feat(coding-agent): add label timestamps to the session tree (#2691)

packages/coding-agent/README.md

@@ -226,7 +226,7 @@ pi --fork <path>       # Fork specific session file or ID into a new session
 
 - Search by typing, fold/unfold and jump between branches with Ctrl+←/Ctrl+→ or Alt+←/Alt+→, page with ←/→
 - Filter modes (Ctrl+O): default → no-tools → user-only → labeled-only → all
-- Press `l` to label entries as bookmarks
+- Press Shift+L to label entries as bookmarks and Shift+T to toggle label timestamps
 
 **`/fork`** - Create a new session file from the current branch. Opens a selector, copies history up to the selected point, and places that message in the editor for modification.
 

packages/coding-agent/docs/keybindings.md

@@ -128,6 +128,8 @@ Modifier combinations: `ctrl+shift+x`, `alt+ctrl+x`, `ctrl+shift+alt+x`, `ctrl+1
 |--------|---------|-------------|
 | `app.tree.foldOrUp` | `ctrl+left`, `alt+left` | Fold current branch segment, or jump to the previous segment start |
 | `app.tree.unfoldOrDown` | `ctrl+right`, `alt+right` | Unfold current branch segment, or jump to the next segment start or branch end |
+| `app.tree.editLabel` | `shift+l` | Edit the label on the selected tree node |
+| `app.tree.toggleLabelTimestamp` | `shift+t` | Toggle label timestamps in the tree |
 
 ## Custom Configuration
 

packages/coding-agent/docs/tree.md

@@ -35,6 +35,8 @@ Sessions are stored as trees where each entry has an `id` and `parentId`. The "l
 | ↑/↓ | Navigate (depth-first order) |
 | ←/→ | Page up/down |
 | Ctrl+←/Ctrl+→ or Alt+←/Alt+→ | Fold/unfold and jump between branch segments |
+| Shift+L | Set or clear a label on the selected node |
+| Shift+T | Toggle label timestamps |
 | Enter | Select node |
 | Escape/Ctrl+C | Cancel |
 | Ctrl+U | Toggle: user messages only |
@@ -49,6 +51,7 @@ Sessions are stored as trees where each entry has an `id` and `parentId`. The "l
 - Height: half terminal height
 - Current leaf marked with `← active`
 - Labels shown inline: `[label-name]`
+- `Shift+T` shows the latest label-change timestamp next to labeled nodes
 - Foldable branch starts show `⊟` in the connector. Folded branches show `⊞`
 - Active path marker `•` appears after the fold indicator when applicable
 - Search and filter changes reset all folds

packages/coding-agent/src/core/keybindings.ts

@@ -32,6 +32,8 @@ export interface AppKeybindings {
 	"app.session.resume": true;
 	"app.tree.foldOrUp": true;
 	"app.tree.unfoldOrDown": true;
+	"app.tree.editLabel": true;
+	"app.tree.toggleLabelTimestamp": true;
 	"app.session.togglePath": true;
 	"app.session.toggleSort": true;
 	"app.session.rename": true;
@@ -101,6 +103,14 @@ export const KEYBINDINGS = {
 		defaultKeys: ["ctrl+right", "alt+right"],
 		description: "Unfold tree branch or move down",
 	},
+	"app.tree.editLabel": {
+		defaultKeys: "shift+l",
+		description: "Edit tree label",
+	},
+	"app.tree.toggleLabelTimestamp": {
+		defaultKeys: "shift+t",
+		description: "Toggle tree label timestamps",
+	},
 	"app.session.togglePath": {
 		defaultKeys: "ctrl+p",
 		description: "Toggle session path display",
@@ -176,6 +186,8 @@ const KEYBINDING_NAME_MIGRATIONS = {
 	resume: "app.session.resume",
 	treeFoldOrUp: "app.tree.foldOrUp",
 	treeUnfoldOrDown: "app.tree.unfoldOrDown",
+	treeEditLabel: "app.tree.editLabel",
+	treeToggleLabelTimestamp: "app.tree.toggleLabelTimestamp",
 	toggleSessionPath: "app.session.togglePath",
 	toggleSessionSort: "app.session.toggleSort",
 	renameSession: "app.session.rename",

