feat(ui): the board — the main area's second view

A Board row under the sidebar search (with a count of agents waiting on
you) swaps the terminal area for five columns of cards: this workspace's
tasks, plus every tab running an agent no task claims. Columns come from
`task::column` / `task::live_column` on every frame.

- New task (N): title, prompt, agent; Add to queue or Start. Start opens a
  tab named for the task and launches the agent with the prompt as its
  first message, staying on the board.
- Cards: agent avatar, title, repo · branch, what a running agent is doing,
  the question a waiting one asks with an Open button, diff counts, age.
  Click opens the tab; right-click has start/resume/done/reopen/edit/delete,
  and "keep as task" for an agent started by hand.
- Runs record their agent's session id, so a closed run can be resumed.
- Toggle Board: secondary-alt-b, and in the command palette.

assets/icons/board.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round"><rect x="3" y="4" width="5" height="16" rx="1.6"/><rect x="9.5" y="4" width="5" height="11" rx="1.6"/><rect x="16" y="4" width="5" height="13.5" rx="1.6"/></svg>

src/core/actions.rs

@@ -119,6 +119,7 @@ actions!(
         ShowSshForwards,
         ToggleCodePanel,
         ToggleDocumentFill,
+        ToggleBoard,
         DocumentWidthThird,
         DocumentWidthHalf,
         DocumentWidthTwoThirds,

src/ui/agent_launch.rs

@@ -149,7 +149,7 @@ pub(crate) fn fork_line(
 
 /// Type `command` into the shell `slot` holds — now if it is up, or the
 /// moment it lands if it is still connecting.
-fn run_when_ready(slot: &PaneSlot, command: String, cx: &mut App) {
+pub(crate) fn run_when_ready(slot: &PaneSlot, command: String, cx: &mut App) {
     match slot {
         PaneSlot::Ready(view) => view.read(cx).run_command_line(&command),
         PaneSlot::Connecting(pending) => {

src/ui/app.rs

@@ -878,6 +878,9 @@ pub struct Tty7App {
     pub(crate) closed: Vec<SessionTab>,
     pub(crate) renaming: Option<Renaming>,
     pub(crate) worktree_prompt: Option<crate::ui::worktree_prompt::WorktreePrompt>,
+    /// What the main area shows: the terminal, or the board over it.
+    pub(crate) main_view: crate::ui::board::MainView,
+    pub(crate) board: crate::ui::board::Board,
     pub(crate) maximized: Option<Entity<TerminalView>>,
     pub(crate) mod_hint_badges: bool,
     pub(crate) mod_hint_gen: u64,
@@ -1516,6 +1519,8 @@ impl Tty7App {
             closed: Vec::new(),
             renaming: None,
             worktree_prompt: None,
+            main_view: crate::ui::board::MainView::Terminal,
+            board: crate::ui::board::Board::new(cx),
             maximized: None,
             mod_hint_badges: false,
             mod_hint_gen: 0,
@@ -3765,6 +3770,10 @@ impl Tty7App {
             window.focus(&settings.focus_handle, cx);
             return;
         }
+        if self.board_open() {
+            window.focus(&self.board.focus, cx);
+            return;
+        }
         let Some(tab) = self.tabs.get(self.active) else {
             window.focus(&self.home_focus, cx);
             return;
@@ -4056,6 +4065,9 @@ impl Tty7App {
         };
         // Something opened, so whatever the last failure was is stale.
         self.startup_error = None;
+        // A new tab is one to look at. The board's own Start puts the board
+        // back once the tab is open.
+        self.main_view = crate::ui::board::MainView::Terminal;
         self.remember_active_pane(window, cx);
         self.maximized = None;
         let insert_at = self.new_tab_insert_at(cx);
@@ -4908,6 +4920,12 @@ impl Tty7App {
     }
 
