test(app): match the turn collapse reply by its last streamed chunk

Back-to-back text chunks from the mock stream merge into one message depending on delivery timing, so the final reply and the folded message count vary run to run.
test(app): seed e2e settings fields without assuming an empty settings blob
2026-10-24 10:12:44 +00:00 · 2026-10-24 08:28:49 +02:00 · 2026-10-24 08:11:53 +02:00 · 2026-10-24 07:54:07 +02:00
40 changed files with 874 additions and 170 deletions
@@ -1415,12 +1415,14 @@ test("collapsing and expanding restores the real horizontal scroll offset", asyn
 async function useCodeFont(page: Page, codeFontSize: number): Promise<void> {
  await page.addInitScript(
    ({ settingsKey, fontSize }) => {
-      if (localStorage.getItem(settingsKey)) {
+      const settings = JSON.parse(localStorage.getItem(settingsKey) ?? "{}");
+      if (settings.codeFontSize !== undefined) {
        return;
      }
      localStorage.setItem(
        settingsKey,
        JSON.stringify({
+          ...settings,
          theme: "dark",
          sendBehavior: "interrupt",
          serviceUrlBehavior: "ask",
@@ -143,7 +143,7 @@ async function configureOverviewToolCalls(page: Page): Promise<void> {
  await page.addInitScript(() => {
    localStorage.setItem(
      "@paseo:app-settings",
-      JSON.stringify({ toolCallDetailLevel: "overview" }),
+      JSON.stringify({ chatDisplay: "collapseToolCalls" }),
    );
  });
 }
@@ -161,7 +161,7 @@ test("measures an overview heading that becomes loading after its idle mount", a
  await page.addInitScript(() => {
    localStorage.setItem(
      "@paseo:app-settings",
-      JSON.stringify({ toolCallDetailLevel: "overview" }),
+      JSON.stringify({ chatDisplay: "collapseToolCalls" }),
    );
  });
  const agent = await seedMockAgentWorkspace({
@@ -0,0 +1,67 @@
+import type { Page } from "@playwright/test";
+import { test, expect } from "../support/fixtures";
+import { expectComposerVisible } from "../support/helpers/composer";
+import { openAgentRoute, seedMockAgentWorkspace } from "../support/helpers/mock-agent";
+
+type ChatDisplay = "full" | "collapseToolCalls" | "collapseTurns";
+
+async function useChatDisplay(page: Page, chatDisplay: ChatDisplay): Promise<void> {
+  await page.addInitScript((value) => {
+    localStorage.setItem("@paseo:app-settings", JSON.stringify({ chatDisplay: value }));
+  }, chatDisplay);
+}
+
+async function seedAnsweredAgent(title: string) {
+  const agent = await seedMockAgentWorkspace({
+    repoPrefix: "turn-collapse-",
+    title,
+    model: "ten-second-stream",
+    initialPrompt: "Why does the chat stop following new output?",
+  });
+  await agent.client.waitForFinish(agent.agentId, 30_000);
+  await agent.client.sendAgentMessage(agent.agentId, "Make the fix and run the burst script.");
+  await agent.client.waitForFinish(agent.agentId, 30_000);
+  return agent;
+}
+
+/** Chat rows between the latest turn's summary line and its reply, in document order. */
+async function rowsBetweenLatestSummaryAndReply(page: Page): Promise<number> {
+  return page.evaluate(() => {
+    const rows = [...document.querySelectorAll("[data-message-id]")];
+    const summaryRow = rows.findLastIndex((row) => row.querySelector("[data-testid=turn-summary]"));
+    const replyRow = rows.findLastIndex((row) =>
+      row.querySelector("[data-testid=assistant-message]"),
+    );
+    return replyRow - summaryRow - 1;
+  });
+}
+
+test.describe("Turn collapse", () => {
+  test("folds each answered turn behind a summary line that opens it", async ({ page }) => {
+    test.setTimeout(120_000);
+    await useChatDisplay(page, "collapseTurns");
+    const agent = await seedAnsweredAgent("Turn collapse");
+    try {
+      await openAgentRoute(page, agent);
+      await expectComposerVisible(page);
+
+      const summary = page.getByTestId("turn-summary").last().getByRole("button");
+      await expect(summary).toHaveText(/^Wrote \d+ messages?, edited 1 file/);
+      // Text chunks that stream back to back merge into one message, so the reply holds
+      // at least the stream's last chunk.
+      await expect(page.getByTestId("assistant-message").last()).toHaveText(
+        /\(end of synthetic stream\)$/,
+      );
+      await expect.poll(() => rowsBetweenLatestSummaryAndReply(page)).toBe(0);
+
+      await summary.click();
+      await expect.poll(() => rowsBetweenLatestSummaryAndReply(page)).toBeGreaterThan(0);
+      await expect(summary).toBeInViewport();
+
+      await summary.click();
+      await expect.poll(() => rowsBetweenLatestSummaryAndReply(page)).toBe(0);
+    } finally {
+      await agent.cleanup();
+    }
+  });
+});
@@ -180,6 +180,11 @@ const test = daemonTest.extend<{
          localStorage.setItem("@paseo:daemon-registry", JSON.stringify([daemon, ...extraHosts]));
          localStorage.removeItem("@paseo:settings");
          localStorage.setItem("@paseo:create-agent-preferences", JSON.stringify(preferences));
+          // New installs collapse finished turns; specs assert on the rows inside them, so they
+          // start from the full chat unless they seed their own settings.
+          if (!localStorage.getItem("@paseo:app-settings")) {
+            localStorage.setItem("@paseo:app-settings", JSON.stringify({ chatDisplay: "full" }));
+          }
        },
        {
          daemon: testDaemon,
@@ -116,7 +116,7 @@ export async function withTimelinePlugin(
  await page.addInitScript(() => {
    localStorage.setItem(
      "@paseo:app-settings",
-      JSON.stringify({ toolCallDetailLevel: "overview" }),
+      JSON.stringify({ chatDisplay: "collapseToolCalls" }),
    );
  });
  const agent = await seedMockAgentWorkspace({
@@ -63,8 +63,9 @@ export async function seedSidebarFooterPreferences(
 ): Promise<void> {
  await page.addInitScript(
    ({ key, sidebarFooterItems }) => {
-      if (localStorage.getItem(key)) return;
-      localStorage.setItem(key, JSON.stringify({ sidebarFooterItems }));
+      const settings = JSON.parse(localStorage.getItem(key) ?? "{}");
+      if (settings.sidebarFooterItems) return;
+      localStorage.setItem(key, JSON.stringify({ ...settings, sidebarFooterItems }));
    },
    { key: APP_SETTINGS_KEY, sidebarFooterItems: preferences },
  );
@@ -24,6 +24,7 @@ function viewport(root: HTMLElement, capture: Capture) {
  const handle: StreamViewportHandle = {
    scrollToBottom() {},
    prepareForViewportChange() {},
+    holdReadingPosition() {},
    scrollToMessage(_messageId, occurrence) {
      if (occurrence) capture.occurrence = occurrence;
    },
@@ -265,6 +265,7 @@ describe("useChatOutline", () => {
    const viewport: StreamViewportHandle = {
      scrollToBottom: vi.fn(),
      prepareForViewportChange: vi.fn(),
+      holdReadingPosition: vi.fn(),
      scrollToMessage,
    };
    const viewportRef = { current: viewport };
@@ -316,6 +317,7 @@ describe("useChatOutline", () => {
      current: {
        scrollToBottom: vi.fn(),
        prepareForViewportChange: vi.fn(),
+        holdReadingPosition: vi.fn(),
        scrollToMessage,
      },
    };
@@ -371,6 +373,7 @@ describe("useChatOutline", () => {
    const viewport: StreamViewportHandle = {
      scrollToBottom: vi.fn(),
      prepareForViewportChange: vi.fn(),
+      holdReadingPosition: vi.fn(),
      scrollToMessage,
    };
    const livePrompt = {
@@ -4,6 +4,7 @@ import { transformTimelineItem, type TimelineItemTransform } from "@/plugins/tim
 import type { InstalledPlugin } from "@/plugins/types";
 import {
  applyStreamEvent,
+  getStreamItemMessageId,
  hydrateStreamState,
  type StreamItem,
  type ToolCallItem,
@@ -13,7 +14,7 @@ import type { AgentStreamEventPayload } from "@getpaseo/protocol/messages";
 import { QueryClient } from "@tanstack/react-query";
 import { describe, expect, it } from "vitest";
 import { buildAgentStreamRenderModel } from "./model";
-import { createStreamPresentation, getStreamItemMessageId } from "./presentation";
+import { createStreamPresentation } from "./presentation";

 const runtime = {
  paseo: {},
@@ -97,7 +98,11 @@ function pluginData(items: StreamItem[]): unknown[] {
  return items.flatMap((item) => (item.kind === "plugin" ? [item.data] : []));
 }

