agent-desktop/docs/phases.md

agent-desktop — Phase Roadmap

Source of truth for the phased delivery plan. Derived from PRD v2.0 and the Skill Maintenance Addendum.

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Phase Overview

Phase	Name	Status	Platforms
1	Foundation + macOS MVP	Completed	macOS
2	Windows Adapter	Planned	macOS, Windows
3	Linux Adapter	Planned	macOS, Windows, Linux
4	MCP Server Mode	Planned	All
5	Production Hardening	Planned	All

Each phase is strictly additive. Core engine, CLI parser, JSON contract, error types, snapshot engine, and command registry are never modified — only new PlatformAdapter implementations, new transports, and new modes are added.

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Phase 1 — Foundation + macOS MVP

Status: Completed

Phase 1 is the load-bearing phase. It establishes every shared abstraction, every trait boundary, every output contract, every error type, the complete command trait and registry, and the full workspace structure. All subsequent phases build on top of this foundation without modifying core.

Objectives

ID	Objective	Success Metric
P1-O1	Working macOS snapshot CLI	snapshot --app Finder returns valid JSON with refs for all interactive elements
P1-O2	Platform adapter trait	Trait compiles with mock adapter; macOS adapter satisfies all trait methods
P1-O3	Ref-based interaction	click @e3 successfully invokes AXPress on the resolved element
P1-O4	Context efficiency	Typical Finder snapshot < 500 tokens (measured via tiktoken)
P1-O5	Typed JSON contract	Output validates against JSON Schema; schema is versioned
P1-O6	Permission detection	Missing Accessibility permission prints specific macOS setup instructions
P1-O7	Command extensibility	Adding a new command requires exactly 1 new file + 2 registration lines
P1-O8	50 working commands	All commands pass integration tests
P1-O9	CI pipeline	GitHub Actions macOS runner executes full test suite on every PR
P1-O10	Progressive skeleton traversal	Skeleton + drill-down workflow achieves 78%+ token savings on Electron apps

Workspace Structure

agent-desktop/
├── Cargo.toml              # workspace: members, shared deps
├── rust-toolchain.toml     # pinned Rust version
├── clippy.toml             # project-wide lint config
├── schemas/                # JSON Schema files for output validation
│   ├── snapshot_response.json
│   ├── action_response.json
│   └── error_response.json
├── crates/
│   ├── core/               # agent-desktop-core (platform-agnostic)
│   │   └── src/
│   │       ├── lib.rs          # public re-exports only
│   │       ├── node.rs         # AccessibilityNode, Rect, WindowInfo
│   │       ├── adapter.rs      # PlatformAdapter trait
│   │       ├── action.rs       # Action enum, ActionResult, InputEvent, WindowOp
│   │       ├── refs.rs         # RefAllocator, RefMap, RefEntry
│   │       ├── ref_alloc.rs      # Shared ref-allocation logic (RefAllocConfig, allocate_refs, INTERACTIVE_ROLES, is_collapsible)
│   │       ├── snapshot_ref.rs   # Ref-rooted drill-down (run_from_ref) — delegates allocation to ref_alloc
│   │       ├── snapshot.rs     # SnapshotEngine (filter, allocate, serialize)
│   │       ├── error.rs        # ErrorCode enum, AdapterError, AppError
│   │       ├── output.rs       # Response envelope, JSON formatting
│   │       ├── command.rs      # Command trait + CommandRegistry
│   │       └── commands/       # one file per command
│   ├── macos/              # agent-desktop-macos (Phase 1)
│   ├── windows/            # agent-desktop-windows (stub → Phase 2)
│   └── linux/              # agent-desktop-linux (stub → Phase 3)
├── src/                    # agent-desktop binary (entry point)
│   ├── main.rs
│   ├── cli.rs
│   ├── cli_args.rs
│   ├── dispatch.rs
│   └── batch_dispatch.rs
└── tests/
    ├── fixtures/
    └── integration/

PlatformAdapter Trait

The single most important abstraction. Every platform-specific operation goes through this trait. Core never imports platform crates. 12 methods with default implementations returning not_supported():

pub trait PlatformAdapter: Send + Sync {
    fn list_windows(&self, filter: &WindowFilter) -> Result<Vec<WindowInfo>>;
    fn list_apps(&self) -> Result<Vec<AppInfo>>;
    fn get_tree(&self, win: &WindowInfo, opts: &TreeOptions) -> Result<AccessibilityNode>;
    fn execute_action(&self, handle: &NativeHandle, action: Action) -> Result<ActionResult>;
    fn resolve_element(&self, entry: &RefEntry) -> Result<NativeHandle>;
    fn check_permissions(&self) -> PermissionStatus;
    fn focus_window(&self, win: &WindowInfo) -> Result<()>;
    fn launch_app(&self, id: &str, wait: bool) -> Result<WindowInfo>;
    fn close_app(&self, id: &str, force: bool) -> Result<()>;
    fn screenshot(&self, target: ScreenshotTarget) -> Result<ImageBuffer>;
    fn get_clipboard(&self) -> Result<String>;
    fn set_clipboard(&self, text: &str) -> Result<()>;
    fn synthesize_input(&self, input: InputEvent) -> Result<()>;
    fn manage_window(&self, win: &WindowInfo, op: WindowOp) -> Result<()>;
    fn get_subtree(&self, handle: &NativeHandle, opts: &TreeOptions) -> Result<AccessibilityNode>;
    fn list_notifications(&self) -> Result<Vec<NotificationInfo>>;
    fn dismiss_notification(&self, id: &str) -> Result<()>;
    fn interact_notification(&self, id: &str, action_name: &str) -> Result<ActionResult>;
    fn list_tray_items(&self) -> Result<Vec<TrayItemInfo>>;
    fn interact_tray_item(&self, id: &str, action: Action) -> Result<ActionResult>;
}

Key Supporting Types

• Action — Click, DoubleClick, RightClick, SetValue(String), SetFocus, Expand, Collapse, Select(String), Toggle, Scroll(Direction, Amount), PressKey(KeyCombo)
• InputEvent — MouseMove(x,y), MouseClick(x,y,button,count), MouseDown(button), MouseUp(button), MouseWheel(dy,dx), KeyDown(key), KeyUp(key), Drag(from,to)
• WindowOp — Resize(w,h), Move(x,y), Minimize, Maximize, Restore, Close
• ScreenshotTarget — Screen(index), Window(id), Element(NativeHandle), FullScreen
• NotificationInfo — id, app_name, title, body, timestamp, actions: Vec<String>, is_persistent
• TrayItemInfo — id, app_name, title, tooltip, has_menu
• TreeOptions — max_depth, include_bounds, interactive_only, compact, surface, skeleton (root is CLI-only via SnapshotArgs.root_ref, not plumbed into TreeOptions)

macOS Adapter Implementation

Located in crates/macos/src/ following the platform crate folder structure:

crates/macos/src/
├── lib.rs              # mod declarations + re-exports only
├── adapter.rs          # MacOSAdapter: PlatformAdapter impl
├── tree/
│   ├── mod.rs          # re-exports
│   ├── element.rs      # AXElement struct + attribute readers
│   ├── builder.rs      # build_subtree, tree traversal
│   ├── roles.rs        # AXRole string → unified role enum mapping
│   ├── resolve.rs      # Element re-identification for ref resolution
│   └── surfaces.rs     # Surface detection (menu, sheet, alert, popover)
├── actions/
│   ├── mod.rs          # re-exports
│   ├── dispatch.rs     # perform_action match arms
│   ├── activate.rs     # Smart AX-first activation chain (15-step)
│   └── extras.rs       # select_value, ax_scroll
├── input/
│   ├── mod.rs          # re-exports
│   ├── keyboard.rs     # CGEventCreateKeyboardEvent, key synthesis, text typing
│   ├── mouse.rs        # CGEventCreateMouseEvent, mouse events
│   └── clipboard.rs    # NSPasteboard.generalPasteboard read/write
├── notifications/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List notifications via Notification Center AX tree
│   ├── dismiss.rs      # Dismiss individual or all notifications via AXPress
│   └── interact.rs     # Click notification action buttons
├── tray/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List menu bar extras via SystemUIServer AX tree
│   └── interact.rs     # Click menu bar extras, expand menus
└── system/
    ├── mod.rs          # re-exports
    ├── app_ops.rs      # launch, close, focus via NSWorkspace / AppleScript
    ├── window_ops.rs   # window resize, move, minimize, maximize, restore
    ├── key_dispatch.rs # app-targeted key press
    ├── permissions.rs  # AXIsProcessTrusted(), AXIsProcessTrustedWithOptions(prompt: true)
    ├── screenshot.rs   # CGWindowListCreateImage
    └── wait.rs         # wait utilities

