Add id:/needs: task dependencies

src/action.rs

@@ -49,6 +49,7 @@ pub enum Action {
     ToggleLineNum,
     ToggleShowDone,
     ToggleShowFuture,
+    ToggleShowBlocked,
     CopyLine,
     CopyBody,
     OpenNote,
@@ -108,6 +109,7 @@ impl Action {
             "toggle_line_num" | "toggle_line_numbers" => Some(Self::ToggleLineNum),
             "toggle_show_done" => Some(Self::ToggleShowDone),
             "toggle_show_future" => Some(Self::ToggleShowFuture),
+            "toggle_show_blocked" => Some(Self::ToggleShowBlocked),
             "copy_line" => Some(Self::CopyLine),
             "copy_body" => Some(Self::CopyBody),
             "open_note" | "note" => Some(Self::OpenNote),

src/app/palette.rs

@@ -187,6 +187,11 @@ pub const ENTRIES: &[PaletteEntry] = &[
         keys: "F",
         action: Action::ToggleShowFuture,
     },
+    PaletteEntry {
+        label: "show blocked in list",
+        keys: "B",
+        action: Action::ToggleShowBlocked,
+    },
     PaletteEntry {
         label: "toggle filter pane",
         keys: "[",
@@ -553,6 +558,7 @@ mod tests {
             Action::ToggleLineNum,
             Action::ToggleShowDone,
             Action::ToggleShowFuture,
+            Action::ToggleShowBlocked,
             Action::CopyLine,
             Action::CopyBody,
             Action::EscapeStack,

src/app/prefs.rs

@@ -35,6 +35,7 @@ pub struct Prefs {
     pub layout: Layout,
     pub show_done: bool,
     pub show_future: bool,
+    pub show_blocked: bool,
     /// Metadata keys whose `key:value` tokens are hidden from task rows.
     /// Config-only (no in-app toggle); see `Config::hidden_keys`.
     pub hidden_keys: Vec<String>,
@@ -64,6 +65,7 @@ impl Prefs {
             },
             show_done: cfg.show_done.unwrap_or(false),
             show_future: cfg.show_future.unwrap_or(false),
+            show_blocked: cfg.show_blocked.unwrap_or(true),
             hidden_keys: cfg.hidden_keys,
             week_start: cfg.week_start.unwrap_or(WeekStart::Sunday),
             recurrence_builder: cfg.recurrence_builder.unwrap_or(true),
@@ -133,6 +135,10 @@ impl Prefs {
         self.show_future = !self.show_future;
     }
 
+    pub fn toggle_show_blocked(&mut self) {
+        self.show_blocked = !self.show_blocked;
+    }
+
     pub fn cycle_week_start(&mut self) -> String {
         self.week_start = match self.week_start {
             WeekStart::Sunday => WeekStart::Monday,
@@ -160,6 +166,7 @@ impl Prefs {
         cfg.show_status_bar = Some(self.layout.status_bar);
         cfg.show_done = Some(self.show_done);
         cfg.show_future = Some(self.show_future);
+        cfg.show_blocked = Some(self.show_blocked);
         cfg.hidden_keys = self.hidden_keys.clone();
         cfg.save()
     }

src/app/visibility.rs

@@ -1,6 +1,7 @@
 use super::App;
 use super::types::{Sort, View};
 use crate::core::filter::{self, ListDueBucket};
+use crate::todo::Task;
 
 /// One entry per visible row, parallel to `visible_cache`. Renderers detect
 /// group transitions by comparing successive entries; under `Sort::File` every
@@ -44,8 +45,22 @@ impl App {
         let needle = (!self.filter.search.is_empty())
             .then(|| filter::resolve_needle(&self.filter.search, today));
 
+        let undone_ids: std::collections::HashSet<&str> = tasks
+            .iter()
+            .filter(|t| !t.done)
+            .filter_map(|t| t.id.as_deref())
+            .collect();
+        let is_blocked = |t: &Task| {
+            t.needs
+                .as_deref()
+                .is_some_and(|dep| undone_ids.contains(dep))
+        };
+
         let mut idxs: Vec<usize> = (0..tasks.len())
             .filter(|&i| {
+                if !self.prefs.show_blocked && is_blocked(&tasks[i]) {
+                    return false;
+                }
                 filter::list_predicate(
                     &tasks[i],
                     self.prefs.show_done,