-const presentationOptions = { level: "overview" as const, isTurnActive: true };
+const presentationOptions = {
+  display: "collapseToolCalls" as const,
+  expandedTurnHostIds: new Set<string>(),
+  isTurnActive: true,
+};

 function streamHarness(transform?: TimelineItemTransform) {
  let state: { tail: StreamItem[]; head: StreamItem[] } = { tail: [], head: [] };
@@ -1,3 +1,4 @@
+import type { ChatDisplay } from "@/hooks/use-settings";
 import type { TimelineItemTransform } from "@/plugins/timeline/model";
 import { projectPluginTimelineItems } from "@/plugins/timeline/projection";
 import {
@@ -5,23 +6,32 @@ import {
  projectToolCallDetailLevel,
  type PreparedToolCallHistory,
  type ToolCallDetailLevel,
+  type ToolCallDetailProjection,
 } from "@/tool-calls/detail-level/projection";
 import type { StreamItem, UserMessageItem } from "@/types/stream";
+import { collapseTurns, type TurnCollapse } from "./turn-collapse/model";

 interface PresentationInput {
  tail: StreamItem[];
  head: StreamItem[];
  transform: TimelineItemTransform | undefined;
-  level: ToolCallDetailLevel;
+  display: ChatDisplay;
+  /** User messages whose collapsed turn the reader opened. */
+  expandedTurnHostIds: ReadonlySet<string>;
  isTurnActive: boolean;
 }

-/** Find and scrolling address a plugin row by the source it replaces. */
-export function getStreamItemMessageId(item: StreamItem): string {
-  if (item.kind === "plugin") return item.sourceId ?? item.id;
-  return item.id;
+export interface StreamPresentation extends ToolCallDetailProjection {
+  turns: Omit<TurnCollapse, "tail">;
 }

+const NO_COLLAPSED_TURNS: StreamPresentation["turns"] = collapseTurns({
+  tail: [],
+  isLatestTurnOpen: false,
+  expandedHostIds: new Set(),
+  getGroupedCalls: () => undefined,
+});
+
 /** Source messages reach plugins before display projection. */
 export function createStreamPresentation() {
  const userMessageCache = new WeakMap<UserMessageItem, UserMessageItem>();
@@ -47,12 +57,47 @@ export function createStreamPresentation() {
  let preparedTail: StreamItem[] | undefined;
  let preparedLevel: ToolCallDetailLevel | undefined;
  let preparedHistory: PreparedToolCallHistory | null = null;
+  let collapsedSource: StreamItem[] | undefined;
+  let collapsedIsLatestTurnOpen = false;
+  let collapsedExpandedHostIds: ReadonlySet<string> | undefined;
+  let collapsed: TurnCollapse | undefined;

  function presentRows(item: StreamItem): StreamItem[] {
    return [item.kind === "user_message" ? presentUserMessage(item) : item];
  }

-  return (input: PresentationInput) => {
+  function collapse(
+    projection: ToolCallDetailProjection,
+    input: PresentationInput,
+  ): StreamPresentation {
+    if (input.display !== "collapseTurns") {
+      return { ...projection, turns: NO_COLLAPSED_TURNS };
+    }
+    // Live text updates reach the head only, so the folded history is reused until the
+    // retained rows, the latest turn's liveness, or the reader's expanded turns change.
+    const isLatestTurnOpen = input.isTurnActive || projection.head.length > 0;
+    if (
+      !collapsed ||
+      collapsedSource !== projection.tail ||
+      collapsedIsLatestTurnOpen !== isLatestTurnOpen ||
+      collapsedExpandedHostIds !== input.expandedTurnHostIds
+    ) {
+      collapsed = collapseTurns({
+        tail: projection.tail,
+        isLatestTurnOpen,
+        expandedHostIds: input.expandedTurnHostIds,
+        getGroupedCalls: (itemId) => projection.groupsByHostId.get(itemId)?.run.calls,
+      });
+      collapsedSource = projection.tail;
+      collapsedIsLatestTurnOpen = isLatestTurnOpen;
+      collapsedExpandedHostIds = input.expandedTurnHostIds;
+    }
+    const { tail, ...turns } = collapsed;
+    return { ...projection, tail, turns };
+  }
+
+  return (input: PresentationInput): StreamPresentation => {
+    const level: ToolCallDetailLevel = input.display === "full" ? "detailed" : "overview";
    // Retained history is not reprojected or regrouped on each live text update.
    if (historySource !== input.tail || historyTransform !== input.transform) {
      historyRows = projectPluginTimelineItems(input.tail, input.transform).flatMap<StreamItem>(
@@ -66,17 +111,20 @@ export function createStreamPresentation() {
      const blocks = presentRows(item);
      head.push(...blocks);
    }
-    if (preparedTail !== historyRows || preparedLevel !== input.level) {
-      preparedHistory = prepareToolCallHistory(input.level, historyRows);
+    if (preparedTail !== historyRows || preparedLevel !== level) {
+      preparedHistory = prepareToolCallHistory(level, historyRows);
      preparedTail = historyRows;
-      preparedLevel = input.level;
+      preparedLevel = level;
    }
-    return projectToolCallDetailLevel({
-      level: input.level,
-      tail: historyRows,
-      head,
-      preparedHistory,
-      isTurnActive: input.isTurnActive,
-    });
+    return collapse(
+      projectToolCallDetailLevel({
+        level,
+        tail: historyRows,
+        head,
+        preparedHistory,
+        isTurnActive: input.isTurnActive,
+      }),
+      input,
+    );
  };
 }
@@ -361,6 +361,7 @@ function NativeStreamViewport(props: StreamRenderInput & { strategy: StreamStrat
        bottomAnchorController.prepareForStickyViewportChange();
        markNativeViewportSettling();
      },
+      holdReadingPosition: () => bottomAnchorController.detachByUser(),
    };
    viewportRef.current = handle;
    return () => {
@@ -20,7 +20,7 @@ import { withUnistyles } from "react-native-unistyles";
 import { useRetainedPanelActive } from "@/components/retained-panel";
 import { LoadingSpinner } from "@/components/ui/loading-spinner";
 import { useStableEvent } from "@/hooks/use-stable-event";
-import type { StreamItem } from "@/types/stream";
+import { getStreamItemMessageId, type StreamItem } from "@/types/stream";
 import type { Theme } from "@/styles/theme";
 import { WEB_SCROLLBAR_SIZE_PX } from "@/styles/web-scrollbar";
 import { DomOverlayScrollbar } from "@/components/ui/overlay-scrollbar/dom-overlay-scrollbar";
@@ -44,7 +44,6 @@ import {
  type HistoryStartSettleScheduler,
 } from "./history-start-settle-scheduler";
 import { useChatFindSelectedMessageId } from "@/agent-stream/chat-find";
-import { getStreamItemMessageId } from "./presentation";
 import { useScrollToMessage } from "./use-scroll-to-message.web";

 interface CreateWebStreamStrategyInput {
@@ -1174,6 +1173,11 @@ function WebStreamViewport(props: StreamRenderInput & { isMobileBreakpoint: bool
        }
        scheduleStickToBottom();
      },
+      holdReadingPosition: () => {
+        cancelPendingStickToBottom();
+        setFollowOutput(false);
+        readingAnchor.scroll(scrollContainerRef.current?.scrollTop ?? 0);
+      },
      scrollToMessage,
    };
    viewportRef.current = handle;
@@ -1186,6 +1190,7 @@ function WebStreamViewport(props: StreamRenderInput & { isMobileBreakpoint: bool
  }, [
    cancelPendingStickToBottom,
    forceStickToBottom,
+    readingAnchor,
    scheduleStickToBottom,
    scrollToMessage,
    viewportRef,
@@ -55,6 +55,8 @@ export interface StreamViewportHandle {
  focus?: () => void;
  scrollToBottom: (reason?: BottomAnchorLocalRequest["reason"]) => void;
  prepareForViewportChange: () => void;
+  /** Stop following output so the rows on screen stay put while rows below them open or close. */
+  holdReadingPosition: () => void;
  scrollToMessage?: (messageId: string, occurrence?: ScrollToMessageOccurrence) => void;
 }

