feat: add task duration tracking

README.md

@@ -10,6 +10,7 @@ Hierarchical, session-local task tracking for [Pi](https://pi.dev), with atomic
 - Parent/child task trees with generated integer IDs and atomic append/replace modes
 - Atomic batch mutations: every requested change succeeds or none of it is applied
 - Four states: `pending`, `in-progress`, `blocked`, and `done`
+- Cumulative active-time tracking that pauses outside `in-progress` and survives session restore
 - Session-branch persistence across reload, resume, fork, tree navigation, and context compaction
 - A concise first-action workflow prompt plus a one-shot post-compaction recovery reminder
 - Compact Pi widget with hierarchy, status colors, and an adaptive progress bar
@@ -56,7 +57,7 @@ After automatic or manual context compaction, the extension sends one short hidd
 | `update_task` | `{ tasks: [...] }` | Atomically patches multiple tasks. `parentId: null` moves to the root; `position` is a zero-based sibling index. |
 | `rm_task` | `{ ids: [...], reason }` | Removes only mistaken, duplicate, or canceled tasks. Removing a parent cascades through its descendants. |
 | `list_task` | `{}` | Returns the full tree as compact `id/status/name` lines. |
-| `get_task` | `{ ids: [...] }` | Returns complete task details, including parent and child IDs. |
+| `get_task` | `{ ids: [...] }` | Returns complete task details, including parent/child IDs and timing for tasks that have started. |
 
 Example append call:
 
@@ -81,16 +82,18 @@ Example append call:
 
 Descriptions are optional, but useful scope, constraints, and done criteria improve recovery through `get_task`. IDs are not reused by append/remove operations; `replace` deliberately rebuilds IDs from `1`. Replace forbids `parentId`, so new hierarchy must use nested `children`. Multiple tasks may be `in-progress`. A parent can be marked `done` only when all descendants are also `done`.
 
+A task starts timing the first time it enters `in-progress`. Leaving that state records a stop and pauses the timer; entering it again resumes with a new active segment while preserving the cumulative duration. Repeated updates with the same status, as well as name, description, hierarchy, and position changes, do not reset timing. For started tasks, `get_task` includes the first `startedAt` timestamp, a `stoppedAt` timestamp while paused, and cumulative `durationMs`. Timestamps use ISO 8601.
+
 ## Pi Widget
 
 The widget appears above Pi's editor while tasks exist. Run `/tasks` to hide or show it for the current Pi runtime.
 
 ```text
  Tasks 2/6 · !1  ━━━━━────────
-  ◉ 1. Build auth
+  ◉ 1. Build auth · 12:08
-  ├─ ! 3. Resolve token issue
+  ├─ ! 3. Resolve token issue · 03:41
   └─ ○ 4. Add middleware
-  ✓ 2. Define schema
+  ✓ 2. Define schema · 04:31
 ```
 
 Tool calls remain compact in the conversation. Expand a tool result with Pi's normal tool-output shortcut to inspect affected tasks or full descriptions.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "pi-todo-herdr",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "pi-todo-herdr",
-      "version": "0.2.0",
+      "version": "0.2.1",
       "license": "MIT",
       "devDependencies": {
         "@earendil-works/pi-ai": "^0.81.1",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pi-todo-herdr",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "Hierarchical task tools for Pi with a live widget and Herdr sidebar integration.",
   "type": "module",
   "main": "./index.ts",

src/state.ts

@@ -6,12 +6,14 @@ import type {
   TaskSnapshot,
   TaskStats,
   TaskStatus,
+  TaskTimingSnapshot,
   TaskToolDetails,
 } from "./types.ts";
 import { TaskValidationError } from "./types.ts";
 
 const MUTATION_TOOLS = new Set(["add_task", "set_tasks", "update_task", "rm_task"]);
 const VALID_STATUSES = new Set<TaskStatus>(["pending", "in-progress", "blocked", "done"]);
+const MAX_DATE_MS = 8_640_000_000_000_000;
 
 interface TaskRecord {
   id: number;
@@ -19,6 +21,10 @@ interface TaskRecord {
   description?: string;
   status: TaskStatus;
   parentId: number | null;
+  startedAt?: number;
+  activeStartedAt?: number;
+  stoppedAt?: number;
+  accumulatedMs: number;
 }
 
 function cloneRecords(records: TaskRecord[]): TaskRecord[] {
@@ -33,13 +39,74 @@ function childIds(records: TaskRecord[], parentId: number | null): number[] {
   return records.filter((task) => task.parentId === parentId).map((task) => task.id);
 }
 