Tree traversal:

• Entry: AXUIElementCreateApplication(pid) for app root
• Children: kAXChildrenAttribute recursively with ancestor-path set (not global visited set — macOS reuses AXUIElementRef pointers across sibling branches)
• Batch fetch: AXUIElementCopyMultipleAttributeValues for 3-5x faster attribute reads
• Role mapping: AXRole strings → unified role enum in tree/roles.rs
• Max depth default: 10, configurable via --max-depth
• Name: kAXTitleAttribute / kAXDescriptionAttribute. Value: kAXValueAttribute
• Bounds: kAXPositionAttribute + kAXSizeAttribute combined to Rect

Action execution:

• Click: AXUIElementPerformAction(kAXPressAction)
• SetValue: AXUIElementSetAttributeValue(kAXValueAttribute, value)
• SetFocus: AXUIElementSetAttributeValue(kAXFocusedAttribute, true)
• Expand/Collapse: Toggle kAXExpandedAttribute
• Select: AXUIElementSetAttributeValue(kAXSelectedAttribute, true) on child
• Keyboard/Mouse: CGEventCreateKeyboardEvent / CGEventCreateMouseEvent via CoreGraphics
• Clipboard: NSPasteboard.generalPasteboard read/write via Cocoa FFI
• Screenshot: CGWindowListCreateImage for window-specific or full-screen capture

Permission detection:

• Call AXIsProcessTrusted() on startup
• If false, return PERM_DENIED with guidance: "Open System Settings > Privacy > Accessibility and add your terminal"
• Optionally call AXIsProcessTrustedWithOptions(prompt: true) to trigger system dialog

Notification management:

• Open Notification Center via AX: target the NotificationCenter process (bundleId: com.apple.notificationcenterui)
• List notifications: traverse the Notification Center AX tree — each notification is an AXGroup with title, subtitle, and action buttons
• Dismiss: perform AXPress on the notification's close button, or AXRemoveFromParent if supported
• Interact: resolve action buttons within a notification group and perform AXPress
• Dismiss all: AXPress the "Clear All" button at the group level
• Do Not Disturb detection: read Focus/DND state via NSDoNotDisturbEnabled user defaults or CoreFoundation preferences

System tray / Menu bar extras:

• Menu bar extras (status items) live under the SystemUIServer process AX tree
• List items: traverse AXMenuBarItem children of the system menu bar
• Click: AXPress on the target menu bar extra element
• Expand menus: after clicking a tray item, traverse the resulting AXMenu as a surface
• Control Center items: accessible via the ControlCenter process (bundleId: com.apple.controlcenter)

AXElement safety:

• Inner field: pub(crate) not pub (prevents double-free via raw pointer extraction)
• Clone impl must call CFRetain
• Drop impl must call CFRelease

Snapshot Engine and Ref Allocator

Platform-agnostic, lives in agent-desktop-core:

1. Raw tree: Call adapter.get_tree(window, opts)
2. Filter: Remove invisible/offscreen. Remove empty groups with no interactive descendants. Prune beyond max_depth
3. Allocate refs: Depth-first. Interactive roles get @e1, @e2, etc. Store in RefMap
4. Serialize: Omit null fields. Omit empty arrays. Omit bounds in compact mode
5. Estimate tokens: Optionally warn if exceeding threshold

RefMap persisted at ~/.agent-desktop/last_refmap.json with 0o600 permissions, directory at 0o700. Each snapshot replaces the refmap file entirely (atomic write via temp + rename). Action commands use optimistic re-identification: (pid, role, name, bounds_hash). Return STALE_REF on mismatch.

Progressive Skeleton Traversal:

• --skeleton flag clamps depth to min(max_depth, 3), annotates truncated containers with children_count for agent discovery
• --root <REF> flag starts traversal from a previously-discovered ref instead of window root
• Named or described containers at skeleton boundary receive refs as drill-down targets (with empty available_actions)
• Scoped invalidation: re-drilling a ref replaces only that ref's subtree refs, preserving all others
• Core modules: ref_alloc.rs (canonical allocate_refs + RefAllocConfig), snapshot_ref.rs (drill-down flow that delegates allocation to ref_alloc)
• macOS: count_children() uses raw CFArrayGetCount without materializing AXElement wrappers for performance
• RefMap write-side size check prevents >1MB files
• Token savings: 78-96% reduction for dense Electron apps (Slack skeleton: ~3.6KB vs ~17.3KB full)

New Commands — Notification & System Tray (Post Phase 1)

Note: Notification management and system tray interaction were not part of the original Phase 1 delivery. These are new features to be implemented across all platforms as each platform adapter is built. The macOS implementations were added as a follow-up to Phase 1. Windows (Phase 2) and Linux (Phase 3) implementations follow the same pattern.

Notification Commands (macOS — Completed)

Command	Description	Flags	Status
list-notifications	List current notifications with app, title, body, and available actions	--app (filter by app), --text (filter by text), --limit (max results)	Completed
dismiss-notification	Dismiss a specific notification by 1-based index	<index>, --app (filter by app)	Completed
dismiss-all-notifications	Clear all notifications, optionally filtered by app (single NC session, reports failures)	--app (filter by app)	Completed
notification-action	Click an action button on a specific notification	<index> <action-name>	Completed

System Tray / Status Area Commands (New — Not Yet Implemented)

Command	Description	Flags
list-tray-items	List all system tray / menu bar extra items with app name and tooltip	—
click-tray-item	Click a system tray item by ID or app name	<tray-item-id>
open-tray-menu	Click a tray item and snapshot its resulting menu for ref-based interaction	<tray-item-id>

Wait Command Update (Notification — Completed, Menu — Completed)

The wait command has been extended with notification and menu support:

• wait --notification — Wait for any new notification to appear (index-diff based detection)
• wait --notification --app Safari — Wait for a notification from a specific app
• wait --notification --text "Download complete" — Wait for a notification containing specific text
• wait --menu / wait --menu-closed — Wait for context menu open/close

Commands Shipped (57)

Category	Commands	Count
App / Window	launch, close-app, list-windows, list-apps, focus-window, resize-window, move-window, minimize, maximize, restore	10
Observation	snapshot, screenshot, find, get (text, value, title, bounds, role, states, tree-stats), is (visible, enabled, checked, focused, expanded), list-surfaces	6
Interaction	click, double-click, triple-click, right-click, type, set-value, clear, focus, select, toggle, check, uncheck, expand, collapse	14
Scroll	scroll, scroll-to	2
Keyboard	press, key-down, key-up	3
Mouse	hover, drag, mouse-move, mouse-click, mouse-down, mouse-up	6
Clipboard	clipboard-get, clipboard-set, clipboard-clear	3
Notification	list-notifications, dismiss-notification, dismiss-all-notifications, notification-action	4
System Tray	list-tray-items, click-tray-item, open-tray-menu	3
Wait	wait (with --element, --window, --text, --menu, --notification flags)	1
System	status, permissions, version	3
Batch	batch	1

JSON Output Contract

All commands produce a response envelope. Schema files versioned in schemas/.

Success:

{
  "version": "1.0",
  "ok": true,
  "command": "snapshot",
  "data": {
    "app": "Finder",
    "window": { "id": "w-4521", "title": "Documents" },
    "ref_count": 14,
    "tree": { ... }
  }
}

Error:

{
  "version": "1.0",
  "ok": false,
  "command": "click",
  "error": {
    "code": "STALE_REF",
    "message": "RefMap is from a previous snapshot",
    "suggestion": "Run 'snapshot' to refresh, then retry with updated ref"
  }
}

Serialization rules: omit null/None fields (skip_serializing_if), omit empty arrays, omit bounds in compact mode, ref_count and tree inside data.