src/config.rs

@@ -26,6 +26,7 @@ pub struct Config {
     pub show_status_bar: Option<bool>,
     pub show_done: Option<bool>,
     pub show_future: Option<bool>,
+    pub show_blocked: Option<bool>,
     /// 64-character lowercase-hex token gating the in-TUI capture server.
     /// Persisted across sessions so phone bookmarks survive a relaunch.
     /// Stored on disk; only meaningful for LAN access, but flagged here
@@ -154,6 +155,7 @@ fn parse(s: &str) -> Config {
             "show_status_bar" => c.show_status_bar = parse_bool(v),
             "show_done" => c.show_done = parse_bool(v),
             "show_future" => c.show_future = parse_bool(v),
+            "show_blocked" => c.show_blocked = parse_bool(v),
             // Reject anything that isn't a valid hex token so we don't
             // carry forward a corrupt value that the server would later
             // refuse to compare against.
@@ -226,6 +228,9 @@ fn serialize(c: &Config) -> String {
     if let Some(v) = c.show_future {
         let _ = writeln!(out, "show_future = {v}");
     }
+    if let Some(v) = c.show_blocked {
+        let _ = writeln!(out, "show_blocked = {v}");
+    }
     if let Some(v) = &c.share_token {
         let _ = writeln!(out, "share_token = {v}");
     }
@@ -283,6 +288,7 @@ mod tests {
             show_status_bar: Some(true),
             show_done: Some(true),
             show_future: Some(true),
+            show_blocked: Some(true),
             share_token: Some("a".repeat(64)),
             share_port: Some(18080),
             filters: vec![
@@ -443,6 +449,7 @@ mod tests {
             show_status_bar: Some(false),
             show_done: Some(true),
             show_future: Some(false),
+            show_blocked: Some(false),
             share_token: None,
             share_port: None,
             filters: vec![("errand".into(), "@errand".into())],

src/main.rs

@@ -843,6 +843,7 @@ fn handle_settings(app: &mut App, key: KeyEvent) {
         KeyCode::Char(']') => apply_action(app, Action::ToggleRightPane),
         KeyCode::Char('H') => apply_action(app, Action::ToggleShowDone),
         KeyCode::Char('F') => apply_action(app, Action::ToggleShowFuture),
+        KeyCode::Char('B') => apply_action(app, Action::ToggleShowBlocked),
         KeyCode::Char('S') => apply_action(app, Action::CycleSort),
         _ => {}
     }
@@ -1092,6 +1093,7 @@ fn resolve_normal_key(app: &mut App, key: KeyEvent, keybinds: &KeyBindings) -> O
         KeyCode::Char('L') => Action::ToggleLineNum,
         KeyCode::Char('H') => Action::ToggleShowDone,
         KeyCode::Char('F') => Action::ToggleShowFuture,
+        KeyCode::Char('B') => Action::ToggleShowBlocked,
         KeyCode::Esc => Action::EscapeStack,
         KeyCode::Char('W') => Action::ChangeWeekStart,
         _ => return None,
@@ -1136,6 +1138,7 @@ fn apply_action(app: &mut App, action: Action) {
             | Action::CycleSort
             | Action::ToggleShowDone
             | Action::ToggleShowFuture
+            | Action::ToggleShowBlocked
             | Action::Undo => {
                 app.flash("read-only in archive");
                 return;
@@ -1307,6 +1310,12 @@ fn apply_action(app: &mut App, action: Action) {
             app.recompute_visible();
             app.save_prefs();
         }
+        Action::ToggleShowBlocked => {
+            app.prefs.toggle_show_blocked();
+            app.cursor = 0;
+            app.recompute_visible();
+            app.save_prefs();
+        }
         Action::CopyLine => copy_current_task(app, false),
         Action::CopyBody => copy_current_task(app, true),
         Action::OpenNote => app.open_note_for_current(),

src/todo.rs

@@ -56,6 +56,10 @@ pub struct Task {
     /// filter parses it on demand via `crate::threshold`.
     pub threshold: Option<String>,
     pub notes: Vec<String>,
+    /// Raw value of the `id:` tag if present.
+    pub id: Option<String>,
+    /// Raw value of the `needs:` tag if present.
+    pub needs: Option<String>,
 }
 
 pub fn parse_line(raw: &str) -> Result<Task, ParseError> {
@@ -94,6 +98,8 @@ pub fn parse_line(raw: &str) -> Result<Task, ParseError> {
     let rec = find_kv(rest, "rec");
     let threshold = find_kv(rest, "t");
     let notes = find_quoted_kv(rest, "note");
+    let id = find_kv(rest, "id");
+    let needs = find_kv(rest, "needs");
     let clean_raw = body_after_quoted_kv(line);
 
     Ok(Task {
@@ -109,6 +115,8 @@ pub fn parse_line(raw: &str) -> Result<Task, ParseError> {
         rec,
         threshold,
         notes,
+        id,
+        needs,
     })
 }
 
@@ -673,4 +681,11 @@ mod tests {
             assert_eq!(a.raw, b.raw);
         }
     }
+
+    #[test]
+    fn parses_id_and_needs() {
+        let t = parse_line("Build wall id:wall needs:foundation").unwrap();
+        assert_eq!(t.id.as_deref(), Some("wall"));
+        assert_eq!(t.needs.as_deref(), Some("foundation"));
+    }
 }

src/ui/archive.rs

@@ -98,6 +98,7 @@ pub fn render(frame: &mut Frame, area: Rect, app: &App) {
             match_term: None,
             today: app.today(),
             hidden_keys: &app.prefs.hidden_keys,
+            blocked: false,
         };
         if i == app.cursor {
             cursor_line = Some(lines.len());

src/ui/help.rs

@@ -62,6 +62,7 @@ const VIEW: Section = (
         ("A", "archive completed"),
         ("H", "show done in list"),
         ("F", "show future in list"),
+        ("B", "show blocked in list"),
         ("[ / ]", "toggle filter / detail"),
         ("T", "theme picker"),
         ("D", "cycle density"),

src/ui/list.rs

@@ -68,6 +68,13 @@ pub fn render(frame: &mut Frame, area: Rect, app: &App) {
         let last = visible.len().saturating_sub(1);
         let mut last_group: Option<&GroupKey> = None;
 