-function publicTasks(records: TaskRecord[]): Task[] {
+function snapshotTasks(records: TaskRecord[]): Task[] {
   return records.map((task) => ({
-    ...task,
+    id: task.id,
+    name: task.name,
+    ...(task.description !== undefined ? { description: task.description } : {}),
+    status: task.status,
+    parentId: task.parentId,
     childrenIds: childIds(records, task.id),
   }));
 }
 
+function durationMs(task: TaskRecord, now: number): number {
+  const activeMs = task.activeStartedAt === undefined ? 0 : Math.max(0, now - task.activeStartedAt);
+  return task.accumulatedMs + activeMs;
+}
+
+function publicTasks(records: TaskRecord[], now: number): Task[] {
+  const byId = indexRecords(records);
+  return snapshotTasks(records).map((task) => {
+    const record = byId.get(task.id);
+    if (!record || record.startedAt === undefined) return task;
+    return {
+      ...task,
+      startedAt: new Date(record.startedAt).toISOString(),
+      ...(record.stoppedAt !== undefined ? { stoppedAt: new Date(record.stoppedAt).toISOString() } : {}),
+      durationMs: durationMs(record, now),
+    };
+  });
+}
+
+function timingSnapshots(records: TaskRecord[]): TaskTimingSnapshot[] {
+  const timings: TaskTimingSnapshot[] = [];
+  for (const task of records) {
+    if (task.startedAt === undefined) continue;
+    timings.push({
+      taskId: task.id,
+      startedAt: task.startedAt,
+      ...(task.activeStartedAt !== undefined ? { activeStartedAt: task.activeStartedAt } : {}),
+      ...(task.stoppedAt !== undefined ? { stoppedAt: task.stoppedAt } : {}),
+      accumulatedMs: task.accumulatedMs,
+    });
+  }
+  return timings;
+}
+
+function startTimer(task: TaskRecord, now: number): void {
+  const startedAt = Math.max(now, task.stoppedAt ?? task.startedAt ?? 0);
+  task.startedAt ??= startedAt;
+  task.activeStartedAt = startedAt;
+  task.stoppedAt = undefined;
+}
+
+function stopTimer(task: TaskRecord, now: number): void {
+  if (task.activeStartedAt === undefined) return;
+  const stoppedAt = Math.max(now, task.activeStartedAt);
+  task.accumulatedMs += stoppedAt - task.activeStartedAt;
+  task.activeStartedAt = undefined;
+  task.stoppedAt = stoppedAt;
+}
+
+function isNonNegativeSafeInteger(value: unknown): value is number {
+  return Number.isSafeInteger(value) && (value as number) >= 0;
+}
+
+function isValidTimestamp(value: unknown): value is number {
+  return isNonNegativeSafeInteger(value) && value <= MAX_DATE_MS;
+}
+
 function collectDescendantIds(records: TaskRecord[], rootId: number): number[] {
   const result: number[] = [];
   const visit = (id: number) => {
@@ -67,6 +134,38 @@ function validateGraph(records: TaskRecord[]): string[] {
       errors.push(`task ${task.id}: description must not be empty`);
     }
     if (!VALID_STATUSES.has(task.status)) errors.push(`task ${task.id}: invalid status '${task.status}'`);
+    if (!isNonNegativeSafeInteger(task.accumulatedMs)) {
+      errors.push(`task ${task.id}: accumulatedMs must be a non-negative safe integer`);
+    }
+    if (task.startedAt === undefined) {
+      if (task.activeStartedAt !== undefined || task.stoppedAt !== undefined || task.accumulatedMs !== 0) {
+        errors.push(`task ${task.id}: timer fields require startedAt`);
+      }
+      if (task.status === "in-progress") errors.push(`task ${task.id}: in-progress task is missing timer data`);
+    } else {
+      if (!isValidTimestamp(task.startedAt)) {
+        errors.push(`task ${task.id}: startedAt must be a valid non-negative timestamp`);
+      }
+      if (task.activeStartedAt !== undefined && !isValidTimestamp(task.activeStartedAt)) {
+        errors.push(`task ${task.id}: activeStartedAt must be a valid non-negative timestamp`);
+      }
+      if (task.stoppedAt !== undefined && !isValidTimestamp(task.stoppedAt)) {
+        errors.push(`task ${task.id}: stoppedAt must be a valid non-negative timestamp`);
+      }
+      if (task.activeStartedAt !== undefined && task.activeStartedAt < task.startedAt) {
+        errors.push(`task ${task.id}: activeStartedAt must not precede startedAt`);
+      }
+      if (task.stoppedAt !== undefined && task.stoppedAt < task.startedAt) {
+        errors.push(`task ${task.id}: stoppedAt must not precede startedAt`);
+      }
+      if (task.status === "in-progress") {
+        if (task.activeStartedAt === undefined) errors.push(`task ${task.id}: active timer is missing its segment start`);
+        if (task.stoppedAt !== undefined) errors.push(`task ${task.id}: active timer must not have stoppedAt`);
+      } else {
+        if (task.activeStartedAt !== undefined) errors.push(`task ${task.id}: inactive task has an active timer segment`);
+        if (task.stoppedAt === undefined) errors.push(`task ${task.id}: paused timer is missing stoppedAt`);
+      }
+    }
     if (task.parentId !== null && !byId.has(task.parentId)) {
       errors.push(`task ${task.id}: parent ${task.parentId} does not exist`);
     }
@@ -153,8 +252,17 @@ export class TaskState {
   private records: TaskRecord[] = [];
   private nextId = 1;
 