@@ -0,0 +1,134 @@
+import { describe, expect, it } from "vitest";
+import type { StreamItem, ToolCallItem } from "@/types/stream";
+import { collapseTurns, type CollapseTurnsInput } from "./model";
+
+const at = new Date("2026-01-01T00:00:00.000Z");
+
+function user(id: string): StreamItem {
+  return { kind: "user_message", id, text: id, timestamp: at };
+}
+
+function reply(id: string): StreamItem {
+  return { kind: "assistant_message", id, text: id, timestamp: at };
+}
+
+function thought(id: string): StreamItem {
+  return { kind: "thought", id, text: id, timestamp: at, status: "ready" };
+}
+
+function shell(id: string): ToolCallItem {
+  return {
+    kind: "tool_call",
+    id,
+    timestamp: at,
+    payload: {
+      source: "agent",
+      data: {
+        provider: "claude",
+        callId: id,
+        name: "Bash",
+        status: "completed",
+        error: null,
+        detail: { type: "shell", command: "ls" },
+      },
+    },
+  };
+}
+
+function collapse(tail: StreamItem[], options: Partial<CollapseTurnsInput> = {}) {
+  return collapseTurns({
+    tail,
+    isLatestTurnOpen: false,
+    expandedHostIds: new Set(),
+    getGroupedCalls: () => undefined,
+    ...options,
+  });
+}
+
+const ids = (items: StreamItem[]) => items.map((item) => item.id);
+
+describe("collapseTurns", () => {
+  it("folds a finished turn's work into its user message and keeps the reply", () => {
+    const result = collapse([
+      user("u1"),
+      thought("t1"),
+      reply("early"),
+      shell("c1"),
+      shell("c2"),
+      reply("final"),
+    ]);
+
+    expect(ids(result.tail)).toEqual(["u1", "final"]);
+    expect(result.turnsByHostId.get("u1")).toEqual({
+      hostId: "u1",
+      expanded: false,
+      summary: {
+        messageCount: 1,
+        tools: expect.objectContaining({ commandCount: 2 }),
+      },
+    });
+    expect(result.hostIdByFoldedMessageId.get("early")).toBe("u1");
+  });
+
+  it("shows an expanded turn's work as nested rows between the prompt and the reply", () => {
+    const result = collapse([user("u1"), thought("t1"), shell("c1"), reply("final")], {
+      expandedHostIds: new Set(["u1"]),
+    });
+
+    expect(ids(result.tail)).toEqual(["u1", "t1", "c1", "final"]);
+    expect([...result.nestedItemIds]).toEqual(["t1", "c1"]);
+    expect(result.turnsByHostId.get("u1")?.expanded).toBe(true);
+  });
+
+  it("leaves the latest turn alone while it is still producing output", () => {
+    const tail = [user("u1"), shell("c1"), reply("r1"), user("u2"), shell("c2"), reply("r2")];
+
+    const result = collapse(tail, { isLatestTurnOpen: true });
+
+    expect(ids(result.tail)).toEqual(["u1", "r1", "u2", "c2", "r2"]);
+    expect([...result.turnsByHostId.keys()]).toEqual(["u1"]);
+  });
+
+  it("keeps rows after the reply, and turns with no work before the reply, as they are", () => {
+    const result = collapse([
+      user("u1"),
+      shell("c1"),
+      reply("r1"),
+      shell("after"),
+      user("u2"),
+      reply("r2"),
+    ]);
+
+    expect(ids(result.tail)).toEqual(["u1", "r1", "after", "u2", "r2"]);
+    expect([...result.turnsByHostId.keys()]).toEqual(["u1"]);
+  });
+
+  it("does not fold a turn that only thought before its reply", () => {
+    const tail = [user("u1"), thought("t1"), reply("r1")];
+
+    const result = collapse(tail);
+
+    expect(result.tail).toBe(tail);
+    expect(result.turnsByHostId.size).toBe(0);
+  });
+
+  it("does not fold a turn without a reply or whose prompt is above the loaded history", () => {
+    const tail = [shell("c0"), reply("r0"), user("u1"), shell("c1")];
+
+    const result = collapse(tail);
+
+    expect(result.tail).toBe(tail);
+    expect(result.turnsByHostId.size).toBe(0);
+  });
+
+  it("counts every call a tool-call group row stands for", () => {
+    const group = [shell("c1"), shell("c2"), shell("c3")];
+    const result = collapse([user("u1"), group[0]!, reply("final")], {
+      getGroupedCalls: (itemId) => (itemId === "c1" ? group : undefined),
+    });
+
+    expect(result.turnsByHostId.get("u1")?.summary).toMatchObject({
+      tools: { commandCount: 3 },
+    });
+  });
+});
@@ -0,0 +1,122 @@
+import { getStreamItemMessageId, type StreamItem, type ToolCallItem } from "@/types/stream";
+import { summarizeToolCalls, type OverviewSummary } from "@/tool-calls/detail-level/overview/model";
+
+export interface TurnSummary {
+  messageCount: number;
+  tools: OverviewSummary;
+}
+
+export interface CollapsedTurn {
+  /** The user message the turn answers. Its row carries the turn's summary line. */
+  hostId: string;
+  expanded: boolean;
+  summary: TurnSummary;
+}
+
+export interface TurnCollapse {
+  tail: StreamItem[];
+  turnsByHostId: ReadonlyMap<string, CollapsedTurn>;
+  /** Rows of expanded turns, which render inside the turn's indent rail. */
+  nestedItemIds: ReadonlySet<string>;
+  /** The turn a folded message belongs to, for surfaces that must reveal it. */
+  hostIdByFoldedMessageId: ReadonlyMap<string, string>;
+}
+
+export interface CollapseTurnsInput {
+  tail: StreamItem[];
+  /** The latest turn is still producing output, so it stays unfolded. */
+  isLatestTurnOpen: boolean;
+  expandedHostIds: ReadonlySet<string>;
+  /** The calls a tool-call group row stands for; undefined for a single call. */
+  getGroupedCalls: (itemId: string) => readonly ToolCallItem[] | undefined;
+}
+
+const EMPTY_TURNS: ReadonlyMap<string, CollapsedTurn> = new Map();
+const EMPTY_IDS: ReadonlySet<string> = new Set();
+const EMPTY_HOSTS: ReadonlyMap<string, string> = new Map();
+
+function summarizeTurn(
+  items: readonly StreamItem[],
+  getGroupedCalls: CollapseTurnsInput["getGroupedCalls"],
+): TurnSummary {
+  const calls: ToolCallItem[] = [];
+  let messageCount = 0;
+  for (const item of items) {
+    if (item.kind === "assistant_message") messageCount += 1;
+    else if (item.kind === "tool_call") calls.push(...(getGroupedCalls(item.id) ?? [item]));
+  }
+  return { messageCount, tools: summarizeToolCalls(calls) };
+}
+
+function hasWork(summary: TurnSummary): boolean {
+  return summary.messageCount > 0 || Object.values(summary.tools).some((count) => count > 0);
+}
+
+function findLastAssistantIndex(tail: StreamItem[], start: number, end: number): number {
+  for (let index = end - 1; index >= start; index -= 1) {
+    if (tail[index]?.kind === "assistant_message") return index;
+  }
+  return -1;
+}
+
+/**
+ * Folds each answered turn into its user message: everything the agent did before its last
+ * message collapses into one summary line, and that message stays in the chat. A turn folds
+ * only once it is complete, its user message is loaded, and it sent messages or called tools
+ * before its reply. Thoughts fold with the turn but are not counted.
+ */
+export function collapseTurns(input: CollapseTurnsInput): TurnCollapse {
+  const { tail } = input;
+  const output: StreamItem[] = [];
+  const turnsByHostId = new Map<string, CollapsedTurn>();
+  const nestedItemIds = new Set<string>();
+  const hostIdByFoldedMessageId = new Map<string, string>();
+
+  let runStart = 0;
+  const flushRun = (runEnd: number) => {
+    const host = tail[runStart - 1];
+    const isClosed = runEnd < tail.length || !input.isLatestTurnOpen;
+    const replyIndex = findLastAssistantIndex(tail, runStart, runEnd);
+    if (host?.kind !== "user_message" || !isClosed || replyIndex <= runStart) {
+      output.push(...tail.slice(runStart, runEnd));
+      return;
+    }
+    const folded = tail.slice(runStart, replyIndex);
+    const summary = summarizeTurn(folded, input.getGroupedCalls);
+    if (!hasWork(summary)) {
+      output.push(...tail.slice(runStart, runEnd));
+      return;
+    }
+    const expanded = input.expandedHostIds.has(host.id);
+    turnsByHostId.set(host.id, { hostId: host.id, expanded, summary });
+    for (const item of folded) {
+      hostIdByFoldedMessageId.set(getStreamItemMessageId(item), host.id);
+      if (expanded) nestedItemIds.add(item.id);
+    }
+    if (expanded) output.push(...folded);
+    output.push(...tail.slice(replyIndex, runEnd));
+  };
+
+  for (let index = 0; index < tail.length; index += 1) {
+    if (tail[index]?.kind !== "user_message") continue;
+    flushRun(index);
+    output.push(tail[index]!);
+    runStart = index + 1;
+  }
+  flushRun(tail.length);
+
+  if (turnsByHostId.size === 0) {
+    return {
+      tail,
+      turnsByHostId: EMPTY_TURNS,
+      nestedItemIds: EMPTY_IDS,
+      hostIdByFoldedMessageId: EMPTY_HOSTS,
+    };
+  }
+  return {
+    tail: output.length === tail.length ? tail : output,
+    turnsByHostId,
+    nestedItemIds,
+    hostIdByFoldedMessageId,
+  };
+}
@@ -0,0 +1,48 @@
+import { memo, useCallback, useMemo } from "react";
+import { useTranslation } from "react-i18next";
+import { Summary } from "lucide-react-native";
+import { ExpandableBadge } from "@/components/message";
+import { useOverviewSummaryLabel } from "@/tool-calls/detail-level/overview/label";
+import type { CollapsedTurn } from "./model";
+
+/**
+ * The row a collapsed turn leaves under its user message, styled like a tool-call group.
+ * Pressing it opens the turn's rows beneath it.
+ */
+export const TurnSummaryLine = memo(function TurnSummaryLine({
+  turn,
+  onExpandedChange,
+}: {
+  turn: CollapsedTurn;
+  onExpandedChange: (hostId: string, expanded: boolean) => void;
+}) {
+  const { t } = useTranslation();
+  const { messageCount, tools } = turn.summary;
+  const messageParts = useMemo(
+    () =>
+      messageCount > 0
+        ? [
+            t(`turnSummary.messages.${messageCount === 1 ? "one" : "other"}`, {
+              count: messageCount,
+            }),
+          ]
+        : [],
+    [messageCount, t],
+  );
+  const label = useOverviewSummaryLabel(tools, messageParts);
+  const toggle = useCallback(
+    () => onExpandedChange(turn.hostId, !turn.expanded),
+    [onExpandedChange, turn.expanded, turn.hostId],
+  );
+
+  return (
+    <ExpandableBadge
+      testID="turn-summary"
+      label={label}
+      icon={Summary}
+      isExpanded={turn.expanded}
+      onToggle={toggle}
+      borderlessWhenExpanded
+    />
+  );
+});
@@ -1,8 +1,7 @@
 import type React from "react";
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef } from "react";
 import type { Virtualizer } from "@tanstack/react-virtual";
-import type { StreamItem } from "@/types/stream";
-import { getStreamItemMessageId } from "./presentation";
+import { getStreamItemMessageId, type StreamItem } from "@/types/stream";
 import { createPromptJumpSettleController, PROMPT_JUMP_TOP_INSET_PX } from "./prompt-jump-settle";
 import type { ScrollToMessageOccurrence } from "./strategy";

