features.md

Dao Browser Feature Inventory

This document catalogs the features Dao Browser adds on top of the Chromium baseline configured in dao.json. Dao-owned code lives in src/dao/; Chromium integration patches live in src/patches/.

Android GeckoView features, including the native Compose browser shell, are documented separately in features-android.md. The Android shell now uses Android Components BrowserStore tabs with regular-session restore and real tab thumbnails, plus persistent history and bookmarks, Android system downloads, persistent engine preferences, installed-extension state, and QR scanning.

Desktop platform scope

Human-readable release notes are maintained in English and Simplified Chinese, with other languages generated by i18n.sh --only changelog. Desktop version bumps archive only desktop Unreleased entries before packaging; release failures restore them along with version metadata. Windows attachments and --skip-bump preserve pending notes. See the changelog guide.

The development CLI supports native macOS arm64 and an experimental Windows x64 target. Windows uses the existing setup/import/rebuild commands, a local chrome.exe, and separate Dao debug/release profiles. Normal Windows browser windows combine their address row and native Chromium minimize/maximize/close controls, removing the separate title-bar row. Caption buttons stay at the window's top right while either sidebar toggles or split panes resize. Address bars reserve the actual caption bounds, shrink the URL, and hide actions that cannot fit in narrow panes; the Agent uses Chromium's Window Controls Overlay geometry to fit its compact header beside them, with a distinct collapse button and an overflow menu for new chat, history, and settings. Fullscreen hides the caption buttons and restores the regular Agent header. Native caption hit testing preserves Snap Layouts, window close handling, and dragging from sidebar-header and address-row empty space. Popup and app window frames retain their existing layout. Native caption buttons use a transparent layer over the address row or Agent, with glyph contrast following the underlying surface as page colors, tabs, split panes, and Agent visibility change. Caption hover and pressed backgrounds are clipped to the underlying surface's bounds and rounded corners. Caption glyphs are centered within that visible hover area, excluding the frame gutters and inter-button spacing. Caption hit testing uses Chromium's overlay routing so the Agent's native WebView does not interrupt minimize/close hover; Windows 11 maximize keeps Snap Layouts. Sidebar windows also clip the parked native toolbar's composited children to the top container so duplicate navigation controls cannot cover the frame. Windows event interception uses Aura with restoration on overlay close and drag cancellation. Closing site controls or the command bar after switching tabs restores the originally blocked page. Download cards use Windows file type icons when an image thumbnail is unavailable. Agent workspace paths accept UTF-8 input. On Windows, existing path components are resolved through directory junctions before checking workspace containment, including ancestors of files that do not yet exist. Dao Home project scans use portable forward-slash file names and reject Windows directory junctions as well as file symlinks. Chromium tab search uses dao://tab-search.top-chrome/ to match its registered WebUI configuration, including when opened with Ctrl+Shift+A on Windows.

The Windows port excludes the macOS MCP transport and its settings/copy-ID actions, native share pickers, AppKit drag-to-new-window completion detection, ImageIO thumbnails, the external-URL Little Dao launcher, and Sparkle updates. Windows reuses Chromium's mini_installer for unsigned x64 installation, shortcuts, browser registration, upgrades, and uninstall. The distributed NSIS EXE opens a Win32/WebView2 installer with bundled HTML/CSS in a fixed, DPI-scaled 560 x 420 window. Its custom title bar supports dragging, minimizing and closing; the centered Dao mark, halo and ring follow the supplied compact installer design. English and Simplified Chinese, system light/dark themes, keyboard navigation, high contrast and reduced motion are supported; logos retain square proportions. The installation path expands inline for editing: Enter confirms, Escape cancels the edit, and Browse starts from the current path's nearest existing parent. The picker appends a Dao product folder unless that folder is already selected. Progress remains indeterminate while the native backend runs, with rotating product tips. Completion offers an explicit launch button; closing never launches Dao. Installation failures retain retry and a dialog with the error code and log location. The bridge accepts only fixed installer actions, and external navigation is blocked. WebView2 is never downloaded on the user's machine: a missing runtime or startup failure opens the native NSIS wizard instead. /NATIVE selects that wizard explicitly; /S bypasses both interfaces. Once installation starts, closing is blocked until the backend exits, and a WebView failure cannot start another installation. Fresh per-user installations can choose a writable directory on a local fixed drive; binaries go into its Application child while profiles stay under %LOCALAPPDATA%\Dao\User Data. Repair and upgrades retain the registered location. When a per-user installation is detected, both installer interfaces offer Uninstall Dao and hand off to the registered Chromium uninstaller, which owns confirmation and the browsing-data removal choice. Uninstall is unavailable during installation and after completion; launch failures show localized guidance. Moving requires uninstalling while preserving browsing data, then installing again. System folders, profile folders, and existing unowned Application/Temp contents are rejected. Native install and profile paths use Dao, with Dao AppUserModelID/ProgID prefixes and separate COM server identities. Chrome and Chromium installations remain independent. release --platform windows reuses dao.json's desktop version and v<version> tag and attaches only the EXE to the shared GitHub Release after checking its local SHA-256 checksum. GitHub archival also verifies signed Windows metadata, but does not upload .sha256 or .update.json attachments. The default npm run release bumps the desktop version once, builds macOS and Windows sequentially on a Mac, and uploads both installers to R2 before publishing the signed Windows feed. Artifact uploads rely on Wrangler success; the release command does not download them for verification. Existing objects are checked with HEAD for uncompressed size when provided and skipped on retry; local Windows signatures and checksums and the public update feed are still verified. release:mac retains the Mac-only workflow; release:windows retains the existing tag attachment workflow without advancing the Windows feed. Windows does not use Apple signing, notarization, or Sparkle at runtime. macOS hosts can select --platform windows to cross-compile the browser and WebView2 installer host from source and package the NSIS EXE locally. The pipeline reuses Chromium's hermetic Windows SDK and bundled host tools, keeps the cross build in out/dao-win-x64[-debug], and preserves native Mac caches. windows-toolchain setup --accept-license can download Microsoft's public VS 2026/Windows SDK packages and create the required archive entirely on Mac, including ATL, DIA, debugging tools, runtime DLLs, and Chromium environment files. The pinned downloader and package hashes are verified; downloads are cached and incomplete inputs fail before an archive is configured. Existing private SDK archives remain supported through configure/setup/export; native Mac remains the default target. Both hosts publish Windows assets under the same existing desktop version/tag. Windows build/release cancellation stops the owned process tree and waits for cleanup; unrelated build jobs remain independent. Failed tree termination is reported explicitly instead of claiming successful cancellation. rebuild -- -- --release reuses the release cache for installer verification; plain rebuild continues to use the debug cache. See development.md for setup and verification requirements.

Windows updates

browser/updater/dao_windows_updater.* uses Chromium networking to check https://dao-release.msgbyte.com/windows-update.json after a 30-second startup delay when due, then daily. It runs only for registered per-user x64 installations using the default user-data directory, excluding component builds and Guest/Incognito-only starts. macOS continues using Sparkle.

The updater verifies an Ed25519 signature over the exact metadata payload, requires a newer Dao version and no Chromium downgrade, and accepts only the fixed R2 installer URL. Metadata is limited to 64 KiB and installers to 1 GiB; redirects and credentials are disabled. Size and SHA-256 are checked before caching in the user-restricted Dao/Updates directory and again before launch. A signed ready update survives browser restarts. Settings About exposes localized checking, downloading, current, ready, unsupported-installation, and error states; the sidebar only shows its existing update control for ready/applying states.

Applying an update starts an authenticated, current-user-only named-pipe handoff to the existing NSIS installer host without WebView2. The helper waits for an explicit graceful-exit commit and the original browser process to exit. Cancelling an unload/download prompt cancels the handoff, including a later unrelated quit. The helper rechecks registration and other processes, silently installs into the existing directory, and relaunches with session restoration. It never force-kills browsers. Installer errors show localized retry guidance and log locations. Existing Windows versions without this updater need one manual upgrade first.

1. Vertical Sidebar

An Arc-inspired vertical sidebar replaces Chromium's top tab strip — the single biggest UI change in Dao Browser. The sidebar is a hybrid: a C++ Views container hosts a Lit/TypeScript WebUI that renders the actual tab list, favorites, and controls.

1.1 Sidebar Core (C++ Views)

• DaoSidebarView (sidebar/dao_sidebar_view.{h,cc}) — Main container, 240px default, collapsible to 4px with animation
• Drag-to-resize — Mouse drag, 150–400px range, ignored while collapsed; width preserved across collapse/expand cycles
• Edge hover auto-expand — Hovering the collapsed sidebar's left-edge strip temporarily expands it; leaving collapses it again. A window-wide mouse monitor keeps the edge active in fullscreen (where the collapsed sidebar has zero width) and collapses even when the cursor leaves before entering the expanded sidebar. Webpage fullscreen never reveals it. Manual collapse state is unchanged
• DaoSidebarUIHandler — Mojo bridge between sidebar C++ and the WebUI (media state, folder persistence, tab commands)
• Incognito indicator — Native shield-check status icon beside the sidebar collapse button in Incognito windows, with a localized privacy tooltip
• Sidebar context menu — Native right-click menu support with registered shortcut labels for Duplicate Tab, Copy Link, and Close Tab. When the local MCP server is enabled, regular-profile tabs also expose Copy Tab ID for stable MCP targeting. Incognito and Guest windows keep the action hidden.
• Move tab to top — The regular tab context menu moves a tab to the top of the sidebar list, or to the top of its current folder without changing membership. Loose split tabs move together in their existing order. The saved sidebar order survives reloads and session restore.
• Close duplicate tabs — The sidebar context menu keeps the most recently active tab for each URL. After all close attempts finish, a localized native toast reports how many duplicate tabs actually closed. Pages retain their normal leave-confirmation flow; cancelled closures are excluded from the count.
• DaoTabTooltipView (sidebar/dao_tab_tooltip_view.{h,cc}) — Hover contextual info next to the sidebar
• Tab hover previews — Settings > You and Dao exposes the profile-scoped dao.tab_hover_preview_enabled preference, off by default, with a text-free, theme-aware illustration of the feature. Chromium's ThumbnailTabHelper is attached on every platform (tab_helpers.cc.patch) so page readiness is tracked from the first navigation, but its switch-away capture in tab_strip_model.cc.patch only runs while the preference is on. Only the tab the user is leaving is snapshotted, as a downscaled in-memory JPEG; background tabs are never force-rendered because Dao reads the stored data instead of subscribing to the thumbnail. Entering a sidebar tab row immediately sends showTabPreview; for tabs that are not on screen, HandleShowTabPreview draws that snapshot above the title in a card pinned just right of the sidebar and level with the row, sliding up to stay inside the window. The card is as wide as the 240 DIP snapshot and wraps the title to two lines before eliding. The card takes no sidebar space, hides on leave, click, or drag, and suppresses the delayed title tooltip; tabs without a snapshot keep the settled title tooltip. Navigations clear stale snapshots, and tall cursor-anchored tooltips flip to stay inside the window. Toggling applies without restart; turning it off stops captures and hides previews, while snapshots already in memory are released as their tabs navigate or close.