+  constructor(private readonly now: () => number = Date.now) {}
+
+  private currentTime(): number {
+    const now = Math.floor(this.now());
+    if (!isValidTimestamp(now)) throw new Error("task clock must return a valid non-negative timestamp");
+    return now;
+  }
+
   list(): Task[] {
-    return publicTasks(this.records);
+    const now = this.records.some((task) => task.startedAt !== undefined) ? this.currentTime() : 0;
+    return publicTasks(this.records, now);
   }
 
   get(ids: number[]): Task[] {
@@ -163,7 +271,12 @@ export class TaskState {
   }
 
   snapshot(): TaskSnapshot {
-    return { tasks: this.list(), nextId: this.nextId };
+    const timings = timingSnapshots(this.records);
+    return {
+      tasks: snapshotTasks(this.records),
+      nextId: this.nextId,
+      ...(timings.length > 0 ? { timings } : {}),
+    };
   }
 
   stats(): TaskStats {
@@ -183,6 +296,7 @@ export class TaskState {
 
     const working = cloneRecords(this.records);
     const existingIds = new Set(working.map((task) => task.id));
+    const now = this.currentTime();
     let nextId = this.nextId;
     const addedIds: number[] = [];
 
@@ -212,13 +326,16 @@ export class TaskState {
       }
 
       const id = nextId++;
+      const status = draft.status ?? "pending";
       addedIds.push(id);
       working.push({
         id,
         name: typeof draft.name === "string" ? draft.name.trim() : "",
         ...(typeof draft.description === "string" ? { description: draft.description.trim() } : {}),
-        status: draft.status ?? "pending",
+        status,
         parentId,
+        accumulatedMs: 0,
+        ...(status === "in-progress" ? { startedAt: now, activeStartedAt: now } : {}),
       });
 
       for (const [index, child] of (draft.children ?? []).entries()) {
@@ -252,7 +369,7 @@ export class TaskState {
     });
     if (errors.length > 0) throw new TaskValidationError(errors);
 
