List application windows (front to back): hwnd, title, process, UI framework (Win32, WPF, Chromium…), size; [dialog of N "title"] = dialog or other window owned by window N (file picker, "Open", "Save as"); [hidden] = Store app Windows never shows (launched in the background), readable and drivable all the same. Then Windows itself: window="taskbar" and window="desktop" (icons). filter: part of a title or process name.

See a window without bringing it to the front: numbered elements [N] (role, name, value, states, position @x,y), and an image when the text is not enough. window: title (part of it), process ("notepad"), hwnd, or Windows itself: "taskbar" (buttons, tray, clock), "desktop" (icons), "screen" (whole screen as the user sees it, with the windows' places: overview only); omitted = current window. show: auto (default: the list, plus the image only when the tree is too thin to act on — canvas, game, page that publishes nothing — or after an unverified action), both (list and image), image, elements, changes (only what changed since the last list: added "+", changed "~", removed "-", the others keep their [N]), text (text of documents, no image), none. query: list only the elements containing this text. region [x1,y1,x2,y2]: zoom on an area of the image (fine reading; coordinates stay those of the full image). Images: WebP, at most 2000 px and 2.56 Mpx (detail=high gives the same size: zoom with region to read small text); an image identical to the last one sent for this window is not attached again (show=image always attaches it). marks: numbers drawn on the image (auto = unnamed elements; all; none).

Act in the background: steps run in order (stops at the first error or unknown outcome), then the updated state (then: auto = list + image if a step is not verified; both, image, elements, changes, none). Per-step report: ✓ invoked or effect read, = already done (nothing sent), ~ unknown outcome (batch stopped: inspect the state), ✗ failed or not reached; then the summary. Steps (do): click, double_click, right_click, type (appends text; no target = focused element), set (replaces the text), clear, key (keys "ctrl+s", "enter", "alt+f4"), select (option in a list), check, uncheck, toggle, expand, collapse, scroll (direction, amount), focus, menu (path "File > Open"), wait (text appeared, or gone=true; timeout), drag (target → to), hover. expect: text expected after the step. check: wanted state of an element ({"target":"Name","value":"Alice"}; also contains, checked, selected, expanded, focused, enabled, exists): already true → step skipped, read back after → ✓, otherwise ✗ not reached. confirm=true: paying, sending, publishing, permanent deletion… (refused otherwise, before any input); only on the user's explicit order or "yes" for THIS action. Outward ones (send, pay, publish…) also need accord: the token from the refusal, after the user's own yes. target: [N] from the last look, visible name ("Save", "button:OK", "edit:Name") or "x,y" in image pixels. Example: steps=[{"do":"set","target":"Name","text":"Alice"},{"do":"click","target":"OK"}]. Routines: remember="name" saves the batch if it is verified (✓/=, targets by name; {{x}} = variable text, only in text and check.value/contains; typed text made only of {{x}}); routine="name" (without steps) replays it, params={"x": "…"}; remember="name" with steps=[] forgets it; look lists them. foreground=true: window kept in front for the whole batch, real mouse/keyboard when the background is impossible or ignored (drag, hover, WPF/UWP/Chromium shortcuts, Tk); only with the user's consent. Panels window="quick settings", "notifications", "start": foreground=true only.

Open an application in the background (without giving it the foreground) and see it. app: Start menu name ("Calculator", "Notepad"), executable ("notepad.exe") or path. args: arguments. app = path of a FOLDER or a DOCUMENT: opened by its file association (Explorer, default application), opening verified (displayed folder read back, or title carrying the file name). app = ADDRESS: ms-settings: opens that Settings page behind the user's window (Windows flashes it ~1 s; foreground given back); any other scheme (mailto:, https:, tel:…) by its app. Calling or sending stays a click, guarded in act (confirm + accord). devtools=true (Chromium/Electron/Edge only, application not already open): opens a local DevTools port for more reliable clicks, typing and shortcuts. The window becomes the current window. Steam: always launched readable even when covered; devtools=true opens its DevTools port (127.0.0.1:8080, its own session); when already open, restart=true closes and relaunches it (refused while a game runs). Both: only with the user's consent.

Manage a window without bringing it to the front: restore (restore behind the others), minimize, maximize, close (polite request: the application may offer to save), bottom (bottom of the z-order), move (x, y) / resize (width, height) in screen pixels. front: bring it to the front (foreground=true, only with the user's consent).

Notifications shown by Windows (notification center), most recent first: app, time, texts; read without opening anything on screen; security codes masked. app: part of the app name.

Log of the latest calls (debugging): tool, arguments, techniques tried per step, durations, errors. Full files: ~/.claude/nexus-claude/logs/YYYY-MM-DD.jsonl.