1.2 Sidebar WebUI (dao://sidebar)

• dao_sidebar_app.ts + sidebar.{html,css,ts} — Lit application root
• sidebar_bridge.ts — Mojo client wrapper
• dao_sidebar_section.ts — Reusable collapsible section container
• dao_tab_list.ts / dao_tab_item.ts — Vertical tab list, dual-line layout for the active tab (title + URL)
• Tab close-button focus — Close buttons stay out of sequential Tab navigation, and mouse clicks do not leave them focused for accidental Space/Enter activation. Close-tab shortcuts and context-menu actions remain available.
• Active-tab auto-scroll — Expands a collapsed folder when one of its tabs becomes active, then smoothly keeps the active tab inside the tab-list viewport
• dao_favorites_view.ts — Pinned site icon row
• dao_pinned_tabs_grid.ts + DaoPinnedTabModel — Persistent Pin grid with stable logical backing identities across navigation, discard/WebContents replacement, session restore, and Chromium session-command compaction. Open backing tabs are resolved across every browser window in the same profile, so activating a Pin focuses the existing tab instead of opening a second copy. Pin mutations are propagated to every same-profile sidebar handler before persistence, preventing a stale window from rewriting newer state. Dragging a Pin into another window's ordinary tab list moves its backing tab into that window. URL remains display/reopen metadata and is used for legacy migration only when exactly one candidate exists. Confirmed dormant items reopen once; identity conflicts fail closed without increasing the tab count. Pin state is serialized through a shared sequenced writer and atomically replaces the previous profile file.
• dao_folder_item.ts / dao_folder_model.ts — Folder grouping with profile-wide persistence and per-window rendering. Ordinary tab identities are recorded in the session log as soon as the sidebar exposes them. Stable session tab IDs preserve membership across window transfers and restart; partial restore and other windows never prune unmatched references. Explicit edits are merged against the latest profile snapshot, written in sequence with atomic file replacement, and propagated to all same-profile windows. Initial loads and refreshes do not rewrite the file. Drag ordering maps visible rows back to stored positions, including when other windows have hidden tabs or folders. Concurrent moves and unfoldering preserve one global membership per tab; stale edits cannot resurrect closed tabs. Legacy window snapshots are merged on read without losing their folders. URL matching for legacy references without a stable ID is restricted to session-restored tabs, so newly opened tabs never inherit an old folder or position merely by visiting the same URL. Off-the-record windows keep folders in profile-owned memory and never access the regular profile's folder file. Every folder context menu exposes Unfolder, which removes the folder and releases its child tabs in place, and Delete Folder, which uses a Dao native system confirmation dialog before closing the folder's currently matched child tabs. The folder is deleted only after those tabs actually close; cancelling either confirmation or a page's beforeunload prompt preserves the folder and remaining tabs.
• AI tab classification — Once an Agent model is configured, the sidebar background and ordinary-tab context menus expose Classify Tabs with AI. The tab menu also offers Classify Tabs Below with AI, using sidebar visual order and excluding the clicked tab. Both actions group only loose HTTP(S) tabs in the current window; pinned tabs, split panes, existing folder members, and Agent/MCP-controlled tabs are preserved. Off-the-record and Guest windows do not expose classification. Each request sends the chosen tabs' titles and URLs plus the profile's existing folder names and IDs to the configured model, without page content, chat history, or browser tools. Existing categories are preferred; new folders are created only when needed, in the interface language. Categories are the existing folders, with no separate category database or pre-created empty folders. You and Dao > Tab categories lists all of them and supports adding, renaming, and deleting categories. Deleting a category there releases its tabs in place across windows without closing pages; the sidebar's separate Delete Folder action retains its close-confirmation flow. Names must be nonblank, unique without regard to case, and at most 100 Unicode codepoints. Changes persist through the existing profile folder file and notify both Settings and all same-profile sidebars. Classification uses the resident Agent's model adapter without opening a chat, permits one request per profile, and aborts after 60 seconds. Invalid, incomplete, or duplicate assignments fail without changing folders. Closed, transferred, navigated, pinned, or newly grouped tabs are excluded when results are applied; manual edits or reordered snapshots can discard the result with retry feedback. Closing a tab, including one outside the chosen range, does not discard the classification of surviving tabs, even when the newly active tab automatically expands its folder. The final atomic write compares normalized snapshots so unchanged legacy data remains writable, and rejects newer folder data rather than overwriting it. Classification does not activate or navigate tabs, and uses Dao native toasts for progress, completion, empty scope, and failure. Requests exceeding 1,000 tabs, 500 existing folders, or 512 KiB fail without partial classification.
• Configurable stale-tab expiration — The "You and Dao" Settings page stores a profile-scoped integer from 1–720 hours (24 hours by default); the sidebar's "Move Stale Tabs to stale" action reads that value when run, validates it defensively, and archives only qualifying ordinary tabs. Closing an ordinary active tab skips archived tabs when another ordinary tab remains. If only stale tabs remain, or the closed tab was already in stale, Chromium's normal choice is kept and the folder expands to it.
• dao_new_tab_button.ts — New-tab button
• dao_download_button.ts — Download flyout trigger
• dao_media_control.ts — Per-tab media playback controls

1.3 Tab System Foundations

• New-tab placement — Ordinary new tabs default to the top of the unpinned list, including foreground/background links and navigation into another window. Link tabs retain their opener without automatically joining its native group. Explicit insertion positions and groups, session restoration, duplication, drag placement, and Split View retain their intended positions.
• DaoTabIdentity (dao_tab_identity.h) — Stable cross-window tab IDs decoupled from TabStripModel indices, migrated across WebContents replacement and persisted in session extra data
• DaoTabCommands (dao_tab_commands.h) — Tab action vocabulary (duplicate, pin, copy URL, close, etc.)
• DaoCrossWindowDrag (dao_cross_window_drag.{h,cc}) — Shared parsing and tab resolution for dao-tab-drag:<session_id>:<tab_index>:<tab_id> payloads; legacy index-only identities remain readable. Stable IDs prevent moving a different tab when the source window reorders during a drag. Existing-window and Split View drops use the same transfer helper.
• Move tab to a new window — The ordinary tab context menu uses Chromium's native move command and localized label. Dragging a tab onto the desktop creates a window before transferring its contents; dragging the only tab moves the existing window. Desktop drop detection and window placement use primary-display global coordinates, including on displays of different sizes. Native drag completion controls tear-off, while successful drops and Escape cancellation only clean up drag state. Cross-window folder drops are rejected; ordinary tab-list drops never remove a destination window's folder membership by interpreting a foreign tab index.
• Detach guards — Prevents accidental reordering while dragging
• Patches: tab_strip_model.cc.patch, tab_helpers.cc.patch

1.4 Address Bar and Active-Tab URL

• DaoAddressBarView (dao_address_bar_view.{h,cc}) — Embedded URL pill (14px radius), referenced by sidebar / command bar / control center; adapts text color to background luminance
  • Shows a separately clickable red Lucide ShieldOff before the URL pill when Chromium reports a warning or dangerous connection state; clicking it opens native Page Info
  • The stop/reload button and page-load glow follow Chromium's loading UI state. Late iframe loads and same-document navigation stay quiet, including when switching tabs; normal page navigation still shows loading feedback.
• Active-tab URL display is rendered inline in the dual-line tab item
• Native Side Panel compatibility — Chromium Side Panel content and its 40px header remain client-hit-testable where they overlap Dao's macOS titlebar, so header controls such as Pin and Close continue to receive clicks

1.5 Command Bar (Spotlight-style)

• DaoCommandBarView (dao_command_bar_view.{h,cc}) — Translucent scrim + frosted floating panel + layered shadows
  • Cmd+L → Show() pre-fills current URL (SetFocusToLocationBar(is_user_initiated=true))
  • Cmd+T → ShowForNewTab() opens the Command Bar without creating a tab; navigation creates the destination tab only after submission
  • Ask AI — Submits prompt directly to the Agent
  • System commands — Normal input supplements Chromium results with at most two whole-title or alias prefix matches; an exact safe UI command is promoted to the front. The Enable > command mode toggle in You and Dao settings is off by default and independent of enhanced suggestions. When enabled, > switches to provider-free command mode and lists or filters all eight commands: Open Settings, Reopen Closed Tab, Copy Current Link, Open Downloads, Open History, Manage Extensions, Open Agent Settings, and Open Task Manager. Localized aliases augment the English matching vocabulary. When disabled, > remains ordinary input; normal command suggestions remain available.
  • Command rows use localized titles, native Lucide icons, a Command intent, availability checks, and disabled reasons. Arrow keys skip disabled rows; Tab and Right Arrow fill the title without executing it; Enter and clicks recheck availability before dispatch. Copy Current Link remains bound to the tab that was active when the bar opened, and Task Manager reuses its existing native window.
  • Asynchronous results preserve explicitly selected rows. Restore uses the current tab, window, or group title for display and completion; Agent Settings follows the browser's existing Settings availability checks.
  • URL-vs-query detection heuristics + provider inline completion when no selection preview is active; the native textfield contains the typed prefix plus a selected completion suffix, so Select All, copy, and replacement edits include the completed text, while long suffixes keep the typed prefix and caret boundary visible
  • Every non-blank query keeps one exact-input Search action alongside the full Chromium autocomplete result. The dropdown remains five rows tall and scrolls by pointer or keyboard when more results are available; empty and whitespace-only input shows no suggestions
  • The first result is highlighted automatically without writing that row's fill_into_edit value into the native textfield; provider-owned inline completion remains a distinct selected suffix, and only explicit arrow-key browsing previews a row while the original query remains separate and autocomplete is not restarted
  • Keyboard-first: Backspace rejects a non-identical preview without deleting the query; that exact rejected suggestion stays suppressed while the user continues typing, and later provider results remain highlight-only until the user browses or accepts them; Right Arrow or Tab accepts the highlighted or previewed row without navigating, Enter submits the selected result, and Esc dismisses
• DaoSuggestionItemView (dao_suggestion_item_view.{h,cc}) — Suggestion row for autocomplete matches, Ask AI, and accessible enabled or disabled commands
• DaoNewTabButton also routes through ShowForNewTab() without creating a tab until the user navigates