-    const replacement = new TaskState();
+    const replacement = new TaskState(this.now);
     const affected = drafts.length === 0 ? [] : replacement.add(drafts);
     this.restore(replacement.snapshot());
     return affected;
@@ -268,6 +385,7 @@ export class TaskState {
     if (duplicateIds.length > 0) errors.push(`duplicate task patches: ${[...new Set(duplicateIds)].join(", ")}`);
 
     const working = cloneRecords(this.records);
+    const now = this.currentTime();
     for (const [index, patch] of patches.entries()) {
       const path = `tasks[${index}]`;
       const task = working.find((candidate) => candidate.id === patch.id);
@@ -296,7 +414,11 @@ export class TaskState {
 
       if (patch.name !== undefined) task.name = patch.name.trim();
       if (patch.description !== undefined) task.description = patch.description.trim();
-      if (patch.status !== undefined) task.status = patch.status;
+      if (patch.status !== undefined && patch.status !== task.status) {
+        if (task.status === "in-progress" && patch.status !== "in-progress") stopTimer(task, now);
+        if (task.status !== "in-progress" && patch.status === "in-progress") startTimer(task, now);
+        task.status = patch.status;
+      }
       if (patch.parentId !== undefined && (patch.parentId === null || working.some((item) => item.id === patch.parentId))) {
         task.parentId = patch.parentId;
         moveToSiblingEnd(working, task.id);
@@ -325,7 +447,11 @@ export class TaskState {
       removedIds.add(id);
       for (const descendantId of collectDescendantIds(this.records, id)) removedIds.add(descendantId);
     }
-    const removed = this.list().filter((task) => removedIds.has(task.id));
+    const now = this.currentTime();
+    for (const task of this.records) {
+      if (removedIds.has(task.id) && task.status === "in-progress") stopTimer(task, now);
+    }
+    const removed = publicTasks(this.records, now).filter((task) => removedIds.has(task.id));
     this.records = this.records.filter((task) => !removedIds.has(task.id));
     return removed;
   }
@@ -334,13 +460,56 @@ export class TaskState {
     if (!snapshot || !Array.isArray(snapshot.tasks) || !Number.isInteger(snapshot.nextId)) {
       throw new TaskValidationError(["invalid task snapshot"]);
     }
+    if (snapshot.timings !== undefined && !Array.isArray(snapshot.timings)) {
+      throw new TaskValidationError(["invalid task snapshot timings"]);
+    }
+
     const records = snapshot.tasks.map(({ id, name, description, status, parentId }) => ({
       id,
       name,
       description,
       status,
       parentId,
+      accumulatedMs: 0,
     }));
+    const byId = indexRecords(records);
+    const timingErrors: string[] = [];
+    const timedIds = new Set<number>();
+
+    for (const [index, timing] of (snapshot.timings ?? []).entries()) {
+      const path = `timings[${index}]`;
+      if (!timing || typeof timing !== "object") {
+        timingErrors.push(`${path} must be an object`);
+        continue;
+      }
+      if (!Number.isInteger(timing.taskId) || timing.taskId < 1) {
+        timingErrors.push(`${path}.taskId must be a positive integer`);
+        continue;
+      }
+      if (timedIds.has(timing.taskId)) {
+        timingErrors.push(`${path}.taskId ${timing.taskId} is duplicated`);
+        continue;
+      }
+      timedIds.add(timing.taskId);
+      const task = byId.get(timing.taskId);
+      if (!task) {
+        timingErrors.push(`${path}.taskId ${timing.taskId} does not exist`);
+        continue;
+      }
+      task.startedAt = timing.startedAt;
+      task.activeStartedAt = timing.activeStartedAt;
+      task.stoppedAt = timing.stoppedAt;
+      task.accumulatedMs = timing.accumulatedMs;
+    }
+
+    if (timingErrors.length > 0) throw new TaskValidationError(timingErrors);
+    if (snapshot.timings === undefined && records.some((task) => task.status === "in-progress")) {
+      const now = this.currentTime();
+      for (const task of records) {
+        if (task.status === "in-progress") startTimer(task, now);
+      }
+    }
+
     const errors = validateGraph(records);
     const maxId = records.reduce((max, task) => Math.max(max, task.id), 0);
     if (snapshot.nextId <= maxId) errors.push(`nextId must be greater than ${maxId}`);

