762CC7C132D01D4B3090 /* cliUtil.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5EB6F0170422A7606D89BCF0 /* cliUtil.swift */; };
+		21D0512B48E0E3C28F8CA42A /* parseOnWindowDetected.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0A9DFF8980BB3F90A3793BE9 /* parseOnWindowDetected.swift */; };
 		22175400298B985658E774EE /* ResizeCommandTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7ACD4E9C6C0C08F1B0622C57 /* ResizeCommandTest.swift */; };
 		238EF26CAAADD1FE11312D7C /* default-config.toml in Resources */ = {isa = PBXBuildFile; fileRef = 8FE45A887100EB70912B07F0 /* default-config.toml */; };
 		2821C1C7AAEF4C290633EA72 /* FullscreenCommand.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9ECC990B6C2D66D343216A12 /* FullscreenCommand.swift */; };
@@ -115,6 +116,7 @@
 		07A342893BEB5525BA1F8B74 /* ResultEx.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ResultEx.swift; sourceTree = "<group>"; };
 		083785CBAE36EC57F5F51BC8 /* main.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = main.swift; sourceTree = "<group>"; };
 		09685297933511208058F7CF /* AeroSpace.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = AeroSpace.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		0A9DFF8980BB3F90A3793BE9 /* parseOnWindowDetected.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = parseOnWindowDetected.swift; sourceTree = "<group>"; };
 		0AEE5470AF418906B180A593 /* mouse.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = mouse.swift; sourceTree = "<group>"; };
 		0D36D0F8EEB30A7BABC42343 /* LazySequenceProtocolEx.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LazySequenceProtocolEx.swift; sourceTree = "<group>"; };
 		0D9301F99737BE4888DBC2A3 /* FocusedWorkspaceSourceOfTruth.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FocusedWorkspaceSourceOfTruth.swift; sourceTree = "<group>"; };
@@ -308,6 +310,7 @@
 				9752080BBA547C2A0EF076F0 /* Config.swift */,
 				1C0D40CBD65704BA9595C2FA /* keysMap.swift */,
 				67DBAF4ECF8A0B931FC34EAD /* parseConfig.swift */,
+				0A9DFF8980BB3F90A3793BE9 /* parseOnWindowDetected.swift */,
 				9164C9401F7DDCACE9278DA4 /* startAtLogin.swift */,
 			);
 			path = config;
@@ -656,6 +659,7 @@
 				B19980B36D066FD4947D2F92 /* normalizeContainers.swift in Sources */,
 				A5BFF75CF8021A585BC1F9D5 /* parseCommand.swift in Sources */,
 				A0765C31043BCFB0420BF1C9 /* parseConfig.swift in Sources */,
+				21D0512B48E0E3C28F8CA42A /* parseOnWindowDetected.swift in Sources */,
 				B3702BB393A9B03CCAE4C60E /* refresh.swift in Sources */,
 				8086A22EDCDC4C906C337D0B /* resizeWithMouse.swift in Sources */,
 				43E3628E37D2439B820FFC82 /* server.swift in Sources */,
@@ -750,7 +754,7 @@
 				MACOSX_DEPLOYMENT_TARGET = 13.0;
 				PRODUCT_NAME = "aerospace-debug";
 				SDKROOT = macosx;
-				SWIFT_VERSION = 5.8;
+				SWIFT_VERSION = 5.9;
 			};
 			name = Debug;
 		};
@@ -770,7 +774,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = bobko.aerospace.cli;
 				PRODUCT_NAME = aerospace;
 				SDKROOT = macosx;
-				SWIFT_VERSION = 5.8;
+				SWIFT_VERSION = 5.9;
 			};
 			name = Release;
 		};
@@ -794,7 +798,7 @@
 				PRODUCT_NAME = "AeroSpace-Debug";
 				SDKROOT = macosx;
 				SWIFT_OBJC_BRIDGING_HEADER = "src/Bridged-Header.h";
-				SWIFT_VERSION = 5.8;
+				SWIFT_VERSION = 5.9;
 			};
 			name = Debug;
 		};
@@ -865,6 +869,7 @@
 					"@loader_path/../Frameworks",
 				);
 				SDKROOT = macosx;
+				SWIFT_VERSION = 5.9;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/AeroSpace-Debug.app/Contents/MacOS/AeroSpace-Debug";
 			};
 			name = Release;
@@ -881,6 +886,7 @@
 					"@loader_path/../Frameworks",
 				);
 				SDKROOT = macosx;
+				SWIFT_VERSION = 5.9;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/AeroSpace-Debug.app/Contents/MacOS/AeroSpace-Debug";
 			};
 			name = Debug;
@@ -908,7 +914,7 @@
 				PRODUCT_NAME = AeroSpace;
 				SDKROOT = macosx;
 				SWIFT_OBJC_BRIDGING_HEADER = "src/Bridged-Header.h";
-				SWIFT_VERSION = 5.8;
+				SWIFT_VERSION = 5.9;
 			};
 			name = Release;
 		};
diff --git a/config-examples/default-config.toml b/config-examples/default-config.toml
index 80c79bea..c57ed9af 100644
--- a/config-examples/default-config.toml
+++ b/config-examples/default-config.toml
@@ -18,7 +18,7 @@ indent-for-nested-containers-with-the-same-orientation = 30
 # Start AeroSpace at login
 start-at-login = false
 
-# Normalization. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#normalization
+# Normalizations. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#normalization
 enable-normalization-flatten-containers = true
 enable-normalization-opposite-orientation-for-nested-containers = true
 
@@ -50,7 +50,12 @@ default-root-container-orientation = 'auto'
 # workspace_name_5 = '^built-in retina display$'  # Case insensitive regex match
 # workspace_name_6 = ['secondary', 'dell']        # You can specify multiple patterns. The first matching pattern will be used
 
-# It's a declaration of 'main' binding mode. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
+# See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#on-window-detected-callback
+# [[on-window-detected]]
+# appId = 'com.apple.systempreferences'                  # Application ID match
+# run = ['move-node-to-workspace S', 'layout floating']  # The callback itself
+
+# 'main' binding mode declaration. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
 # 'main' binding mode must be always presented
 [mode.main.binding]
 