Error Taxonomy

Code	Category	Example	Recovery Suggestion
PERM_DENIED	Permission	Accessibility not granted	Open System Settings > Privacy > Accessibility and add your terminal
ELEMENT_NOT_FOUND	Ref	@e12 not in current RefMap	Run 'snapshot' to refresh, then retry with updated ref
APP_NOT_FOUND	Application	--app 'Photoshop' not running	Launch the application first with 'launch Photoshop'
ACTION_FAILED	Execution	AXPress returned error on disabled button	Element may be disabled. Check states before acting
ACTION_NOT_SUPPORTED	Execution	Expand on a button element	This element does not support the requested action
TREE_TIMEOUT	Performance	Traversal exceeded 5s	Try --max-depth 3 or target a specific window
STALE_REF	Ref	RefMap is from a previous snapshot	UI may have changed. Run 'snapshot' again
WINDOW_NOT_FOUND	Window	--window w-999 does not exist	Run 'list-windows' to see available windows
PLATFORM_UNSUPPORTED	Platform	Linux adapter not yet shipped	This platform ships in Phase 3. Currently macOS only
CLIPBOARD_EMPTY	Clipboard	clipboard get but clipboard is empty	No text content in clipboard. Copy something first
TIMEOUT	Wait	wait --element exceeded timeout	Element did not appear within timeout. Increase --timeout or check app state
NOTIFICATION_NOT_FOUND	Notification	Notification ID not found	Notification may have been dismissed or expired. Run 'list-notifications' to see current notifications
NOTIFICATION_UNSUPPORTED	Notification	Notification daemon does not support listing	This notification daemon does not expose a history API. Consider using 'wait --notification' to catch notifications in real-time
TRAY_NOT_FOUND	System Tray	Tray item not found	Tray item may have been removed. Run 'list-tray-items' to see current items
TRAY_UNSUPPORTED	System Tray	No system tray available	System tray not available on this desktop environment. On GNOME, install the AppIndicator extension

Exit codes: 0 success, 1 structured error (JSON on stdout), 2 argument/parse error.

Testing

Unit tests (core):

• AccessibilityNode ser/de roundtrips
• Ref allocator only assigns interactive roles
• SnapshotEngine filtering
• Error serialization
• JSON schema validation
• MockAdapter: in-memory PlatformAdapter returning hardcoded trees

Unit tests (macos):

• Role mapping coverage
• Permission check with mocks
• Tree traversal cycle detection

Integration tests (macOS CI):

• Snapshot Finder, TextEdit, System Settings — non-empty trees with refs
• Click button in test app — verify action succeeded
• Type text into TextEdit via ref — verify content changed
• Clipboard get/set roundtrip
• Wait for window
• Launch + close app lifecycle
• Permission denied scenario — correct error code and guidance
• Large tree (Xcode) snapshot in under 2 seconds
• List notifications — returns non-empty list when Notification Center has entries
• Dismiss notification — verify notification removed from Notification Center AX tree
• List tray items — returns known menu bar extras (Wi-Fi, Bluetooth, Clock)
• Click tray item — verify menu bar extra menu opens

Golden fixtures (tests/fixtures/):

• Real snapshots from Finder, TextEdit, etc. checked into repo
• Regression-test serialization format changes

CI

• GitHub Actions macOS runner on every PR
• cargo clippy --all-targets -- -D warnings (zero warnings)
• cargo test --workspace
• cargo tree -p agent-desktop-core must not contain platform crate names
• Binary size check: fail if release binary exceeds 15MB

Dependencies

Crate	Version	Purpose
clap	4.x	CLI parsing with derive macros
serde + serde_json	1.x	JSON serialization
thiserror	2.x	Error derive macros
tracing	0.1+	Structured logging
base64	0.22+	Screenshot encoding
accessibility-sys	0.1+	macOS AXUIElement FFI
core-foundation	0.10+	macOS CF types
core-graphics	0.24+	macOS CG types

Documentation Delivered

• README with installation (npm + source), core workflow, command reference, JSON output, ref system, platform support table
• PRD v2.0
• Architecture diagram
• Claude Code skills: .claude/skills/agent-desktop/ (core, platform-agnostic) + .claude/skills/agent-desktop-macos/ (macOS-specific)
• Quick reference slash command: .claude/commands/desktop.md

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Phase 2 — Windows Adapter

Status: Planned

Phase 2 brings agent-desktop to Windows. Core engine, CLI parser, JSON contract, error types, snapshot engine, and command registry are untouched. Only the new WindowsAdapter implementation is added inside crates/windows/. The existing stub is replaced with a full implementation.

Objectives

ID	Objective	Metric
P2-O1	Windows adapter	snapshot on Windows returns valid tree for Explorer, Notepad, Settings
P2-O2	All existing commands cross-platform	Identical JSON schema output on macOS and Windows for every command
P2-O3	Windows input synthesis	click, type, press, all mouse commands working via UIA + SendInput
P2-O4	Windows screenshot	screenshot produces PNG via BitBlt / PrintWindow or xcap crate
P2-O5	Windows clipboard	clipboard-get / clipboard-set / clipboard-clear working via Win32 Clipboard API
P2-O6	Windows CI	GitHub Actions Windows runner executes full test suite on every PR
P2-O7	Windows binary release	Prebuilt .exe published via GitHub Releases and npm

Windows Adapter Implementation

Full WindowsAdapter in crates/windows/src/ following the identical platform crate folder structure:

crates/windows/src/
├── lib.rs              # mod declarations + re-exports only
├── adapter.rs          # WindowsAdapter: PlatformAdapter impl
├── tree/
│   ├── mod.rs          # re-exports
│   ├── element.rs      # UIA element wrapper + attribute readers
│   ├── builder.rs      # IUIAutomationTreeWalker traversal with CacheRequest
│   ├── roles.rs        # UIA ControlType → unified role enum mapping
│   ├── resolve.rs      # Element re-identification for ref resolution
│   └── surfaces.rs     # Surface detection (menus, dialogs, flyouts)
├── actions/
│   ├── mod.rs          # re-exports
│   ├── dispatch.rs     # perform_action match arms via UIA patterns
│   ├── activate.rs     # Smart activation chain (InvokePattern → Toggle → coordinate)
│   └── extras.rs       # SelectionPattern, ScrollPattern helpers
├── input/
│   ├── mod.rs          # re-exports
│   ├── keyboard.rs     # SendInput keyboard synthesis
│   ├── mouse.rs        # SendInput mouse events
│   └── clipboard.rs    # OpenClipboard / GetClipboardData / SetClipboardData Win32 APIs
├── notifications/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List toast/Action Center notifications via UIA
│   ├── dismiss.rs      # Dismiss individual or all notifications
│   └── interact.rs     # Click notification action buttons
├── tray/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List system tray items via Shell_TrayWnd UIA tree
│   └── interact.rs     # Click tray items, open tray menus
└── system/
    ├── mod.rs          # re-exports
    ├── app_ops.rs      # Process launch via CreateProcess, close via TerminateProcess
    ├── window_ops.rs   # SetWindowPos, ShowWindow for resize/move/minimize/maximize/restore
    ├── key_dispatch.rs # App-targeted key press via SetForegroundWindow + SendInput
    ├── permissions.rs  # COM security check, UAC elevation detection
    ├── screenshot.rs   # BitBlt / PrintWindow or xcap crate
    └── wait.rs         # wait utilities (polling UIA element existence)

Windows API Mapping

Capability	Technology	Details
Tree root	IUIAutomation.ElementFromHandle()	Via uiautomation crate (v0.24+) wrapping UIA COM APIs via windows crate
Children	IUIAutomationTreeWalker.GetFirstChild / GetNextSibling	With CacheRequest for batch attribute retrieval (3-5x faster)
Role mapping	UIA ControlType integers	Map to unified role enum in tree/roles.rs — e.g. UIA_ButtonControlTypeId → button
Click	InvokePattern.Invoke()	Pattern-based, falls back to TogglePattern.Toggle(), then coordinate click via SendInput
Set text	ValuePattern.SetValue()	Falls back to SelectAll + SendInput keystroke sequence
Expand/Collapse	ExpandCollapsePattern.Expand() / .Collapse()	Native UIA pattern
Select	SelectionItemPattern.Select()	For combobox, listbox, tab items
Toggle	TogglePattern.Toggle()	For checkboxes, switches
Scroll	ScrollPattern.Scroll() / ScrollPattern.SetScrollPercent()	Native UIA scroll, falls back to mouse wheel
Keyboard	SendInput API	INPUT_KEYBOARD structs with virtual key codes and scan codes
Mouse	SendInput API	INPUT_MOUSE structs with MOUSEEVENTF_* flags
Clipboard	OpenClipboard / GetClipboardData / SetClipboardData	Win32 APIs, handle CF_UNICODETEXT format
Screenshot	BitBlt / PrintWindow	Window capture; or xcap crate for cross-platform consistency
App launch	CreateProcess / ShellExecuteEx	Launch by name or path, wait for main window
App close	WM_CLOSE / TerminateProcess	Graceful close first, force kill with --force
Window ops	SetWindowPos / ShowWindow	Resize, move, minimize (SW_MINIMIZE), maximize (SW_MAXIMIZE), restore (SW_RESTORE)
Permissions	COM security / UAC	Detect elevation requirements; return PERM_DENIED if UIA access blocked
Notifications	UIA + Action Center	Toast notifications accessible via UIA tree of Windows.UI.Notifications.Manager. List via IUIAutomationElement traversal of Action Center pane. Dismiss via InvokePattern on close button. Interact via InvokePattern on action buttons. Do Not Disturb (Focus Assist) state via WNF_SHEL_QUIETHOURS_ACTIVE_PROFILE_CHANGED or registry query
System tray	UIA + Shell_TrayWnd	System tray items accessible via UIA tree of Shell_TrayWnd class. Overflow items in NotifyIconOverflowWindow. List via IUIAutomationTreeWalker on tray area. Click via InvokePattern or coordinate-based SendInput. Expand overflow via click on chevron button

Notification Management (New Feature — Windows Implementation)

Windows notification management must be implemented from scratch as part of Phase 2. The macOS notification implementation (completed as a follow-up to Phase 1) serves as the reference pattern — same PlatformAdapter trait methods (list_notifications, dismiss_notification, dismiss_all_notifications, notification_action), same JSON output contract, same 1-based indexing.