     pub(crate) fn activate(&mut self, index: usize, window: &mut Window, cx: &mut Context<Self>) {
+        // Picking a tab is asking to see it, board or not.
+        if self.board_open() && index < self.tabs.len() {
+            self.main_view = crate::ui::board::MainView::Terminal;
+            self.focus_active(window, cx);
+            cx.notify();
+        }
         // A tab is woken by being looked at, the way a browser reloads a
         // discarded tab when it is selected: a tab on screen is always a
         // running one, so there is no third state to draw. A wake that fails
@@ -6365,6 +6383,7 @@ impl Tty7App {
             ShowSshForwards => self.show_ssh_forwards(window, cx),
             ToggleCodePanel => self.toggle_code_panel(window, cx),
             ToggleDocumentFill => self.toggle_document_fill(cx),
+            ToggleBoard => self.toggle_board(window, cx),
             DocumentWidthThird => {
                 self.set_document_ratio(crate::core::config::DOCUMENT_RATIO_THIRD, cx)
             }
@@ -8947,6 +8966,7 @@ impl Render for Tty7App {
             .when_some(self.render_remote_workspace_strip(cx), |this, el| {
                 this.child(el)
             })
+            .when_some(self.render_board(window, cx), |this, el| this.child(el))
             // Both of these used to anchor themselves at `bottom_4` and centre
             // themselves, as siblings here — so a remote workspace whose ssh
             // link had also dropped drew them one on top of the other. One
@@ -9379,6 +9399,9 @@ impl Render for Tty7App {
                 .on_action(cx.listener(|this, _: &ToggleDiffViewMode, _window, cx| {
                     this.toggle_diff_view_mode(cx)
                 }))
+                .on_action(
+                    cx.listener(|this, _: &ToggleBoard, window, cx| this.toggle_board(window, cx)),
+                )
                 .on_action(cx.listener(|this, _: &ToggleDocumentFill, _window, cx| {
                     this.toggle_document_fill(cx)
                 }))

src/ui/assets.rs

@@ -33,6 +33,7 @@ fn agent_icon(path: &str) -> Option<&'static [u8]> {
         "icons/git-sync.svg" => include_bytes!("../../assets/icons/git-sync.svg"),
         "icons/git-commit.svg" => include_bytes!("../../assets/icons/git-commit.svg"),
         "icons/panel-left.svg" => include_bytes!("../../assets/icons/panel-left.svg"),
+        "icons/board.svg" => include_bytes!("../../assets/icons/board.svg"),
         "icons/panel-right.svg" => include_bytes!("../../assets/icons/panel-right.svg"),
         "icons/plus.svg" => include_bytes!("../../assets/icons/plus.svg"),
         "icons/ellipsis.svg" => include_bytes!("../../assets/icons/ellipsis.svg"),

src/ui/i18n/en.rs

@@ -1766,6 +1766,49 @@ pub fn translate_en(key: L10nKey) -> &'static str {
         L10nKey::CmdDocumentDock => "Document: Dock Beside Terminal",
         L10nKey::CmdDocumentFill => "Document: Fill Window",
         L10nKey::CmdToggleDocumentFill => "Toggle Document Fill / Dock",
+        L10nKey::CmdToggleBoard => "Toggle Board",
+        L10nKey::BoardTitle => "Board",
+        L10nKey::BoardNewTask => "New task",
+        L10nKey::BoardEditTask => "Edit task",
+        L10nKey::BoardColQueued => "Queued",
+        L10nKey::BoardColRunning => "Running",
+        L10nKey::BoardColNeedsInput => "Needs input",
+        L10nKey::BoardColReview => "Review",
+        L10nKey::BoardColDone => "Done",
+        L10nKey::BoardAllAgents => "All agents",
+        L10nKey::BoardSummary => "{running} running  ·  {input} need you  ·  {review} to review",
+        L10nKey::BoardEmpty => "Nothing on the board yet",
+        L10nKey::BoardEmptyHint => {
+            "Add a task with New task (N), or start an agent in any tab — it shows up here on its own."
+        }
+        L10nKey::BoardOpen => "Open",
+        L10nKey::BoardStart => "Start",
+        L10nKey::BoardResume => "Resume",
+        L10nKey::BoardResumable => "Resumable",
+        L10nKey::BoardMarkDone => "Mark done",
+        L10nKey::BoardReopen => "Reopen",
+        L10nKey::BoardEdit => "Edit",
+        L10nKey::BoardDelete => "Delete",
+        L10nKey::BoardKeep => "Keep as task",
+        L10nKey::BoardFieldTitle => "Title",
+        L10nKey::BoardFieldPrompt => "Prompt",
+        L10nKey::BoardFieldAgent => "Agent",
+        L10nKey::BoardTitlePlaceholder => "What should the agent do?",
+        L10nKey::BoardPromptPlaceholder => {
+            "Details, context, how to check it’s done… (optional — the title is sent if this is empty)"
+        }
+        L10nKey::BoardSave => "Save",
+        L10nKey::BoardAddToQueue => "Add to queue",
+        L10nKey::BoardStartNow => "Start",
+        L10nKey::BoardNeedsTitle => "A task needs a title",
+        L10nKey::BoardNoAgent => "No agent found",
+        L10nKey::BoardPromptCopied => {
+            "{agent} can’t be given a starting prompt, so it was copied — paste it in once {agent} is up"
+        }
+        L10nKey::BoardUnavailable => {
+            "This machine’s server can’t keep tasks yet — update it to use the board"
+        }
+        L10nKey::BoardNow => "now",
         L10nKey::CmdDocumentWidthThird => "Document: Third Width",
         L10nKey::CmdDocumentWidthHalf => "Document: Half Width",
         L10nKey::CmdDocumentWidthTwoThirds => "Document: Two-Thirds Width",