@@ -158,20 +163,18 @@ alt-shift-tab = 'move-workspace-to-monitor next'
 alt-shift-semicolon = 'mode service'
 alt-shift-slash = 'mode join'
 
-# It's a declaration of binding mode. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
+# 'service' binding mode declaration. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
 [mode.service.binding]
 r = ['flatten-workspace-tree', 'mode main'] # reset layout
 #s = ['layout sticky tiling', 'mode main'] # sticky is not yet supported https://github.com/nikitabobko/AeroSpace/issues/2
 f = ['layout floating tiling', 'mode main'] # Toggle between floating and tiling layout
 backspace = ['close-all-windows-but-current', 'mode main']
 esc = 'mode main'
-enter = 'mode main'
 
-# It's a declaration of binding mode. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
+# 'join' binding mode declaration. See: https://github.com/nikitabobko/AeroSpace/blob/main/docs/guide.md#bindings-modes
 [mode.join.binding]
 alt-shift-h = ['join-with left', 'mode main']
 alt-shift-j = ['join-with down', 'mode main']
 alt-shift-k = ['join-with up', 'mode main']
 alt-shift-l = ['join-with right', 'mode main']
 esc = ['reload-config', 'mode main']
-enter = 'mode main'
diff --git a/docs/cli-commands.md b/docs/cli-commands.md
index b765da10..b5348673 100644
--- a/docs/cli-commands.md
+++ b/docs/cli-commands.md
@@ -12,8 +12,6 @@ In addition to [regular commands](./commands.md), the CLI provides commands list
 list-apps
 ```
 
-- Available since: 0.6.0-Beta
-
 Prints the list of ordinary applications that appears in the Dock and may have a user interface.
 
 Output format is the table with the following colums:
@@ -31,6 +29,9 @@ Output example:
 
 The command is useful to inspect list of applications to compose filter for [`on-window-detected`](./guide.md#on-window-detected-callback)
 
+- Available since: 0.6.0-Beta
+- The command doesn't have arguments
+
 ## version
 
 ```
@@ -39,8 +40,7 @@ version
 -v
 ```
 
-- Available since: 0.4.0-Beta
-
 Prints the version and commit hash to stdout
 
-This command doesn't have any arguments
+- Available since: 0.4.0-Beta
+- The command doesn't have arguments
diff --git a/docs/commands.md b/docs/commands.md
index e6ceb141..5de890ce 100644
--- a/docs/commands.md
+++ b/docs/commands.md
@@ -28,7 +28,9 @@ Commands listed in this file can be used in the config and CLI
 close-all-windows-but-current
 ```
 
-On the focused workspace, closes all windows but current. This command doesn't have any arguments.
+On the focused workspace, closes all windows but current.
+
+- The command doesn't have arguments.
 
 ## enable
 
@@ -84,7 +86,7 @@ Flattens [the tree](./guide.md#tree) of currently focused workspace.
 
 The command is useful when you messed up with your layout, and it's easier to "reset" it and start again.
 
-- This command doesn't have any arguments.
+- The command doesn't have arguments.
 
 ## focus
 
@@ -115,8 +117,8 @@ Toggles the fullscreen mode for the currently focused window.
 Switching to a different window within the same workspace while the current focused window is in fullscreen mode results
 in the fullscreen window exiting fullscreen mode.
 
-- This command doesn't have any arguments.
 - Available since: 0.3.0-Beta
+- The command doesn't have arguments.
 
 ## join-with
 
@@ -291,7 +293,7 @@ reload-config
 
 Reloads currently active config.
 
-- This command doesn't have any arguments.
+- The command doesn't have arguments.
 
 ## resize
 
@@ -345,7 +347,7 @@ workspace-back-and-forth
 
 Switches between currently active workspace and previously active workspace back and forth.
 
-- This command doesn't have any arguments.
+- The command doesn't have arguments.
 
 ## workspace
 
diff --git a/docs/guide.md b/docs/guide.md
index 97759ebd..c802bf8f 100644
--- a/docs/guide.md
+++ b/docs/guide.md
@@ -12,6 +12,7 @@
 - [Emulation of virtual workspaces](#emulation-of-virtual-workspaces)
   - [A note on mission control](#a-note-on-mission-control)
   - [A note on 'Displays have separate Spaces'](#a-note-on-displays-have-separate-spaces)
+- ['on-window-detected' callback](#on-window-detected-callback)
 - [Multiple monitors](#multiple-monitors)
   - [Assign workspaces to monitors](#assign-workspaces-to-monitors)
 
@@ -225,6 +226,55 @@ Overview of 'Displays have separate Spaces'
 | Is it possible for window to span across several monitors? | 😔 No                                      | 😊 Yes                                      |
 | macOS status bar ...                                       | ... is displayed on both monitors          | ... is displayed only on main monitor       |
 
+## 'on-window-detected' callback
+
+- Available since: 0.6.0-Beta
+
+You can use `on-window-detected` callback to run commands that run on new window detection.
+
+```toml
+[[on-window-detected]]
+app-id = 'com.apple.systempreferences'                # Application ID match
+app-name-regex-substring = 'settings'                 # Case insensetive regex substring
+window-title-regex-substring = 'substring'      # Case insensetive regex substring
+run = ['move-node-to-workspace S', 'layout floating'] # The callback itself
+```
+
+> [!IMPORTANT]
+> Some windows initialize their title after window appears. `window-title-regex-substring` may not work as expected 
+> for such windows
+
+Examples of automations:
+
+- Assign apps on particular workspaces
+  ```toml
+  [[on-window-detected]]
+  app-id = 'org.alacritty'
+  run = 'move-node-to-workspace T' # mnemonics 'Terminal'
+  
+  [[on-window-detected]]
+  app-id = 'com.google.Chrome'
+  run = 'move-node-to-workspace W' # mnemonics 'Web browser'
+
+  [[on-window-detected]]
+  app-id = 'com.jetbrains.intellij'
+  run = 'move-node-to-workspace I' # mnemonics 'Ide'
+  ```
+- Make all windows float by default
+  ```toml
+  [[on-window-detected]]
+  run = 'layout floating'
+  ```
+- Float 'System Settings' app
+  ```toml
+  [[on-window-detected]]
+  app-id = 'com.apple.systempreferences'
+  run = 'layout floating'
+  ```
+
+See the [list of popular application IDs](./popular-apps-ids.md), or you can
+use [`aerospace list-apps`](./cli-commands.md#list-apps) CLI command to get IDs of running applications
+
 ## Multiple monitors
 
 - The pool of workspaces is shared between monitors
@@ -252,6 +302,8 @@ monitor often makes sense.
 