Implementation approach:

• List notifications: Open Action Center via UIA (Windows.UI.Notifications). Traverse the notification list — each toast is a UIA element with Name (title), FullDescription (body), app info, and child action buttons
• Dismiss: InvokePattern.Invoke() on the notification's dismiss/close button. For "dismiss all", invoke the "Clear all" button in Action Center
• Interact with actions: Resolve action buttons within a toast element tree, invoke via InvokePattern
• Focus Assist / Do Not Disturb: Query via WNF_SHEL_QUIETHOURS_ACTIVE_PROFILE_CHANGED state notification or registry key HKCU\Software\Microsoft\Windows\CurrentVersion\CloudStore\Store\DefaultAccount\Current\default$windows.data.notifications.quiethourssettings
• Edge case: Some notifications may be transient (disappear after timeout). The wait --notification command should monitor for new toasts via UIA event subscription (UIA_Notification_EventId)

System Tray (New Feature — Windows Implementation)

System tray interaction must be implemented from scratch as part of Phase 2.

Implementation approach:

• List items: Access the system tray via UIA tree of Shell_TrayWnd window class. Tray items are children of the notification area. Overflow items live in NotifyIconOverflowWindow
• Click: InvokePattern on tray items, falling back to coordinate-based SendInput for items that don't expose UIA patterns
• Open menu: After clicking a tray item, detect the resulting popup menu via UIA focus-changed events and expose it for ref-based interaction

Web/Electron App Compatibility

Chromium-based apps (Electron, Chrome, Edge, VS Code) expose deep, noisy accessibility trees where every HTML <div> becomes a UIA Group element. The macOS adapter solved this with three patterns that must be replicated identically on Windows.

Chromium detection:

• Detect Chromium-based windows via UIA process name or Chrome_WidgetWin_1 window class matching
• If tree is empty or minimal for a Chromium window, warn: "This appears to be a Chromium app. Run the app with --force-renderer-accessibility to expose the accessibility tree"
• Include this guidance in the platform_detail field of the error response

Web-aware tree traversal (depth-skip):

• Non-semantic wrapper elements (UIA_GroupControlTypeId / UIA_CustomControlTypeId) with empty Name AND empty Value properties do NOT consume depth budget during tree traversal
• This matches the macOS pattern where AXGroup/AXGenericElement wrappers are skipped
• Without this, default --max-depth 10 finds ~3 refs in Slack; with it, finds 100+ refs
• Implement in crates/windows/src/tree/builder.rs with the same is_web_wrapper logic

Resolver depth:

• Element re-identification must search up to ABSOLUTE_MAX_DEPTH (50), not a lower hardcoded limit
• Electron elements commonly sit at depth 25+ in the raw tree; a shallow resolver cap causes STALE_REF errors
• Implement in crates/windows/src/tree/resolve.rs matching the macOS pattern

Surface detection for Electron:

• When an Electron app opens a modal (file picker, dialog), UIA may report the dialog as the focused window itself rather than a child of the parent window
• Surface detection (list-surfaces, --surface sheet/alert) must check if the focused window IS the target surface, not only search its children
• Check both ControlType and LocalizedControlType / UIA patterns (analogous to macOS checking both AXRole and AXSubrole)
• Implement in crates/windows/src/tree/surfaces.rs

Progressive skeleton traversal works identically on Windows — --skeleton and --root flags are platform-agnostic, handled entirely by core. The Windows adapter only needs to implement get_subtree() (which delegates to the same build_subtree() as get_tree()). Token savings for Electron apps (VS Code, Slack) apply equally.

Minimum OS Requirements

• Windows 10 1809+ (October 2018 update)
• UIA COM interfaces available since Windows 7, but modern patterns require 10+

New Dependency

Crate	Version	Purpose	License
uiautomation	0.24+	Windows UIA wrapper via windows crate	Apache-2.0

Added to Cargo.toml as target-gated dependency:

[target.'cfg(target_os = "windows")'.dependencies]
agent-desktop-windows = { path = "crates/windows" }

Testing

Unit tests (windows):

• UIA ControlType → role mapping coverage for all control types
• Permission check with mocks (COM security state)
• CacheRequest attribute batching correctness
• Element resolution round-trip (pid, role, name, bounds_hash)

Integration tests (Windows CI):

• Snapshot Explorer — non-empty tree with refs, buttons, text fields
• Snapshot Notepad — text area with value, menu items
• Snapshot Settings — modern WinUI controls
• Click button in test app — verify action succeeded
• Type text into Notepad via ref — verify content changed
• Set-value on a text field — verify value set via UIA
• Clipboard get/set/clear roundtrip
• Wait for window title pattern
• Launch + close app lifecycle (Notepad: launch, type, close)
• Resize, move, minimize, maximize, restore window operations
• Screenshot produces valid PNG
• Large tree snapshot performance validation
• Chromium detection — verify warning when tree is empty
• Electron app snapshot (VS Code) — default depth finds 50+ refs via web-aware depth-skip
• Electron surface detection — file picker dialog detected as sheet surface
• List notifications — returns non-empty list when notifications exist
• Dismiss notification — verify notification removed from Action Center
• Notification action — click action button on a test toast notification
• List tray items — returns known system tray entries (volume, network, clock)
• Click tray item — verify tray menu opens

Cross-platform validation:

• Same snapshot of a cross-platform app (e.g., VS Code) produces structurally identical JSON on macOS and Windows
• All error codes produce identical JSON envelope format

CI

• Add GitHub Actions Windows runner alongside existing macOS runner
• Both runners execute: cargo clippy --all-targets -- -D warnings, cargo test --workspace
• cargo tree -p agent-desktop-core continues to contain zero platform crate names
• Binary size check: Windows .exe must be under 15MB

Release

• Prebuilt Windows .exe binary published to GitHub Releases via cargo-dist
• npm package updated to include Windows binary (platform-specific download)
• GitHub Release notes document Windows support and installation

Skill Update

Per Skill Maintenance Addendum:

• Create .claude/skills/agent-desktop-windows/SKILL.md:
  • UIA permission model and UAC handling
  • Windows-specific behaviors (UIA patterns, WinUI3 quirks, COM initialization)
  • Chromium/Electron compatibility: depth-skip, resolver depth, surface detection patterns
  • --force-renderer-accessibility guidance for empty trees
  • Windows error codes and platform_detail examples (HRESULT codes)
  • Troubleshooting guide (empty trees, COM errors, elevation failures)
• Update core SKILL.md:
  • Add Windows platform skill to skill graph table
  • Update platform support section
• Update workflows.md:
  • Add cross-platform patterns noting Windows-specific differences
  • Add Windows-specific workflow examples (e.g., navigating UWP apps)

README Update

• Update Platform Support table: Windows column → Yes
• Add Windows installation instructions:
  • npm (same command, auto-detects platform)
  • Direct .exe download from GitHub Releases
  • From source: cargo build --release on Windows (note: requires MSVC toolchain)
• Add Windows permissions section:
  • UIA works without special permissions for most apps
  • UAC elevation may be required for elevated processes
  • Chromium apps need --force-renderer-accessibility
• Update "From source" section with Windows build requirements (Rust + MSVC)

---

Phase 3 — Linux Adapter

Status: Planned

Phase 3 brings agent-desktop to Linux, completing the three-platform story. Same additive approach — only the LinuxAdapter implementation is added inside crates/linux/. The existing stub is replaced with a full implementation.