src/ui/i18n/ja.rs

@@ -1811,6 +1811,49 @@ pub fn translate_ja(key: L10nKey) -> Option<&'static str> {
         L10nKey::CmdDocumentDock => "ドキュメント: ターミナルの隣にドック",
         L10nKey::CmdDocumentFill => "ドキュメント: ウィンドウ全体",
         L10nKey::CmdToggleDocumentFill => "ドキュメントのフィル / ドックを切り替え",
+        L10nKey::CmdToggleBoard => "ボードの表示を切り替え",
+        L10nKey::BoardTitle => "ボード",
+        L10nKey::BoardNewTask => "新しいタスク",
+        L10nKey::BoardEditTask => "タスクを編集",
+        L10nKey::BoardColQueued => "待機",
+        L10nKey::BoardColRunning => "実行中",
+        L10nKey::BoardColNeedsInput => "入力待ち",
+        L10nKey::BoardColReview => "レビュー",
+        L10nKey::BoardColDone => "完了",
+        L10nKey::BoardAllAgents => "すべてのエージェント",
+        L10nKey::BoardSummary => "実行中 {running}  ·  入力待ち {input}  ·  レビュー待ち {review}",
+        L10nKey::BoardEmpty => "ボードはまだ空です",
+        L10nKey::BoardEmptyHint => {
+            "「新しいタスク」(N) でタスクを追加するか、どれかのタブでエージェントを起動してください。自動的にここに表示されます。"
+        }
+        L10nKey::BoardOpen => "開く",
+        L10nKey::BoardStart => "開始",
+        L10nKey::BoardResume => "再開",
+        L10nKey::BoardResumable => "再開可能",
+        L10nKey::BoardMarkDone => "完了にする",
+        L10nKey::BoardReopen => "再度開く",
+        L10nKey::BoardEdit => "編集",
+        L10nKey::BoardDelete => "削除",
+        L10nKey::BoardKeep => "タスクとして残す",
+        L10nKey::BoardFieldTitle => "タイトル",
+        L10nKey::BoardFieldPrompt => "プロンプト",
+        L10nKey::BoardFieldAgent => "エージェント",
+        L10nKey::BoardTitlePlaceholder => "エージェントに何をさせますか？",
+        L10nKey::BoardPromptPlaceholder => {
+            "詳細、背景、完了の確認方法など（任意 — 空ならタイトルを送ります）"
+        }
+        L10nKey::BoardSave => "保存",
+        L10nKey::BoardAddToQueue => "キューに追加",
+        L10nKey::BoardStartNow => "開始",
+        L10nKey::BoardNeedsTitle => "タスクにはタイトルが必要です",
+        L10nKey::BoardNoAgent => "エージェントが見つかりません",
+        L10nKey::BoardPromptCopied => {
+            "{agent} は起動時にプロンプトを受け取れないため、コピーしました。起動したら貼り付けてください"
+        }
+        L10nKey::BoardUnavailable => {
+            "このマシンのサーバーはまだタスクを保存できません。ボードを使うには更新してください"
+        }
+        L10nKey::BoardNow => "たった今",
         L10nKey::CmdDocumentWidthThird => "ドキュメント: 幅3分の1",
         L10nKey::CmdDocumentWidthHalf => "ドキュメント: 幅半分",
         L10nKey::CmdDocumentWidthTwoThirds => "ドキュメント: 幅3分の2",

