A Windows desktop app that tracks which window (and, for browsers, which tab) is in the foreground and how long you spend on it, with a WPF UI, a CLI summary command, and both a SQLite database and structured JSONL logs.

Website: https://blankscreen-exe.github.io/activity-tracker-prototype/

Preview

Features

• Tracks the active window/process, and for supported browsers (Chrome, Edge, Brave, Firefox) the active tab title, URL, and domain via Windows UI Automation.
• Event-driven focus tracking (SetWinEventHook) plus periodic idle detection (GetLastInputInfo) - idle time is excluded from active session durations.
• Every session is persisted to a SQLite database (via EF Core) and appended to a per-day JSONL log file, so you always have both a queryable DB and a plain-text log.
• ActivityTracker.exe summary [date] prints a detailed daily report to the console.
• WPF UI with six tabs: Tracker (Play/Pause toggle, current-memo tagging, live KPI/marquee status, today's stats + pie chart), Summary (per-day breakdown with charts, tables, and a date picker limited to days that actually have data), Timeline (chronological session list with search and memo filters, multi-select bulk memo tagging/deletion, and a color-coded visual timeline strip), Trends (activity by hour, app usage over the last 7 days), Memos (create, rename, recolor, and delete memos), and Settings (poll interval, idle threshold, process-name lists, wallpaper).
• Manual activity tagging via memos: set a "current memo" that auto-tags every session going forward until you change it, retroactively re-tag past sessions from the Timeline tab, and give each memo its own color (native color picker) that shows up everywhere it's referenced, including the timeline strip.
• Tracking does not start automatically - launch the app and click the Play icon on the Tracker tab when you're ready.
• Charts (via LiveCharts2) on the Tracker, Summary, and Trends tabs.
• Retro Windows XP / Windows Media Player-styled theme (Tahoma font, Luna-blue gradients, rounded buttons) applied across the whole UI.

Requirements

• Windows (the app relies on Win32 APIs and UI Automation, so it will not run on other platforms).
• .NET 9 SDK.

Build & run

From the repo root:

dotnet build

The built executable lands at src\ActivityTracker\bin\Debug\net9.0-windows\ActivityTracker.exe. Just run it - on first launch it automatically applies EF Core migrations, so no manual dotnet ef database update step is required.

Usage

GUI: launch ActivityTracker.exe with no arguments. Tracking does not start automatically - click the Play icon on the Tracker tab, and it runs in the background while you use your PC normally.

CLI summary:

ActivityTracker.exe summary                  # today
ActivityTracker.exe summary 08-07-2026       # a specific date (MM-DD-YYYY by default)

The date format is controlled by summaryDateFormat in config.json (see below); it's not editable from the Settings tab, only by hand-editing the config file.

Configuration

Settings live in %LOCALAPPDATA%\ActivityTracker\config.json, created with defaults on first run:

Field	Meaning
idlePollIntervalSeconds	How often the tracker polls for idle time and in-window tab changes.
idleThresholdSeconds	How long without input before a session is cut off as idle.
summaryDateFormat	.NET date format string used to parse the CLI summary command's date argument.
codingProcessNames	Process names counted toward "coding time" (e.g. Code, devenv).
browserProcessNames	Process names treated as browsers for tab/URL extraction and "browsing time".
wallpaperPath	Optional background image for the main window.
activeMemoName	The memo currently auto-applied to new sessions (set via the Tracker tab); null when none is active.

Most of these (aside from the date format) are also editable from the Settings tab, which writes back to the same file.

Data storage

• SQLite database: %LOCALAPPDATA%\ActivityTracker\activitytracker.db
• JSONL logs: %LOCALAPPDATA%\ActivityTracker\logs\yyyy-MM-dd.jsonl (one file per local calendar day; restarting the tracker just resumes appending to today's file)

Timestamps are stored in UTC on disk (both DB and JSONL) but always converted to the machine's local timezone for display in the UI and CLI output.

Project structure

Folder	Contents
Models	Session (tracked-activity record) and Memo (a tag with a name and color).
Data	EF Core AppDbContext, migrations, MemoRepository (find-or-create memos by name), and ColorUtil (deterministic label-to-color hashing).
Native	Win32 P/Invoke, the foreground-window event hook, and UI Automation browser-tab reading.
Tracking	TrackingService, which ties the hook, idle polling, DB, JSONL logger, and current-memo auto-tagging together.
Logging	The JSONL session logger.
Stats	Daily/weekly/hourly stats calculations and the CLI summary text formatter.
Config	AppSettings, loaded from and saved to config.json.
Themes	The retro XP/WMP WPF style resources.
Assets	The application icon (AppIcon.ico).

Known limitations

• Browser tab/URL extraction is best-effort: it walks the browser's UI Automation tree looking for an address-bar-like edit control, which can fail silently on browser versions/localizations that don't match the expected element names.
• The Trends tab's "activity by hour" chart is a column/bar chart (24 hourly totals across all history), not a literal day-of-week x hour-of-day heatmap grid.
• Tab switches within the same browser window rely on polling (window title changes), not an instant event, so detection latency is bounded by idlePollIntervalSeconds.