Objectives

ID	Objective	Metric
P3-O1	Linux adapter	snapshot on Ubuntu GNOME returns valid tree for Files, Terminal, Settings
P3-O2	All commands cross-platform	Identical JSON schema output on all 3 platforms for every command
P3-O3	Linux input synthesis	click, type, press, all mouse commands via AT-SPI actions + xdotool/ydotool
P3-O4	Linux screenshot	screenshot produces PNG via PipeWire ScreenCast (Wayland) / XGetImage (X11)
P3-O5	Linux clipboard	clipboard-get / clipboard-set / clipboard-clear via wl-clipboard (Wayland) / xclip (X11)
P3-O6	Cross-platform CI	GitHub Actions matrix: macOS + Windows + Ubuntu
P3-O7	Linux binary release	Prebuilt binary published via GitHub Releases and npm

Linux Adapter Implementation

Full LinuxAdapter in crates/linux/src/ following the identical platform crate folder structure:

crates/linux/src/
├── lib.rs              # mod declarations + re-exports only
├── adapter.rs          # LinuxAdapter: PlatformAdapter impl
├── tree/
│   ├── mod.rs          # re-exports
│   ├── element.rs      # AT-SPI Accessible wrapper + attribute readers
│   ├── builder.rs      # D-Bus tree traversal via GetChildren
│   ├── roles.rs        # AT-SPI Role enum → unified role enum mapping
│   ├── resolve.rs      # Element re-identification for ref resolution
│   └── surfaces.rs     # Surface detection (menus, dialogs, popovers)
├── actions/
│   ├── mod.rs          # re-exports
│   ├── dispatch.rs     # perform_action via AT-SPI Action interface
│   ├── activate.rs     # Smart activation chain (DoAction → coordinate fallback)
│   └── extras.rs       # Text.InsertText, Selection helpers
├── input/
│   ├── mod.rs          # re-exports
│   ├── keyboard.rs     # xdotool (X11) / ydotool (Wayland) keyboard synthesis
│   ├── mouse.rs        # xdotool (X11) / ydotool (Wayland) mouse events
│   └── clipboard.rs    # wl-clipboard (Wayland) / xclip (X11) clipboard ops
├── notifications/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List notifications via D-Bus org.freedesktop.Notifications or daemon-specific API
│   ├── dismiss.rs      # Dismiss/close notifications via CloseNotification D-Bus method
│   └── interact.rs     # Invoke notification actions via ActionInvoked D-Bus signal
├── tray/
│   ├── mod.rs          # re-exports
│   ├── list.rs         # List tray items via StatusNotifierItem D-Bus interface or AT-SPI
│   └── interact.rs     # Activate/context-menu tray items via D-Bus methods
└── system/
    ├── mod.rs          # re-exports
    ├── app_ops.rs      # App launch via xdg-open / process spawn, close via SIGTERM/SIGKILL
    ├── window_ops.rs   # xdotool / wmctrl for resize/move/minimize/maximize/restore
    ├── key_dispatch.rs # App-targeted key press via window focus + input synthesis
    ├── permissions.rs  # AT-SPI2 bus availability check, DBUS_SESSION_BUS_ADDRESS detection
    ├── screenshot.rs   # PipeWire ScreenCast portal (Wayland) / XGetImage (X11) / xcap crate
    └── wait.rs         # wait utilities (polling AT-SPI element existence)

Linux API Mapping

Capability	Technology	Details
Tree root	atspi Accessible on bus	Via atspi crate (v0.28+) + zbus (5.x) — pure Rust, no libatspi/GLib dependency
Children	org.a11y.atspi.Accessible.GetChildren	Async D-Bus calls to AT-SPI2 registry daemon
Role mapping	AT-SPI Role enum	Map to unified role enum in tree/roles.rs — e.g. Role::PushButton → button
Click	org.a11y.atspi.Action.DoAction(0)	AT-SPI actions preferred over coordinate-based input
Set text	org.a11y.atspi.Text.InsertText	AT-SPI text interface; falls back to clipboard paste
Expand/Collapse	Action.DoAction("expand") / Action.DoAction("collapse")	Action name-based dispatch
Select	org.a11y.atspi.Selection.SelectChild	For combobox, listbox, tab items
Toggle	Action.DoAction("toggle") or Action.DoAction("click")	For checkboxes, switches
Scroll	Coordinate-based scroll events via xdotool/ydotool	AT-SPI has no native scroll pattern
Keyboard	xdotool key (X11) / ydotool key (Wayland)	Shelling out for input synthesis
Mouse	xdotool mousemove/click (X11) / ydotool mousemove/click (Wayland)	Display server detected at runtime
Clipboard	wl-copy / wl-paste (Wayland) / xclip (X11)	Shelling out; display server detected at runtime
Screenshot	PipeWire ScreenCast portal (Wayland) / XGetImage (X11)	Or xcap crate for consistency
App launch	xdg-open / direct process spawn	Launch by .desktop file or command name
App close	SIGTERM / SIGKILL	Graceful close first, force with --force
Window ops	xdotool / wmctrl	Window resize, move, minimize, maximize, restore
Permissions	AT-SPI2 bus availability	Check for org.a11y.Bus on D-Bus session bus. Return PLATFORM_UNSUPPORTED with enable instructions if missing
Notifications	D-Bus org.freedesktop.Notifications	List via GetServerInformation + monitoring Notify signals. History varies by daemon: GNOME uses org.gnome.Shell.Notifications, KDE uses org.freedesktop.Notifications with GetNotifications. Dismiss via CloseNotification(id). Interact via ActionInvoked signal. Do Not Disturb: GNOME org.gnome.desktop.notifications.show-banners, KDE org.kde.notificationmanager
System tray	D-Bus org.kde.StatusNotifierWatcher	SNI (StatusNotifierItem) protocol for modern tray items. Legacy XEmbed tray items via AT-SPI tree of the tray window. List via RegisteredStatusNotifierItems property. Activate via Activate(x, y) method. Context menu via ContextMenu(x, y) method. Fallback: coordinate-based click for XEmbed items

Notification Management (New Feature — Linux Implementation)

Linux notification management must be implemented from scratch as part of Phase 3. The macOS implementation (completed) and Windows implementation (Phase 2) serve as reference patterns — same trait methods, same JSON output contract, same 1-based indexing.

Implementation approach:

• List notifications: The standard org.freedesktop.Notifications D-Bus interface does NOT provide a "list current notifications" method. Approach varies by desktop environment:
  • GNOME: org.gnome.Shell exposes org.gnome.Shell.Notifications interface with GetNotifications() method (returns array of notification dicts)
  • KDE Plasma: org.freedesktop.Notifications with GetNotifications() extension, or org.kde.notificationmanager D-Bus interface
  • Other DEs: Monitor Notify D-Bus signals to maintain an in-memory notification history within the daemon session
• Dismiss: org.freedesktop.Notifications.CloseNotification(id) D-Bus method call. Works across all notification daemons
• Interact with actions: Listen for user-triggered actions or programmatically invoke via ActionInvoked signal. Note: the D-Bus spec does not define a method to programmatically trigger actions — coordinate-based click on the notification popup via AT-SPI may be needed as a fallback
• Do Not Disturb:
  • GNOME: gsettings get org.gnome.desktop.notifications show-banners (boolean)
  • KDE: org.kde.notificationmanager D-Bus interface, inhibited property
• Edge case: Notification daemon varies by DE — detect via GetServerInformation() D-Bus method. Return PLATFORM_UNSUPPORTED with daemon-specific guidance if the notification interface is unreachable

System Tray (New Feature — Linux Implementation)

System tray interaction must be implemented from scratch as part of Phase 3.

Implementation approach:

• Modern tray (SNI): Most modern Linux apps use the StatusNotifierItem (SNI) D-Bus protocol. Discover items via org.kde.StatusNotifierWatcher.RegisteredStatusNotifierItems property
• Legacy tray (XEmbed): Older apps use XEmbed protocol. Access via AT-SPI tree of the tray window, or coordinate-based interaction
• List items: Query StatusNotifierWatcher for registered items. Each item exposes Title, IconName, ToolTip, Menu (D-Bus menu path) properties
• Activate: Call Activate(x, y) method on the StatusNotifierItem D-Bus interface
• Context menu: Call ContextMenu(x, y) method, or read the Menu property to get the com.canonical.dbusmenu path and traverse the menu tree
• Edge case: GNOME does not natively support SNI (requires AppIndicator extension). Detect and report via error suggestion if no tray is available

Display Server Detection

Runtime detection required for input, clipboard, and screenshot since Linux runs either X11 or Wayland:

• Check $WAYLAND_DISPLAY environment variable — if set, use Wayland path
• Check $DISPLAY environment variable — if set and no Wayland, use X11 path
• If neither, return PLATFORM_UNSUPPORTED with guidance to check display server configuration
• Input tools: verify xdotool (X11) or ydotool (Wayland) is installed; error with install instructions if missing
• Clipboard tools: verify xclip (X11) or wl-clipboard (Wayland) is installed; error with install instructions if missing

Web/Electron App Compatibility

Same Chromium/Electron compatibility patterns as Phase 2 (Windows), adapted for AT-SPI2. These patterns ensure default --max-depth 10 works with Electron apps like Slack, VS Code, and Chrome.