packages/coding-agent/src/core/session-manager.ts

@@ -154,6 +154,8 @@ export interface SessionTreeNode {
 	children: SessionTreeNode[];
 	/** Resolved label for this entry, if any */
 	label?: string;
+	/** Timestamp of the latest label change for this entry, if any */
+	labelTimestamp?: string;
 }
 
 export interface SessionContext {
@@ -669,6 +671,7 @@ export class SessionManager {
 	private fileEntries: FileEntry[] = [];
 	private byId: Map<string, SessionEntry> = new Map();
 	private labelsById: Map<string, string> = new Map();
+	private labelTimestampsById: Map<string, string> = new Map();
 	private leafId: string | null = null;
 
 	private constructor(cwd: string, sessionDir: string, sessionFile: string | undefined, persist: boolean) {
@@ -746,6 +749,7 @@ export class SessionManager {
 	private _buildIndex(): void {
 		this.byId.clear();
 		this.labelsById.clear();
+		this.labelTimestampsById.clear();
 		this.leafId = null;
 		for (const entry of this.fileEntries) {
 			if (entry.type === "session") continue;
@@ -754,8 +758,10 @@ export class SessionManager {
 			if (entry.type === "label") {
 				if (entry.label) {
 					this.labelsById.set(entry.targetId, entry.label);
+					this.labelTimestampsById.set(entry.targetId, entry.timestamp);
 				} else {
 					this.labelsById.delete(entry.targetId);
+					this.labelTimestampsById.delete(entry.targetId);
 				}
 			}
 		}
@@ -1007,8 +1013,10 @@ export class SessionManager {
 		this._appendEntry(entry);
 		if (label) {
 			this.labelsById.set(targetId, label);
+			this.labelTimestampsById.set(targetId, entry.timestamp);
 		} else {
 			this.labelsById.delete(targetId);
+			this.labelTimestampsById.delete(targetId);
 		}
 		return entry.id;
 	}
@@ -1067,7 +1075,8 @@ export class SessionManager {
 		// Create nodes with resolved labels
 		for (const entry of entries) {
 			const label = this.labelsById.get(entry.id);
-			nodeMap.set(entry.id, { entry, children: [], label });
+			const labelTimestamp = this.labelTimestampsById.get(entry.id);
+			nodeMap.set(entry.id, { entry, children: [], label, labelTimestamp });
 		}
 
 		// Build tree
@@ -1179,10 +1188,10 @@ export class SessionManager {
 
 		// Collect labels for entries in the path
 		const pathEntryIds = new Set(pathWithoutLabels.map((e) => e.id));
-		const labelsToWrite: Array<{ targetId: string; label: string }> = [];
+		const labelsToWrite: Array<{ targetId: string; label: string; timestamp: string }> = [];
 		for (const [targetId, label] of this.labelsById) {
 			if (pathEntryIds.has(targetId)) {
-				labelsToWrite.push({ targetId, label });
+				labelsToWrite.push({ targetId, label, timestamp: this.labelTimestampsById.get(targetId)! });
 			}
 		}
 
@@ -1191,12 +1200,12 @@ export class SessionManager {
 			const lastEntryId = pathWithoutLabels[pathWithoutLabels.length - 1]?.id || null;
 			let parentId = lastEntryId;
 			const labelEntries: LabelEntry[] = [];
-			for (const { targetId, label } of labelsToWrite) {
+			for (const { targetId, label, timestamp: labelTimestamp } of labelsToWrite) {
 				const labelEntry: LabelEntry = {
 					type: "label",
 					id: generateId(new Set(pathEntryIds)),
 					parentId,
-					timestamp: new Date().toISOString(),
+					timestamp: labelTimestamp,
 					targetId,
 					label,
 				};
@@ -1229,12 +1238,12 @@ export class SessionManager {
 		// In-memory mode: replace current session with the path + labels
 		const labelEntries: LabelEntry[] = [];
 		let parentId = pathWithoutLabels[pathWithoutLabels.length - 1]?.id || null;
-		for (const { targetId, label } of labelsToWrite) {
+		for (const { targetId, label, timestamp: labelTimestamp } of labelsToWrite) {
 			const labelEntry: LabelEntry = {
 				type: "label",
 				id: generateId(new Set([...pathEntryIds, ...labelEntries.map((e) => e.id)])),
 				parentId,
-				timestamp: new Date().toISOString(),
+				timestamp: labelTimestamp,
 				targetId,
 				label,
 			};