src/types.ts

@@ -7,11 +7,23 @@ export interface Task {
   status: TaskStatus;
   parentId: number | null;
   childrenIds: number[];
+  startedAt?: string;
+  stoppedAt?: string;
+  durationMs?: number;
+}
+
+export interface TaskTimingSnapshot {
+  taskId: number;
+  startedAt: number;
+  activeStartedAt?: number;
+  stoppedAt?: number;
+  accumulatedMs: number;
 }
 
 export interface TaskSnapshot {
   tasks: Task[];
   nextId: number;
+  timings?: TaskTimingSnapshot[];
 }
 
 export interface AddTaskDraft {

src/ui.ts

@@ -49,6 +49,16 @@ function styleStatusIcon(task: Task, theme: Theme): string {
   return theme.fg("dim", icon);
 }
 
+export function formatDuration(durationMs: number): string {
+  const safeMs = Number.isFinite(durationMs) && durationMs >= 0 ? durationMs : 0;
+  const totalSeconds = Math.floor(safeMs / 1000);
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = totalSeconds % 60;
+  const minuteClock = [minutes, seconds].map((part) => String(part).padStart(2, "0")).join(":");
+  return hours === 0 ? minuteClock : `${String(hours).padStart(2, "0")}:${minuteClock}`;
+}
+
 export function renderTaskLine(task: Task, prefix: string, theme: Theme, width: number): string {
   const line =
     theme.fg("dim", prefix) +
@@ -57,7 +67,13 @@ export function renderTaskLine(task: Task, prefix: string, theme: Theme, width:
     theme.fg("accent", `${task.id}.`) +
     " " +
     styleTaskName(task, theme);
-  return truncateToWidth(line, Math.max(1, width));
+  if (task.durationMs === undefined) return truncateToWidth(line, Math.max(1, width));
+
+  const duration = theme.fg("dim", ` · ${formatDuration(task.durationMs)}`);
+  const durationWidth = visibleWidth(duration);
+  if (width <= durationWidth + 6) return truncateToWidth(line, Math.max(1, width));
+  const taskWidth = Math.max(1, width - durationWidth);
+  return truncateToWidth(line, taskWidth) + duration;
 }
 
 export function renderTree(tasks: Task[], theme: Theme, width: number, padding = "  "): string[] {
@@ -182,7 +198,7 @@ export function renderToolResult(
   return new TaskResultComponent((width) => {
     const lines = [theme.fg("success", "✓ ") + theme.fg("muted", summaryFor(details))];
     if (!expanded || details.affected.length === 0) return lines;
-    if (details.action === "list") return [...lines, ...renderTree(details.snapshot.tasks, theme, width)];
+    if (details.action === "list") return [...lines, ...renderTree(details.affected, theme, width)];
     if (details.action === "get") return [...lines, ...renderTaskDetails(details.affected, theme, width)];
     return [...lines, ...renderFlatTasks(details.affected, theme, width)];
   });

src/widget.ts

@@ -3,23 +3,40 @@ import type { TaskState } from "./state.ts";
 import { renderProgressHeader, renderTree } from "./ui.ts";
 
 const WIDGET_ID = "pi-todo-herdr";
+const TIMER_REFRESH_MS = 1000;
 
 export function clearTaskWidget(ctx: ExtensionContext): void {
   ctx.ui.setWidget(WIDGET_ID, undefined);
 }
 
-export function updateTaskWidget(state: TaskState, ctx: ExtensionContext, visible: boolean): void {
+export function updateTaskWidget(
+  state: TaskState,
+  ctx: ExtensionContext,
+  visible: boolean,
+  refreshMs = TIMER_REFRESH_MS,
+): void {
   const tasks = state.list();
   if (!visible || tasks.length === 0) {
     clearTaskWidget(ctx);
     return;
   }
 