@@ -1,7 +1,6 @@
 import { useCallback, useEffect, useMemo, useState } from "react";
-import type { StreamItem } from "@/types/stream";
+import { getStreamItemMessageId, type StreamItem } from "@/types/stream";
 import { findMountedWindowStart, getMountedRecentStreamItems } from "./history-window";
-import { getStreamItemMessageId } from "./presentation";

 // Callers reveal a message, not a row: an assistant message is several block rows and
 // the window has to open at the first of them.
@@ -41,7 +41,7 @@ import {
  type InlinePathTarget,
 } from "@/components/message";
 import { PlanCard } from "@/components/plan-card";
-import type { StreamItem } from "@/types/stream";
+import { getStreamItemMessageId, type StreamItem } from "@/types/stream";
 import type { PendingMessageSubmission } from "@/composer/submission/model";
 import type { TurnPresentation } from "@/timeline/turn-liveness";
 import type { PendingPermission } from "@/types/shared";
@@ -62,8 +62,10 @@ import type { DaemonClient } from "@getpaseo/client/internal/daemon-client";
 import { ToolCallDetailsContent } from "@/components/tool-call-details";
 import { QuestionFormCard } from "@/components/question-form-card";
 import { ToolCallSheetProvider } from "@/components/tool-call-sheet";
-import { createStreamPresentation, getStreamItemMessageId } from "./presentation";
+import { createStreamPresentation } from "./presentation";
 import { OverviewToolCallGroupView } from "@/tool-calls/detail-level/overview/view";
+import { IndentRail } from "@/components/indent-rail";
+import { TurnSummaryLine } from "./turn-collapse/summary-line";
 import { type AgentStreamRenderModel, buildAgentStreamRenderModel } from "./model";
 import { resolveStreamRenderStrategy } from "./strategy-resolver";
 import { type StreamSegmentRenderers, type StreamViewportHandle } from "./strategy";
@@ -148,9 +150,16 @@ function renderPendingPermissionsNode(input: {
  );
 }

+/**
+ * Where a row sits in an opened turn: its summary line's row, a row inside the turn, or the
+ * turn's last row. The rail runs through the gaps between them so the turn reads as one block.
+ */
+type TurnIndent = "none" | "openedHost" | "nested" | "lastNested";
+
 function renderStreamItemWithTurnFooter(input: {
  content: ReactNode;
  layoutItem: StreamLayoutItem;
+  turnIndent: TurnIndent;
  strategy: TurnContentStrategy;
  supportsTimelineCursor: boolean;
  onForkAssistantTurn?: AssistantTurnForkHandler;
@@ -171,7 +180,7 @@ function renderStreamItemWithTurnFooter(input: {
    />
  ) : null;
  const content = (
-    <StreamItemWrapper itemId={input.layoutItem.item.id} gapBelow={input.layoutItem.gapBelow}>
+    <StreamItemWrapper gapBelow={input.layoutItem.gapBelow} turnIndent={input.turnIndent}>
      {input.content}
    </StreamItemWrapper>
  );
@@ -333,7 +342,7 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
  ) {
    const { t } = useTranslation();
    const autoExpandReasoning = useSettings((settings) => settings.autoExpandReasoning);
-    const toolCallDetailLevel = useSettings((settings) => settings.toolCallDetailLevel);
+    const chatDisplay = useSettings((settings) => settings.chatDisplay);
    const chatOutlineEnabled = useSettings((settings) => settings.chatOutlineEnabled);
    const contentMaxWidth = useSettings(resolveContentMaxWidth);
    const viewportRef = useRef<StreamViewportHandle | null>(null);
@@ -357,6 +366,7 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
    const [expandedToolCallGroupIds, setExpandedToolCallGroupIds] = useState<Set<string>>(
      new Set(),
    );
+    const [expandedTurnHostIds, setExpandedTurnHostIds] = useState<ReadonlySet<string>>(new Set());

    // Get serverId (fallback to agent's serverId if not provided)
    const resolvedServerId = serverId ?? context.serverId ?? "";
@@ -421,6 +431,7 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
      setIsNearBottom(true);
      setExpandedInlineToolCallIds(new Set());
      setExpandedToolCallGroupIds(new Set());
+      setExpandedTurnHostIds(new Set());
    }, [agentId]);

    const isActive = useRetainedPanelActive();
@@ -512,7 +523,8 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
          tail: effectiveStreamItems,
          head: effectiveStreamHead ?? EMPTY_STREAM_HEAD,
          transform: transformTimelineItem,
-          level: toolCallDetailLevel,
+          display: chatDisplay,
+          expandedTurnHostIds,
          isTurnActive,
        }),
      [
@@ -520,7 +532,8 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
        effectiveStreamItems,
        effectiveStreamHead,
        transformTimelineItem,
-        toolCallDetailLevel,
+        chatDisplay,
+        expandedTurnHostIds,
        isTurnActive,
      ],
    );
@@ -651,6 +664,43 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
      [streamRenderStrategy],
    );

+    const setTurnExpanded = useCallback((hostId: string, expanded: boolean) => {
+      // A turn opens below its summary line; keep that line under the reader's pointer.
+      viewportRef.current?.holdReadingPosition();
+      setExpandedTurnHostIds((previous) => {
+        if (previous.has(hostId) === expanded) return previous;
+        const next = new Set(previous);
+        if (expanded) {
+          next.add(hostId);
+        } else {
+          next.delete(hostId);
+        }
+        return next;
+      });
+    }, []);
+    // Chat find reveals a match inside a collapsed turn by opening the turn first.
+    const revealLoadedMessage = useStableEvent((messageId: string): boolean => {
+      const hostId = presentation.turns.hostIdByFoldedMessageId.get(messageId);
+      if (hostId && !expandedTurnHostIds.has(hostId)) {
+        setTurnExpanded(hostId, true);
+        return true;
+      }
+      return revealLoadedHistory(messageId);
+    });
+    // Read through stable events so a collapse rerun does not change the renderer identity;
+    // rows whose turn state changed are revised through `historyRowRevision`.
+    const getCollapsedTurn = useStableEvent((hostId: string) =>
+      presentation.turns.turnsByHostId.get(hostId),
+    );
+    const getTurnIndent = useStableEvent((layoutItem: StreamLayoutItem): TurnIndent => {
+      const { nestedItemIds } = presentation.turns;
+      if (nestedItemIds.has(layoutItem.item.id)) {
+        const below = layoutItem.belowItem;
+        return below && nestedItemIds.has(below.id) ? "nested" : "lastNested";
+      }
+      return getCollapsedTurn(layoutItem.item.id)?.expanded ? "openedHost" : "none";
+    });
+
    const setToolCallGroupExpanded = useCallback((groupId: string, expanded: boolean) => {
      setExpandedToolCallGroupIds((previous) => {
        const next = new Set(previous);
@@ -665,7 +715,8 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi

    const renderUserMessageItem = useCallback(
      (layoutItem: StreamLayoutItem, item: Extract<StreamItem, { kind: "user_message" }>) => {
-        return (
+        const collapsedTurn = getCollapsedTurn(item.id);
+        const message = (
          <UserMessage
            serverId={resolvedServerId}
            agentId={agentId}
@@ -684,8 +735,25 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
            }
          />
        );
+        if (!collapsedTurn) {
+          return message;
+        }
+        return (
+          <>
+            {message}
+            <TurnSummaryLine turn={collapsedTurn} onExpandedChange={setTurnExpanded} />
+          </>
+        );
      },
-      [context.capabilities, agentId, client, pendingClientMessageIds, resolvedServerId],
+      [
+        context.capabilities,
+        agentId,
+        client,
+        getCollapsedTurn,
+        pendingClientMessageIds,
+        resolvedServerId,
+        setTurnExpanded,
+      ],
    );