packages/coding-agent/src/modes/interactive/components/tree-selector.ts

@@ -13,7 +13,7 @@ import {
 import type { SessionTreeNode } from "../../../core/session-manager.js";
 import { theme } from "../theme/theme.js";
 import { DynamicBorder } from "./dynamic-border.js";
-import { keyHint } from "./keybinding-hints.js";
+import { keyHint, keyText } from "./keybinding-hints.js";
 
 /** Gutter info: position (displayIndent where connector was) and whether to show │ */
 interface GutterInfo {
@@ -58,6 +58,7 @@ class TreeList implements Component {
 	private searchQuery = "";
 	private toolCallMap: Map<string, ToolCallInfo> = new Map();
 	private multipleRoots = false;
+	private showLabelTimestamps = false;
 	private activePathIds: Set<string> = new Set();
 	private visibleParentMap: Map<string, string | null> = new Map();
 	private visibleChildrenMap: Map<string | null, string[]> = new Map();
@@ -567,28 +568,36 @@ class TreeList implements Component {
 		return this.filteredNodes[this.selectedIndex]?.node;
 	}
 
-	updateNodeLabel(entryId: string, label: string | undefined): void {
+	updateNodeLabel(entryId: string, label: string | undefined, labelTimestamp?: string): void {
 		for (const flatNode of this.flatNodes) {
 			if (flatNode.node.entry.id === entryId) {
 				flatNode.node.label = label;
+				flatNode.node.labelTimestamp = label ? (labelTimestamp ?? new Date().toISOString()) : undefined;
 				break;
 			}
 		}
 	}
 
-	private getFilterLabel(): string {
+	private getStatusLabels(): string {
+		let labels = "";
 		switch (this.filterMode) {
 			case "no-tools":
-				return " [no-tools]";
+				labels += " [no-tools]";
+				break;
 			case "user-only":
-				return " [user]";
+				labels += " [user]";
+				break;
 			case "labeled-only":
-				return " [labeled]";
+				labels += " [labeled]";
+				break;
 			case "all":
-				return " [all]";
-			default:
-				return "";
+				labels += " [all]";
+				break;
 		}
+		if (this.showLabelTimestamps) {
+			labels += " [+label time]";
+		}
+		return labels;
 	}
 
 	render(width: number): string[] {
@@ -596,7 +605,7 @@ class TreeList implements Component {
 
 		if (this.filteredNodes.length === 0) {
 			lines.push(truncateToWidth(theme.fg("muted", "  No entries found"), width));
-			lines.push(truncateToWidth(theme.fg("muted", `  (0/0)${this.getFilterLabel()}`), width));
+			lines.push(truncateToWidth(theme.fg("muted", `  (0/0)${this.getStatusLabels()}`), width));
 			return lines;
 		}
 
@@ -667,9 +676,13 @@ class TreeList implements Component {
 			const pathMarker = isOnActivePath ? theme.fg("accent", "• ") : "";
 
 			const label = flatNode.node.label ? theme.fg("warning", `[${flatNode.node.label}] `) : "";
+			const labelTimestamp =
+				this.showLabelTimestamps && flatNode.node.label && flatNode.node.labelTimestamp
+					? theme.fg("muted", `${this.formatLabelTimestamp(flatNode.node.labelTimestamp)} `)
+					: "";
 			const content = this.getEntryDisplayText(flatNode.node, isSelected);
 