 ### Assign workspaces to monitors
 
+- Available since: 0.5.0-Beta
+
 You can use `workspace-to-monitor-force-assignment` syntax to assign workspaces to always appear on particular monitors
 
 ```toml
@@ -273,5 +325,3 @@ Supported monitor patterns:
 You can specify multiple patterns as an array. The first matching pattern will be used
 
 [`move-workspace-to-monitor`](./commands.md#move-workspace-to-monitor) command has no effect for workspaces that have monitor assignment
-
-- Available since: 0.5.0-Beta
diff --git a/docs/popular-apps-ids.md b/docs/popular-apps-ids.md
new file mode 100644
index 00000000..c8fbfe0f
--- /dev/null
+++ b/docs/popular-apps-ids.md
@@ -0,0 +1,86 @@
+# List of popular and built-in applications IDs
+
+The list is useful to compose custom [`on-window-detected` callback](./guide.md#on-window-detected-callback)
+
+|Application name|Application ID|
+|----------------|--------------|
+|1Password|`com.1password.1password`|
+|Activity Monitor|`com.apple.ActivityMonitor`|
+|AirPort Utility|`com.apple.airport.airportutility`|
+|Alacritty|`org.alacritty`|
+|Android Studio|`com.google.android.studio`|
+|App Store|`com.apple.AppStore`|
+|AppCode|`com.jetbrains.AppCode`|
+|Arc Browser|`company.thebrowser.Browser`|
+|Audio MIDI Setup|`com.apple.audio.AudioMIDISetup`|
+|Automator|`com.apple.Automator`|
+|Battle.net|`net.battle.app`|
+|Books|`com.apple.iBooksX`|
+|CLion|`com.jetbrains.CLion`|
+|Calculator|`com.apple.calculator`|
+|Calendar|`com.apple.iCal`|
+|Chess|`com.apple.Chess`|
+|Clock|`com.apple.clock`|
+|ColorSync Utility|`com.apple.ColorSyncUtility`|
+|Console|`com.apple.Console`|
+|Contacts|`com.apple.AddressBook`|
+|Dictionary|`com.apple.Dictionary`|
+|Disk Utility|`com.apple.DiskUtility`|
+|Docker|`com.docker.docker`|
+|FaceTime|`com.apple.FaceTime`|
+|Find My|`com.apple.findmy`|
+|Finder|`com.apple.finder`|
+|Firefox|`org.mozilla.firefox`|
+|Freeform|`com.apple.freeform`|
+|GIMP|`org.gimp.gimp-2.10`|
+|Google Chrome|`com.google.Chrome`|
+|Grapher|`com.apple.grapher`|
+|Home|`com.apple.Home`|
+|Inkscape|`org.inkscape.Inkscape`|
+|IntelliJ IDEA Community|`com.jetbrains.intellij.ce`|
+|IntelliJ IDEA Ultimate|`com.jetbrains.intellij`|
+|Karabiner-Elements|`org.pqrs.Karabiner-Elements.Settings`|
+|Keychain Access|`com.apple.keychainaccess`|
+|Keynote|`com.apple.iWork.Keynote`|
+|Kitty|`net.kovidgoyal.kitty`|
+|Mail|`com.apple.mail`|
+|Maps|`com.apple.Maps`|
+|Marta|`org.yanex.marta`|
+|Messages|`com.apple.MobileSMS`|
+|Music|`com.apple.Music`|
+|Notes|`com.apple.Notes`|
+|Pages|`com.apple.iWork.Pages`|
+|Photo Booth|`com.apple.PhotoBooth`|
+|Photos|`com.apple.Photos`|
+|Podcasts|`com.apple.podcasts`|
+|Preview|`com.apple.Preview`|
+|PyCharm Community|`com.jetbrains.pycharm.ce`|
+|PyCharm Professional|`com.jetbrains.pycharm`|
+|QuickTime Player|`com.apple.QuickTimePlayerX`|
+|Reminders|`com.apple.reminders`|
+|Safari|`com.apple.Safari`|
+|Shortcuts|`com.apple.shortcuts`|
+|Slack|`com.tinyspeck.slackmacgap`|
+|Spotify|`com.spotify.client`|
+|Steam|`com.valvesoftware.steam`|
+|Stocks|`com.apple.stocks`|
+|Sublime Merge|`com.sublimemerge`|
+|Sublime Text|`com.sublimetext.4`|
+|System Settings|`com.apple.systempreferences`|
+|TV|`com.apple.TV`|
+|Telegram|`com.tdesktop.Telegram`|
+|Terminal|`com.apple.Terminal`|
+|TextEdit|`com.apple.TextEdit`|
+|Thunderbird|`org.mozilla.thunderbird`|
+|Time Machine|`com.apple.backup.launcher`|
+|Tor Browser|`org.torproject.torbrowser`|
+|Transmission|`org.m0k.transmission`|
+|VLC|`org.videolan.vlc`|
+|Visual Studio Code|`com.microsoft.VSCode`|
+|VoiceMemos|`com.apple.VoiceMemos`|
+|VoiceOver Utility|`com.apple.VoiceOverUtility`|
+|Weather|`com.apple.weather`|
+|Xcode|`com.apple.dt.Xcode`|
+|iMovie|`com.apple.iMovieApp`|
+|iTerm2|`com.googlecode.iterm2`|
+|kdenlive|`org.kde.Kdenlive`|
diff --git a/project.yml b/project.yml
index f1d76f3d..824a33c1 100644
--- a/project.yml
+++ b/project.yml
@@ -25,7 +25,7 @@ targets:
       - package: Socket
     settings:
       base:
-        SWIFT_VERSION: 5.8
+        SWIFT_VERSION: 5.9
         CODE_SIGN_STYLE: Automatic
         GENERATE_INFOPLIST_FILE: YES
         MARKETING_VERSION: 0.6.0-Beta # GENERATED BY generate.sh
@@ -62,7 +62,7 @@ targets:
       - target: AeroSpace
     settings:
       base:
-        # SWIFT_VERSION: 5.8
+        SWIFT_VERSION: 5.9
         TEST_HOST: "$(BUILT_PRODUCTS_DIR)/AeroSpace-Debug.app/Contents/MacOS/AeroSpace-Debug"
         GENERATE_INFOPLIST_FILE: YES
   AeroSpace-cli:
@@ -74,7 +74,7 @@ targets:
       - package: Socket
     settings:
       base:
-        SWIFT_VERSION: 5.8
+        SWIFT_VERSION: 5.9
         CODE_SIGN_STYLE: Automatic
       configs:
         release:
diff --git a/src/command/Command.swift b/src/command/Command.swift
index 281737c6..bed3bf04 100644
--- a/src/command/Command.swift
+++ b/src/command/Command.swift
@@ -14,16 +14,20 @@ extension Command {
         check(Thread.current.isMainThread)
         await [self].run()
     }
+
+    var isExec: Bool { self is ExecAndWaitCommand || self is ExecAndForgetCommand }
 }
 
 extension [Command] {
     @MainActor
-    func run() async {
+    func run(_ initState: FocusState? = nil) async {
         check(Thread.current.isMainThread)
         let commands = TrayMenuModel.shared.isEnabled ? self : (singleOrNil() as? EnableCommand).asList()