Web-aware tree traversal (depth-skip):

• Non-semantic wrapper elements with AT-SPI roles ROLE_PANEL, ROLE_SECTION, or ROLE_FILLER that have empty Name AND empty Value do NOT consume depth budget during tree traversal
• This is the AT-SPI equivalent of macOS AXGroup/AXGenericElement and Windows UIA_GroupControlTypeId skipping
• Implement in crates/linux/src/tree/builder.rs with the same is_web_wrapper logic

Resolver depth:

• Element re-identification must search up to ABSOLUTE_MAX_DEPTH (50), not a lower hardcoded limit
• Electron elements commonly sit at depth 25+ in the raw AT-SPI tree
• Implement in crates/linux/src/tree/resolve.rs matching the macOS/Windows pattern

Surface detection for Electron:

• When an Electron app opens a modal (file picker, dialog), AT-SPI may report the dialog as the active window itself rather than a child of the parent window
• Surface detection must check if the focused window IS the target surface, not only search its children
• Check both Role and RelationSet / RELATION_EMBEDS for dialog detection (analogous to macOS AXRole + AXSubrole)
• Implement in crates/linux/src/tree/surfaces.rs

Chromium detection:

• Detect Chromium-based apps via process name matching (electron, chrome, chromium, code)
• If AT-SPI tree is empty for a Chromium app, warn about --force-renderer-accessibility
• On Linux, Chromium respects ACCESSIBILITY_ENABLED=1 environment variable as an alternative

Progressive skeleton traversal works identically on Linux — --skeleton and --root flags are platform-agnostic, handled entirely by core. The Linux adapter only needs to implement get_subtree() (which delegates to the same async tree walker). Token savings for Electron apps apply equally.

AT-SPI2 Bus Detection

• Check for org.a11y.Bus presence on the D-Bus session bus
• If bus is not running, return PLATFORM_UNSUPPORTED with instructions:
  • GNOME: "AT-SPI2 should be enabled by default. Check gsettings get org.gnome.desktop.interface toolkit-accessibility"
  • Other DEs: "Install at-spi2-core and ensure at-spi-bus-launcher is running"
  • Flatpak/Snap: "Ensure the app has --talk-name=org.a11y.Bus permission"

Minimum OS Requirements

• Ubuntu 22.04+ / Fedora 38+
• GNOME 42+ (primary target), KDE Plasma 5.24+ (secondary)
• at-spi2-core package installed (default on GNOME)
• X11: xdotool installed. Wayland: ydotool installed

Key Risks and Mitigations

Risk	Mitigation
Wayland a11y gaps	Focus on GNOME (best AT-SPI2 support). Prefer AT-SPI actions over coordinate input. Document known gaps clearly in skill and README.
AT-SPI2 bus not running	Detect on first command. Return clear enable instructions specific to the detected distro/DE.
Display server fragmentation	Runtime detection (X11 vs Wayland). Separate code paths for input/clipboard/screenshot. Test both.
Rust a11y crate maintenance stalls	Pin atspi and zbus versions. atspi crate backed by Odilia accessibility project. Maintain patches if upstream stalls.
Input tool availability	Check for xdotool/ydotool on first use. Provide package manager install commands in error suggestion.

New Dependencies

Crate	Version	Purpose	License
atspi	0.28+	Linux AT-SPI2 client	MIT/Apache-2.0
zbus	5.x	D-Bus connection	MIT/Apache-2.0
tokio	1.x	Async runtime (required by atspi/zbus for async D-Bus)	MIT

Added to Cargo.toml as target-gated dependency:

[target.'cfg(target_os = "linux")'.dependencies]
agent-desktop-linux = { path = "crates/linux" }

Note: tokio is introduced here for the first time. Phases 1-2 are fully synchronous. The Linux adapter requires async D-Bus calls via zbus.

Testing

Unit tests (linux):

• AT-SPI Role → role mapping coverage for all role types
• Bus availability detection (mock D-Bus responses)
• Display server detection logic (Wayland vs X11 env vars)
• Element resolution round-trip (pid, role, name, bounds_hash)

Integration tests (Ubuntu CI):

• Snapshot GNOME Files — non-empty tree with refs, buttons, text fields
• Snapshot GNOME Terminal — text area, menu items
• Snapshot GNOME Settings — modern GTK4 controls
• Click button in test app — verify action succeeded
• Type text into GNOME Text Editor via ref — verify content changed
• Clipboard get/set/clear roundtrip (test both X11 and Wayland if CI supports)
• Wait for window title pattern
• Launch + close app lifecycle
• Resize, move, minimize, maximize, restore window operations
• Screenshot produces valid PNG
• AT-SPI2 bus not running — correct error code and guidance
• Electron app snapshot (VS Code) — default depth finds 50+ refs via web-aware depth-skip
• Electron surface detection — file picker dialog detected as sheet surface
• List notifications — returns non-empty list when notifications exist (GNOME)
• Dismiss notification — verify notification dismissed via D-Bus CloseNotification
• List tray items — returns known SNI items (if running under KDE or with AppIndicator extension)
• Click tray item — verify tray menu opens via Activate D-Bus method
• Notification daemon detection — correct GetServerInformation result

Cross-platform validation:

• Same snapshot of a cross-platform app (e.g., VS Code) produces structurally identical JSON on all 3 platforms
• All error codes produce identical JSON envelope format on all 3 platforms
• Notification commands return identical JSON envelope structure across all 3 platforms (list, dismiss, action)
• Tray commands return identical JSON envelope structure across all 3 platforms

CI

• GitHub Actions matrix: macOS + Windows + Ubuntu (all three on every PR)
• All runners execute: cargo clippy --all-targets -- -D warnings, cargo test --workspace
• cargo tree -p agent-desktop-core continues to contain zero platform crate names
• Binary size check: all platform binaries must be under 15MB

Release

• Prebuilt Linux binary published to GitHub Releases via cargo-dist
• npm package updated to include Linux binary (platform-specific download)
• GitHub Release notes document Linux support, requirements, and installation

Skill Update

Per Skill Maintenance Addendum:

• Create .claude/skills/agent-desktop-linux/SKILL.md:
  • AT-SPI2/D-Bus setup and bus detection
  • Wayland vs X11 differences (input via xdotool/ydotool, clipboard via wl-clipboard/xclip, screenshot via PipeWire/XGetImage)
  • Required system tools: xdotool or ydotool, xclip or wl-clipboard
  • Linux error codes and platform_detail examples (D-Bus errors, bus not found)
  • Troubleshooting guide (bus not running, empty trees, missing tools, Flatpak/Snap permissions)
• Update core SKILL.md:
  • Add Linux platform skill to skill graph table
  • Update platform support section to show all 3 platforms
• Update workflows.md:
  • Add cross-platform patterns noting Linux-specific differences
  • Add Linux-specific workflow examples (e.g., GNOME app automation)
  • Document display server detection behavior

README Update

• Update Platform Support table: Linux column → Yes
• Add Linux installation instructions:
  • npm (same command, auto-detects platform)
  • Direct binary download from GitHub Releases
  • From source: cargo build --release on Linux (note: requires pkg-config, libdbus-1-dev)
• Add Linux permissions section:
  • AT-SPI2 bus must be running (default on GNOME, may need enabling on other DEs)
  • Required tools: xdotool (X11) or ydotool (Wayland) for input synthesis
  • Required tools: xclip (X11) or wl-clipboard (Wayland) for clipboard
  • How to check: busctl --user list | grep a11y
• Update minimum OS versions: Ubuntu 22.04+ / Fedora 38+
• Update "From source" section with Linux build requirements

---

Phase 4 — MCP Server Mode

Status: Planned

Phase 4 adds a new I/O layer. Core engine and all three platform adapters are unchanged. The MCP server wraps existing command logic in JSON-RPC tool definitions, enabling agent-desktop to work as an MCP server for Claude Desktop, Cursor, and other MCP-compatible hosts.