1.6 Downloads (sidebar-anchored)

• Parallel downloading — Settings > You and Dao exposes the profile-scoped dao.parallel_downloading_enabled preference, explicitly off by default. Changes apply immediately to new downloads without restarting Dao. Each item captures the choice before its job and file writer start; active downloads and same-session resumptions retain that choice. Restored downloads with persisted parallel slices retain parallel mode so partial files can resume safely. Chromium's native eligibility checks, request splitting, retry, and assembly remain in charge; unsupported downloads stay serial. Dao's preference is the desktop source of truth, independent of chrome://flags and its restart state. Upstream tracking: this reuses Chromium's experimental ParallelDownloading implementation (flag enable-parallel-downloading), not a Dao download engine. On each Chromium upgrade, track whether that experiment ships, changes default, gains runtime configuration, or is removed; review its Finch parameters, protocol eligibility, job selection, resume/slice handling, and file obfuscation checks. Adapt or retire these integration patches when upstream provides an equivalent runtime setting. Source entry points are components/download/internal/common/{parallel_download_utils,download_job_factory, download_item_impl,download_file_impl}.cc and chrome/browser/download/chrome_download_manager_delegate.cc.
• Download-start feedback — A blue download icon pops out at the pointer position captured when a new download is created, follows a 560ms upward quadratic throw into the sidebar button, and shrinks/fades on arrival. The button briefly pulses and highlights. Feedback is independent of progress, including files that complete immediately, and only runs in the active source window. Bursts before the sidebar replies coalesce into the latest flight. Reduced motion uses a highlight without flight or scaling; a collapsed sidebar uses the shared localized Dao toast. Restored and transient downloads do not trigger the animation.
• DaoDownloadFlyoutView (sidebar/dao_download_flyout_view.{h,cc}) — Anchored flyout panel
• DaoFileIconUtilMac (sidebar/dao_file_icon_util_mac.{h,mm}) — Native macOS file icon retrieval
• Active-download hover details — After a settled 400ms hover, an active download row reuses the native sidebar tooltip to show the full filename, transferred/total size, percentage, current speed, and reliable remaining time. Long filenames wrap in detailed mode, and the popup flips above its anchor when needed to remain inside the browser window. Unknown totals, percentages, speeds, and estimates are omitted rather than replaced with misleading values; leaving or removing the row hides the popup immediately.
• Latest completed download — The sidebar download button becomes a persistent filename label when an observed in-progress download completes. Clicking the label opens that file, while its close button only dismisses the label. Dragging the label starts a native file copy drag to the desktop, folders, or applications that accept files, then dismisses the label and download list without opening the file. Holding the left mouse button keeps the label alive when leaving its hover area, so outward drags can start even at the label edge; releasing without a drag or losing focus dismisses it. The drag uses the download's actual target path, including custom save locations. Hovering opens the existing download list; the label stays visible while moving between both surfaces and is dismissed after leaving their shared hover area. It never expires on a timer, and later completions replace the displayed item without adding a separate history queue.

1.7 Content Area Styling

• DaoCornerOverlayView (dao_corner_overlay_view.{h,cc}) — 10px rounded corners + 6-step soft shadow overlay on web contents
• Adaptive theming — Content area switches light/dark text and separators based on page luminance
• DaoColors (dao_colors.{h,cc}) — Shared blue accent (70,120,190) plus the light/dark hierarchy tokens; consumed by chrome_color_mixer.cc.patch
• DaoLucideIcons (dao_lucide_icons.{h,cc}) — Unified Lucide icon set

1.8 Toast and Feedback

• DaoToastView (dao_toast_view.{h,cc}) — Shared lightweight fade-in/fade-out toast for native browser feedback, including Copy URL, webpage Copy Image, QR decode failures, Control Center actions, and pinned-tab close confirmation. The pinned-tab message stays inside the Dao content area, is exposed as an accessibility alert, and preserves the existing per-tab repeat-to-close behavior. The Control Center Dark action remains clickable while system appearance is light and explains the system-dark requirement through this toast; callers retain action-specific localized text

2. AI Agent System

The AI Agent is Dao's flagship feature. Unlike browsers that bolt on a chat sidebar, Dao integrates the agent into the page lifecycle itself — it can read DOM, click elements, navigate, and remember context across sessions. Every layer (C++ Views, WebUI, Mojo bridge, LLM runtime, vendor pipeline) is purpose-built for agentic browsing.

The stack includes: LLM tool calling, long-term memory (SQLite + FTS5), proactive suggestions, a skill system, and page-aware tools (page capture, readable extraction, element interaction, accessibility tree, resource inspection).

2.1 Agent Core Services (src/dao/browser/agent/)

• DaoAgentMemoryService (+ DaoAgentMemoryServiceFactory) — Profile-keyed long-term memory service, SQLite backend, background sequenced execution
• DaoAgentMemoryStore — SQLite FTS5 full-text search store. Five direct store round-trip tests remain disabled because test-time RazeAndPoison conflicts with direct Init(); focused service and read-path coverage remain active.
• DaoAgentMemoryTypes (dao_agent_memory_types.{h,cc}) — Episodic / semantic memory record types
• DaoAgentProactiveEngine — Navigation-triggered proactive suggestion engine
  • Scenario matching (URL pattern + page hints)
  • Episodic memory matching
  • Learning pipeline triggers
• DaoAgentScenarioRegistry — Scenario registry (seed + personal)
• DaoAgentSkillService (+ DaoAgentSkillServiceFactory)
• DaoAgentSkillTypes (dao_agent_skill_types.{h,cc})

2.2 Agent Tab Integration (C++ Views)

• DaoAgentSidebarView (dao_agent_sidebar_view.{h,cc}) — WebUI-driven container, preloaded for fast toggle
• DaoAgentCursorView (dao_agent_cursor_view.{h,cc}) — Native Codex-style black-and-white cursor with a blue glow, direction-aware tilt/compression, damped arrival wobble, and the existing Dao click ripple. Visuals render only when the pinned target is the active tab of a visible, non-minimized, active window. Background moves are successful visual no-ops, while background clicks skip animation and keep dispatching through the pinned DevTools target. Short foreground moves use direct easing; long moves follow a bounded curved path.
• DaoAgentLockBannerView (dao_agent_lock_banner_view.{h,cc}) — Animated banner shown while AI controls a tab
• DaoAgentLockTabHelper (agent/dao_agent_lock_tab_helper.{h,cc}) — Per-tab lock state observer
• Window-scoped tab automation (automation/dao_tab_tools.{h,cc}) — Shared Agent/MCP list, switch, open, and close operations stay inside the authorized browser window. Agent turns start on the current page, then keep their stable target when the user changes tabs, windows, or applications; Agent switch_tab retargets without activation and open_tab creates a background target. MCP retains its existing activating switch/open behavior. Sessions follow the same stable tab across WebContents replacement, tab IDs are reconciled to remain unique within a window, and ambiguous selectors fail closed. New targets are limited to HTTP, HTTPS, or about:blank; close results wait for unload approval and retarget only after the tab is actually removed.
• Scoped semantic page automation (automation/dao_page_tools.{h,cc}) — Agent and MCP clients can query a bounded set of elements by selector/ref scope, role, accessible name, text, visibility, enabled state, and first/last/index selection. Ref scopes require the document and snapshot tokens that produced the ref, preventing a reused ref label from resolving inside a newer snapshot. Query and full-tree results carry document and snapshot tokens; click_by_ref revalidates those tokens plus optional URL, visibility, enabled, text, role, and ancestor preconditions in the same page script that dispatches the click, so navigation, a newer snapshot, or a changed target fails closed.
• Batched Agent browser actions (resources/agent/pi_tool_adapter.ts, agent_bridge.ts) — Browser tools emitted in the same model response execute sequentially through the existing runtime. A failed or invalid earlier tool call skips later browser actions in that response, including legacy error results without a code. The default prompt batches only known arguments and observes again at decision boundaries; callers must reacquire refs after any successful query or tree snapshot.
• Guarded form input and semantic waits (automation/dao_page_tools.{h,cc}) — Shared Agent/MCP fill_by_ref replaces or clears a visible, enabled, writable text input or textarea after validating document/snapshot/ref tokens, optional click preconditions, and focus. A synthetic, cancelable beforeinput hook runs in the same page task as the Chromium editor operation; cancellation preserves the value, and focus, target identity, editability, and preconditions are checked again after handlers run. The editor restores the full selection before replacing or clearing and emits trusted input events for controlled fields; success describes the local value, not submission or task completion. press_key_chord dispatches trusted Chromium key events using US-layout key names. Keydown and keyup are queued together so cancelling or timing out while a page handles keydown does not leave the key held. Shortcut letters are case-insensitive without adding Shift; explicit Shift and standalone uppercase letters retain their meaning. Supported macOS editor commands include Cmd+A, Cmd+ArrowLeft/Right for line boundaries, Cmd+ArrowUp/Down for document boundaries, Shift selection variants, Cmd+Backspace, and Cmd+Z/Shift+Z, alongside page defaults such as Enter and Tab. wait_for_element reuses semantic query filters with bounded 100 ms polling, a 30-second maximum, and cancellation/navigation cleanup; pending waits preserve refs, success creates a fresh snapshot, and exact zero matches requires an existing scope. Agent bridge deadlines accommodate the full native element/network wait budgets.
• Session-scoped DevTools automation (automation/dao_devtools_tools.{h,cc}) — Agent and MCP clients share native network, console, and page-resource tools. Network tracking returns a monotonic cursor, and wait_for_network_response waits for a later completed response by wildcard URL, method, status, or a bounded simple dotted JSON path while projecting only requested values. Domain requests persist independently from confirmed state; events arriving while an enable attempt is pending are staged for that exact generation and host, then committed by a matching success or dropped after all matching attempts fail, cancellation, or a binding change. Clear actions remove both committed and currently staged events without cancelling the matching enable attempt, so only later events can commit. Within one binding, confirmation is monotonic after any successful enable and resets only when the binding changes. Network and console capture retain recent entries under UTF-8-safe field, entry-count, and aggregate-byte budgets with explicit dropped/truncated metadata. One iterative, deduplicating resource traversal synthesizes each frame's Document and reports item, URL-byte, depth, source, scan, and match limits separately. Resource reads require the current exact (frame, URL) tree entry when a frame is supplied and reject known decoded sizes over 1 MiB before fetching content; independent per-command response ceilings cover missing metadata. Resource search reports attempted, successfully searched, failed, and content-limited sources plus explicit incompleteness, including bounded Document DOM ingress.

