return to agents view when leaving a subagent opened from it

packages/coding-agent/src/modes/agents-view/agents-view-mode.ts

@@ -92,10 +92,23 @@ export interface AgentsViewModeOptions {
 	verbose?: boolean;
 }
 
-type AgentsViewRunResult = { type: "exit" } | { type: "open"; summary: SessionSummary; subagent?: SessionSummary };
+type AgentsViewRunResult =
+	| { type: "exit" }
+	| {
+			type: "open";
+			summary: SessionSummary;
+			subagent?: SessionSummary;
+			// Session ids of every ancestor that must be expanded to reveal the
+			// opened subagent, from the root agent down to its immediate parent.
+			subagentAncestorSessionIds?: string[];
+	  };
 type AgentsViewPersistentState = {
 	selectedRowIdentity?: string;
 	selectedSessionKey?: AgentsViewSelectionKey;
+	// Session ids of the ancestor chain to re-expand when returning to a subagent.
+	// Resolved to live row identities on first build, then cleared; kept by
+	// sessionId so it survives a parent's active→persisted identity flip.
+	pendingExpandedAncestorSessionIds?: string[];
 	statusMessage?: string;
 	initialPromptsSent?: boolean;
 	// Gathered once and reused across agents-view instances so the notices survive
@@ -232,8 +245,17 @@ export async function runAgentsViewMode(options: AgentsViewModeOptions): Promise
 		if (result.type === "exit") {
 			return;
 		}
-		persistentState.selectedRowIdentity = getSummaryIdentity(result.summary);
-		persistentState.selectedSessionKey = getAgentsViewSelectionKey(result.summary);
+		if (result.subagent) {
+			// Returning from a subagent reopens the agents view with every ancestor
+			// list expanded and that subagent reselected.
+			persistentState.selectedRowIdentity = getSummaryIdentity(result.subagent);
+			persistentState.selectedSessionKey = getAgentsViewSelectionKey(result.subagent);
+			persistentState.pendingExpandedAncestorSessionIds = result.subagentAncestorSessionIds ?? [];
+		} else {
+			persistentState.selectedRowIdentity = getSummaryIdentity(result.summary);
+			persistentState.selectedSessionKey = getAgentsViewSelectionKey(result.summary);
+			persistentState.pendingExpandedAncestorSessionIds = undefined;
+		}
 
 		let opened: { connection: DaemonAgentConnection; summary: SessionSummary } | undefined;
 		try {
@@ -706,6 +728,32 @@ class AgentsViewMode implements Component, Focusable {
 		this.ui.requestRender();
 	}
 
+	/**
+	 * Resolve the persisted ancestor breadcrumb (session ids) to live row
+	 * identities and expand them, so returning to a subagent reopens its whole
+	 * chain. Identity-keyed from here on, matching the rest of the expansion
+	 * lifecycle; runs once then clears.
+	 */
+	private applyPendingAncestorExpansion(): void {
+		const sessionIds = this.persistentState.pendingExpandedAncestorSessionIds;
+		if (!sessionIds || sessionIds.length === 0) {
+			this.persistentState.pendingExpandedAncestorSessionIds = undefined;
+			return;
+		}
+		this.persistentState.pendingExpandedAncestorSessionIds = undefined;
+		const wanted = new Set(sessionIds);
+		let added = false;
+		for (const row of this.rows) {
+			if (wanted.has(row.summary.sessionId) && !this.expandedSubagentParents.has(row.identity)) {
+				this.expandedSubagentParents.add(row.identity);
+				added = true;
+			}
+		}
+		if (added) {
+			this.rebuildRows();
+		}
+	}
+
 	/** Expanded subagent lists collapse back to their summary row once selection leaves them. */
 	private collapseSubagentListsOutsideSelection(): void {
 		if (this.expandedSubagentParents.size === 0) {
@@ -1061,7 +1109,31 @@ class AgentsViewMode implements Component, Focusable {
 			this.setStatusMessage("Cannot open subagent without its parent agent");
 			return;
 		}
-		this.finish({ type: "open", summary: root.summary, subagent: row.summary });
+		this.finish({
+			type: "open",
+			summary: root.summary,
+			subagent: row.summary,
+			subagentAncestorSessionIds: this.collectSubagentAncestorSessionIds(row),
+		});
+	}
+
+	/**
+	 * Session ids of every ancestor of a subagent row, root-most first. Keyed by
+	 * sessionId rather than row identity so the breadcrumb survives a parent's
+	 * active→persisted identity flip while the subagent is open.
+	 */
+	private collectSubagentAncestorSessionIds(row: AgentsViewRow): string[] {
+		const ancestors: string[] = [];
+		let parentIdentity = row.parentIdentity;
+		while (parentIdentity !== undefined) {
+			const parent = this.rows.find((candidate) => candidate.identity === parentIdentity);
+			if (!parent) {
+				break;
+			}
+			ancestors.unshift(parent.summary.sessionId);
+			parentIdentity = parent.parentIdentity;
+		}
+		return ancestors;
 	}
 
 	/**
@@ -1485,6 +1557,7 @@ class AgentsViewMode implements Component, Focusable {
 				this.expandedSubagentParents,
 				this.programShownParents,
 			);
+			this.applyPendingAncestorExpansion();
 			this.restoreSelection();
 			this.ui.requestRender();
 		} catch (error) {

packages/coding-agent/src/modes/interactive/components/child-agent-inspector.ts

@@ -592,6 +592,7 @@ export class ChildAgentDetailComponent implements Component, Focusable {
 	private toolsExpanded = false;
 	private killConfirmExpiresAt = 0;
 	private killConfirmTimer: ReturnType<typeof setTimeout> | undefined;
+	private backHintLabel = "back to chat";
 
 	onCancel?: () => void;
 	onToggleToolsExpanded?: () => void;
@@ -613,6 +614,10 @@ export class ChildAgentDetailComponent implements Component, Focusable {
 		this.rebuildTranscriptComponents();
 	}
 