-			let line = cursor + theme.fg("dim", prefix) + foldMarker + pathMarker + label + content;
+			let line = cursor + theme.fg("dim", prefix) + foldMarker + pathMarker + label + labelTimestamp + content;
 			if (isSelected) {
 				line = theme.bg("selectedBg", line);
 			}
@@ -678,7 +691,7 @@ class TreeList implements Component {
 
 		lines.push(
 			truncateToWidth(
-				theme.fg("muted", `  (${this.selectedIndex + 1}/${this.filteredNodes.length})${this.getFilterLabel()}`),
+				theme.fg("muted", `  (${this.selectedIndex + 1}/${this.filteredNodes.length})${this.getStatusLabels()}`),
 				width,
 			),
 		);
@@ -772,6 +785,31 @@ class TreeList implements Component {
 		return isSelected ? theme.bold(result) : result;
 	}
 
+	private formatLabelTimestamp(timestamp: string): string {
+		const date = new Date(timestamp);
+		const now = new Date();
+		const hours = date.getHours().toString().padStart(2, "0");
+		const minutes = date.getMinutes().toString().padStart(2, "0");
+		const time = `${hours}:${minutes}`;
+
+		if (
+			date.getFullYear() === now.getFullYear() &&
+			date.getMonth() === now.getMonth() &&
+			date.getDate() === now.getDate()
+		) {
+			return time;
+		}
+
+		const month = date.getMonth() + 1;
+		const day = date.getDate();
+		if (date.getFullYear() === now.getFullYear()) {
+			return `${month}/${day} ${time}`;
+		}
+
+		const year = date.getFullYear().toString().slice(-2);
+		return `${year}/${month}/${day} ${time}`;
+	}
+
 	private extractContent(content: unknown): string {
 		const maxLen = 200;
 		if (typeof content === "string") return content.slice(0, maxLen);
@@ -945,11 +983,13 @@ class TreeList implements Component {
 				this.foldedNodes.clear();
 				this.applyFilter();
 			}
-		} else if (matchesKey(keyData, "shift+l")) {
+		} else if (kb.matches(keyData, "app.tree.editLabel")) {
 			const selected = this.filteredNodes[this.selectedIndex];
 			if (selected && this.onLabelEdit) {
 				this.onLabelEdit(selected.node.entry.id, selected.node.label);
 			}
+		} else if (kb.matches(keyData, "app.tree.toggleLabelTimestamp")) {
+			this.showLabelTimestamps = !this.showLabelTimestamps;
 		} else {
 			const hasControlChars = [...keyData].some((ch) => {
 				const code = ch.charCodeAt(0);
@@ -1140,8 +1180,10 @@ export class TreeSelectorComponent extends Container implements Focusable {
 		this.addChild(new Text(theme.bold("  Session Tree"), 1, 0));
 		this.addChild(
 			new TruncatedText(
-				theme.fg("muted", "  ↑/↓: move. ←/→: page. ^←/^→ or Alt+←/Alt+→: fold/branch. Shift+L: label. ") +
-					theme.fg("muted", "^D/^T/^U/^L/^A: filters (^O/⇧^O cycle)"),
+				theme.fg(
+					"muted",
+					`  ↑/↓: move. ←/→: page. ^←/^→ or Alt+←/Alt+→: fold/branch. ${keyText("app.tree.editLabel")}: label. ^D/^T/^U/^L/^A: filters (^O/⇧^O cycle). ${keyText("app.tree.toggleLabelTimestamp")}: label time`,
+				),
 				0,
 				0,
 			),

packages/coding-agent/test/session-manager/labels.test.ts

@@ -43,9 +43,15 @@ describe("SessionManager labels", () => {
 
 		session.appendLabelChange(msgId, "first");
 		session.appendLabelChange(msgId, "second");
-		session.appendLabelChange(msgId, "third");
+		const lastLabelId = session.appendLabelChange(msgId, "third");
 
 		expect(session.getLabel(msgId)).toBe("third");
+
+		const entries = session.getEntries();
+		const lastLabelEntry = entries.find((e) => e.id === lastLabelId) as LabelEntry;
+		const tree = session.getTree();
+		const msgNode = tree.find((n) => n.entry.id === msgId);
+		expect(msgNode?.labelTimestamp).toBe(lastLabelEntry.timestamp);
 	});
 
 	it("labels are included in tree nodes", () => {
@@ -70,18 +76,23 @@ describe("SessionManager labels", () => {
 			timestamp: 2,
 		});
 