2.3 Local MCP Server

• Process-global native service (mcp/dao_mcp_service.{h,cc}) — A default-off Local State preference controls a single browser-process MCP endpoint that keeps up to 32 authenticated local clients admitted. When a new client completes hello beyond that count, the service closes an idle connection (no pending approval or tool call), preferring never-approved sockets and then the least recently active one, releasing any tab leases it held, so the newcomer is admitted and the evicted helper reconnects lazily and re-approves on its next tool call; pre-hello sockets neither count nor get evicted; if every admitted client is busy, the newcomer receives an id-bound TOO_MANY_CLIENTS retryable error instead of a silent disconnect. Authentication and catalog discovery never start the approval timer, so idle clients can remain connected and continue listing tools. Each connection's first tool call snapshots the exact last-active eligible normal browser window and active tab, then requests native user approval before execution. Approval prompts are serialized. Each approved connection can retain multiple isolated tab targets in that window: non-tab tools accept an optional routing-only tab_id, while omission uses that connection's current target. MCP switch_tab and open_tab keep their activating behavior, make the resulting tab current for later omitted routing, and leave earlier controlled tabs available by ID.
• Explicit single-tab authorization — Supplying tab_id on a connection's first page, list, switch, or close tool call requests access only to that exact tab, including a background tab in another window. The native dialog shows its recorded title and URL and explains the single-tab scope. Unknown, ambiguous, forbidden, or lost targets fail closed without falling back to the active tab. list_tabs returns only the authorized tab; switching or closing other tabs and open_tab are denied before mutation. Closing the authorized tab ends control without adopting or disclosing a replacement. To authorize a different tab, reconnect with its ID and a reason. First calls without tab_id retain window authorization. Pending tool dispatch rechecks the live connection after each call so disabling MCP from an in-flight tool cannot access destroyed connection state.
• Settings master switch, connection, quick setup, and usage (mcp/dao_mcp_settings_handler.{h,cc}, resources/settings/dao_page/) — You and Dao groups the process-global MCP Local State switch, live connection status, profile-scoped usage, and enabled-only setup into one native-style card. It renders Disabled, Ready, Approval requested, and Connected states; shows sanitized client details and Stop only for an active authorized lease; and lists total and per-tool calls with a reset action. Usage counts each call that reaches the real executor, whether it succeeds or fails; validation, denial, unknown-tool, and pre-execution target failures are excluded. Quick setup defaults to Codex CLI and also offers a user-scoped Claude Code CLI command plus Generic MCP JSON. The preview and clipboard always contain the same native-generated content: CLI commands remain single-line, while Generic MCP is Chromium-native three-space pretty JSON. Malformed Generic MCP JSON fails closed by clearing the preview and leaving the clipboard unchanged; the former standalone configuration button is removed. Native POSIX shell quoting protects the running bundle's actual helper path and its explicit current user-data-directory argument, so Debug and custom-profile installs connect to the correct runtime endpoint.
• Hardened local transport (mcp/dao_mcp_transport.{h,cc}, dao_mcp_connection.{h,cc}, dao_mcp_runtime_files.{h,mm}) — The server owns all listener and connection I/O on Chromium's browser IO thread, uses a non-abstract Unix domain socket inside the user-data MCP directory, enforces owner-only directory/socket/metadata permissions, authenticates the peer UID plus a fresh 256-bit nonce, caps open sockets at four times the 32-client admission limit so hello-time eviction and rejection can drain while aggregate ingress credits stay sized for 32 admitted clients, and removes runtime artifacts on disable or shutdown. Atomic runtime.json metadata publishes the socket and nonce only inside that private directory. Per-connection and aggregate IO-thread credits bound requests posted but not yet consumed by the UI thread, terminal responses synchronously close only that connection's logical request gate, aggregate write budgets fail closed under backpressure, and graceful close has bounded request and write-drain deadlines.
• Versioned NDJSON protocol (mcp/dao_mcp_protocol.{h,cc}) — Protocol version 1 supports hello, tools/list, tools/call, and tools/cancel, with an 8 MiB line ceiling, 64-request/8 MiB pending-ingress budget, and structured errors. Catalog discovery is available before approval, while execution waits for approval and the external automation lease. Every MCP tool advertises a reason argument required on the first call of each connection; missing, blank, invalid UTF-8, or reasons over 1024 UTF-8 bytes fail before opening a prompt. Later calls may omit it, and this permission metadata is removed before tool execution.
• Central external-target eligibility and MCP lifecycle policy (automation/dao_browser_target_policy.{h,cc}, mcp/dao_mcp_session_lifecycle_monitor.{h,cc}) — Every MCP target stays pinned to its exact tab in the approved normal Browser and regular Profile, with no eligible-tab or active-tab fallback. HTTP, HTTPS, literal about:blank, and web-hosted PDFs are allowed; popup, Incognito, Guest, internal, extension, DevTools, Agent WebUI, file, data, and custom-scheme targets are rejected. Target destruction or forbidden navigation cancels and removes only that tab's work, lock, overlay, and CDP state; losing the last target, the Browser, or the Profile closes only the affected logical connection and releases its leases.
• Exact-window approval and control UX (dao_mcp_approval_dialog.{h,cc}, dao_mcp_control_banner_view.{h,cc}, dao_address_bar_view.{h,cc}, ui/webui/dao_sidebar_ui.{h,cc}, resources/sidebar/dao_tab_item.ts) — Execution leases display localized, fail-closed Dao system dialogs one at a time in the exact normal Browser selected for approval, with sanitized reported client metadata, the browser-recorded request date/time with time zone, a sanitized reason labeled as client-provided, window, Profile, and current-login warning. Queued prompts preserve their original reason and timestamp, and long reasons scroll within a bounded area. Before showing a prompt, Dao activates that native Browser window so approval requests arriving while Dao is behind another application come to the foreground; unanswered prompts time out after 60 seconds. Allow is intentionally not the default action. A robot button immediately before the URL pill appears only when the active tab is controlled; every controlled tab also shows a quiet robot in its sidebar close-button slot, replaced by the normal close button on pointer hover or keyboard focus. The address-bar popup shows that connection's client, version, current target, latest accepted tool call with live updates, controlled-tab count, and Stop. Stop cancels that connection's external work, releases its leases, and closes it without inserting a control row above page content.
• Per-tab peer contention — The browser-automation lease is exclusive per tab, so different Codex or Dao Agent sessions can operate different tabs concurrently. A second browser-tool session targeting an already controlled tab waits or fails with the stable retryable busy error before CDP execution; chat and non-browser tools remain available.
• Native stdio MCP helper (mcp/helper/) — The standalone dao-mcp executable speaks newline-delimited JSON-RPC and negotiates MCP 2025-11-25 or 2025-06-18 over stdin/stdout, discovers the authenticated browser endpoint from the active user-data directory, and bridges MCP string or numeric request IDs to bounded browser IPC IDs. Its initialization response opts out of Codex's shared tool-catalog cache and directs MCP clients to prefer Dao tools for Dao Browser work, use list_tabs to establish the initial target, preserve that target across follow-ups, and treat ambiguous open/click/select requests as page-local query_elements plus guarded click_by_ref interactions. switch_tab is reserved for explicit browser-tab navigation, while exported tool descriptions retain only the general Dao MCP preference. It maps the 34-tool catalog to MCP annotations, normalized object/scalar/list results to text plus object structuredContent, screenshot media to image content with its real MIME type, and tool failures to isError: true. Cancellation is forwarded to the browser and late responses are discarded. Stdout remains protocol-only; unavailable-browser diagnostics are deterministic stderr output.
• 34-tool external scope — The shared native catalog contains 35 Dao Agent browser tools; MCP exposes 34 and excludes only the Agent-specific resolve_element_context. Agent memory, skill, workspace, and web-provider tools are not part of the local MCP server.
• macOS helper packaging (mcp/BUILD.gn, dao_version.gni, chrome/BUILD_mcp_helper.gn.patch) — The helper is built independently from the browser service, receives the same Dao product-version build argument as the app, and is copied with executable permissions to Dao.app/Contents/Helpers/dao-mcp.
• Independent execution peer — MCP owns one isolated automation session, DevTools client, executor, cursor integration, and cancellation state per controlled tab. It reuses the shared native tab/page/DevTools implementations and lease coordinator without depending on the Agent WebUI lifecycle.

2.4 Agent WebUI (dao://agent and dao://skills)

Application shell (src/dao/browser/ui/webui/resources/agent/)

• agent.{html,css,ts} + dao_agent_app.ts — Chat app entry; its settings button uses a fixed native navigation command to open the unified dao://settings/agent secondary page and closes the sidebar only after the navigation succeeds
• skills.html + skills.ts — Skill manager standalone entry
• agent_bridge.ts — Mojo bridge
• agent_settings_{sync,native_bridge}.ts — One-time migration from the dao://agent local-storage origin and live synchronization with the Profile-scoped settings source of truth

Chat surface

• dao_chat_view.ts — Main conversation view (session resume, skill picker, dynamic chips, composer height tracking, cost stats / usage)
• Agent browser-turn lifecycle — New sends, retries, regeneration, and edited-message resends each acquire their own native turn before execution and release it on completion or failure. Editing an active response waits for both model cancellation and native cleanup before starting the next turn. Agent and MCP share the native browser tools and per-tab lease coordinator; their sessions, authorization, and turn lifecycles remain independent.
• Historical message editing — After stopping a response, use the user message's More actions > Edit menu to change its text and remove individual page, selection, element, PDF, image, or file attachments. Cancel keeps the original message intact. Save and resend persists the edited message, excludes removed context from the model request, and replaces all later messages while preserving earlier conversation history. Attachment-only messages remain valid while at least one attachment is kept.
• Latest Agent error retry — A terminal provider error exposes a retry action that reuses the original user submission, replaces only its failed assistant/tool branch, and preserves every earlier timeline entry; cancelled and historical errors cannot truncate the conversation
• dao_chat_history_panel.ts — History panel
• dao_compact.ts — Conversation compaction for context management
• dao_page_capture.ts — Convert current page to markdown and insert into the message
• dao_share_image.ts — Share-card image generation
• dao_tool_renderer.ts — Tool-call result rendering
  • Every tool call keeps its stable tool name visible; provider-specific search/fetch context is shown as secondary summary text, while parameters and output stay collapsed by default and can be expanded per call

Skills + tools

• dao_skill_manager_view.ts — Skill management surface
• skill_registry.ts — Skill catalog and lookup
• tool_catalog.ts — Tool catalog schema

Unified Agent settings (dao://settings/agent, overview entry #agent)