-  const stats = state.stats();
+  const hasActiveTimer = tasks.some((task) => task.status === "in-progress" && task.startedAt !== undefined);
-  ctx.ui.setWidget(WIDGET_ID, (_tui, theme) => ({
+  ctx.ui.setWidget(WIDGET_ID, (tui, theme) => {
-    render(width: number): string[] {
+    const timer = hasActiveTimer
-      return [renderProgressHeader(stats, theme, width), ...renderTree(tasks, theme, width)];
+      ? setInterval(() => tui.requestRender(), Math.max(1, refreshMs))
-    },
+      : undefined;
-    invalidate(): void {},
+    timer?.unref();
-  }));
+
+    return {
+      render(width: number): string[] {
+        const currentTasks = state.list();
+        return [renderProgressHeader(state.stats(), theme, width), ...renderTree(currentTasks, theme, width)];
+      },
+      invalidate(): void {},
+      dispose(): void {
+        if (timer !== undefined) clearInterval(timer);
+      },
+    };
+  });
 }

tests/state.test.ts

@@ -68,6 +68,144 @@ test("enforces done descendants against the final atomic update state", () => {
   assert.deepEqual(state.list().map((task) => task.status), ["in-progress", "in-progress"]);
 });
 
+test("preserves and accumulates timing across repeated updates and status changes", () => {
+  const startedAt = Date.UTC(2026, 0, 1);
+  let now = startedAt;
+  const state = new TaskState(() => now);
+
+  const [started] = state.add([{ name: "Timed", status: "in-progress" }]);
+  assert.equal(started?.startedAt, new Date(startedAt).toISOString());
+  assert.equal(started?.stoppedAt, undefined);
+  assert.equal(started?.durationMs, 0);
+
+  now += 5_000;
+  const [repeated] = state.update([{ id: 1, name: "Renamed", status: "in-progress" }]);
+  assert.equal(repeated?.startedAt, started?.startedAt);
+  assert.equal(repeated?.stoppedAt, undefined);
+  assert.equal(repeated?.durationMs, 5_000);
+
+  now += 2_000;
+  const [paused] = state.update([{ id: 1, status: "blocked" }]);
+  assert.equal(paused?.startedAt, started?.startedAt);
+  assert.equal(paused?.stoppedAt, new Date(now).toISOString());
+  assert.equal(paused?.durationMs, 7_000);
+
+  now += 10_000;
+  assert.equal(state.get([1])[0]?.durationMs, 7_000);
+  const [resumed] = state.update([{ id: 1, status: "in-progress" }]);
+  assert.equal(resumed?.startedAt, started?.startedAt);
+  assert.equal(resumed?.stoppedAt, undefined);
+  assert.equal(resumed?.durationMs, 7_000);
+
+  now += 3_000;
+  const [done] = state.update([{ id: 1, status: "done" }]);
+  assert.equal(done?.startedAt, started?.startedAt);
+  assert.equal(done?.stoppedAt, new Date(now).toISOString());
+  assert.equal(done?.durationMs, 10_000);
+  assert.deepEqual(state.snapshot().timings, [
+    { taskId: 1, startedAt, stoppedAt: now, accumulatedMs: 10_000 },
+  ]);
+});
+
+test("does not stop a timer when an atomic update fails", () => {
+  const startedAt = Date.UTC(2026, 0, 1);
+  let now = startedAt;
+  const state = new TaskState(() => now);
+  state.add([
+    {
+      name: "Parent",
+      status: "in-progress",
+      children: [{ name: "Unfinished child" }],
+    },
+  ]);
+
+  now += 5_000;
+  assert.throws(() => state.update([{ id: 1, status: "done" }]), /unfinished descendants/);
+  const afterFailure = state.get([1])[0];
+  assert.equal(afterFailure?.stoppedAt, undefined);
+  assert.equal(afterFailure?.durationMs, 5_000);
+
+  now += 2_000;
+  assert.equal(state.get([1])[0]?.durationMs, 7_000);
+});
+
+test("restores timers and starts legacy in-progress snapshots at load time", () => {
+  const startedAt = Date.UTC(2026, 0, 1);
+  let now = startedAt;
+  const source = new TaskState(() => now);
+  source.add([{ name: "Persisted", status: "in-progress" }]);
+  now += 2_500;
+  source.update([{ id: 1, status: "pending" }]);
+
+  now += 20_000;
+  const restored = new TaskState(() => now);
+  restored.restore(source.snapshot());
+  assert.equal(restored.get([1])[0]?.startedAt, new Date(startedAt).toISOString());
+  assert.equal(restored.get([1])[0]?.stoppedAt, new Date(startedAt + 2_500).toISOString());
+  assert.equal(restored.get([1])[0]?.durationMs, 2_500);
+
+  const legacy = new TaskState(() => now);
+  legacy.restore({
+    tasks: [
+      {
+        id: 1,
+        name: "Legacy active",
+        status: "in-progress",
+        parentId: null,
+        childrenIds: [],
+      },
+    ],
+    nextId: 2,
+  });
+  assert.equal(legacy.get([1])[0]?.startedAt, new Date(now).toISOString());
+  assert.equal(legacy.get([1])[0]?.durationMs, 0);
+  assert.equal(legacy.snapshot().timings?.[0]?.activeStartedAt, now);
+});
+
+test("rejects out-of-range persisted timestamps without replacing state", () => {
+  const state = new TaskState(() => 0);
+  state.add([{ name: "Keep" }]);
+  const before = state.snapshot();
+
+  assert.throws(
+    () =>
+      state.restore({
+        tasks: [
+          {
+            id: 1,
+            name: "Corrupt timer",
+            status: "in-progress",
+            parentId: null,
+            childrenIds: [],
+          },
+        ],
+        nextId: 2,
+        timings: [
+          {
+            taskId: 1,
+            startedAt: Number.MAX_SAFE_INTEGER,
+            activeStartedAt: Number.MAX_SAFE_INTEGER,
+            accumulatedMs: 0,
+          },
+        ],
+      }),
+    /startedAt must be a valid non-negative timestamp/,
+  );
+  assert.deepEqual(state.snapshot(), before);
+});
+
+test("finalizes an active timer in removed task details", () => {
+  let now = Date.UTC(2026, 0, 1);
+  const state = new TaskState(() => now);
+  state.add([{ name: "Canceled", status: "in-progress" }]);
+  now += 4_000;
+
+  const [removed] = state.remove([1]);
+  assert.equal(removed?.stoppedAt, new Date(now).toISOString());
+  assert.equal(removed?.durationMs, 4_000);
+  assert.deepEqual(state.list(), []);
+});
+
 test("rejects cycles and duplicate patches without partial changes", () => {
   const state = new TaskState();
   state.add([{ name: "Root", description: "Root", children: [{ name: "Child", description: "Child" }] }]);