src/ui/i18n/mod.rs

@@ -1500,6 +1500,41 @@ l10n_keys! {
     CmdDocumentDock,
     CmdDocumentFill,
     CmdToggleDocumentFill,
+    CmdToggleBoard,
+    BoardTitle,
+    BoardNewTask,
+    BoardEditTask,
+    BoardColQueued,
+    BoardColRunning,
+    BoardColNeedsInput,
+    BoardColReview,
+    BoardColDone,
+    BoardAllAgents,
+    BoardSummary,
+    BoardEmpty,
+    BoardEmptyHint,
+    BoardOpen,
+    BoardStart,
+    BoardResume,
+    BoardResumable,
+    BoardMarkDone,
+    BoardReopen,
+    BoardEdit,
+    BoardDelete,
+    BoardKeep,
+    BoardFieldTitle,
+    BoardFieldPrompt,
+    BoardFieldAgent,
+    BoardTitlePlaceholder,
+    BoardPromptPlaceholder,
+    BoardSave,
+    BoardAddToQueue,
+    BoardStartNow,
+    BoardNeedsTitle,
+    BoardNoAgent,
+    BoardPromptCopied,
+    BoardUnavailable,
+    BoardNow,
     CmdDocumentWidthThird,
     CmdDocumentWidthHalf,
     CmdDocumentWidthTwoThirds,

src/ui/i18n/zh.rs

@@ -1638,6 +1638,47 @@ pub fn translate_zh(key: L10nKey) -> Option<&'static str> {
         L10nKey::CmdDocumentDock => "文档：停靠在终端旁",
         L10nKey::CmdDocumentFill => "文档：铺满窗口",
         L10nKey::CmdToggleDocumentFill => "切换文档铺满 / 停靠",
+        L10nKey::CmdToggleBoard => "切换看板",
+        L10nKey::BoardTitle => "看板",
+        L10nKey::BoardNewTask => "新任务",
+        L10nKey::BoardEditTask => "编辑任务",
+        L10nKey::BoardColQueued => "排队",
+        L10nKey::BoardColRunning => "运行中",
+        L10nKey::BoardColNeedsInput => "等待输入",
+        L10nKey::BoardColReview => "待审阅",
+        L10nKey::BoardColDone => "完成",
+        L10nKey::BoardAllAgents => "全部 Agent",
+        L10nKey::BoardSummary => "{running} 运行中  ·  {input} 等你  ·  {review} 待审阅",
+        L10nKey::BoardEmpty => "看板上还没有东西",
+        L10nKey::BoardEmptyHint => {
+            "用「新任务」(N) 添加一个任务，或者在任意标签页里启动 Agent——它会自己出现在这里。"
+        }
+        L10nKey::BoardOpen => "打开",
+        L10nKey::BoardStart => "开始",
+        L10nKey::BoardResume => "恢复会话",
+        L10nKey::BoardResumable => "可恢复",
+        L10nKey::BoardMarkDone => "标记完成",
+        L10nKey::BoardReopen => "重新打开",
+        L10nKey::BoardEdit => "编辑",
+        L10nKey::BoardDelete => "删除",
+        L10nKey::BoardKeep => "保留为任务",
+        L10nKey::BoardFieldTitle => "标题",
+        L10nKey::BoardFieldPrompt => "提示词",
+        L10nKey::BoardFieldAgent => "使用的 Agent",
+        L10nKey::BoardTitlePlaceholder => "要 Agent 做什么？",
+        L10nKey::BoardPromptPlaceholder => "细节、上下文、怎么算完成……（可选，留空则发送标题）",
+        L10nKey::BoardSave => "保存",
+        L10nKey::BoardAddToQueue => "加入排队",
+        L10nKey::BoardStartNow => "开始",
+        L10nKey::BoardNeedsTitle => "任务需要一个标题",
+        L10nKey::BoardNoAgent => "没有找到 Agent",
+        L10nKey::BoardPromptCopied => {
+            "{agent} 不支持启动时带提示词，已复制到剪贴板——{agent} 启动后粘贴进去"
+        }
+        L10nKey::BoardUnavailable => {
+            "这台机器的 server 版本太旧，还不能保存任务——更新后即可使用看板"
+        }
+        L10nKey::BoardNow => "刚刚",
         L10nKey::CmdDocumentWidthThird => "文档：三分之一宽",
         L10nKey::CmdDocumentWidthHalf => "文档：一半宽",
         L10nKey::CmdDocumentWidthTwoThirds => "文档：三分之二宽",