+	setBackHintLabel(label: string): void {
+		this.backHintLabel = label;
+	}
+
 	setToolsExpanded(expanded: boolean): void {
 		this.toolsExpanded = expanded;
 		for (const component of this.transcriptComponents) {
@@ -848,7 +853,7 @@ export class ChildAgentDetailComponent implements Component, Focusable {
 				? theme.fg("error", `${keyText("app.agents.delete", { primaryOnly: true }).trim()} again to stop`)
 				: keyAction("app.agents.delete", "stop", { primaryOnly: true });
 		return hintLine(
-			[keyAction("app.agents.back", "back to chat", { primaryOnly: true }), expandAction, stopAction],
+			[keyAction("app.agents.back", this.backHintLabel, { primaryOnly: true }), expandAction, stopAction],
 			width,
 		);
 	}

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -565,6 +565,7 @@ export class InteractiveMode {
 	private childAgentNodes: ChildAgentInspectorNode[] = [];
 	private childAgentDetailNodeId: string | undefined;
 	private childAgentPanelMode: "detail" | undefined;
+	private enteredSessionViaSubagentDetail = false;
 
 	// Tool output expansion state
 	private toolOutputExpanded = false;
@@ -686,7 +687,13 @@ export class InteractiveMode {
 			getHideThinkingBlock: () => this.hideThinkingBlock,
 			getHiddenThinkingLabel: () => this.hiddenThinkingLabel,
 		});
-		this.childAgentDetail.onCancel = () => this.closeChildAgentPanel({ selectNodeId: this.childAgentDetailNodeId });
+		this.childAgentDetail.onCancel = () => {
+			if (this.options.returnToAgentsView && this.enteredSessionViaSubagentDetail) {
+				void this.returnToAgentsView();
+				return;
+			}
+			this.closeChildAgentPanel({ selectNodeId: this.childAgentDetailNodeId });
+		};
 		this.childAgentDetail.onToggleToolsExpanded = () => this.toggleToolOutputExpansion();
 		this.childAgentDetail.onKill = (nodeId) => void this.killChildAgent(nodeId);
 		this.widgetContainerAbove = new Container();
@@ -978,11 +985,18 @@ export class InteractiveMode {
 
 		// Jump straight into a subagent's read-only detail view when the agents
 		// view opened this session targeting one of its subagents.
-		if (this.options.initialSubagentNodeId && !this.openChildAgentDetail(this.options.initialSubagentNodeId)) {
-			// The subagent can finish and get released between the agents view
-			// listing it and this session attaching; say so instead of silently
-			// landing in the parent chat.
-			this.showStatus("Subagent already finished; showing its parent session");
+		if (this.options.initialSubagentNodeId) {
+			if (this.openChildAgentDetail(this.options.initialSubagentNodeId)) {
+				if (this.options.returnToAgentsView) {
+					this.enteredSessionViaSubagentDetail = true;
+					this.childAgentDetail.setBackHintLabel("back to agents");
+				}
+			} else {
+				// The subagent can finish and get released between the agents view
+				// listing it and this session attaching; say so instead of silently
+				// landing in the parent chat.
+				this.showStatus("Subagent already finished; showing its parent session");
+			}
 		}
 
 		// Set up theme file watcher
@@ -3105,6 +3119,8 @@ export class InteractiveMode {
 			// Re-render queued previews cleared on panel entry; the queue may still hold messages.
 			this.updatePendingMessagesDisplay();
 			this.childAgentDetailNodeId = undefined;
+			this.enteredSessionViaSubagentDetail = false;
+			this.childAgentDetail.setBackHintLabel("back to chat");
 			this.childAgentDetail.setNode(undefined);
 		}
 		this.childAgentPanelMode = undefined;
@@ -4652,6 +4668,8 @@ export class InteractiveMode {
 	private closeChildAgentPanel(options: { selectNodeId?: string } = {}): void {
 		this.childAgentPanelMode = undefined;
 		this.childAgentDetailNodeId = undefined;
+		this.enteredSessionViaSubagentDetail = false;
+		this.childAgentDetail.setBackHintLabel("back to chat");
 		this.childAgentDetail.setNode(undefined);
 		this.childAgentSummary.setHidden(false);
 		this.restoreMainAgentView();

packages/coding-agent/test/daemon-list-format.test.ts

@@ -10,9 +10,19 @@ describe("formatSessionListTable", () => {
 		const table = stripAnsi(
 			formatSessionListTable(
 				[
-					makeSummary({ name: "sleep", id: "019e71ec-e08a-75a9-b573-fc10e9f8380f", lifecycle: "archived", activity: "idle" }),
+					makeSummary({
+						name: "sleep",
+						id: "019e71ec-e08a-75a9-b573-fc10e9f8380f",
+						lifecycle: "archived",
+						activity: "idle",
+					}),
 					makeSummary({ name: "tool", id: "ccccddddeeee", lifecycle: "live", activity: "working" }),
-					makeSummary({ name: "crash", id: "019e71ec-e08a-75a9-b573-abcdef123456", lifecycle: "archived", activity: "idle" }),
+					makeSummary({
+						name: "crash",
+						id: "019e71ec-e08a-75a9-b573-abcdef123456",
+						lifecycle: "archived",
+						activity: "idle",
+					}),
 					makeSummary({ name: "idle", id: "bbbbccccdddd", lifecycle: "live", activity: "idle" }),
 					makeSummary({ name: "model", id: "ddddeeeeffff", lifecycle: "live", activity: "working" }),
 					makeSummary({