tests/tools.test.ts

@@ -113,3 +113,42 @@ test("list is compact and get returns available details for multiple IDs", async
   assert.equal(parsed[1].description, undefined);
   assert.equal(parsed[1].parentId, 1);
 });
+
+test("get_task exposes cumulative timing while list output stays compact", async () => {
+  const startedAt = Date.UTC(2026, 0, 1);
+  let now = startedAt;
+  const harness = registeredTools(new TaskState(() => now));
+  const added = await execute(harness.tools.get("set_tasks"), {
+    mode: "append",
+    tasks: [{ name: "Timed", status: "in-progress" }],
+  });
+  assert.equal(added.content[0].text, "Added 1 task: 1. 0/1 done.");
+  assert.equal(added.details.snapshot.timings[0].activeStartedAt, startedAt);
+
+  now += 65_432;
+  const list = await execute(harness.tools.get("list_task"), {});
+  assert.equal(list.content[0].text, "1 [in-progress] Timed");
+
+  const active = JSON.parse((await execute(harness.tools.get("get_task"), { ids: [1] })).content[0].text);
+  assert.deepEqual(active[0], {
+    id: 1,
+    name: "Timed",
+    status: "in-progress",
+    parentId: null,
+    childrenIds: [],
+    startedAt: new Date(startedAt).toISOString(),
+    durationMs: 65_432,
+  });
+
+  now += 568;
+  const updated = await execute(harness.tools.get("update_task"), {
+    tasks: [{ id: 1, status: "blocked" }],
+  });
+  assert.equal(updated.content[0].text, "Updated 1 task: 1. 0/1 done.");
+
+  now += 10_000;
+  const paused = JSON.parse((await execute(harness.tools.get("get_task"), { ids: [1] })).content[0].text);
+  assert.equal(paused[0].startedAt, new Date(startedAt).toISOString());
+  assert.equal(paused[0].stoppedAt, new Date(startedAt + 66_000).toISOString());
+  assert.equal(paused[0].durationMs, 66_000);
+});