src/ui/keymap.rs

@@ -659,6 +659,7 @@ fn shipped_bindings() -> Vec<(&'static str, &'static str)> {
         // terminal back, so a default chord here would only be one more thing
         // competing for a two-key combination nobody asked for.
         ("ToggleDocumentFill", ""),
+        ("ToggleBoard", "secondary-alt-b"),
         ("DocumentWidthThird", ""),
         ("DocumentWidthHalf", ""),
         ("DocumentWidthTwoThirds", ""),
@@ -946,6 +947,7 @@ fn authored_entry(action: &str) -> Option<(CommandGroup, String)> {
             CommandGroup::View,
             t(L10nKey::CmdToggleDocumentFill).to_string(),
         ),
+        "ToggleBoard" => (CommandGroup::View, t(L10nKey::CmdToggleBoard).to_string()),
         "DocumentWidthThird" => (
             CommandGroup::View,
             t(L10nKey::CmdDocumentWidthThird).to_string(),
@@ -1799,6 +1801,7 @@ fn make_binding(action: &str, keystroke: &str) -> Option<KeyBinding> {
         "ShowSshForwards" => KeyBinding::new(keystroke, ShowSshForwards, None),
         "ToggleCodePanel" => KeyBinding::new(keystroke, ToggleCodePanel, None),
         "ToggleDocumentFill" => KeyBinding::new(keystroke, ToggleDocumentFill, None),
+        "ToggleBoard" => KeyBinding::new(keystroke, ToggleBoard, None),
         "DocumentWidthThird" => KeyBinding::new(keystroke, DocumentWidthThird, None),
         "DocumentWidthHalf" => KeyBinding::new(keystroke, DocumentWidthHalf, None),
         "DocumentWidthTwoThirds" => KeyBinding::new(keystroke, DocumentWidthTwoThirds, None),

src/ui/machine_mirror.rs

@@ -316,6 +316,17 @@ fn apply(machine: &mut Machine, workspace: WorkspaceId, delta: &LayoutDelta) ->
             ws.groups = groups.clone();
             true
         }
+        LayoutDelta::TaskPut { task } => {
+            match ws.tasks.iter_mut().find(|t| t.id == task.id) {
+                Some(slot) => *slot = task.clone(),
+                None => ws.tasks.push(task.clone()),
+            }
+            true
+        }
+        LayoutDelta::TaskRemoved { task } => {
+            ws.tasks.retain(|t| t.id != *task);
+            true
+        }
         LayoutDelta::TabMoved { tab, to } => {
             let Some(from) = ws.tabs.iter().position(|t| t.id == *tab) else {
                 return false;

src/ui/mod.rs

@@ -1,6 +1,7 @@
 pub mod agent_launch;
 pub mod app;
 pub mod assets;
+pub mod board;
 pub mod code_editor;
 pub mod dialog;
 pub mod diff_list;

src/ui/search/command.rs

@@ -85,6 +85,7 @@ pub enum CommandKind {
     ShowSshForwards,
     ToggleCodePanel,
     ToggleDocumentFill,
+    ToggleBoard,
     DocumentWidthThird,
     DocumentWidthHalf,
     DocumentWidthTwoThirds,
@@ -265,6 +266,7 @@ impl CommandKind {
             ShowSshForwards => "ssh-port-forwarding",
             ToggleCodePanel => "code-panel",
             ToggleDocumentFill => "document-fill",
+            ToggleBoard => "board",
             DocumentWidthThird => "document-width-third",
             DocumentWidthHalf => "document-width-half",
             DocumentWidthTwoThirds => "document-width-two-thirds",
@@ -407,6 +409,7 @@ impl CommandKind {
             ShowSshForwards => "ShowSshForwards",
             ToggleCodePanel => "ToggleCodePanel",
             ToggleDocumentFill => "ToggleDocumentFill",
+            ToggleBoard => "ToggleBoard",
             DocumentWidthThird => "DocumentWidthThird",
             DocumentWidthHalf => "DocumentWidthHalf",
             DocumentWidthTwoThirds => "DocumentWidthTwoThirds",
@@ -690,6 +693,7 @@ impl Item {
                 ToggleRightPanel,
             ),
             Item::localized(L10nKey::CmdShowCodePanel, ToggleCodePanel),
+            Item::localized(L10nKey::CmdToggleBoard, ToggleBoard),
             Item::localized(L10nKey::CmdGoToFile, QuickOpenFile),
             Item::localized(
                 if document_filled {

src/ui/tab_sidebar.rs

@@ -72,7 +72,7 @@ const META_SEP: &str = " · ";
 const META_SEP_TRIMMED: &str = "·";
 