• The optional bundled Jev plugin has an experimental, default-off connection checkbox after the main provider settings and a separate default-off global tool permission. Its full HTTP(S) API URL, masked Bearer token and optional model ID persist in Profile settings independently of the main model. The model ID is trimmed for requests; empty or whitespace-only values use jev-latest. Opening or editing settings sends no inference request. Invalid or incomplete configuration is unavailable. MCP discovery lists run_browser_task only when the connection and tool permission are enabled with valid configuration; clients must refresh the tool list after settings changes.
• With both switches enabled, run_browser_task delegates a bounded subtask through a shared native executor available to Dao Agent and external MCP. Agent calls retain the existing turn and sequential scheduler; MCP calls retain connection approval and the exact authorized tab lease, and work with the Agent panel closed. Both enforce browser permissions. Jev uses the choice protocol, selects fill targets and known inputs separately to keep every choice below the service's 255-option limit, accepts only offered actions and known non-sensitive inputs, and verifies all completion predicates locally. Compact viewport snapshots and guarded refs support click, fill, scroll and wait (at most 20 steps / 60 seconds). Native input buttons and ARIA buttons retain their visible names in both observations and action guards. Main-document navigation waits within the task deadline, discards obsolete decisions, and rechecks completion on the new page before choosing another action. This initial snapshot excludes sensitive form controls (links and buttons that merely mention passwords stay clickable), all editable contenteditable forms (empty, true, and plaintext-only, case-insensitively), their nested controls, iframe and shadow-root contents; unsupported tasks return to the caller, and a non-HTTP(S) target stops with unsupported_target.
• Permission/configuration changes, stopping, cancelling an MCP call, revoking its connection or losing its target cancel pending plugin requests and prevent late responses from acting. Agent-owned tasks also stop when their WebUI unloads. Unloading also invalidates native tool callbacks before cancellation so pending ordinary tools cannot respond into a disabled WebUI; a reloaded Agent can start a new turn. Native checks reject old configuration revisions; credentialed redirects are disabled. Errors retain partial action evidence and timing/count metrics, with bounded stale-ref recovery and no-progress detection. MCP failures retain this structured outcome with isError: true. Ordinary browser tools do not invoke Jev automatically. Actual service compatibility and performance require a configured endpoint and representative end-to-end trials; no speedup is assumed.
• DaoAgentSettingsHandler stores durable Agent choices in Profile prefs and is shared by the Agent and Settings WebUIs
• Agent remains a compact top-level Dao-exclusive Settings entry beside You and Dao. You and Dao owns browser capabilities only; the complete Agent configuration, Memory, Workspace, Usage, Skills, and Dream controls appear exactly once on the Agent secondary page
• The Agent module is packaged in Chromium's shared Settings lazy bundle and reached from the compact overview entry. The detail page uses five vertical Settings sections: Model and connection, Behavior and context, Capabilities, Learning and analysis, and Data and management. It adds no section rail or tabs
• Model/provider credentials, session/display behavior, persona, page and conversation context, web search, memory/proactive suggestions, and Dream analysis are managed in the Agent Settings section
• The provider selector groups API formats (OpenAI-compatible, Anthropic-compatible) apart from named service providers. Only API formats show the Base URL field; its placeholder shows whether to include /v1 (OpenAI-style URLs do, Anthropic's does not, and a trailing /v1 on an Anthropic-compatible URL is dropped). Named providers always use pi-ai's catalog endpoint, and model ids outside the catalog (new releases, gateway aliases) reuse the provider's native API via pi_model.ts
• Test connection sends a one-line prompt with the current form values through the preloaded chrome://agent page (llm_connection_test.ts), so it exercises the same pi-ai path as chat. DaoAgentSettingsHandler relays the request between the two pages; the card shows the latency on success, or the provider's raw error, a timeout, or that the agent panel is not ready yet
• The persona card can restore the runtime default, while the Dream card can generate a report immediately when Memory and Dream analysis are enabled and keeps the existing Dream report history link available
• Tool group shortcuts and the expandable individual-permission list preserve the existing per-tool enable/disable controls. Rapid changes update one optimistic disabled-tool set and serialize complete-array writes before resynchronizing from the Profile snapshot
• Existing origin-scoped Agent settings migrate once, filling only values that have not already been configured in Settings; runtime/session state remains local to the Agent. Partial legacy usage records receive canonical defaults, while malformed values are rejected and initialized Profile data wins
• Session resume retains its established three-hour default and accepts zero hours. Configuration has independent loading, error, and retry feedback, so a configuration failure does not hide or disable management summaries
• The Agent section owns complete Memory, Workspace, and Usage management. These modules render as independent compact cards inside Data and management so their headings and actions remain visually separated. Memory and workspace data come from their Profile-keyed services; usage counters are stored in the Profile dao.agent_usage_stats pref, which is the source of truth shared with already-open Agent WebUIs
• DaoAgentSettingsHandler exposes only the management facade needed by the Agent section: memory summary/clear, workspace summary/reveal, and usage read/reset/record. It does not register workspace mutation messages
• dao://memory, dao://skills, and dao://dream remain secondary management pages linked from the Agent section rather than duplicate top-level settings

Settings shell (dao://settings)

• All top-level Chromium and Dao settings render as one continuous overview in the Dao Open Design shell. Its 184px table of contents, integrated search, 680px content column, 30px section rhythm, and light/dark tokens share one page background without a repeated Dao brand header or footer. Nested page index views are kept in normal document flow so their cards contribute real height instead of overlapping later sections. Search filters the table of contents to matching sections, clears hidden selection on zero results, and restores the captured pre-search scroll position without top-level routing
• Table-of-contents activation scrolls to a section and updates the URL hash; scrolling updates the selected item. Direct legacy top-level paths continue to resolve and normalize to overview hashes
• Complex management flows remain independent secondary pages. Returning from one restores the overview and its section/scroll context. Entering a secondary page from the overview starts at the top, including repeated visits to Agent configuration, without inheriting the overview's scroll offset
• Chromium settings components continue to own their routes, preferences, visibility gates, search integration, and external destinations; the shell changes presentation without replacing the settings inventory

LLM / runtime plumbing

• llm_config.ts — Model + provider configuration
• pi_app_storage.ts — Persistent storage abstraction
• pi_llm_stream.ts — Streaming LLM client
• pi_model.ts — Resolves provider/model/base URL into a pi-ai model
• llm_connection_test.ts — Runs the Settings "Test connection" request
• pi_tool_adapter.ts — Tool adapter
• chromium_types.d.ts — Type bindings for chromium WebUI APIs
• readability_bundle.ts / turndown_bundle.ts — Reader-mode + HTML→Markdown bundles

LLM tool set (see agent-console-api.md for the full schema)

• Page access: get_page_content / get_page_info / get_readable_content
• Page interaction: click_element, fill, scroll, etc.
• Accessibility tree generation and interaction
• Resource inspection (reverse-engineering helpers)
• Web access: web_search uses provider built-in search when available, optional Jina Search with a user-supplied API key as the local fallback, and DuckDuckGo HTML as a best-effort final tier with explicit anomaly verification-page reporting; fetch_url uses Jina Reader before browser fetch.

2.5 Vendor Pipeline (Generated, never hand-edit)

• npm run vendor — Compiles pi-mono / pi-web-ui and related deps from vendor.config.ts + vendor/entries/*
• Artifacts: agent/vendor/pi_runtime_bundle.ts and agent/vendor/pi_web_ui.css
• manifest.json sha256 drift check guards against direct edits

2.6 Dream Analysis (nightly behavior learning)

• Shared foreground activity service — an eager service runs once for each regular Profile, independently of Dream and Agent Memory; it is not created for off-the-record Profiles. At most one page is timed: the selected HTTP(S) tab in the active, visible, non-minimized browser window, or the selected pane when that tab is in Split View. Tab, navigation, window, suspend/resume, and timezone events settle elapsed time with a monotonic clock. A 60-second checkpoint bounds loss before an abrupt exit, normal shutdown writes a final checkpoint, suspended time is excluded, and a timezone change starts new local-calendar attribution without rewriting prior aggregates. Local midnight and 06:00, 12:00, 18:00, and 22:00 are exact boundaries, including 23- and 25-hour DST days.
• Privacy-minimized activity store — each regular Profile keeps its own DaoForegroundActivity.db, containing only aggregate elapsed milliseconds by local date, time bucket, and canonical host. It stores no full URL, path, query, fragment, page title, page content, or interaction log; snapshots checkpoint before reading, and retention is the current local date plus the preceding 370 dates.
• DaoDreamService (+ Factory) — profile-keyed scheduler: nightly (22:00–06:00 local, system idle ≥1h), daytime catch-up for yesterday, and manual trigger from Agent settings. Off by default (dao.dream_enabled), double-gated behind agent memory.
• DreamMaterialCollector — aggregates one day of signals: history (domain+title+time-bucket granularity, top 50; full URLs never leave the browser), search keywords (extracted in C++), agent conversation excerpts, proactive-feedback stats. Visit-count buckets remain available to the model, while measured foreground seconds are also aggregated by morning, afternoon, evening, and night for the report rhythm visualization. History continues to provide visits, titles, searches, coarse visit buckets, and visit duration. For each exact 06:00-to-06:00 Dream window, foreground time is selected per local date without overlap: dates before native tracking use legacy History; the tracking-start date and current date are native partial; completed retained dates are native full, including measured zero when no row exists; and pruned or failed native queries are unavailable rather than falling back. Daily and weekly reports never add History foreground time to native foreground time for the same date, though a weekly report may mix sources across different dates.
• dao_dream_runner.ts — resident agent WebUI executes the LLM summarization (user's configured provider) and returns structured one-minute recap data (summary, time-of-day rhythm, and up to three themes), habits, and a full morning-report markdown. The recap is persisted inside the report's existing material-stats JSON, so older databases need no migration.
• Results: memory suggestions remain report-local candidates until the user confirms one at confidence 0.95; rejection never deletes or rewrites an existing preference. The report is archived in the dream_reports table, with a morning report card in the Agent panel, per-candidate confirm/reject, and an optional debug view of the exact LLM input (dao.dream_debug).
• Agent morning report card — yesterday's unviewed report shows its one-sentence recap directly above the chat, with a localized read-report button below and a close button halfway outside the top-right corner. Legacy reports reuse the report page's markdown-summary fallback. Reading opens the standalone report and immediately dismisses the card locally; closing also persists the dismissal without marking the report viewed or removing it from history.
• dao://dream one-minute recap — responsive two-column report with a 53-week real-report activity heatmap, compact daily-and-weekly history rail, localized date-and-active-duration tooltips for report-bearing heatmap cells on pointer hover and keyboard focus, summary card, measured foreground-focus rhythm, topic cards, aggregate counts, memory-candidate actions, and a folded full report. Existing rerun, image sharing, source-domain exclusion, and debug controls remain available. Legacy markdown-only reports derive a summary and topic cards locally instead of rendering an incomplete page. Newly generated reports persist foreground_source, foreground_coverage, and coverage_seconds; the UI labels partial coverage and does not present unavailable coverage as measured zero, while older reports without these keys retain their legacy rendering unchanged.