tests/ui.test.ts

@@ -4,6 +4,7 @@ import { visibleWidth } from "@earendil-works/pi-tui";
 import { currentTaskLabel, currentTaskTokens } from "../src/herdr.ts";
 import { TaskState } from "../src/state.ts";
 import {
+  formatDuration,
   renderProgressHeader,
   renderTaskLine,
   renderToolResult,
@@ -23,7 +24,7 @@ function stripAnsi(text: string): string {
 }
 
 function fixture(): TaskState {
-  const state = new TaskState();
+  const state = new TaskState(() => 0);
   state.add([
     {
       name: "Build auth",
@@ -58,7 +59,7 @@ test("renders an adaptive progress bar and stays within width", () => {
 test("renders lightweight connectors without a detached root continuation", () => {
   const output = renderTree(fixture().list(), plainTheme as never, 80).map(stripAnsi);
   assert.deepEqual(output, [
-    "  ◉ 1. Build auth",
+    "  ◉ 1. Build auth · 00:00",
     "  ├─ ! 2. Resolve token issue",
     "  │  └─ ○ 3. Inspect provider response",
     "  └─ ○ 4. Add middleware",
@@ -66,6 +67,21 @@ test("renders lightweight connectors without a detached root continuation", () =
   ]);
 });
 
+test("formats compact timers and adds hours only when needed", () => {
+  assert.equal(formatDuration(0), "00:00");
+  assert.equal(formatDuration(65_432), "01:05");
+  assert.equal(formatDuration(3_599_999), "59:59");
+  assert.equal(formatDuration(3_600_000), "01:00:00");
+
+  let now = 0;
+  const state = new TaskState(() => now);
+  state.add([{ name: "Timed", status: "in-progress" }]);
+  now = 65_432;
+  const line = stripAnsi(renderTaskLine(state.get([1])[0]!, "  ", plainTheme as never, 24));
+  assert.match(line, / · 01:05$/);
+  assert.ok(visibleWidth(line) <= 24);
+});
+
 test("truncates every task row at narrow widths", () => {
   const lines = renderTree(fixture().list(), plainTheme as never, 20);
   assert.ok(lines.every((line) => visibleWidth(line) <= 20));
@@ -147,6 +163,51 @@ test("hides an empty widget and renders a populated one", () => {
   assert.ok(lines.every((line) => visibleWidth(line) <= 30));
 });
 
+test("live widgets request rerenders and dispose their interval", async () => {
+  let now = 0;
+  const state = new TaskState(() => now);
+  state.add([{ name: "Timed", status: "in-progress" }]);
+
+  let widget: unknown;
+  const ctx = {
+    ui: {
+      setWidget: (_id: string, content: unknown) => {
+        widget = content;
+      },
+    },
+  };
+  updateTaskWidget(state, ctx as never, true, 5);
+
+  let renderRequests = 0;
+  const component = (
+    widget as unknown as (
+      tui: { requestRender(): void },
+      theme: unknown,
+    ) => { render(width: number): string[]; dispose?(): void }
+  )(
+    {
+      requestRender() {
+        renderRequests += 1;
+      },
+    },
+    plainTheme,
+  );
+
+  try {
+    assert.match(stripAnsi(component.render(40)[1] ?? ""), / · 00:00$/);
+    now = 65_000;
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    assert.ok(renderRequests > 0);
+    assert.match(stripAnsi(component.render(40)[1] ?? ""), / · 01:05$/);
+  } finally {
+    component.dispose?.();
+  }
+
+  const requestsAfterDispose = renderRequests;
+  await new Promise((resolve) => setTimeout(resolve, 15));
+  assert.equal(renderRequests, requestsAfterDispose);
+});
+
 test("tool results collapse summaries and expand themed details", () => {
   const state = fixture();
   const details = { action: "list" as const, snapshot: state.snapshot(), affected: state.list() };