         refresh(layout: false)
         var state: FocusState
-        if let window = focusedWindowOrEffectivelyFocused {
+        if let initState {
+            state = initState
+        } else if let window = focusedWindowOrEffectivelyFocused {
             state = .windowIsFocused(window)
         } else {
             state = .emptyWorkspaceIsFocused(focusedWorkspaceName)
diff --git a/src/command/cli/ListAppsCommand.swift b/src/command/cli/ListAppsCommand.swift
new file mode 100644
index 00000000..b39aa1a9
--- /dev/null
+++ b/src/command/cli/ListAppsCommand.swift
@@ -0,0 +1,47 @@
+struct ListAppsCommand: QueryCommand {
+    @MainActor
+    func run() -> String {
+        check(Thread.current.isMainThread)
+        return apps
+            .map { app in
+                let pid = String(app.pid)
+                let appId = app.id ?? "NULL"
+                let name = app.name ?? "NULL"
+                return [pid, appId, name]
+            }
+            .paddingTable
+    }
+}
+
+extension [[String]] {
+    var paddingTable: String {
+        let pads: [Int] = transposed.map { column in column.map { $0.count }.max()! }
+        return self
+            .map { (row: [String]) in
+                zip(row, pads)
+                    .map { (elem: String, pad: Int) in
+                        elem.padding(toLength: pad, withPad: " ", startingAt: 0)
+                    }
+                    .joined(separator: " ")
+            }
+            .joined(separator: "\n")
+    }
+}
+
+private extension [[String]] {
+    var transposed: [[String]] {
+        if isEmpty {
+            return []
+        }
+        let table: [[String]] = self
+        var result: [[String]] = []
+        for columnIndex in 0... {
+            if columnIndex < table.first!.count {
+                result += [table.map { row in row[columnIndex] }]
+            } else {
+                break
+            }
+        }
+        return result
+    }
+}
diff --git a/src/command/parseCommand.swift b/src/command/parseCommand.swift
index 8d624136..2b360fc2 100644
--- a/src/command/parseCommand.swift
+++ b/src/command/parseCommand.swift
@@ -4,8 +4,8 @@ typealias Parsed<T> = Result<T, String>
 extension String: Error {}
 
 func parseQueryCommand(_ raw: String) -> Parsed<QueryCommand> {
-    if raw.contains("'") {
-        return .failure("Single quotation mark is reserved for future use")
+    if raw.contains("'") || raw.contains("\"") {
+        return .failure("Quotation marks are reserved for future use")
     } else if raw == "version" || raw == "--version" || raw == "-v" {
         return .success(VersionCommand())
     } else if raw == "list-apps" {
@@ -35,8 +35,8 @@ func parseCommand(_ raw: String) -> Parsed<Command> {
     let words: [String] = raw.split(separator: " ").map { String($0) }
     let args: [String] = Array(words[1...])
     let firstWord = String(words.first ?? "")
-    if raw.contains("'") {
-        return .failure("Single quotation mark is reserved for future use")
+    if raw.contains("'") || raw.contains("\"") {
+        return .failure("Quotation marks are reserved for future use")
     } else if firstWord == "workspace" {
         return parseSingleArg(args, firstWord).map { WorkspaceCommand(workspaceName: $0) }
     } else if firstWord == "move-node-to-workspace" {
diff --git a/src/config/Config.swift b/src/config/Config.swift
index 3873e7ee..5c600b91 100644
--- a/src/config/Config.swift
+++ b/src/config/Config.swift
@@ -15,8 +15,10 @@ struct RawConfig: Copyable {
     var startAtLogin: Bool?
     var accordionPadding: Int?
     var enableNormalizationOppositeOrientationForNestedContainers: Bool?
+
     var workspaceToMonitorForceAssignment: [String: [MonitorDescription]]?
     var modes: [String: Mode]?
+    var onWindowDetected: [WindowDetectedCallback]?
 }
 struct Config {
     var afterLoginCommand: [Command]
@@ -29,12 +31,29 @@ struct Config {
     var startAtLogin: Bool
     var accordionPadding: Int
     var enableNormalizationOppositeOrientationForNestedContainers: Bool
-    var workspaceToMonitorForceAssignment: [String: [MonitorDescription]]
 
+    var workspaceToMonitorForceAssignment: [String: [MonitorDescription]]
     let modes: [String: Mode]
+    var onWindowDetected: [WindowDetectedCallback]
+
     var preservedWorkspaceNames: [String]
 }
 
+struct RawWindowDetectedCallback: Copyable {
+    var appId: String?
+    var appNameRegexSubstring: Regex<AnyRegexOutput>?
+    var windowTitleRegexSubstring: Regex<AnyRegexOutput>?
+
+    var run: [any Command]?
+}
+struct WindowDetectedCallback {
+    let appId: String?
+    let appNameRegexSubstring: Regex<AnyRegexOutput>?
+    let windowTitleRegexSubstring: Regex<AnyRegexOutput>?
+
+    let run: [any Command]
+}
+
 enum DefaultContainerOrientation: String {
     case horizontal, vertical, auto
 }
diff --git a/src/config/parseConfig.swift b/src/config/parseConfig.swift
index 15cb988a..de262a2c 100644
--- a/src/config/parseConfig.swift
+++ b/src/config/parseConfig.swift
@@ -29,10 +29,7 @@ private func showConfigParsingErrorsToUser(_ errors: [TomlParseError], configUrl
 
         \(errors.map(\.description).joined(separator: "\n"))
         """
-    showMessageToUser(
-        filename: "config-parse-error.txt",
-        message: message