2.7 Dao Home Personal Web Runtime (dao://home)

• URL-only personal website — dao://home/ and its internal paths load one Profile-owned project. v1 has no new-tab, startup, sidebar, Settings, or other discovery entry, and regular Profile is required; Incognito/Guest are disabled.
• Existing Agent integration — The two empty-state actions open the existing right-side Agent. Home-specific atomic tools are injected only for a turn pinned to the exact active Home tab and published revision, and native code revalidates the pinned document and its one-way Home authorization before and after asynchronous work. That document authorization is the authoritative lifecycle signal: focusing the Agent sidebar or a different browser window does not retarget the turn, and macOS occlusion does not invalidate a still-selected Home document. Selecting another tab in the initiating window, truly hiding the Home document, or navigating it still invalidates the authorization. Each active Home turn also receives a bounded construction contract covering the required manifest, directly runnable browser files, V4A patch grammar, strict CSP and opaque-origin runtime constraints, and the atomic apply-preview-publish sequence. It directs generated interaction code into project script files, memory-only state through dao.session, and external navigation through the trusted confirmation API instead of inline script, Web Storage, or raw network APIs. Native tool failures include their stable error code in the model-visible message so the Agent can correct a rejected patch instead of guessing another project format. Re-entrant manual or command-bar submits are ignored while a send is establishing or running its native turn, so a duplicate UI event cannot replace the turn and invalidate its Home lease. Publication, trusted import, and rollback calls carry a one-way document/turn lease into the blocking project store; tab, navigation, visibility, or turn loss invalidates the lease, and a stale turn cannot acquire a replacement after the Home returns to the foreground. Publication rechecks the lease while holding the final commit guard. A cancelled rollback also discards its browser-owned temporary draft before returning. The Agent tool settings expose the complete Home group, including asset import, so the group or individual Home tools can be disabled with the shared tool policy. home_preview loads the exact immutable draft in a temporary untrusted sandbox; both regular and permission-expanding Agent publication paths require that draft's in-memory success receipt. Existing-project edits must list and read every target file first. Focused changes use exact V4A hunks, while whole-file rewrites use the atomic home_replace_files tool, which puts all related full-file replacements in one atomic draft instead of deleting and re-adding paths. Both routes create an unpublished validated draft and retain the same preview and publication gates. The Agent composer's DOM-context and element-screenshot pickers also work on the active Home document. A narrowly scoped legacy UI session may capture that exact dao://home target. While picking, the trusted host temporarily covers the generated-app iframe so pointer events never reach project code, then asks the fixed runtime to hit-test the pointer coordinates without dispatching a click. The cover is removed immediately after selection or cancellation and is never installed during ordinary Home use. Selection prefers a stable data-dao-node-id and records it for home_get_selected_element; existing projects without node IDs receive a bounded unique CSS locator instead. Selection suppresses the element's normal action and translates its bounds back into top-level screenshot coordinates. Other internal pages remain ineligible for browser automation.
• Built-in design direction — Every Home creation and editing turn receives a compact browser-owned design-director contract, so users do not install or select a design skill. The Agent chooses one coherent visual point of view, uses explicit hierarchy, spacing, type, color, radius, and responsive rules, rejects common generic AI-page defaults, and silently reviews the draft for hierarchy, craft, function, originality, responsiveness, and runtime safety before preview. The approach is adapted from the MIT-licensed OpenDesign director protocol and is bundled locally; generation does not depend on a live third-party design service.
• Local project ownership — DaoHomeProjectService stores validated text files, immutable published revisions, drafts, summaries, grants, rollback, and grant-free JSON export/import under the Profile. A secondary trusted menu exposes summary-first version history, a read-only source tree, and an explicit older-version-to-current source diff. Export includes runtime dependency guidance but excludes approvals, credentials, Agent data, and collected source content. A destructive trusted-menu reset requires explicit confirmation, then atomically returns Home to its initial empty state and deletes every project revision, temporary draft, connector grant, and local diagnostic; a failed or stale reset leaves the published project unchanged. Export/import round-trips the bounded immutable revision history and its source files. After explicit confirmation, the imported draft must pass the same isolated preview as an Agent draft before it can create a new local head, and the imported project always remains disconnected. Import rejects a package whose declared current files differ from its exported head, whose exported revision is not the final head, or whose parent/restore graph is disconnected. It discards all temporary draft/history files on any failed, cancelled, or abandoned operation.
• Privacy-minimized history bootstrap — Only an explicit user action reads the last 30 days of local history. A native reducer converts eligible HTTP(S) visits into at most 12 ranked origin-root launch targets and at most three feed-capable source candidates discovered from distinct routes in a repeated route family. Candidate slots are reserved independently from the twelve most-frequent launch origins, so high-frequency utility sites cannot crowd every content source out of the brief. Origin identity includes scheme and port, and route-family working state is strictly bounded. No domain catalog or site-specific collection recipe participates in discovery. Generic semantic route signals keep account, authentication, mail, payment, settings, search, and discovery surfaces out of automatic feed collection. The Agent receives only stable action IDs, label/category hints, canonical root URLs, source eligibility, and locale—no browsing titles, visit counts, time buckets, paths, or full visited URLs. Feed candidates include a browser-owned bounded result schema and generic collection, intent, and content-kind starting hints. The Agent dynamically proposes the exact same-site feed URL and its site_feed, following, subscription, or activity semantics while authoring the collector. The trusted browser rejects missing, duplicate, unsupported, credential-bearing, or cross-site proposals and binds the accepted URL and semantics to the visible permission and test transaction. This lets the generated collector adapt to the site's actual feed conventions, including a meaningful same-site subdomain, without turning site identities, collection paths, or DOM selectors into browser code. The Agent dynamically authors each collector from the candidate website and the fixed page RPC instead of selecting a browser-hardcoded site recipe. Personalized feed intents must stay inside semantic feed-card or activity containers; the trusted manifest validator requires every collection query to use an inline quoted selector for structured repeated-card roots, so its scope can be audited without evaluating generated code. It rejects both generic and content-path-constrained whole-page link fallbacks, so a successful collector cannot silently degrade into recommendations or site navigation. Personalized collectors query card roots and extract structured fields through ordered descendant-selector fallbacks, making them less dependent on a single internal title-link class. When card classes have drifted, a collector may try a bounded union of alternate semantic card roots but must return an empty result rather than leave the personalized container. The brief is never persisted by Home. The exact Home tab must still be active when the asynchronous history query completes, and leaving that Home document clears any unconsumed material. A random one-shot token binds the material to the exact external history prompt and Agent turn for that document; a normal or replacement prompt, another window, or another turn cannot consume it. Replacing or failing to dispatch the prompt and timing out or failing Agent chat initialization, and aborting or ending the claimed turn clear the material. Losing the Home owner while Agent bootstrap still awaits the project snapshot also releases the browser-control lease, and the native begin operation is explicitly cancelled if its WebUI callback times out, so MCP and later Agent turns are not left busy.
• Feed-first history Home — The history turn builds a comprehensive information portal, never a launchpad or browsing report. Quick navigation remains compact and preserves every launch target, while successful sources produce a prominent continuous feed and source/category controls. The Agent chooses a top-aligned, inline, single-column, split, or lateral composition from the actual content and viewport instead of inheriting a mandatory sidebar or fixed column width. Source-free fallbacks keep the required feed state compact rather than turning most of the page into an empty panel. It asks the trusted Home UI for one grouped decision covering up to three proposed live sources, tests selected sources sequentially, and publishes one final revision. Rejected, authentication-required, runtime- failed, and schema-failed sources degrade to launch-only actions; an empty selection or all-failed run still publishes a useful launchpad. If no source candidate exists, the browser binds every supplied candidate up to the three-source limit to its AI-authored conventional collector module in the provisional draft, replaces model-authored connector declarations with canonical read-only permissions, and writes the bounded result schema before permission is shown. The detached executor uses the regular Profile so these collectors reuse an existing signed-in session without receiving credentials. A missing, empty, or structurally unsafe authored collector is omitted on a per-source basis before the grouped permission request; valid collectors in the same batch still proceed to permission and testing instead of one broken candidate invalidating the whole bootstrap. A brief with no candidates transitions directly to disconnected final construction without presenting an empty permission dialog. Provisional drafts are never previewed or published. The grouped decision is exempt from the ordinary Agent bridge timeout, completed decisions are idempotent, and a timed-out pending decision can be atomically resolved to an empty selection on the same provisional draft instead of stranding the transaction in an already_exists state. Successful tests expose only bounded native-generated sample_shape type and empty/non-empty metadata to the Agent; raw values, dynamic keys, media handles, and error payloads remain ephemeral and cannot enter drafts, revisions, or exports. Browser-owned preview validation requires every canonical action and successful source slot exactly once, rejects report persistence and direct HTTP(S) anchors/forms/submit overrides, and permits publication only from the exact live turn, base revision, and tested connector fingerprints. Before final preview, the browser overwrites experience.json with canonical metadata derived from the four highest-ranked launch actions and the final successfully tested connector IDs. Additional valid launch actions remain allowed and every launch target from the brief must be present, while the highest-ranked controls remain visible and focusable. The launch index cannot be the entire page: preview requires a visible, non-empty data-dao-feed region with explicit loading, populated, empty, and unavailable states. Successful sources populate that region with fresh cards; a source-free fallback remains honest about having no collected items. Each successful source is represented exactly once by matching data-dao-source-slot and data-dao-connector semantics, including when its current collection is empty; failed and deselected sources cannot claim a slot. The generation contract states these required attributes explicitly so preview validation does not depend on an undocumented convention. Final UI drafts remain connector-free: immediately before preview, the trusted browser copies only successfully tested modules and schemas from the provisional draft and binds their exact canonical declarations and limits. This preserves approved fingerprints without asking the model to reconstruct security-sensitive manifest fields. This removes model-authored experience metadata as a failure point and prevents ordinary single-source permission requests from bypassing the grouped bootstrap flow.
• Untrusted generated application — User HTML/CSS/JavaScript runs at chrome-untrusted://dao-home-app without WebUI bindings or arbitrary network access. The fixed runtime exposes only session state, source collection, bounded HTTP(S) navigation, media-resolution requests, and stable node selection. The fixed runtime automatically connects canonical data-dao-action / data-dao-action-url controls to trusted navigation, so a validated launch action opens directly without an extra confirmation. Collected cards marked with data-dao-feed-link, data-dao-feed-url, and data-dao-feed-source use the same direct user-click path. Arbitrary dao.navigation.open calls still require browser-owned confirmation. A synchronous trusted prelude owns canonical action clicks before project scripts run, so generated capture handlers cannot replace or suppress the confirmation path. The host inserts that prelude after a real leading doctype and before all project markup, without mistaking HTML comments for document structure. The generated canvas fills the browser-owned content card without adding another inset or border, and the prelude clears only the browser's default html and body margins before project styles run so generated layouts start edge-to-edge but can still add intentional spacing. Unpublished preview resources are available only while the trusted Home host owns an active, timed preview request. Generated code cannot submit its own preview verdict: the trusted parent reports only the iframe load, while the browser process binds the exact preview frame and rejects console errors, failed loads, or cross-document replacement before issuing the draft receipt. A trusted Home dialog displays and confirms non-action generated-app navigation before it occurs.
• Generated connector isolation — Connector modules run in a second no-bindings chrome-untrusted://dao-home-connector sandbox and receive only a fixed, audited page RPC. Native code owns a detached, never-focused regular Profile WebContents, origin/path/capability checks, sensitive-control rejection, login-state detection, JSON-schema/result limits, timeout, and active-Home cancellation. Page-visible media becomes an opaque session handle; generated code can resolve only a bounded local blob and never sees the original media URL. Finishing a collection snapshots referenced media into a bounded immutable in-memory payload and immediately destroys the detached source page, so cached handles cannot drift after page navigation or DOM changes. Unique media URLs are encoded sequentially; a canvas is rejected before allocation when its raw pixels exceed the remaining 5 MiB session budget, and repeated handles share one retained blob. Completed executors retain only those snapshots for a bounded session window. The trusted host keeps at most the same 16 successful collection results, evicts them in executor-completion order, and reruns an evicted request so returned media handles always have a retained native owner.
• Trusted source permission — Agent code can create an opaque permission request but cannot grant access. Home shows normalized website, path, read-only capability, lifecycle scope, and collection budgets. For budget expansion, the trusted dialog shows each increased dimension as the exact previous and requested values. Confirmation grants only the exact draft connector and budget fingerprint; the Agent must successfully test every expanded connector before Home atomically publishes the previewed draft and its grants. Budget increases require renewed approval, while decreases migrate an existing exact grant without widening access. Rollback never restores a revoked grant, and import clears all grants.
• No automatic maintenance — Opening Home renders published code without an LLM call. Source collection is visible-card initiated, duplicate requests are coalesced for the active session, and successful results (including an empty result) are reused for ten minutes before the next foreground collection can refresh them. Generated feed apps keep the same per-connector ten-minute memory cache and never create a refresh timer or background crawl. The connector sandbox is also present on an empty active Home so the first approved connector draft can be tested before its initial publication. Source payloads and generated-app session state remain memory-only and are cleared when Home loses active ownership; both untrusted frames and native executors are torn down and recreated only after Home becomes active again. Agent draft sampling uses a separate executor: ending or replacing the Agent turn cancels its draft work without interrupting an in-flight published Home card, while Home navigation, hiding, closure, or revision replacement cancels both classes. Connector and generated-runtime failures record bounded non-content diagnostics; only the explicit Ask Dao to fix action starts a repair turn. A Home-scoped Agent sample request is routed through the same trusted host, detached executor, schema validation, and lifecycle cancellation as a visible source card.