    const renderAssistantMessageItem = useCallback(
@@ -893,12 +961,14 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
        return renderStreamItemWithTurnFooter({
          content,
          layoutItem,
+          turnIndent: getTurnIndent(layoutItem),
          strategy: streamRenderStrategy,
          supportsTimelineCursor: supportsAgentForkContextCursor,
          onForkAssistantTurn: readOnly ? undefined : handleForkAssistantTurn,
        });
      },
      [
+        getTurnIndent,
        handleForkAssistantTurn,
        readOnly,
        renderStreamItemContent,
@@ -1060,13 +1130,25 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
    const streamScrollEnabled =
      !streamRenderStrategy.shouldDisableParentScrollOnInlineDetailsExpansion() ||
      expandedInlineToolCallIds.size === 0;
+    const { nestedItemIds } = presentation.turns;
    const historyRowRevision = useMemo(
      () => ({
        contentById: presentation.historyGroupUpdatesByHostId,
-        displayStateById: expandedToolCallGroupIds,
+        displayStateById: {
+          has: (id: string) =>
+            expandedToolCallGroupIds.has(id) ||
+            expandedTurnHostIds.has(id) ||
+            nestedItemIds.has(id),
+        },
        globalDisplayState: isMobile,
      }),
-      [expandedToolCallGroupIds, isMobile, presentation.historyGroupUpdatesByHostId],
+      [
+        expandedToolCallGroupIds,
+        expandedTurnHostIds,
+        isMobile,
+        nestedItemIds,
+        presentation.historyGroupUpdatesByHostId,
+      ],
    );

    const findItems = useMemo(
@@ -1080,7 +1162,7 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
        epoch={timelineEpoch}
        items={findItems}
        viewportRef={viewportRef}
-        revealLoadedMessage={revealLoadedHistory}
+        revealLoadedMessage={revealLoadedMessage}
        visibleMessageIds={mountedMessageIds}
      >
        <ToolCallSheetProvider>
@@ -1763,15 +1845,41 @@ const permissionStyles = StyleSheet.create((theme) => ({
 }));

 interface StreamItemWrapperProps {
-  itemId: string;
  gapBelow: number;
+  turnIndent: TurnIndent;
  children: ReactNode;
 }

-function StreamItemWrapper({ gapBelow, children }: StreamItemWrapperProps) {
+function StreamItemWrapper({ gapBelow, turnIndent, children }: StreamItemWrapperProps) {
  const wrapperStyle = useMemo(
-    () => [stylesheet.streamItemWrapper, { marginBottom: gapBelow }],
-    [gapBelow],
+    () => [
+      stylesheet.streamItemWrapper,
+      { marginBottom: turnIndent === "nested" || turnIndent === "openedHost" ? 0 : gapBelow },
+    ],
+    [gapBelow, turnIndent],
  );
-  return <View style={wrapperStyle}>{children}</View>;
+  const gapStyle = useMemo(() => ({ paddingBottom: gapBelow }), [gapBelow]);
+  switch (turnIndent) {
+    case "none":
+      return <View style={wrapperStyle}>{children}</View>;
+    case "openedHost":
+      return (
+        <View style={wrapperStyle}>
+          {children}
+          <IndentRail style={gapStyle} />
+        </View>
+      );
+    case "nested":
+      return (
+        <View style={wrapperStyle}>
+          <IndentRail style={gapStyle}>{children}</IndentRail>
+        </View>
+      );
+    case "lastNested":
+      return (
+        <View style={wrapperStyle}>
+          <IndentRail>{children}</IndentRail>
+        </View>
+      );
+  }
 }
@@ -0,0 +1,32 @@
+import type { ReactNode } from "react";
+import { View, type StyleProp, type ViewStyle } from "react-native";
+import { StyleSheet } from "react-native-unistyles";
+
+/**
+ * Collapsed chat rows badge their summary with an icon whose center sits 7px into the content
+ * column (`ExpandableBadge` bleeds 13px left, then 1px border, 8px padding, 22px icon). The rail
+ * hangs from that center so opened rows read as children of the line that opened them.
+ */
+const RAIL_LEFT = 7;
+const RAIL_WIDTH = 1;
+export const INDENT_RAIL_CONTENT_OFFSET = 21;
+
+/** Indents opened chat rows under the summary that collapsed them, behind a vertical line. */
+export function IndentRail({
+  children,
+  style,
+}: {
+  children?: ReactNode;
+  style?: StyleProp<ViewStyle>;
+}) {
+  return <View style={[styles.rail, style]}>{children}</View>;
+}
+
+const styles = StyleSheet.create((theme) => ({
+  rail: {
+    marginLeft: RAIL_LEFT,
+    paddingLeft: INDENT_RAIL_CONTENT_OFFSET - RAIL_LEFT - RAIL_WIDTH,
+    borderLeftWidth: RAIL_WIDTH,
+    borderLeftColor: theme.colors.border,
+  },
+}));
@@ -971,6 +971,10 @@ const expandableBadgeStylesheet = StyleSheet.create((theme) => ({
    borderBottomLeftRadius: 0,
    borderBottomRightRadius: 0,
  },
+  // Details that do not sit in a card leave the header as a lone highlighted pill.
+  pressableExpandedDetached: {
+    borderRadius: theme.borderRadius.full,
+  },
  detailWrapperBorderless: {
    borderWidth: 0,
  },
@@ -2048,7 +2052,10 @@ export const ExpandableBadge = memo(function ExpandableBadge({
      expandableBadgeStylesheet.pressable,
      isPressed && isInteractive ? expandableBadgeStylesheet.pressablePressed : null,
      isExpanded && expandableBadgeStylesheet.pressableExpanded,
-      isExpanded && !borderlessWhenExpanded && expandableBadgeStylesheet.pressableExpandedAttached,
+      isExpanded &&
+        (borderlessWhenExpanded
+          ? expandableBadgeStylesheet.pressableExpandedDetached
+          : expandableBadgeStylesheet.pressableExpandedAttached),
    ],
    [borderlessWhenExpanded, isExpanded, isInteractive, isPressed],
  );
@@ -42,6 +42,7 @@ import {
  saveAppSettings as saveAppSettingsPure,
  type AppSettings,
  type AppSettingsUpdate,
+  type ChatDisplay,
  type OpenInSidePanePreferences,
  type PullRequestOpenLocation,
  type DesktopSettingsBridge,
@@ -84,6 +85,7 @@ export {
 export type {
  AppSettings,
  AppSettingsUpdate,
+  ChatDisplay,
  AppLanguage,
  OpenInSidePanePreferences,
  PullRequestOpenLocation,
@@ -185,6 +185,7 @@ describe("loadAppSettingsFromStorage", () => {

    expect(result).toEqual(DEFAULT_CLIENT_SETTINGS);
    expect(DEFAULT_CLIENT_SETTINGS.language).toBe("system");
+    expect(DEFAULT_CLIENT_SETTINGS.chatDisplay).toBe("collapseTurns");
    expect(JSON.parse(deps.storage.entries.get(APP_SETTINGS_KEY) ?? "null")).toEqual(
      DEFAULT_CLIENT_SETTINGS,
    );
@@ -454,6 +455,7 @@ describe("loadAppSettingsFromStorage", () => {
      ...DEFAULT_CLIENT_SETTINGS,
      theme: "dark",
      contentFontSize: DEFAULT_UI_BASE_FONT_SIZE,
+      chatDisplay: "full",
    });
    expect(JSON.parse(deps.storage.entries.get(APP_SETTINGS_KEY) ?? "null")).toEqual({
      manageBuiltInDaemon: false,
@@ -592,6 +594,7 @@ describe("loadSettingsFromStorage", () => {
      ...DEFAULT_APP_SETTINGS,
      theme: "light",
      contentFontSize: DEFAULT_UI_BASE_FONT_SIZE,
+      chatDisplay: "full",
    });
  });

@@ -636,6 +639,7 @@ describe("loadSettingsFromStorage", () => {
      ...DEFAULT_APP_SETTINGS,
      theme: "light",
      contentFontSize: DEFAULT_UI_BASE_FONT_SIZE,
+      chatDisplay: "full",
      manageBuiltInDaemon: false,
      releaseChannel: "beta",
    });
@@ -657,6 +661,7 @@ describe("loadSettingsFromStorage", () => {
      ...DEFAULT_APP_SETTINGS,
      theme: "light",
      contentFontSize: DEFAULT_UI_BASE_FONT_SIZE,
+      chatDisplay: "full",
    });
  });
 });
@@ -732,7 +737,7 @@ describe("saveAppSettings", () => {
      ...DEFAULT_CLIENT_SETTINGS,
      theme: "light",
      contentFontSize: DEFAULT_UI_BASE_FONT_SIZE,
-      toolCallDetailLevel: "overview",
+      chatDisplay: "collapseToolCalls",
    });
  });