-    )
+    showMessageToUser(filename: "config-parse-error.txt", message: message)
 }
 
 enum TomlParseError: Error, CustomStringConvertible {
@@ -53,56 +50,58 @@ enum TomlParseError: Error, CustomStringConvertible {
     }
 }
 
-private typealias ParsedToml<T> = Result<T, TomlParseError>
+typealias ParsedToml<T> = Result<T, TomlParseError>
 
-private extension ParserProtocol {
-    func transformRawConfig(_ raw: RawConfig,
+extension ParserProtocol {
+    func transformRawConfig(_ raw: S,
                             _ value: TOMLValueConvertible,
                             _ backtrace: TomlBacktrace,
-                            _ errors: inout [TomlParseError]) -> RawConfig {
+                            _ errors: inout [TomlParseError]) -> S {
         raw.copy(keyPath, parse(value, backtrace, &errors).getOrNil(appendErrorTo: &errors))
     }
 }
 
-private protocol ParserProtocol<T> {
+protocol ParserProtocol<S> {
     associatedtype T
-    var keyPath: WritableKeyPath<RawConfig, T?> { get }
+    associatedtype S where S : Copyable
+    var keyPath: WritableKeyPath<S, T?> { get }
     var parse: (TOMLValueConvertible, TomlBacktrace, inout [TomlParseError]) -> ParsedToml<T> { get }
 }
 
-private struct Parser<T>: ParserProtocol {
-    let keyPath: WritableKeyPath<RawConfig, T?>
+struct Parser<S: Copyable, T>: ParserProtocol {
+    let keyPath: WritableKeyPath<S, T?>
     let parse: (TOMLValueConvertible, TomlBacktrace, inout [TomlParseError]) -> ParsedToml<T>
 
-    init(_ keyPath: WritableKeyPath<RawConfig, T?>, _ parse: @escaping (TOMLValueConvertible, TomlBacktrace, inout [TomlParseError]) -> ParsedToml<T>) {
+    init(_ keyPath: WritableKeyPath<S, T?>, _ parse: @escaping (TOMLValueConvertible, TomlBacktrace, inout [TomlParseError]) -> T) {
         self.keyPath = keyPath
-        self.parse = parse
+        self.parse = { raw, backtrace, errors -> ParsedToml<T> in .success(parse(raw, backtrace, &errors)) }
     }
 
-    init(_ keyPath: WritableKeyPath<RawConfig, T?>, _ parse: @escaping (TOMLValueConvertible, TomlBacktrace) -> ParsedToml<T>) {
+    init(_ keyPath: WritableKeyPath<S, T?>, _ parse: @escaping (TOMLValueConvertible, TomlBacktrace) -> ParsedToml<T>) {
         self.keyPath = keyPath
         self.parse = { raw, backtrace, errors -> ParsedToml<T> in parse(raw, backtrace) }
     }
 }
 
-private let parsers: [String: any ParserProtocol] = [
+private let parsers: [String: any ParserProtocol<RawConfig>] = [
     "after-login-command": Parser(\.afterLoginCommand, { parseCommandOrCommands($0).toParsedToml($1) }),
     "after-startup-command": Parser(\.afterStartupCommand, { parseCommandOrCommands($0).toParsedToml($1) }),
 
-    "enable-normalization-flatten-containers": Parser(\.enableNormalizationFlattenContainers, { parseBool($0, $1) }),
-    "enable-normalization-opposite-orientation-for-nested-containers": Parser(\.enableNormalizationOppositeOrientationForNestedContainers, { parseBool($0, $1) }),
+    "enable-normalization-flatten-containers": Parser(\.enableNormalizationFlattenContainers, parseBool),
+    "enable-normalization-opposite-orientation-for-nested-containers": Parser(\.enableNormalizationOppositeOrientationForNestedContainers, parseBool),
 
-    "non-empty-workspaces-root-containers-layout-on-startup": Parser(\.nonEmptyWorkspacesRootContainersLayoutOnStartup, { parseStartupRootContainerLayout($0, $1) }),
+    "non-empty-workspaces-root-containers-layout-on-startup": Parser(\.nonEmptyWorkspacesRootContainersLayoutOnStartup, parseStartupRootContainerLayout),
 
-    "default-root-container-layout": Parser(\.defaultRootContainerLayout, { parseLayout($0, $1) }),
-    "default-root-container-orientation": Parser(\.defaultRootContainerOrientation, { parseDefaultContainerOrientation($0, $1) }),
+    "default-root-container-layout": Parser(\.defaultRootContainerLayout, parseLayout),
+    "default-root-container-orientation": Parser(\.defaultRootContainerOrientation, parseDefaultContainerOrientation),
 
-    "indent-for-nested-containers-with-the-same-orientation": Parser(\.indentForNestedContainersWithTheSameOrientation, { parseInt($0, $1) }),
-    "start-at-login": Parser(\.startAtLogin, { parseBool($0, $1) }),
-    "accordion-padding": Parser(\.accordionPadding, { parseInt($0, $1) }),
+    "indent-for-nested-containers-with-the-same-orientation": Parser(\.indentForNestedContainersWithTheSameOrientation, parseInt),
+    "start-at-login": Parser(\.startAtLogin, parseBool),
+    "accordion-padding": Parser(\.accordionPadding, parseInt),
 
-    "mode": Parser(\.modes, { .success(parseModes($0, $1, &$2)) }),
-    "workspace-to-monitor-force-assignment": Parser(\.workspaceToMonitorForceAssignment, { .success(parseWorkspaceToMonitorAssignment($0, $1, &$2)) }),
+    "mode": Parser(\.modes, parseModes),
+    "workspace-to-monitor-force-assignment": Parser(\.workspaceToMonitorForceAssignment, parseWorkspaceToMonitorAssignment),
+    "on-window-detected": Parser(\.onWindowDetected, parseOnWindowDetectedArray)
 ]
 
 func parseConfig(_ rawToml: String) -> (config: Config, errors: [TomlParseError]) {
@@ -141,9 +140,11 @@ func parseConfig(_ rawToml: String) -> (config: Config, errors: [TomlParseError]
         startAtLogin: raw.startAtLogin ?? defaultConfig.startAtLogin,