3. Picture-in-Picture Enhancements

Built on Chromium's native PiP, adds a Document-PiP interception layer plus several visual + behavior tweaks.

3.1 Dao-owned (src/dao/browser/pip/)

• DaoPipInterceptor — Intercepts PiP requests on configured sites and redirects to Document PiP with a specific DOM element; selecting the opener tab closes the active Document PiP and restores the moved element for both manual and automatic entry, while capture-driven visibility changes leave the PiP open
• DaoPipSiteRules — Site rules loaded from pip_site_rules.json

3.2 Auto-PiP triggers

• DaoAutoPipVisibilityHelper (browser/dao_auto_pip_visibility_helper.{h,cc}) — Watches window-visibility changes (minimize, hide) and triggers auto-PiP for the active tab's playing video; complements Chromium's AutoPictureInPictureTabHelper (which handles tab switching). Both paths obey Chromium's native automatic Picture-in-Picture content setting, exposed as a switch on You and Dao
• Patches: auto_picture_in_picture_tab_helper.cc.patch, picture_in_picture_window_manager.cc.patch

3.3 PiP window chrome

• Patches: picture_in_picture_browser_frame_view.{h,cc}.patch — Custom Document-PiP top bar
• Patches: back_to_tab_button.cc.patch, minimize_button.cc.patch, video_overlay_window_views.cc.patch — Overlay button restyling
• Patches: video_picture_in_picture_window_controller_impl.cc.patch — Capturer guard preventing tab throttling
• User-interaction event forwarding via chrome_render_widget_host_view_mac_delegate.mm.patch
• Full-work-area manual resize — Document PiP and video PiP windows can be enlarged to the display's complete usable work area; initial sizing and site-request limits remain unchanged

4. Split View

• DaoSplitView (split/dao_split_view.{h,cc}) — Split container whose rounded backing matches the dividers through inner pane corner cutouts, preserves the outer frame shadow, and remains transparent in single-pane mode
• DaoSplitNode / DaoSplitPaneView — Split tree nodes and panes
• DaoSplitDividerView — Draggable divider with an opaque fill matching the shadowed content-frame edge in light/dark and incognito windows, including appearance changes; blue hover/drag feedback stays visible, and the content backing uses the Dao-themed surface
• Native tab-drag cleanup — Successful and cancelled macOS tab drags reset drag-only Split View hit testing in every browser window, so WebContents mouse interaction cannot remain blocked when WebUI dragend is skipped
• Status: wired up but not enabled by default

5. Control Center

macOS-style floating control center panel bundling extensions and utilities.

• DaoControlCenterButton — Trigger button
• DaoControlCenterPopup — Floating popup with transparent overlay click-to-close
• DaoControlCenterExtensionsSection — Extensions grid
• DaoControlCenterUtilitySection — Utility buttons (share, QR, lock, more)
• DaoControlCenterQrView — QR code generation
• DaoControlCenterMoreMenu — More menu, including cache and cookie cleanup scoped to the active page's current site with completion toast feedback
• DaoPinnedExtensionsContainer — Pinned extension icon container
• Extension action badges — Pinned and Control Center extension icons render the active tab's badge text and extension-defined badge colors using Chromium's native badge compositor, with independently compacted text and a 10px-tall background sized for Dao's smaller icon surfaces
• DaoNativeShareMac (dao_native_share_mac.{h,mm}) — Native macOS share sheet
• DaoNativeUtilMac (dao_native_util_mac.{h,mm}) — Misc native helpers (incl. cross-window-drag drop side)

6. Welcome Page

• DaoWelcomeUI (webui/dao_welcome_ui.{h,cc}) — dao://welcome WebUI controller
• WebUI: welcome.{html,css,ts} + dao_welcome_app.ts + welcome_bridge.ts (Lit)
• Menu item + command handling — User can reopen anytime
• First-run preference tracking — Auto-opens only on first launch (managed via dao_pref_names)
• Localized tutorial — The document title, welcome heading and subtitle, all seven shortcut descriptions, demonstration labels and copy feedback, and GitHub link use Dao's GRIT/WebUI strings. Simplified Chinese is provided; untranslated locales fall back to English.
• Browser migration entry — A compact localized link in the page's top trailing corner opens dao://import/ in the current tab, where users choose a source browser and data categories before starting migration. It sits outside the centered tutorial layout and supports visible keyboard focus.

6.1 Browser Data Migration

• Standalone migration surface — dao://import is a dedicated Lit WebUI, with a localized Import browser data document title for its browser tab, exposed as an explicit Import browser data row on the You and Dao Settings page and from the existing system Import Bookmarks and Settings… command instead of Chromium's modal importer. Its source grid uses the native browser catalog: Chrome, Arc, Edge, and Firefox on Windows, plus Safari on macOS. Detected profiles remain individually selectable, while supported browser kinds without a detected profile appear as disabled cards. The flow lets the user choose supported data categories, reconnects to an active profile-scoped job after reload, and reports per-category progress and retryable partial failures. Stopped jobs retain completed-batch counts and are presented as cancelled, not completed. Partial completion identifies the categories that need retrying in a dedicated summary and visually marks their result cards without hiding any items that were imported before the failure. The active migration rail uses the detected source browser's product logo and Dao's packaged product logo instead of generic letter placeholders.
• Asynchronous candidate counts — Selecting a Chromium-family profile starts independent background counts for each supported category without blocking navigation or migration. Bookmark, history, password, and extension counts read source metadata directly; password counting never decrypts a credential or triggers Keychain authorization. Tab sessions are counted only from a temporary snapshot because Chromium's session reader can rotate files. These preflight values describe scanned candidates and may differ from final imported totals if the source changes or Dao skips conflicts. Legacy Safari and Firefox importers report the count as unavailable until migration.
• Supported sources — Chrome, Arc, and Edge profiles use Dao's snapshot adapters. A shared native catalog supplies localized names, platform roots, and adapter selection. Windows roots use Local AppData, including Arc's packaged LocalCache profile; macOS roots use Application Support. Default root discovery and profile scanning run off the UI thread. Safari and Firefox use Chromium's platform importers and their reported category capabilities.
• Safe source reads — Chromium-family stores are copied to a temporary profile snapshot with bounded metadata-stability retries. SQLite sidecars and session directories are included. The background reader owns its snapshot until reading finishes, independently of callback argument evaluation order. Session file reads use a single-thread worker and read the latest saved session without rotating it away; session objects are restored on the UI thread to preserve Chromium's global session-ID ownership. Tab import keeps standard tab/window, navigation, pin, and closure commands while ignoring unrelated metadata, including Edge-specific commands that would otherwise stop Chromium's restore parser and incorrectly report zero tabs. Windows session files locked by a running source browser require fully quitting that browser; the completion page explains this and offers a retry. Temporary snapshots are deleted with the category operation. Cleanup stays off the UI thread and blocks browser shutdown until copied history, password, and session data has been removed.
• Merge-only destination writes — Bookmarks are placed under a localized imported root, destination password conflicts are preserved, already-open tab URLs and installed extensions are skipped, and history writes use the profile History service. History and password counts advance only after the destination services confirm the persisted records. No category replaces existing Dao data.
• Accurate failure summary — If every selected category fails without importing data, the completion page reports failure instead of partial success. Failed or cancelled jobs use an attention indicator.
• Passwords and extensions — Chromium-family password import is offered only on macOS, where its source capability enables the Keychain authorization notice. Windows does not offer it until a source password decryptor exists; Firefox retains the capabilities of Chromium's platform importer without a Keychain notice. A denial fails only passwords. Extension scans and snapshots include optional Secure Preferences; protected entries override ordinary Preferences entries by extension ID. Compatible web-store extensions are reinstalled in sequence; extension storage and sign-in state are not copied.
• Imported tabs — Source session tabs retain order, become background discarded tabs, and are collected in a collapsed sidebar folder. Tabs are created in cancellable batches; a failed folder write rolls back tabs from that import instead of leaving orphaned browser tabs. Successful folder persistence invalidates every live same-profile sidebar cache. Migration reads and commits folder data through the shared background storage queue, and reports completion only after the asynchronous write succeeds.
• Privacy boundary — Migration records, snapshots, and progress stay local; only official extension reinstallation may use the network. Cookies are not imported because Chromium does not expose a safe cross-profile cookie import API and copied encrypted cookie stores are not portable.
• Core owners: browser/import/dao_migration_service.*, dao_profile_snapshot.*, source adapters and target writers; webui/dao_import_ui.* and webui/resources/import/ own the WebUI.

7. Little Dao Window

Lightweight window form factor for popups / mini-tools.

• DaoLittleDaoController / DaoLittleDaoView (little_dao/) — Top bar (48px) with hostname display + "Open in Dao" button
• Address click feedback — Clicking the address opens the command bar and fades out the pressed highlight, so the address does not stay dark after the command bar closes
• Browser::Create timing control — Static-flag pattern (IsCreatingLittleDao()) to pass state into BrowserView during construction
• Permanently windowed — Mini Dao disables browser fullscreen commands and macOS native maximize/fullscreen eligibility, including when an external link creates it while the main Dao window is fullscreen
• macOS traffic-light repositioning

8. Webstore Branding

• DaoWebstoreBrandingTabHelper (browser/dao_webstore_branding_tab_helper.{h,cc}) — WebContentsObserver that injects a script on Chrome Web Store pages to rewrite "Add to Chrome" / "Remove from Chrome" → "Add to Dao" / "Remove from Dao"

9. Preferences and Centralized Pref Names

• DaoPrefNames (browser/dao_pref_names.{h,cc}) — Single source of truth for Dao-owned pref keys (welcome shown, sidebar width, folder file path, etc.)
• Patches: prefs/browser_prefs.cc.patch, prefs/session_startup_pref.cc.patch

10. Web JavaScript Dialogs

• Dao-styled alert(), confirm(), and prompt() — Keeps Chromium's tab-modal JavaScript dialog lifecycle, origin title, accessibility behavior, and callbacks while centering the dialog within the active web contents and applying Dao's rounded surface, primary/secondary actions, Enter/Esc keycaps, and themed prompt input
• Patches: chrome/browser/ui/views/javascript_tab_modal_dialog_view_views.{cc,h}.patch, components/constrained_window/constrained_window_views.cc.patch, ui/views/window/dialog_delegate.h.patch