-		session.appendLabelChange(msg1Id, "start");
-		session.appendLabelChange(msg2Id, "response");
+		const msg1LabelId = session.appendLabelChange(msg1Id, "start");
+		const msg2LabelId = session.appendLabelChange(msg2Id, "response");
 
+		const entries = session.getEntries();
+		const msg1LabelEntry = entries.find((e) => e.id === msg1LabelId) as LabelEntry;
+		const msg2LabelEntry = entries.find((e) => e.id === msg2LabelId) as LabelEntry;
 		const tree = session.getTree();
 
 		// Find the message nodes (skip label entries)
 		const msg1Node = tree.find((n) => n.entry.id === msg1Id);
 		expect(msg1Node?.label).toBe("start");
+		expect(msg1Node?.labelTimestamp).toBe(msg1LabelEntry.timestamp);
 
 		// msg2 is a child of msg1
 		const msg2Node = msg1Node?.children.find((n) => n.entry.id === msg2Id);
 		expect(msg2Node?.label).toBe("response");
+		expect(msg2Node?.labelTimestamp).toBe(msg2LabelEntry.timestamp);
 	});
 
 	it("labels are preserved in createBranchedSession", () => {
@@ -106,8 +117,11 @@ describe("SessionManager labels", () => {
 			timestamp: 2,
 		});
 
-		session.appendLabelChange(msg1Id, "important");
-		session.appendLabelChange(msg2Id, "also-important");
+		const msg1LabelId = session.appendLabelChange(msg1Id, "important");
+		const msg2LabelId = session.appendLabelChange(msg2Id, "also-important");
+		const originalEntries = session.getEntries();
+		const msg1LabelEntry = originalEntries.find((e) => e.id === msg1LabelId) as LabelEntry;
+		const msg2LabelEntry = originalEntries.find((e) => e.id === msg2LabelId) as LabelEntry;
 
 		// Branch from msg2 (in-memory mode returns null, but updates internal state)
 		session.createBranchedSession(msg2Id);
@@ -120,6 +134,12 @@ describe("SessionManager labels", () => {
 		const entries = session.getEntries();
 		const labelEntries = entries.filter((e) => e.type === "label") as LabelEntry[];
 		expect(labelEntries).toHaveLength(2);
+
+		const tree = session.getTree();
+		const msg1Node = tree.find((n) => n.entry.id === msg1Id);
+		const msg2Node = msg1Node?.children.find((n) => n.entry.id === msg2Id);
+		expect(msg1Node?.labelTimestamp).toBe(msg1LabelEntry.timestamp);
+		expect(msg2Node?.labelTimestamp).toBe(msg2LabelEntry.timestamp);
 	});
 
 	it("labels not on path are not preserved in createBranchedSession", () => {

packages/coding-agent/test/tree-selector.test.ts

@@ -248,6 +248,36 @@ describe("TreeSelectorComponent", () => {
 		});
 	});
 
+	describe("label timestamps", () => {
+		test("toggles label timestamps for labeled nodes", () => {
+			const entries = [userMessage("user-1", null, "hello"), assistantMessage("asst-1", "user-1", "hi")];
+			const tree = buildTree(entries);
+			const labelDate = new Date(2026, 2, 28, 14, 32, 0);
+			tree[0]!.label = "checkpoint";
+			tree[0]!.labelTimestamp = labelDate.toISOString();
+
+			const selector = new TreeSelectorComponent(
+				tree,
+				"asst-1",
+				24,
+				() => {},
+				() => {},
+			);
+
+			const list = selector.getTreeList();
+			let render = list.render(200).join("\n");
+			expect(render).toContain("[checkpoint]");
+			expect(render).not.toContain("3/28 14:32");
+			expect(render).not.toContain("[+label time]");
+
+			selector.handleInput("T");
+
+			render = list.render(200).join("\n");
+			expect(render).toContain("3/28 14:32");
+			expect(render).toContain("[+label time]");
+		});
+	});
+
 	describe("empty filter preservation", () => {
 		test("preserves selection when switching to empty labeled filter and back", () => {
 			// Tree with no labels