         accordionPadding: raw.accordionPadding ?? defaultConfig.accordionPadding,
         enableNormalizationOppositeOrientationForNestedContainers: raw.enableNormalizationOppositeOrientationForNestedContainers ?? defaultConfig.enableNormalizationOppositeOrientationForNestedContainers,
-        workspaceToMonitorForceAssignment: raw.workspaceToMonitorForceAssignment ?? [:],
 
+        workspaceToMonitorForceAssignment: raw.workspaceToMonitorForceAssignment ?? [:],
         modes: modesOrDefault,
+        onWindowDetected: raw.onWindowDetected ?? [],
+
         preservedWorkspaceNames: modesOrDefault.values.lazy
             .flatMap { (mode: Mode) -> [HotkeyBinding] in mode.bindings }
             .compactMap { (binding: HotkeyBinding) -> String? in (binding.commands.singleOrNil() as? WorkspaceCommand)?.workspaceName ?? nil }
@@ -170,7 +171,7 @@ private func parseInt(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace) -
     raw.int.orFailure { expectedActualTypeError(expected: .int, actual: raw.type, backtrace) }
 }
 
-private func parseString(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace) -> ParsedToml<String> {
+func parseString(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace) -> ParsedToml<String> {
     raw.string.orFailure { expectedActualTypeError(expected: .string, actual: raw.type, backtrace) }
 }
 
@@ -238,11 +239,13 @@ private func parseMonitorDescription(_ raw: TOMLValueConvertible, _ backtrace: T
         return .success(.secondary)
     }
 
-    let pattern = (try? Regex(rawString))?.lets { MonitorDescription.pattern($0.ignoresCase()) }
-
     return rawString.isEmpty
         ? .failure(.semantic(backtrace, "Empty string is an illegal monitor description"))
-        : pattern.orFailure(.semantic(backtrace, "Can't parse '\(rawString)' regex"))
+        : parseCaseInsensitiveRegex(rawString).toParsedToml(backtrace).map(MonitorDescription.pattern)
+}
+
+func parseCaseInsensitiveRegex(_ raw: String) -> Parsed<Regex<AnyRegexOutput>> {
+    (try? Regex(raw)).orFailure("Can't parse '\(raw)' regex").map { $0.ignoresCase() }
 }
 
 private func parseModes(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace, _ errors: inout [TomlParseError]) -> [String: Mode] {
@@ -279,7 +282,7 @@ private func parseMode(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace,
     return result
 }
 
-private extension Parsed where Failure == String {
+extension Parsed where Failure == String {
     func toParsedToml(_ backtrace: TomlBacktrace) -> ParsedToml<Success> {
         mapError { .semantic(backtrace, $0) }
     }
@@ -350,14 +353,14 @@ indirect enum TomlBacktrace: CustomStringConvertible {
     }
 }
 
-private func unknownKeyError(_ backtrace: TomlBacktrace) -> TomlParseError {
+func unknownKeyError(_ backtrace: TomlBacktrace) -> TomlParseError {
     .semantic(backtrace, "Unknown key")
 }
 
-private func expectedActualTypeError(expected: TOMLType, actual: TOMLType, _ backtrace: TomlBacktrace) -> TomlParseError {
+func expectedActualTypeError(expected: TOMLType, actual: TOMLType, _ backtrace: TomlBacktrace) -> TomlParseError {
     .semantic(backtrace, expectedActualTypeError(expected: expected, actual: actual))
 }
 
-private func expectedActualTypeError(expected: [TOMLType], actual: TOMLType, _ backtrace: TomlBacktrace) -> TomlParseError {
+func expectedActualTypeError(expected: [TOMLType], actual: TOMLType, _ backtrace: TomlBacktrace) -> TomlParseError {
     .semantic(backtrace, expectedActualTypeError(expected: expected, actual: actual))
 }
diff --git a/src/config/parseOnWindowDetected.swift b/src/config/parseOnWindowDetected.swift
new file mode 100644
index 00000000..eaf380cb
--- /dev/null
+++ b/src/config/parseOnWindowDetected.swift
@@ -0,0 +1,58 @@
+import TOMLKit
+
+private let windowDetectedParsers: [String: any ParserProtocol<RawWindowDetectedCallback>] = [
+    "app-id": Parser(\.appId, parseString),
+    "app-name-regex-substring": Parser(\.appNameRegexSubstring, parseCasInsensitiveRegex),
+    "window-title-regex-substring": Parser(\.windowTitleRegexSubstring, parseCasInsensitiveRegex),
+    "run": Parser(\.run, { parseCommandOrCommands($0).toParsedToml($1) }),
+]
+
+func parseOnWindowDetectedArray(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace, _ errors: inout [TomlParseError]) -> [WindowDetectedCallback] {
+    if let array = raw.array {
+        return array.withIndex.mapToResult(appendErrorsTo: &errors) { (index, raw) in parseWindowDetectedCallback(raw, backtrace + .index(index)) }
+    } else {
+        errors += [expectedActualTypeError(expected: .array, actual: raw.type, backtrace)]
+        return []
+    }
+}
+
+private func parseCasInsensitiveRegex(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace) -> ParsedToml<Regex<AnyRegexOutput>> {
+    parseString(raw, backtrace).flatMap { parseCaseInsensitiveRegex($0).toParsedToml(backtrace) }
+}
+
+private func parseWindowDetectedCallback(_ raw: TOMLValueConvertible, _ backtrace: TomlBacktrace) -> ParsedToml<WindowDetectedCallback> {
+    guard let table = raw.table else {
+        return .failure(expectedActualTypeError(expected: .table, actual: raw.type, backtrace))
+    }
+
+    var raw = RawWindowDetectedCallback()
+
+    for (key, value) in table {
+        let backtrace: TomlBacktrace = backtrace + .key(key)