 /// Tabular numerals, so a column of diff counts lines up digit for digit.
-fn tabular() -> gpui::FontFeatures {
+pub(crate) fn tabular() -> gpui::FontFeatures {
     gpui::FontFeatures(std::sync::Arc::new(vec![("tnum".to_string(), 1)]))
 }
 
@@ -1774,7 +1774,8 @@ impl Tty7App {
             .pt(px(4.))
             .pb(px(16.))
             .child(self.workspace_head(cx))
-            .child(search);
+            .child(search)
+            .child(self.render_board_nav(cx));
 
         let container: Rc<Cell<Option<Bounds<Pixels>>>> = Rc::new(Cell::new(None));
         // Read while there is still a `cx` to read it from: the drag handler

src/ui/tree_sync.rs

@@ -16,6 +16,7 @@ use crate::core::session::{Session, SessionPane, SessionTab, WorkspaceId, Worksp
 use crate::ui::app::Tty7App;
 use crate::ui::i18n::{L10nKey, t};
 use crate::ui::pane::{Pane, PaneSlot};
+use tty7_core::core::task::{Task, TaskId};
 
 pub(crate) fn control_for(cx: &mut App, host: HostId) -> Option<Arc<ControlClient>> {
     if host.is_local() {
@@ -340,6 +341,7 @@ pub(crate) struct WsMirror {
     pub tabs: Vec<TreeTab>,
     pub active: Option<TabId>,
     pub groups: WorkspaceGroups,
+    pub tasks: Vec<Task>,
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
@@ -1571,6 +1573,7 @@ fn primed(ws: Workspace, arrival: Arrival) -> (WsMirror, Option<String>, Arrival
             tabs: ws.tabs,
             active: ws.active_tab,
             groups: ws.groups,
+            tasks: ws.tasks,
         },
         ws.name,
         arrival,
@@ -1611,6 +1614,7 @@ fn finish_prime(
         }
     };
     adopt_groups(cx, client_ws);
+    adopt_tasks(cx, client_ws);
     let host = WorkspaceStore::host_of(cx, client_ws);
     let machine_ws = tree_workspace_id(cx, client_ws);
     crate::ui::machine_mirror::MachineMirrors::note_synced_workspace(
@@ -1712,6 +1716,104 @@ fn adopt_groups(cx: &mut App, client_ws: WorkspaceId) {
     });
 }
 