Objectives

ID	Objective	Metric
P4-O1	MCP server mode via --mcp	Responds to MCP initialize handshake, reports capabilities
P4-O2	All commands as MCP tools	tools/list returns all tools with JSON Schema specs
P4-O3	Claude Desktop validated	Claude Desktop invokes tools to control desktop apps end-to-end on all platforms
P4-O4	Tool annotations	readOnlyHint, destructiveHint, idempotentHint on every tool

Entry Point

The binary crate's main.rs detects mode:

• If invoked with --mcp or stdin is a pipe: enter MCP server mode
• Otherwise: parse CLI arguments, execute command, print JSON to stdout

This is the invariant: every MCP tool maps 1:1 to a CLI command. agent-desktop snapshot --app Finder is identical to invoking the MCP desktop_snapshot tool. Testing, debugging, and documentation are never fragmented.

New Crate: agent-desktop-mcp

crates/mcp/src/
├── lib.rs              # mod declarations + re-exports
├── server.rs           # MCP server bootstrap, initialize handler, capabilities reporting
├── tools.rs            # Tool definitions with #[tool] macro, parameter JSON Schemas
└── transport.rs        # Stdio transport (primary), optional HTTP+SSE

MCP Tool Surface

Each MCP tool maps 1:1 to a CLI command. Tool names are prefixed with desktop_ to avoid collision with other MCP servers.

MCP Tool	CLI Equivalent	readOnly	destructive
desktop_snapshot	snapshot	true	false
desktop_click	click <ref>	false	false
desktop_type_text	type <ref> <text>	false	false
desktop_set_value	set-value <ref> <text>	false	false
desktop_press_key	press <keys>	false	false
desktop_find	find <query>	true	false
desktop_list_windows	list-windows	true	false
desktop_focus_window	focus-window	false	false
desktop_launch_app	launch <app>	false	false
desktop_close_app	close-app <app>	false	true
desktop_screenshot	screenshot	true	false
desktop_scroll	scroll <dir>	false	false
desktop_drag	drag <from> <to>	false	false
desktop_select	select <ref> <val>	false	false
desktop_toggle	toggle <ref>	false	false
desktop_clipboard_get	clipboard get	true	false
desktop_clipboard_set	clipboard set <text>	false	false
desktop_wait	wait	true	false
desktop_get	get <prop> <ref>	true	false
desktop_is	is <state> <ref>	true	false
desktop_list_notifications	list-notifications	true	false
desktop_dismiss_notification	dismiss-notification <id>	false	true
desktop_dismiss_all_notifications	dismiss-all-notifications	false	true
desktop_notification_action	notification-action <id> <action>	false	false
desktop_list_tray_items	list-tray-items	true	false
desktop_click_tray_item	click-tray-item <id>	false	false
desktop_open_tray_menu	open-tray-menu <id>	false	false

Transport

• Stdio (primary): MCP host spawns agent-desktop --mcp as child process. JSON-RPC over stdin/stdout. This is the only required transport.
• HTTP+SSE (optional, stretch goal): For remote scenarios. Additive, non-blocking for core milestone.
• Session: On MCP initialize, detect platform, check accessibility permissions, report capabilities. RefMap is session-scoped (held in memory, not persisted to disk like CLI mode).

Initialize Handler

On receiving MCP initialize:

1. Detect platform (macOS / Windows / Linux)
2. Check accessibility permissions (check_permissions())
3. Report capabilities: list of available tools, platform, permission status
4. If permissions not granted, include guidance in capabilities response

New Dependencies

Crate	Version	Purpose	License
rmcp	0.15.0+	Official MCP Rust SDK — #[tool] macro, JSON-RPC handling, transport	MIT/Apache-2.0
schemars	0.8+	JSON Schema generation for tool parameter definitions	MIT/Apache-2.0
tokio	1.x	Async runtime (required by rmcp for MCP server event loop)	MIT

Note: If tokio was already introduced in Phase 3 (Linux), it is already available. Otherwise, it is introduced here.

Binary Crate Changes

• src/main.rs — Add --mcp flag detection, route to MCP server mode
• Cargo.toml — Add agent-desktop-mcp dependency (non-platform-gated, available on all platforms)
• No changes to dispatch.rs, cli.rs, or any command files — MCP tools call the same execute() functions

Testing

Unit tests (mcp):

• Tool definition schema validation — every tool's JSON Schema is valid
• Tool invocation round-trip — call tool, verify response matches CLI output
• Initialize handler — correct capabilities, platform detection, permission status

Integration tests:

• Full MCP protocol compliance — initialize, tools/list, tool invocation, error responses
• Claude Desktop end-to-end: launch app → snapshot → click button → verify action
• Cursor end-to-end: same workflow
• Session isolation: RefMap is session-scoped, not shared across sessions
• Protocol edge cases: malformed requests, unknown tools, invalid parameters

Cross-platform:

• MCP server works identically on macOS, Windows, and Linux
• Same tool invocations produce same JSON structure on all platforms

MCP Config Examples

Provide ready-to-use config snippets for:

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "agent-desktop": {
      "command": "agent-desktop",
      "args": ["--mcp"]
    }
  }
}

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "agent-desktop": {
      "command": "agent-desktop",
      "args": ["--mcp"]
    }
  }
}

Skill Update

Per Skill Maintenance Addendum:

• Create .claude/skills/agent-desktop-mcp/SKILL.md:
  • MCP tool surface documentation (all tools, parameters, annotations)
  • Transport configuration (stdio setup, optional SSE)
  • Session management (RefMap scoping, initialize flow)
  • Tool-to-CLI mapping reference
  • MCP-specific error handling
• Update core SKILL.md:
  • Add MCP mode section
  • Add MCP skill to skill graph table
• Update workflows.md:
  • Add MCP workflow patterns (tool invocation from Claude Desktop, Cursor)
  • Add session lifecycle patterns

README Update

• Add "MCP Server" section:
  • How to start: agent-desktop --mcp
  • What it does: wraps all CLI commands as MCP tools
  • Session behavior: RefMap scoped per session
• Add Claude Desktop configuration snippet
• Add Cursor configuration snippet
• Document --mcp flag in CLI reference
• Add note: every MCP tool maps 1:1 to a CLI command

---

Phase 5 — Production Hardening

Status: Planned

Phase 5 transforms agent-desktop from functional to enterprise-grade. Persistent daemon process, session isolation for concurrent agents, comprehensive quality gates, and distribution via native package managers.

Objectives

ID	Objective	Metric
P5-O1	Persistent daemon	Warm snapshot completes in <50ms (vs 200ms+ cold start)
P5-O2	Session isolation	Two agents hold independent RefMaps without interference
P5-O3	Enterprise quality gates	All gates in quality gates table pass
P5-O4	Package manager distribution	Available via brew (macOS), winget/scoop (Windows), snap/apt (Linux)

Daemon Architecture

The daemon is a long-running process that maintains state between CLI/MCP invocations, dramatically reducing startup latency.

Auto-start:

• CLI detects if daemon is running by checking for socket file (~/.agent-desktop/daemon.sock on Unix, named pipe on Windows)
• If not running, spawns daemon as background process
• Daemon listens on the socket for incoming commands

Auto-stop:

• Daemon exits after configurable idle timeout (default 5 minutes)
• No active sessions = idle timer starts
• Any new connection resets the idle timer

Session multiplexing:

• Each CLI invocation or MCP session gets a unique session ID
• Each session has its own RefMap (held in memory by daemon, not on disk)
• Sessions are isolated: agent A's refs never collide with agent B's refs
• Session destroyed on disconnect or explicit session kill

Health check:

• agent-desktop status returns: daemon PID, uptime, active session count, platform, permission status

New Commands

Command	Description
session list	List active daemon sessions with IDs, creation time, last activity
session kill <id>	Terminate a specific daemon session, release its RefMap

CLI-to-Daemon Migration

When daemon is running:

1. CLI command parses arguments as usual
2. Instead of directly calling the adapter, CLI connects to daemon socket
3. Sends serialized command to daemon
4. Daemon executes command in the caller's session context
5. Returns JSON response to CLI
6. CLI prints response to stdout

When daemon is not running, CLI falls back to direct execution (same as Phases 1-4). Daemon is purely an optimization, never a requirement.

Enterprise Quality Gates

Gate	Requirement
Security	No arbitrary code execution. No privilege escalation. All actions allowlisted via Action enum. No network access (daemon communicates only via local socket).
Performance	Cold start <200ms. Warm snapshot <50ms via daemon. Tree traversal timeout 5s default, configurable.
Reliability	Zero panics in non-test code. Graceful daemon recovery on crash. Stale socket cleanup on startup.
Observability	Structured logging via tracing crate. --verbose flag for debug output. Timing metrics per operation logged at debug level.
Compatibility	Tested against target app matrix: Finder, TextEdit, Xcode, VS Code, Chrome (macOS); Explorer, Notepad, Settings, VS Code (Windows); Nautilus, Terminal, Firefox (Linux).
Distribution	Single binary per platform. No runtime dependencies. Reproducible builds. SHA256 checksums for every release artifact.
Documentation	README, CLI reference, MCP reference, per-platform setup guides, troubleshooting.