+        if let parser = windowDetectedParsers[key] {
+            var errors: [TomlParseError] = []
+            raw = parser.transformRawConfig(raw, value, backtrace, &errors)
+            if !errors.isEmpty {
+                return .failure(errors.first!)
+            }
+        } else {
+            return .failure(unknownKeyError(backtrace))
+        }
+    }
+
+    guard let run = raw.run else {
+        return .failure(.semantic(backtrace, "'run' is mandatory key"))
+    }
+
+    if run.contains(where: \.isExec) {
+        return .failure(.semantic(backtrace, "'exec' commands are not yet supported in 'on-window-detected'. " +
+            "Please report your use-cases to https://github.com/nikitabobko/AeroSpace/issues/20"))
+    }
+
+    return .success(WindowDetectedCallback(
+        appId: raw.appId,
+        appNameRegexSubstring: raw.appNameRegexSubstring,
+        windowTitleRegexSubstring: raw.windowTitleRegexSubstring,
+        run: run
+    ))
+}
diff --git a/src/server.swift b/src/server.swift
index e6252496..c17b4098 100644
--- a/src/server.swift
+++ b/src/server.swift
@@ -46,7 +46,7 @@ private func newConnection(_ socket: Socket) async { // todo add exit codes
             _ = try? socket.write(from: error1 + "\n" + error2)
             continue
         }
-        if action is ExecAndForgetCommand || action is ExecAndWaitCommand {
+        if action?.isExec == true {
             _ = try? socket.write(from: "exec commands are prohibited in CLI")
             continue
         }
diff --git a/src/tree/AeroApp.swift b/src/tree/AeroApp.swift
index 07b1687f..d39c327e 100644
--- a/src/tree/AeroApp.swift
+++ b/src/tree/AeroApp.swift
@@ -1,12 +1,14 @@
 class AeroApp: Hashable {
-    let id: Int32
+    let pid: Int32
+    let id: String?
 
-    init(id: Int32) {
+    init(pid: Int32, id: String?) {
+        self.pid = pid
         self.id = id
     }
 
     static func ==(lhs: AeroApp, rhs: AeroApp) -> Bool {
-        if lhs.id == rhs.id {
+        if lhs.pid == rhs.pid {
             check(lhs === rhs)
             return true
         } else {
@@ -16,7 +18,7 @@ class AeroApp: Hashable {
     }
 
     func hash(into hasher: inout Hasher) {
-        hasher.combine(id)
+        hasher.combine(pid)
     }
 
     var name: String? { nil }
diff --git a/src/tree/MacApp.swift b/src/tree/MacApp.swift
index 77ed02b0..9eb2cb12 100644
--- a/src/tree/MacApp.swift
+++ b/src/tree/MacApp.swift
@@ -7,7 +7,7 @@ final class MacApp: AeroApp {
     private init(_ nsApp: NSRunningApplication, _ axApp: AXUIElement) {
         self.nsApp = nsApp
         self.axApp = axApp
-        super.init(id: nsApp.processIdentifier)
+        super.init(pid: nsApp.processIdentifier, id: nsApp.bundleIdentifier)
     }
 
     private static var allAppsMap: [pid_t: MacApp] = [:]
diff --git a/src/tree/MacWindow.swift b/src/tree/MacWindow.swift
index 131e1916..93f217fa 100644
--- a/src/tree/MacWindow.swift
+++ b/src/tree/MacWindow.swift
@@ -31,6 +31,7 @@ final class MacWindow: Window, CustomStringConvertible {
                        window.observe(resizedObs, kAXResizedNotification) {
                 debug("New window detected: \(window)")
                 allWindowsMap[id] = window
+                onWindowDetected(window)
                 return window
             } else {
                 window.garbageCollect()
@@ -61,7 +62,7 @@ final class MacWindow: Window, CustomStringConvertible {
     }
 
     private func observe(_ handler: AXObserverCallback, _ notifKey: String) -> Bool {
-        guard let observer = AXObserver.observe(app.id, notifKey, axWindow, handler, data: self) else { return false }
+        guard let observer = AXObserver.observe(app.pid, notifKey, axWindow, handler, data: self) else { return false }
         axObservers.append(AxObserverWrapper(obs: observer, ax: axWindow, notif: notifKey as CFString))
         return true
     }
@@ -189,3 +190,29 @@ private func destroyedObs(_ obs: AXObserver, ax: AXUIElement, notif: CFString, d
     data?.window?.garbageCollect()
     refresh()
 }
+
+func onWindowDetected(_ window: Window) {
+    Task { @MainActor in
+        check(Thread.current.isMainThread)
+        for callback in config.onWindowDetected {
+            if callback.matches(window) {
+                await callback.run.run(.windowIsFocused(window))
+            }
+        }
+    }
+}
+
+extension WindowDetectedCallback {
+    func matches(_ window: Window) -> Bool {
+        if let windowTitleRegexSubstring, !(window.title ?? "").contains(windowTitleRegexSubstring) {
+            return false
+        }
+        if let appId, appId != window.app.id {
+            return false
+        }
+        if let appNameRegexSubstring, !(window.app.name ?? "").contains(appNameRegexSubstring) {
+            return false
+        }
+        return true
+    }
+}
diff --git a/src/util/SequenceEx.swift b/src/util/SequenceEx.swift
index 4798c2e4..d1ff76fb 100644
--- a/src/util/SequenceEx.swift
+++ b/src/util/SequenceEx.swift
@@ -26,6 +26,16 @@ extension Sequence {
         return .success(result)
     }
 
+    func mapToResult<T, E>(appendErrorsTo errors: inout [E], _ transform: (Self.Element) -> Result<T, E>) -> [T] {
+        var result: [T] = []
+        for element in self {
+            if let good = transform(element).getOrNil(appendErrorTo: &errors) {