+        let undone_ids: std::collections::HashSet<&str> = app
+            .tasks()
+            .iter()
+            .filter(|t| !t.done)
+            .filter_map(|t| t.id.as_deref())
+            .collect();
+
         for (i, (&abs, gk)) in visible.iter().zip(groups.iter()).enumerate() {
             // Emit a section header on group transitions. `GroupKey::None`
             // means the active sort is `Sort::File`; we never render a header
@@ -81,6 +88,10 @@ pub fn render(frame: &mut Frame, area: Rect, app: &App) {
             }
 
             let task = &app.tasks()[abs];
+            let blocked = task
+                .needs
+                .as_deref()
+                .is_some_and(|dep| undone_ids.contains(dep));
             let opts = task_row::RowOpts {
                 idx_label: i,
                 cursor: i == app.cursor && app.mode != Mode::Help && app.mode != Mode::Settings,
@@ -91,6 +102,7 @@ pub fn render(frame: &mut Frame, area: Rect, app: &App) {
                 match_term,
                 today: app.today(),
                 hidden_keys: &app.prefs.hidden_keys,
+                blocked,
             };
             if i == app.cursor {
                 cursor_line = Some(lines.len());

src/ui/settings.rs

@@ -75,6 +75,10 @@ pub fn render(frame: &mut Frame, area: Rect, app: &App) {
             "  show future in list",
             Some(format!("{}  (F to toggle)", on(app.prefs.show_future))),
         ),
+        (
+            "  show blocked in list",
+            Some(format!("{}  (B to toggle)", on(app.prefs.show_blocked))),
+        ),
         ("", Some("".into())),
         ("BEHAVIOR", None),
         (

src/ui/task_row.rs

@@ -19,6 +19,9 @@ pub struct RowOpts<'a> {
     /// rendered body. Empty (the common case) means render everything,
     /// byte-for-byte as before.
     pub hidden_keys: &'a [String],
+    /// True when this task has a `needs:` reference pointing to an existing
+    /// undone task.
+    pub blocked: bool,
 }
 
 pub fn build_line<'a>(task: &'a Task, opts: RowOpts<'a>, theme: &Theme) -> Line<'a> {
@@ -141,7 +144,11 @@ pub fn build_line<'a>(task: &'a Task, opts: RowOpts<'a>, theme: &Theme) -> Line<
     } else {
         Style::default()
     };
-    Line::from(spans).style(line_style)
+    Line::from(spans).style(line_style.add_modifier(if opts.blocked {
+        Modifier::DIM
+    } else {
+        Modifier::empty()
+    }))
 }
 
 fn push_token_spans<'a>(
@@ -389,6 +396,7 @@ mod tests {
             match_term: Some("a"),
             today: "2026-05-06",
             hidden_keys: &[],
+            blocked: false,
         };
         // Build must not panic; we don't assert on the rendered spans.
         let _ = build_line(&task, opts, &MUTED);
@@ -410,6 +418,7 @@ mod tests {
             match_term: Some("cade"),
             today: "2026-05-06",
             hidden_keys: &[],
+            blocked: false,
         };
         let line = build_line(&task, opts, &MUTED);
         let highlight_bg = MUTED.matched;
@@ -438,6 +447,7 @@ mod tests {
             match_term: None,
             today: "2026-05-06",
             hidden_keys: hidden,
+            blocked: false,
         };
         let line = build_line(&task, opts, &MUTED);
         line.spans
@@ -505,6 +515,7 @@ mod tests {
             match_term: None,
             today: "2026-05-06",
             hidden_keys: &[],
+            blocked: false,
         };
         let line = build_line(&task, opts, &MUTED);
         let url_span = line
@@ -536,6 +547,7 @@ mod tests {
             match_term: None,
             today: "2026-05-06",
             hidden_keys: &[],
+            blocked: false,
         };
         let line = build_line(&task, opts, &MUTED);
         let url_span = line
@@ -559,4 +571,26 @@ mod tests {
             "Pay rent due:2026-05-15",
         );
     }
+
+    #[test]
+    fn blocked_row_is_dimmed() {
+        let task = parse_line("Blocked task +project").unwrap();
+        let opts = RowOpts {
+            idx_label: 0,
+            cursor: false,
+            multi_mode: false,
+            multi_checked: false,
+            selected: false,
+            show_line_num: false,
+            match_term: None,
+            today: "2026-05-06",
+            hidden_keys: &[],
+            blocked: true,
+        };
+        let line = build_line(&task, opts, &MUTED);
+        assert!(
+            line.style.add_modifier.contains(Modifier::DIM),
+            "blocked row line style must carry DIM"
+        );
+    }
 }