+/// Whether the machine holding `client_ws` keeps a board. One that predates
+/// the board would refuse the request that saves a card — and, worse, one it
+/// cannot decode takes the whole link down — so a window never sends it one.
+pub(crate) fn can_board_on(cx: &App, client_ws: WorkspaceId) -> bool {
+    let feature = tty7_core::daemon::control::feature::TASKS;
+    let host = WorkspaceStore::host_of(cx, client_ws);
+    match host.is_local() {
+        true => crate::ui::local_link::LocalLink::supports(cx, feature),
+        false => crate::ui::remote_connect::HostLinks::peer_supports(cx, host, feature),
+    }
+}
+
+/// Sends a card a window just made or changed up to the machine — the whole
+/// card, which replaces whatever the machine had under its id.
+///
+/// Like groups, tasks are never part of the diff [`sync_window`] runs: a
+/// window has nothing to say about a card except the edit someone just made
+/// to it. Returns false when the window's tree has not landed yet (or the
+/// machine keeps no board), in which case nothing was sent and the caller
+/// should not show the edit as made.
+pub(crate) fn push_task(cx: &mut App, client_ws: WorkspaceId, task: Task) -> bool {
+    if !cx.has_global::<crate::core::session::WorkspaceStore>() || !can_board_on(cx, client_ws) {
+        return false;
+    }
+    let machine_ws = tree_workspace_id(cx, client_ws);
+    let state = cx
+        .default_global::<TreeSync>()
+        .windows
+        .entry(client_ws)
+        .or_default();
+    let SyncPhase::Primed(mirror) = &mut state.sync else {
+        return false;
+    };
+    match mirror.tasks.iter_mut().find(|t| t.id == task.id) {
+        Some(slot) if *slot == task => return true,
+        Some(slot) => *slot = task.clone(),
+        None => mirror.tasks.push(task.clone()),
+    }
+    state.queue.push_back(ControlRequest::TaskPut {
+        workspace: machine_ws,
+        task,
+    });
+    pump(cx, client_ws);
+    true
+}
+
+/// Takes a card off the machine's board. See [`push_task`].
+pub(crate) fn remove_task(cx: &mut App, client_ws: WorkspaceId, task: TaskId) -> bool {
+    if !cx.has_global::<crate::core::session::WorkspaceStore>() || !can_board_on(cx, client_ws) {
+        return false;
+    }
+    let machine_ws = tree_workspace_id(cx, client_ws);
+    let state = cx
+        .default_global::<TreeSync>()
+        .windows
+        .entry(client_ws)
+        .or_default();
+    let SyncPhase::Primed(mirror) = &mut state.sync else {
+        return false;
+    };
+    let before = mirror.tasks.len();
+    mirror.tasks.retain(|t| t.id != task);
+    if mirror.tasks.len() == before {
+        return true;
+    }
+    state.queue.push_back(ControlRequest::TaskRemove {
+        workspace: machine_ws,
+        task,
+    });
+    pump(cx, client_ws);
+    true
+}
+
+/// Hands the window the board a pull just brought in. Deferred for the same
+/// reason as [`adopt_groups`].
+fn adopt_tasks(cx: &mut App, client_ws: WorkspaceId) {
+    cx.defer(move |cx| {
+        let tasks = match cx
+            .default_global::<TreeSync>()
+            .windows
+            .get(&client_ws)
+            .map(|s| &s.sync)
+        {
+            Some(SyncPhase::Primed(mirror)) => mirror.tasks.clone(),
+            _ => return,
+        };
+        if !cx.has_global::<crate::ui::windows::WindowRegistry>() {
+            return;
+        }
+        let Some(app) =
+            crate::ui::windows::WindowRegistry::app_for(cx, client_ws).and_then(|a| a.upgrade())
+        else {
+            return;
+        };
+        app.update(cx, |app, cx| app.adopt_board_tasks(tasks, cx));
+    });
+}
+
 fn pump(cx: &mut App, client_ws: WorkspaceId) {
     let host = WorkspaceStore::host_of(cx, client_ws);
     let client = tree_control_for(cx, host);
@@ -2379,6 +2481,7 @@ fn layout_of(
         tabs: ws.tabs.clone(),
         active: ws.active_tab,
         groups: ws.groups.clone(),
+        tasks: ws.tasks.clone(),
     };
     let session = session_from_tree(ws, &machine.panes);
     Ok((machine, mirror, session))
@@ -2460,6 +2563,7 @@ fn settle_hydration(
         dirty
     };
     adopt_groups(cx, client_ws);
+    adopt_tasks(cx, client_ws);
     let Some(app) =
         crate::ui::windows::WindowRegistry::app_for(cx, client_ws).and_then(|app| app.upgrade())
     else {
@@ -2741,6 +2845,17 @@ fn apply_to_mirror(mirror: &mut WsMirror, delta: &LayoutDelta) -> bool {
             mirror.groups = groups.clone();
             true
         }
+        LayoutDelta::TaskPut { task } => {
+            match mirror.tasks.iter_mut().find(|t| t.id == task.id) {
+                Some(slot) => *slot = task.clone(),
+                None => mirror.tasks.push(task.clone()),
+            }
+            true
+        }
+        LayoutDelta::TaskRemoved { task } => {
+            mirror.tasks.retain(|t| t.id != *task);
+            true
+        }
         LayoutDelta::TabMoved { tab, to } => {
             let Some(from) = mirror.tabs.iter().position(|t| t.id == *tab) else {
                 return false;
@@ -2915,6 +3030,14 @@ impl Tty7App {
                 self.adopt_sidebar_groups(groups.clone(), cx);
                 true
             }
+            LayoutDelta::TaskPut { task } => {
+                self.board_task_put(task.clone());
+                true
+            }
+            LayoutDelta::TaskRemoved { task } => {
+                self.board_task_removed(*task);
+                true
+            }
             LayoutDelta::TabMoved { tab, to } => {
                 if let Some(from) = index_of(&self.tabs, *tab) {
                     let active_id = self.tabs.get(self.active).map(|t| t.tree_id.get());