11. Branding and Visuals

• Dao brand assets — Logos / SVGs; product name globally rebranded ("Chromium" → "Dao")
• Platform-specific application icons — macOS uses branding/mac/app.icns; Windows maintains its own branding/win/app.png master with tighter outer spacing, preserving the Dao mark and white rounded tile at a visual size comparable to neighboring taskbar icons. scripts/generate-windows-icon.ps1 packages that master into a 16–256px ICO, including intermediate Windows DPI sizes. Import copies branding/win/dao.ico into Chromium's shared EXE/DLL icon resource for Explorer, the taskbar, and Alt+Tab. Existing profile shortcut icons regenerate on startup through an icon-version bump.
• chrome:// → dao:// — Internal URL schemes rewritten via content/common/url_schemes.cc.patch
• chrome_color_mixer.cc.patch — Threads dao_colors tokens into the global color pipeline
• Custom scrollbar — third_party/blink/renderer/core/css/css_default_style_sheets.cc.patch + html.css.patch for globally restyled scrollbars
• Chromium string rebranding — *_strings.grd[p] patch files plus import-time rewrites for generated / terms resources

12. Shortcuts and Menus

• Dao shortcuts on Windows — Ctrl+S and Ctrl+Backslash toggle the sidebar, Ctrl+D duplicates the active tab, Ctrl+E toggles Agent, and Ctrl+Shift+C copies the active page URL with Dao toast feedback. Little Dao uses Ctrl+O to move its tab into the main browser. macOS keeps the corresponding Command keys. Duplicate, Agent, and Copy URL take precedence over Chromium's conflicting shortcuts while a page, sidebar, or Agent renderer has focus. Ctrl+S lets the webpage handle the first press; if intercepted, a localized toast offers a second press to toggle the sidebar. Button hints, tab-menu shortcut labels, and the welcome tutorial use platform-appropriate keys. Other Chromium shortcuts keep their native platform mappings.
• Google Lens Overlay disabled — components/lens/lens_features.cc.patch permanently disables the overlay capability, removing its toolbar, address-bar, app-menu, and context-menu entry points while preserving ordinary search-provider image search
• macOS global shortcuts — chrome/browser/global_keyboard_shortcuts_mac.mm.patch
• macOS main menu — cocoa/main_menu_builder.mm.patch + cocoa/accelerators_cocoa.mm.patch
• App controller — app_controller_mac.mm.patch (validate + execute commands when no browser window exists)
• IDC_* command IDs — chrome/app/chrome_command_ids.h.patch
• Command handling — browser_command_controller.cc.patch + browser_commands.cc.patch
• Adding a new IDC_* requires keeping its declaration, shortcut/menu wiring, and command-controller handling synchronized.

13. Chromium Core Integration Patches

The live patch inventory is the tracked tree under src/patches/. The groups below describe its major integration surfaces without duplicating a volatile file count.

13.1 URLs and Schemes

• content/common/url_schemes.cc.patch — Register dao://
• chrome/common/url_constants.h.patch, chrome/common/webui_url_constants.h.patch, content/public/common/url_constants.h.patch — Constant tables
• content/browser/webui/{url_data_manager_backend,web_ui_data_source_impl,web_ui_url_loader_factory}.cc.patch + content/public/browser/url_data_source.cc.patch — Data source / loader factory hooks
• Canonical WebUI load-time data — dao://resources/js/load_time_data.js owns the shared data instance. The legacy chrome:// module re-exports that instance so Chromium components read the same strings and flags initialized by Dao pages. Built-in component extensions such as the PDF viewer retain their existing resource access through the canonical Dao scheme; ordinary extensions and untrusted WebUI resources retain their separate permissions.
• chrome/browser/ui/webui/{chrome_web_ui_configs,chrome_web_ui_controller_factory}.cc.patch — Register Dao WebUI controllers
• components/url_formatter/url_fixer.cc.patch — URL fixer adaptations
• chrome/browser/browser_about_handler.cc.patch — dao:// about-page routing
• third_party/blink/public/common/chrome_debug_urls.h.patch — Debug URL alias

13.2 BrowserView Integration

• views/frame/browser_view.{h,cc}.patch — Inject DaoSidebarView and DaoCornerOverlayView; toolbar stays alive but is parked at y=-height so Chromium omnibox and command plumbing remain available
• views/frame/browser_view_layout (implicit via patches) — Layout adjustments
• views/frame/{browser_native_widget_mac,browser_frame_mac,immersive_mode_controller_mac}.mm.patch — macOS frame integrations
• views/frame/contents_web_view.{h,cc}.patch + views/frame/contents_layout_manager.cc.patch — Content area layout
• views/frame/layout/browser_view_{popup,tabbed}_layout_impl.cc.patch — Per-mode layout impls
• views/bubble_anchor_util_views.cc.patch — Bubble anchoring near the sidebar

13.3 Tab Strip and Tab Helpers

• chrome/browser/ui/tabs/tab_strip_model.cc.patch — Tab model hooks (incl. cross-window drag)
• chrome/browser/ui/tab_helpers.cc.patch — Attach Dao tab helpers (DaoAgentLockTabHelper, DaoWebstoreBrandingTabHelper, DaoAutoPipVisibilityHelper)
• content/browser/web_contents/web_contents_view_mac.mm.patch — Native drag-drop integration
• content/browser/renderer_host/render_frame_host_impl.cc.patch — Frame-host hook

13.4 Startup Flow

• ui/startup/startup_browser_creator.cc.patch + startup_browser_creator_impl.cc.patch — Startup behavior
• Always restore regular sessions — Regular profiles restore their saved tabs after clean exits and forced quits, including secondary profiles and windows opened after the process has already started. Stored startup settings cannot disable recovery or append configured startup pages. Settings shows the localized continue-session description instead of conflicting startup choices; the Windows launch-on-login toggle remains available. Incognito and Guest never restore regular tabs or configured startup pages. Pending crash recovery takes precedence over the existing-process new-window path, and the sidebar waits for recovery before reconciling pinned tabs even when an old startup setting requested a blank page. The recovery uses Chromium's session service and resumes normal session saving afterward. Only data already saved to disk can be recovered; pending writes and damaged session files are not covered by this behavior. startup_browser_creator_impl_session_restore.cc.patch owns the deferred-launch fix; scripts/checks/session-restore.mjs exercises repeated force-quits and a subsequent clean restart with disposable profiles that retain legacy blank-page and specified-page startup settings.
• ui/startup/infobar_utils.cc.patch — Infobar suppression
• signin/account_consistency_mode_manager.cc.patch — Account consistency mode
• profiles/chrome_browser_main_extra_parts_profiles.cc.patch — Profile init hook

13.5 Extensions

• views/extensions/extension_popup.cc.patch — Popup layout
• extensions/browser/api/web_request/extension_web_request_event_router.cc.patch — Event router hook
• extensions/common/features/simple_feature.cc.patch + extensions/common/api/_api_features.json.patch + chrome/common/extensions/api/_api_features.json.patch — Feature allowlists

13.6 WebUI Pages (HTML rebranding / customization)

• app_home, bookmarks, certificate_manager, downloads, extensions, history, password_manager, print_preview, settings/people_page, settings/settings, signin/profile_picker — HTML patches
• settings/reset_page/reset_profile_dialog.{html,ts}.patch — Reset profile dialog customization
• chrome/browser/ui/webui/settings/settings_ui.cc.patch

13.7 macOS Platform

• skia/ext/skia_utils_mac.mm.patch
• third_party/blink/renderer/platform/mac/graphics_context_canvas.mm.patch
• ui/display/mac/screen_utils_mac.mm.patch
• ui/gfx/image/image_unittest_util_apple.mm.patch
• services/shape_detection/text_detection_impl_mac_unittest.mm.patch
• components/os_crypt/common/keychain_password_mac.mm.patch
• chrome/common/chrome_paths_mac.mm.patch
• chrome/app/app-Info.plist.patch
• build/toolchain/apple/filter_libtool.py.patch

13.8 Blink and Rendering

• third_party/blink/renderer/core/css/css_default_style_sheets.cc.patch — Default stylesheets
• third_party/blink/renderer/core/html/resources/html.css.patch — Default HTML CSS
• third_party/blink/renderer/platform/graphics/paint/paint_controller.cc.patch — Paint hook
• components/global_media_controls/public/views/media_progress_view.cc.patch — Media progress UI
• media/base/media_switches.cc.patch — Media switches

13.9 Build / WebUI Toolchain

• chrome/BUILD_mcp_helper.gn.patch, chrome/browser/BUILD.gn.patch, chrome/browser/ui/BUILD.gn.patch, chrome/test/BUILD.gn.patch, chrome/chrome_paks.gni.patch, chrome/app/theme/chromium/BRANDING.patch — Build graph
• third_party/lit/v3_0/BUILD.gn.patch — Lit framework integration
• ui/webui/resources/tools/build_webui.gni.patch + ui/webui/webui_util.cc.patch — WebUI build helpers
• tools/gritsettings/resource_ids.spec.patch — Resource ID allocation
• tools/metrics/histograms/metadata/sql/histograms.xml.patch — SQL histograms
• chrome/browser/download/bubble/download_bubble_prefs.cc.patch
• chrome/browser/accessibility/soda_installer_impl.cc.patch
• components/performance_manager/user_tuning/prefs.cc.patch

13.10 String Localization and Rebranding

• chrome/app/*_strings.grd[p] and chromium_strings.grd / google_chrome_strings.grd — Branded strings
• components/*_strings.grdp — Component strings (autofill, crash, error, history clusters, management, omnibox, policy, privacy sandbox, security interstitials, site settings, version, etc.)
• Settings localized-string provider patches — Dao settings page strings
• components/resources/terms/terms_*.html rebranding is handled by import-time rewrites, not patch files

14. Testing

• browser_tests (dao_browser_browsertest.cc) — Integration test framework
• Coverage: sidebar presence / default width / collapse-expand, drag resize, address bar, command bar show/hide & idempotency, tab CRUD, SplitView, CornerOverlay, folder persistence, URL detection heuristics, extension icon and badge updates, PiP site rules / interception / top bar overlay
• Known disabled: 5 DaoAgentMemoryStore round-trip tests due to FTS5 RazeAndPoison under direct Init(), plus 4 PiP overlay tests awaiting replacement after upstream API drift

15. Build and Packaging

• scripts/cli.ts — Unified CLI (download / import / export / build / rebuild / test / start) — the single entrypoint; never run autoninja / ninja / siso directly
• appdmg integration — DMG packaging
• configs/common.gn + configs/macos.gn — Shared + macOS GN args (component build, no NaCl, proprietary codecs, no Google API keys)
• Custom checkout variables — Build configuration flexibility
• Vendor pipeline — Agent WebUI dependency bundling (npm run vendor)

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Current Status

• Version source: dao.json is authoritative for both the Dao display version and Chromium baseline
• Target platform: macOS arm64
• Source inventory: src/dao/ contains Dao-owned sources and src/patches/ contains the live Chromium integration patch set