@@ -787,27 +792,45 @@ describe("appearance settings", () => {
    expect(result.contentFontSize).toBe(DEFAULT_UI_BASE_FONT_SIZE);
    expect(result.codeFontSize).toBe(DEFAULT_CODE_FONT_SIZE);
    expect(result.syntaxTheme).toBe("one");
-    expect(result.toolCallDetailLevel).toBe("detailed");
+    expect(result.chatDisplay).toBe("full");
  });

-  it("migrates the enabled compact tool call preference to overview", async () => {
+  it("migrates the enabled compact tool call preference to collapsed tool calls", async () => {
    const deps = makeDeps({
      storage: createInMemoryKeyValueStorage({
        [APP_SETTINGS_KEY]: JSON.stringify({ compactToolCalls: true }),
      }),
    });

-    expect((await loadAppSettingsFromStorage(deps)).toolCallDetailLevel).toBe("overview");
+    expect((await loadAppSettingsFromStorage(deps)).chatDisplay).toBe("collapseToolCalls");
  });

-  it("clears settings with an unrecognized tool call detail level", async () => {
+  it.each([
+    ["overview", "collapseToolCalls"],
+    ["concise", "collapseToolCalls"],
+    ["detailed", "full"],
+    ["unknown", "full"],
+  ])("reads the %s tool call detail level as the %s chat display", async (legacy, display) => {
    const deps = makeDeps({
      storage: createInMemoryKeyValueStorage({
-        [APP_SETTINGS_KEY]: JSON.stringify({ toolCallDetailLevel: "unknown" }),
+        [APP_SETTINGS_KEY]: JSON.stringify({ toolCallDetailLevel: legacy }),
      }),
    });

-    expect((await loadAppSettingsFromStorage(deps)).toolCallDetailLevel).toBe("detailed");
+    expect((await loadAppSettingsFromStorage(deps)).chatDisplay).toBe(display);
+  });
+
+  it("keeps a stored chat display over the tool call detail level it replaced", async () => {
+    const deps = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({
+          chatDisplay: "collapseTurns",
+          toolCallDetailLevel: "detailed",
+        }),
+      }),
+    });
+
+    expect((await loadAppSettingsFromStorage(deps)).chatDisplay).toBe("collapseTurns");
  });

  it("migrates a switched-off checks row item to the hidden checks display", async () => {
@@ -40,7 +40,8 @@ export type WorkspaceTitleSource = "title" | "branch";
 export type PullRequestOpenLocation = "main" | "side" | "explorer";
 /** What a sidebar workspace row shows in the space to the right of its title. */
 export type SidebarWorkspaceTrailing = "diff" | "timestamp" | "none";
-export type ToolCallDetailLevel = "overview" | "detailed";
+/** How much of an agent's work the chat shows between the user's message and the reply. */
+export type ChatDisplay = "full" | "collapseToolCalls" | "collapseTurns";