Performance Optimizations

Optimization	Platform	Details
CacheRequest batching	Windows	Batch UIA attribute fetches via CacheRequest — reduces COM round-trips
Async tree walking	Linux	Parallel D-Bus calls for tree traversal — concurrent child fetching
Cached subtrees	All (daemon)	Reuse unchanged subtrees between snapshots in same session — skip re-traversal of stable UI regions
Warm adapter	All (daemon)	Adapter stays initialized between commands — skip COM init (Win), D-Bus connect (Linux), AX bootstrap (macOS)
Progressive skeleton drill	All	Skeleton overview + targeted drill-down reduces token consumption 78-96% for dense apps — fewer tokens per snapshot means more budget for actions

Package Manager Distribution

Platform	Package Manager	Format	Install Command
macOS	Homebrew	Formula	brew install agent-desktop
Windows	winget	Manifest	winget install agent-desktop
Windows	scoop	Manifest	scoop install agent-desktop
Linux	snap	Snap package	snap install agent-desktop
Linux	apt	.deb package	apt install agent-desktop

Each package manager distribution includes:

• Prebuilt binary for the target platform
• SHA256 checksum verification
• Automatic PATH setup
• Uninstall support

Testing

Daemon tests:

• Daemon starts on first CLI command when not running
• Daemon stops after idle timeout with no active sessions
• Multiple concurrent sessions have isolated RefMaps
• Session list returns correct session metadata
• Session kill terminates session and releases resources
• Stale socket cleaned up on daemon restart
• Daemon crash recovery — CLI falls back to direct execution
• Warm snapshot performance: <50ms after initial cold start

Quality gate tests:

• Security: verify Action enum is exhaustive, no shell injection vectors
• Performance: benchmark cold start (<200ms) and warm snapshot (<50ms)
• Reliability: stress test with concurrent sessions, verify zero panics
• Compatibility: snapshot + click workflow on each app in target matrix

Package tests:

• brew formula installs and runs on macOS
• winget/scoop manifest installs and runs on Windows
• snap package installs and runs on Ubuntu
• All packages produce correct version output
• All packages handle permissions correctly on their platform

Skill Update

Per Skill Maintenance Addendum:

• Update commands-system.md:
  • Add session list command documentation
  • Add session kill <id> command documentation
  • Update status command to document daemon-specific fields (PID, uptime, sessions)
• Update workflows.md:
  • Add daemon lifecycle patterns (auto-start, idle timeout, health checks)
  • Add concurrent agent patterns (session isolation, multi-agent coordination)
  • Add performance optimization patterns (warm snapshot, cached subtrees)
• Update platform skills:
  • Document enterprise quality gates in each platform skill
  • Add daemon-specific troubleshooting (stale socket, port conflicts)

README Update

• Add "Daemon Mode" section:
  • How it works: auto-start, auto-stop, session isolation
  • Configuration: idle timeout, socket location
  • Health check: agent-desktop status
• Add package manager installation methods:
  • brew install agent-desktop (macOS)
  • winget install agent-desktop (Windows)
  • snap install agent-desktop (Linux)
• Add "Performance" section:
  • Cold start vs warm snapshot benchmarks
  • Daemon mode benefits
• Update installation section with all distribution channels (npm, brew, winget, scoop, snap, apt, source)
• Final polish:
  • Complete CLI reference for all commands including session list and session kill
  • Comprehensive troubleshooting guide covering all platforms
  • Per-platform setup guides linked from main README

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Cross-Phase Requirements

README Update Schedule

The README is updated at the end of each phase to reflect the current state:

Phase	README Changes
Phase 1	Initial README: npm + source installation, core workflow, all 50 commands, JSON output, ref system, error codes, platform support table (macOS only)
Phase 2	Add Windows: .exe installation, Windows permissions, update platform table, Windows build instructions
Phase 3	Add Linux: binary installation, AT-SPI2 setup, update platform table, Linux build instructions, minimum OS versions
Phase 4	Add MCP Server: --mcp usage, Claude Desktop config, Cursor config, tool-to-CLI mapping
Phase 5	Add daemon mode, package managers (brew/winget/snap), performance benchmarks, final troubleshooting guide

Skill Maintenance Rules

Per the Skill Maintenance Addendum:

1. Every new command must be added to the appropriate commands-*.md file
2. Every new platform gets its own skill directory under .claude/skills/agent-desktop-{platform}/
3. Every new mode (MCP, daemon) gets its own skill file
4. Breaking changes to JSON output or CLI flags must update all affected skill files
5. Skill files are reviewed as part of the PR checklist for any command-surface change

CI Matrix Evolution

Phase	CI Runners
Phase 1	macOS
Phase 2	macOS + Windows
Phase 3	macOS + Windows + Ubuntu
Phase 4	macOS + Windows + Ubuntu (+ MCP protocol tests)
Phase 5	macOS + Windows + Ubuntu (+ daemon tests, package build verification)

All runners enforce: cargo clippy --all-targets -- -D warnings, cargo test --workspace, cargo tree -p agent-desktop-core contains zero platform crate names, binary size <15MB.

Dependency Introduction Schedule

Dependency	Introduced In	Purpose
clap 4.x, serde 1.x, thiserror 2.x, tracing 0.1+, base64 0.22+	Phase 1	Core: CLI, JSON, errors, logging, encoding
accessibility-sys 0.1+, core-foundation 0.10+, core-graphics 0.24+	Phase 1	macOS AX API FFI
uiautomation 0.24+	Phase 2	Windows UIA wrapper
atspi 0.28+ + zbus 5.x	Phase 3	Linux AT-SPI2 client via D-Bus
tokio 1.x	Phase 3	Async runtime (required by atspi/zbus)
rmcp 0.15.0+	Phase 4	Official MCP Rust SDK
schemars 0.8+	Phase 4	JSON Schema generation for MCP tool parameters

Platform API Quick Reference

Capability	macOS	Windows	Linux
Tree root	AXUIElementCreateApp(pid)	IUIAutomation.ElementFromHandle()	atspi Accessible on bus
Children	kAXChildrenAttribute	TreeWalker.GetFirstChild	GetChildren D-Bus
Click	AXPress	InvokePattern.Invoke()	Action.DoAction(0)
Set text	AXValue = val	ValuePattern.SetValue()	Text.InsertText
Keyboard	CGEventCreateKeyboard	SendInput	xdotool / ydotool
Clipboard	NSPasteboard	Win32 Clipboard API	wl-clipboard / xclip
Screenshot	CGWindowListCreateImage	BitBlt / PrintWindow	PipeWire / XGetImage
Permissions	AXIsProcessTrusted()	COM security / UAC	Bus availability
Notifications	Notification Center AX tree (com.apple.notificationcenterui)	UIA tree of Action Center / Toast Manager	D-Bus org.freedesktop.Notifications + daemon-specific history
System tray	SystemUIServer AX tree + ControlCenter AX tree	UIA tree of Shell_TrayWnd + overflow window	D-Bus StatusNotifierWatcher + XEmbed fallback

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Risk Register

ID	Risk	Likelihood	Impact	Mitigation
R1	macOS TCC friction deters adoption	High	High	Clear first-run guidance. Detect before any op. One-command setup: permissions --request.
R2	Electron/Chrome no a11y tree by default	High	Medium	Detect Chromium windows. Print --force-renderer-accessibility guidance in error response.
R3	Custom-rendered UIs invisible to a11y	Medium	High	Phase 5 stretch: vision fallback. Short-term: document limitation in README and skills.
R4	Wayland a11y gaps	Medium	Medium	Focus on GNOME (best AT-SPI2 support). Prefer AT-SPI actions over coordinate input. Document gaps.
R5	Rust a11y crate maintenance stalls	Low	High	Pin versions, maintain patches. atspi backed by Odilia project. Fork-ready.
R6	MCP spec changes break compat	Low	Medium	Pin rmcp version. Monitor spec under Linux Foundation governance.
R7	Tree traversal too slow (>5s)	Medium	Medium	Depth limiting via --max-depth. Focused-window-only. Cached subtrees in Phase 5 daemon. Progressive skeleton traversal (--skeleton + --root) reduces token consumption 78-96% for dense apps.
R8	Ref instability confuses agents	Medium	High	Clear docs: refs are snapshot-scoped. STALE_REF error with recovery hint. Stable hashing in Phase 5. Progressive skeleton traversal with scoped invalidation provides a stable drill-down workflow for navigating complex UIs.