+                result.append(good)
+            }
+        }
+        return result
+    }
+
     @inlinable public func minByOrThrow<S: Comparable>(_ selector: (Self.Element) -> S) -> Self.Element {
         minBy(selector) ?? errorT("Empty sequence")
     }
diff --git a/test/config/ConfigTest.swift b/test/config/ConfigTest.swift
index 199166f1..9c7a1af7 100644
--- a/test/config/ConfigTest.swift
+++ b/test/config/ConfigTest.swift
@@ -176,6 +176,57 @@ final class ConfigTest: XCTestCase {
         ], errors.descriptions)
         XCTAssertEqual([:], defaultConfig.workspaceToMonitorForceAssignment)
     }
+
+    func testParseOnWindowDetected() {
+        let (parsed, errors) = parseConfig(
+            """
+            [[on-window-detected]]
+            run = ['layout floating']
+
+            [[on-window-detected]]
+            app-id = 'com.apple.systempreferences'
+            run = []
+
+            [[on-window-detected]]
+            """
+        )
+        XCTAssertEqual(parsed.onWindowDetected, [
+            WindowDetectedCallback(
+                appId: nil,
+                appNameRegexSubstring: nil,
+                windowTitleRegexSubstring: nil,
+                run: [LayoutCommand(toggleBetween: [.floating])!]
+            ),
+            WindowDetectedCallback(
+                appId: "com.apple.systempreferences",
+                appNameRegexSubstring: nil,
+                windowTitleRegexSubstring: nil,
+                run: []
+            )
+        ])
+
+        XCTAssertEqual(errors.descriptions, [
+            "on-window-detected[2]: \'run\' is mandatory key"
+        ])
+    }
+
+    func testParseOnWindowDetectedRegex() {
+        let (config, errors) = parseConfig(
+            """
+            [[on-window-detected]]
+            app-name-regex-substring = '^system settings$'
+            run = []
+            """
+        )
+        XCTAssertTrue(config.onWindowDetected.singleOrNil()!.appNameRegexSubstring != nil)
+        XCTAssertEqual(errors.descriptions, [])
+    }
+
+    func testRegex() {
+        var devNull: [String] = []
+        XCTAssertTrue("System Settings".contains(parseCaseInsensitiveRegex("settings").getOrNil(appendErrorTo: &devNull)!))
+        XCTAssertTrue(!"System Settings".contains(parseCaseInsensitiveRegex("^settings^").getOrNil(appendErrorTo: &devNull)!))
+    }
 }
 
 extension MonitorDescription: Equatable {
@@ -195,18 +246,29 @@ extension MonitorDescription: Equatable {
     }
 }
 
+extension WindowDetectedCallback: Equatable {
+    public static func ==(lhs: WindowDetectedCallback, rhs: WindowDetectedCallback) -> Bool {
+        check(lhs.appNameRegexSubstring == nil &&
+            lhs.windowTitleRegexSubstring == nil &&
+            rhs.appNameRegexSubstring == nil &&
+            rhs.windowTitleRegexSubstring == nil)
+        return lhs.appId == rhs.appId &&
+            lhs.run.map(\.describe) == rhs.run.map(\.describe)
+    }
+}
+
 private extension [TomlParseError] {
     var descriptions: [String] { map(\.description) }
 }
 
 extension Mode: Equatable {
-    public static func ==(lhs: AeroSpace_Debug.Mode, rhs: AeroSpace_Debug.Mode) -> Bool {
+    public static func ==(lhs: Mode, rhs: Mode) -> Bool {
         lhs.name == rhs.name && lhs.bindings == rhs.bindings
     }
 }
 
 extension HotkeyBinding: Equatable {
-    public static func ==(lhs: AeroSpace_Debug.HotkeyBinding, rhs: AeroSpace_Debug.HotkeyBinding) -> Bool {
+    public static func ==(lhs: HotkeyBinding, rhs: HotkeyBinding) -> Bool {
         lhs.modifiers == rhs.modifiers && lhs.key == rhs.key && lhs.commands.map(\.describe) == rhs.commands.map(\.describe)
     }
 }
@@ -217,6 +279,8 @@ extension Command {
             return .focusCommand(focus.direction)
         } else if let resize = self as? ResizeCommand {
             return .resizeCommand(dimension: resize.dimension, mode: resize.mode, unit: resize.unit)
+        } else if let layout = self as? LayoutCommand {
+            return .layoutCommand(layout.toggleBetween)
         }
         error("Unsupported command: \(self)")
     }
@@ -225,4 +289,5 @@ extension Command {
 enum CommandDescription: Equatable {
     case focusCommand(CardinalDirection)
     case resizeCommand(dimension: ResizeCommand.Dimension, mode: ResizeCommand.ResizeMode, unit: UInt)
+    case layoutCommand([LayoutCommand.LayoutDescription])
 }
diff --git a/test/testUtil.swift b/test/testUtil.swift
index 44e8b486..11678141 100644
--- a/test/testUtil.swift
+++ b/test/testUtil.swift
@@ -20,6 +20,7 @@ func setUpWorkspacesForTests() {
 
         // Don't create any workspaces for tests
         modes: [mainModeId: Mode(name: nil, bindings: [])],
+        onWindowDetected: [],
         preservedWorkspaceNames: []
     )
     for workspace in Workspace.all {
diff --git a/test/tree/TestApp.swift b/test/tree/TestApp.swift
index 067c62e5..6073577c 100644
--- a/test/tree/TestApp.swift
+++ b/test/tree/TestApp.swift
@@ -1,10 +1,10 @@
 @testable import AeroSpace_Debug
 
 final class TestApp: AeroApp {
-    static var shared = TestApp(id: 0)
+    static var shared = TestApp()
 
-    private override init(id: Int32) {
-        super.init(id: id)
+    private init() {
+        super.init(pid: 0, id: "bobko.AeroSpace.test-app")
     }
 
     var _windows: [Window] = []