 const ThemePreferenceSchema = z.enum([
  ...THEME_OPTIONS.map((option) => option.name),
@@ -100,7 +101,7 @@ export interface AppSettings {
  /** How usage reads and which windows the sidebar summary shows. */
  usage: UsagePreferences;
  autoExpandReasoning: boolean;
-  toolCallDetailLevel: ToolCallDetailLevel;
+  chatDisplay: ChatDisplay;
  chatOutlineEnabled: boolean;
  vimKeybindings: boolean;
  filePanelAssociations: Record<string, string>;
@@ -156,7 +157,7 @@ export const DEFAULT_CLIENT_SETTINGS: AppSettings = {
  sidebarFooterItems: [],
  usage: DEFAULT_USAGE_PREFERENCES,
  autoExpandReasoning: false,
-  toolCallDetailLevel: "detailed",
+  chatDisplay: "collapseTurns",
  chatOutlineEnabled: true,
  vimKeybindings: false,
  filePanelAssociations: {},
@@ -199,6 +200,7 @@ const SidebarRowItemsSchema = z
 type StoredAppSettingsFallback = AppSettings & {
  uiFontSize?: number;
  compactToolCalls?: boolean;
+  toolCallDetailLevel?: "overview" | "detailed";
  manageBuiltInDaemon?: boolean;
  releaseChannel?: ReleaseChannel;
  needsWrite: boolean;
@@ -251,11 +253,13 @@ const StoredAppSettingsSchema = z
    sidebarFooterItems: z.array(z.object({ key: z.string(), visible: z.boolean() })).catch([]),
    usage: UsagePreferencesSchema,
    autoExpandReasoning: z.boolean().catch(false),
+    chatDisplay: z.enum(["full", "collapseToolCalls", "collapseTurns"]).optional().catch("full"),
+    // COMPAT(toolCallDetailLevel): replaced by chatDisplay in v0.13, remove after 2027-04-24.
    toolCallDetailLevel: z
      .enum(["overview", "detailed"])
      .or(z.literal("concise").transform(() => "overview" as const))
      .optional()
-      .catch("detailed"),
+      .catch(undefined),
    // COMPAT(compactToolCalls): migrated in v0.1.105, remove after 2027-01-12.
    compactToolCalls: z.boolean().optional().catch(undefined),
    chatOutlineEnabled: z.boolean().catch(true),
@@ -305,8 +309,10 @@ const StoredAppSettingsSchema = z
      (isChecksHiddenByLegacyRowItem(stored.sidebarRowItems)
        ? "none"
        : DEFAULT_SIDEBAR_CHECKS_DISPLAY);
-    const toolCallDetailLevel =
-      stored.toolCallDetailLevel ?? (stored.compactToolCalls ? "overview" : "detailed");
+    const groupsToolCalls = stored.toolCallDetailLevel
+      ? stored.toolCallDetailLevel === "overview"
+      : stored.compactToolCalls === true;
+    const chatDisplay = stored.chatDisplay ?? (groupsToolCalls ? "collapseToolCalls" : "full");
    return {
      ...stored,
      openInSidePane,
@@ -321,7 +327,7 @@ const StoredAppSettingsSchema = z
          stored.sidebarRowItems.services ??
          (stored.sidebarRowItems.scripts === false ? false : DEFAULT_SIDEBAR_ROW_ITEMS.services),
      },
-      toolCallDetailLevel,
+      chatDisplay,
      needsWrite,
    };
  })
@@ -449,6 +455,7 @@ export function normalizeAppSettings(value: unknown): AppSettings {
    manageBuiltInDaemon: _manageBuiltInDaemon,
    releaseChannel: _releaseChannel,
    compactToolCalls: _compactToolCalls,
+    toolCallDetailLevel: _toolCallDetailLevel,
    uiFontSize: _uiFontSize,
    ...settings
  } = StoredAppSettingsSchema.parse(value);
@@ -2008,6 +2008,12 @@ export const ar: TranslationResources = {
    input: "مدخل",
    output: "الإخراج",
  },
+  turnSummary: {
+    messages: {
+      one: "كتب {{count}} رسالة",
+      other: "كتب {{count}} رسائل",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "حرّر {{count}} ملفًا",
@@ -2312,12 +2318,13 @@ export const ar: TranslationResources = {
        label: "عرض التفكير دائماً",
        description: "إظهار تفكير الوكيل وخطوات الاستدلال بشكل كامل بشكل افتراضي",
      },
-      toolCallDetail: {
-        label: "عرض استدعاءات الأدوات",
-        description: "كيفية ظهور استدعاءات الأدوات في المخطط الزمني",
+      chatDisplay: {
+        label: "عرض المحادثة",
+        description: "مقدار عمل الوكيل الذي تعرضه المحادثة",
        options: {
-          overview: "ملخص",
-          detailed: "التفاصيل الكاملة",
+          full: "كامل",
+          collapseToolCalls: "طيّ استدعاءات الأدوات",
+          collapseTurns: "طيّ الأدوار",
        },
      },
      language: {
@@ -2033,6 +2033,12 @@ export const en = {
    input: "Input",
    output: "Output",
  },
+  turnSummary: {
+    messages: {
+      one: "wrote {{count}} message",
+      other: "wrote {{count}} messages",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "edited {{count}} file",
@@ -2400,12 +2406,13 @@ export const en = {
        label: "Always expand reasoning",
        description: "Show agent thinking and chain-of-thought blocks fully expanded by default",
      },
-      toolCallDetail: {
-        label: "Tool call display",
-        description: "How tool calls appear in the timeline",
+      chatDisplay: {
+        label: "Chat display",
+        description: "How much of an agent's work the chat shows",
        options: {
-          overview: "Summary",
-          detailed: "Full detail",
+          full: "Full",
+          collapseToolCalls: "Collapse tool calls",
+          collapseTurns: "Collapse turns",
        },
      },
      language: {
@@ -2056,6 +2056,12 @@ export const es: TranslationResources = {
    input: "Aporte",
    output: "Producción",
  },
+  turnSummary: {
+    messages: {
+      one: "escribió {{count}} mensaje",
+      other: "escribió {{count}} mensajes",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "editó {{count}} archivo",
@@ -2328,12 +2334,13 @@ export const es: TranslationResources = {
        description:
          "Mostrar los bloques de pensamiento y razonamiento del agente totalmente expandidos de forma predeterminada",
      },
-      toolCallDetail: {
-        label: "Visualización de llamadas a herramientas",
-        description: "Cómo aparecen las llamadas a herramientas en la cronología",
+      chatDisplay: {
+        label: "Visualización del chat",
+        description: "Cuánto del trabajo del agente muestra el chat",
        options: {
-          overview: "Resumen",
-          detailed: "Detalle completo",
+          full: "Completo",
+          collapseToolCalls: "Contraer llamadas a herramientas",
+          collapseTurns: "Contraer turnos",
        },
      },
      language: {
@@ -2055,6 +2055,12 @@ export const fr: TranslationResources = {
    input: "Entrée",
    output: "Sortie",
  },
+  turnSummary: {
+    messages: {
+      one: "{{count}} message écrit",
+      other: "{{count}} messages écrits",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "{{count}} fichier modifié",
@@ -2326,12 +2332,13 @@ export const fr: TranslationResources = {
        label: "Toujours afficher le raisonnement",
        description: "Afficher par défaut le raisonnement de l’agent entièrement déplié",
      },
-      toolCallDetail: {
-        label: "Affichage des appels d’outils",
-        description: "Comment les appels d’outils apparaissent dans la chronologie",
+      chatDisplay: {
+        label: "Affichage du chat",
+        description: "La part du travail de l’agent affichée dans le chat",
        options: {
-          overview: "Résumé",
-          detailed: "Détails complets",
+          full: "Complet",
+          collapseToolCalls: "Réduire les appels d’outils",
+          collapseTurns: "Réduire les tours",
        },
      },
      language: {
@@ -2028,6 +2028,12 @@ export const ja: TranslationResources = {
    input: "入力",
    output: "出力",
  },
+  turnSummary: {
+    messages: {
+      one: "{{count}}件のメッセージを送信",
+      other: "{{count}}件のメッセージを送信",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "{{count}}個のファイルを編集",
@@ -2296,12 +2302,13 @@ export const ja: TranslationResources = {
        label: "常に思考プロセスを展開",
        description: "デフォルトでAIのエージェント思考・推論ブロックを完全に展開して表示します",
      },
-      toolCallDetail: {
-        label: "ツール呼び出しの表示",
-        description: "タイムラインでのツール呼び出しの表示方法",
+      chatDisplay: {
+        label: "チャットの表示",
+        description: "チャットに表示するエージェントの作業量",
        options: {
-          overview: "要約",
-          detailed: "すべての詳細",
+          full: "すべて",
+          collapseToolCalls: "ツール呼び出しを折りたたむ",
+          collapseTurns: "ターンを折りたたむ",
        },
      },
      language: {
@@ -2018,6 +2018,12 @@ export const ko: TranslationResources = {
    input: "입력",
    output: "출력",
  },
+  turnSummary: {
+    messages: {
+      one: "{{count}} 메시지를 작성했습니다.",
+      other: "{{count}} 메시지를 작성했습니다.",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "{{count}} 파일을 편집했습니다.",
@@ -2287,12 +2293,13 @@ export const ko: TranslationResources = {
        label: "추론 항상 펼치기",
        description: "에이전트의 사고 및 추론 블록을 기본적으로 모두 펼쳐 표시합니다.",
      },
-      toolCallDetail: {
-        label: "도구 호출 표시",
-        description: "타임라인에 도구 호출이 표시되는 방식",
+      chatDisplay: {
+        label: "채팅 표시",
+        description: "채팅에 표시할 에이전트 작업의 양",
        options: {
-          overview: "요약",
-          detailed: "전체 세부정보",
+          full: "전체",
+          collapseToolCalls: "도구 호출 접기",
+          collapseTurns: "턴 접기",
        },
      },
      language: {
@@ -2041,6 +2041,12 @@ export const ptBR: TranslationResources = {
    input: "Entrada",
    output: "Saída",
  },
+  turnSummary: {
+    messages: {
+      one: "escreveu {{count}} mensagem",
+      other: "escreveu {{count}} mensagens",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "editou {{count}} arquivo",
@@ -2311,12 +2317,13 @@ export const ptBR: TranslationResources = {
        description:
          "Mostrar os blocos de pensamento e raciocínio do agente totalmente expandidos por padrão",
      },
-      toolCallDetail: {
-        label: "Exibição de chamadas de ferramentas",
-        description: "Como as chamadas de ferramentas aparecem na linha do tempo",
+      chatDisplay: {
+        label: "Exibição do chat",
+        description: "Quanto do trabalho do agente o chat mostra",
        options: {
-          overview: "Resumo",
-          detailed: "Detalhes completos",
+          full: "Completo",
+          collapseToolCalls: "Recolher chamadas de ferramentas",
+          collapseTurns: "Recolher turnos",
        },
      },
      language: {
@@ -2041,6 +2041,12 @@ export const ru: TranslationResources = {
    input: "Входные данные",
    output: "Выходные данные",
  },
+  turnSummary: {
+    messages: {
+      one: "написано {{count}} сообщение",
+      other: "написаны сообщения ({{count}})",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "изменён {{count}} файл",
@@ -2313,12 +2319,13 @@ export const ru: TranslationResources = {
        description:
          "По умолчанию полностью разворачивать блоки размышлений и хода рассуждений агента",
      },
-      toolCallDetail: {
-        label: "Отображение вызовов инструментов",
-        description: "Как вызовы инструментов отображаются на временной шкале",
+      chatDisplay: {
+        label: "Отображение чата",
+        description: "Какую часть работы агента показывает чат",
        options: {
-          overview: "Сводка",
-          detailed: "Все подробности",
+          full: "Полностью",
+          collapseToolCalls: "Сворачивать вызовы инструментов",
+          collapseTurns: "Сворачивать ходы",
        },
      },
      language: {
@@ -1986,6 +1986,12 @@ export const zhCN: TranslationResources = {
    input: "输入",
    output: "输出",
  },
+  turnSummary: {
+    messages: {
+      one: "写了 {{count}} 条消息",
+      other: "写了 {{count}} 条消息",
+    },
+  },
  toolCallGroup: {
    editedFiles: {
      one: "编辑了 {{count}} 个文件",
@@ -2251,12 +2257,13 @@ export const zhCN: TranslationResources = {
        label: "始终展开推理过程",
        description: "默认情况下完全展开 AI 的思考和推理过程",
      },
-      toolCallDetail: {
-        label: "工具调用显示",
-        description: "工具调用在时间线中的显示方式",
+      chatDisplay: {
+        label: "聊天显示",
+        description: "聊天中显示多少智能体的工作",
        options: {
-          overview: "摘要",
-          detailed: "完整详情",
+          full: "完整",
+          collapseToolCalls: "折叠工具调用",
+          collapseTurns: "折叠轮次",
        },
      },
      language: {
@@ -8,29 +8,25 @@ import {
  SettingsSwitch,
 } from "@/components/settings";
 import { isNative } from "@/constants/platform";
-import { useAppSettings, type AppSettings } from "@/hooks/use-settings";
+import { useAppSettings, type ChatDisplay } from "@/hooks/use-settings";

-const TOOL_CALL_DETAIL_LEVELS: readonly AppSettings["toolCallDetailLevel"][] = [
-  "detailed",
-  "overview",
-];
+const CHAT_DISPLAYS: readonly ChatDisplay[] = ["full", "collapseToolCalls", "collapseTurns"];

 export function ChatSection() {
  const { t } = useTranslation();
  const { settings, updateSettings } = useAppSettings();

-  const toolCallDetailOptions = useMemo(
+  const chatDisplayOptions = useMemo(
    () =>
-      TOOL_CALL_DETAIL_LEVELS.map((value) => ({
+      CHAT_DISPLAYS.map((value) => ({
        value,
-        label: t(`settings.general.toolCallDetail.options.${value}`),
+        label: t(`settings.general.chatDisplay.options.${value}`),
      })),
    [t],
  );

-  const changeToolCallDetailLevel = useCallback(
-    (toolCallDetailLevel: AppSettings["toolCallDetailLevel"]) =>
-      void updateSettings({ toolCallDetailLevel }),
+  const changeChatDisplay = useCallback(
+    (chatDisplay: ChatDisplay) => void updateSettings({ chatDisplay }),
    [updateSettings],
  );
  const changeAutoExpandReasoning = useCallback(
@@ -53,11 +49,11 @@ export function ChatSection() {
            onValueChange={changeAutoExpandReasoning}
          />
          <SettingsSelect
-            label={t("settings.general.toolCallDetail.label")}
-            hint={t("settings.general.toolCallDetail.description")}
-            value={settings.toolCallDetailLevel}
-            options={toolCallDetailOptions}
-            onValueChange={changeToolCallDetailLevel}
+            label={t("settings.general.chatDisplay.label")}
+            hint={t("settings.general.chatDisplay.description")}
+            value={settings.chatDisplay}
+            options={chatDisplayOptions}
+            onValueChange={changeChatDisplay}
          />
          {isNative ? null : (
            <SettingsSwitch
@@ -0,0 +1,45 @@
+import { useMemo } from "react";
+import { useTranslation } from "react-i18next";
+import type { OverviewSummary } from "./model";
+
+function joinSummaryParts(parts: string[], conjunction: string): string {
+  if (parts.length === 0) {
+    return "";
+  }
+  let joined = parts[0] ?? "";
+  if (parts.length === 2) {
+    joined = `${parts[0]} ${conjunction} ${parts[1]}`;
+  } else if (parts.length > 2) {
+    joined = `${parts.slice(0, -1).join(", ")}, ${conjunction} ${parts.at(-1)}`;
+  }
+  const firstCharacter = joined[0];
+  return firstCharacter ? `${firstCharacter.toLocaleUpperCase()}${joined.slice(1)}` : joined;
+}
+
+/**
+ * One sentence of what a stretch of agent work did, such as "Edited 2 files and ran 3 commands".
+ * Leading parts come first, for summaries that count more than tool calls.
+ */
+export function useOverviewSummaryLabel(
+  summary: OverviewSummary,
+  leadingParts: readonly string[] = [],
+): string {
+  const { t } = useTranslation();
+  return useMemo(() => {
+    const parts = [...leadingParts];
+    const entries = [
+      [summary.editedFileCount, "toolCallGroup.editedFiles"],
+      [summary.commandCount, "toolCallGroup.commands"],
+      [summary.readFileCount, "toolCallGroup.readFiles"],
+      [summary.searchCount, "toolCallGroup.searches"],
+      [summary.otherToolCount, "toolCallGroup.otherTools"],
+      [summary.paseoCallCount, "toolCallGroup.paseoCalls"],
+    ] as const;
+    for (const [count, key] of entries) {
+      if (count > 0) {
+        parts.push(t(`${key}.${count === 1 ? "one" : "other"}`, { count }));
+      }
+    }
+    return joinSummaryParts(parts, t("toolCallGroup.and"));
+  }, [leadingParts, summary, t]);
+}
@@ -1,4 +1,5 @@
 import { isPaseoToolName } from "@getpaseo/protocol/tool-name-normalization";
+import type { ToolCallItem } from "@/types/stream";
 import { describeToolCall, type ToolCallRun } from "../grouping";

 const DIRECT_PASEO_TOOL_PREFIX = "paseo_";
@@ -28,19 +29,18 @@ function isSearchCall(name: string): boolean {
  return DIRECT_SEARCH_TOOL_SUFFIX_PATTERN.test(name);
 }

-export function buildOverviewGroup(run: ToolCallRun): OverviewToolCallGroup {
+/** Counts tool calls by what they did, for any summary of a stretch of agent work. */
+export function summarizeToolCalls(calls: readonly ToolCallItem[]): OverviewSummary {
  const editedFiles = new Set<string>();
  const readFiles = new Set<string>();
-  let isLoading = false;
  let commandCount = 0;
  let searchCount = 0;
  let otherToolCount = 0;
  let paseoCallCount = 0;

-  for (const call of run.calls) {
+  for (const call of calls) {
    const descriptor = describeToolCall(call);
    const normalizedName = descriptor.name.trim().toLowerCase();
-    isLoading ||= descriptor.status === "running" || descriptor.status === "executing";
    if (isPaseoCall(descriptor.name, normalizedName)) {
      paseoCallCount += 1;
    } else if (descriptor.detail.type === "edit" || descriptor.detail.type === "write") {
@@ -56,7 +56,7 @@ export function buildOverviewGroup(run: ToolCallRun): OverviewToolCallGroup {
    }
  }

-  const summary = {
+  return {
    editedFileCount: editedFiles.size,
    commandCount,
    readFileCount: readFiles.size,
@@ -64,10 +64,17 @@ export function buildOverviewGroup(run: ToolCallRun): OverviewToolCallGroup {
    otherToolCount,
    paseoCallCount,
  };
+}
+
+export function buildOverviewGroup(run: ToolCallRun): OverviewToolCallGroup {
+  const isLoading = run.calls.some((call) => {
+    const status = describeToolCall(call).status;
+    return status === "running" || status === "executing";
+  });
  return {
    mode: "overview",
    run,
    isLoading,
-    summary,
+    summary: summarizeToolCalls(run.calls),
  };
 }
@@ -1,11 +1,12 @@
-import React, { memo, useCallback, useMemo, useRef, type ReactNode } from "react";
+import React, { memo, useCallback, useRef, type ReactNode } from "react";
 import { ScrollView } from "react-native";
-import { useTranslation } from "react-i18next";
 import { Wrench } from "lucide-react-native";
 import { StyleSheet } from "react-native-unistyles";
+import { IndentRail } from "@/components/indent-rail";
 import { ExpandableBadge } from "@/components/message";
 import { useIsCompactFormFactor } from "@/constants/layout";
-import { type OverviewSummary, type OverviewToolCallGroup } from "./model";
+import { useOverviewSummaryLabel } from "./label";
+import type { OverviewToolCallGroup } from "./model";
 import { OverviewToolCallGroupSheet } from "./sheet";

 interface OverviewGroupProps {
@@ -18,41 +19,6 @@ interface OverviewGroupProps {

 const TOOL_CALL_GROUP_MAX_HEIGHT = 400;

-function joinSummaryParts(parts: string[], conjunction: string): string {
-  if (parts.length === 0) {
-    return "";
-  }
-  let joined = parts[0] ?? "";
-  if (parts.length === 2) {
-    joined = `${parts[0]} ${conjunction} ${parts[1]}`;
-  } else if (parts.length > 2) {
-    joined = `${parts.slice(0, -1).join(", ")}, ${conjunction} ${parts.at(-1)}`;
-  }
-  const firstCharacter = joined[0];
-  return firstCharacter ? `${firstCharacter.toLocaleUpperCase()}${joined.slice(1)}` : joined;
-}
-
-function useOverviewSummary(summary: OverviewSummary): string {
-  const { t } = useTranslation();
-  return useMemo(() => {
-    const parts: string[] = [];
-    const entries = [
-      [summary.editedFileCount, "toolCallGroup.editedFiles"],
-      [summary.commandCount, "toolCallGroup.commands"],
-      [summary.readFileCount, "toolCallGroup.readFiles"],
-      [summary.searchCount, "toolCallGroup.searches"],
-      [summary.otherToolCount, "toolCallGroup.otherTools"],
-      [summary.paseoCallCount, "toolCallGroup.paseoCalls"],
-    ] as const;
-    for (const [count, key] of entries) {
-      if (count > 0) {
-        parts.push(t(`${key}.${count === 1 ? "one" : "other"}`, { count }));
-      }
-    }
-    return joinSummaryParts(parts, t("toolCallGroup.and"));
-  }, [summary, t]);
-}
-
 export const OverviewToolCallGroupView = memo(function OverviewToolCallGroupView({
  group,
  expanded,
@@ -62,7 +28,7 @@ export const OverviewToolCallGroupView = memo(function OverviewToolCallGroupView
 }: OverviewGroupProps) {
  const scrollRef = useRef<ScrollView>(null);
  const isCompact = useIsCompactFormFactor();
-  const aggregateSummary = useOverviewSummary(group.summary);
+  const aggregateSummary = useOverviewSummaryLabel(group.summary);
  const scrollToLatest = useCallback(() => {
    scrollRef.current?.scrollToEnd({ animated: false });
  }, []);
@@ -82,7 +48,7 @@ export const OverviewToolCallGroupView = memo(function OverviewToolCallGroupView
        showsVerticalScrollIndicator
        onContentSizeChange={scrollToLatest}
      >
-        {children}
+        <IndentRail>{children}</IndentRail>
      </ScrollView>
    ),
    [children, scrollToLatest],
@@ -1,5 +1,4 @@
 import type { StreamItem } from "@/types/stream";
-import type { ToolCallDetailLevel } from "@/hooks/use-settings/storage";
 import {
  groupLiveToolCalls,
  prepareGroupedHistory,
@@ -8,7 +7,8 @@ import {
 } from "./grouping";
 import { buildOverviewGroup, type OverviewToolCallGroup } from "./overview/model";

-export type { ToolCallDetailLevel } from "@/hooks/use-settings/storage";
+/** Whether consecutive tool calls show one by one or as one summary row. */
+export type ToolCallDetailLevel = "overview" | "detailed";
 export type ToolCallDetailGroup = OverviewToolCallGroup;

 export interface PreparedToolCallHistory {
@@ -771,6 +771,12 @@ export type AgentToolCallItem = ToolCallItem & {
  payload: { source: "agent"; data: AgentToolCallData };
 };

+/** Find and scrolling address a plugin row by the source it replaces. */
+export function getStreamItemMessageId(item: StreamItem): string {
+  if (item.kind === "plugin") return item.sourceId ?? item.id;
+  return item.id;
+}
+
 export function isAgentToolCallItem(item: StreamItem): item is AgentToolCallItem {
  return item.kind === "tool_call" && item.payload.source === "agent";
 }