fix(app): keep rewound history in its own chat

A restored fork snapshot belongs to the rewound agent. Give it an agent attachment scope so switching chats cannot send or consume that context elsewhere in the workspace.

packages/app/e2e/browser/assistant-fork-menu.spec.ts

@@ -1,6 +1,18 @@
+import {
+  captureChatHistory,
+  expectRewoundHistoryIsPrivate,
+  rewindForkPrompt,
+  closeChatHistory,
+  followChatHistorySource,
+  openChatHistory,
+  sendChatHistoryFromAnotherClient,
+  setChatHistoryViewport,
+} from "../support/helpers/chat-history";
 import { expect, test as base } from "../support/fixtures";
 import { awaitAssistantMessage } from "../support/helpers/agent-stream";
 import {
+  getActiveForkAgentId,
+  expectActiveForkAgent,
   expectChatHistoryAttachment,
   expectInFlightForkAvailable,
   expectLiveAssistantText,
@@ -38,6 +50,97 @@ const test = base.extend<{
 test.describe("Assistant fork menu", () => {
   test.describe.configure({ timeout: 180_000 });
 
+  test("reads fork history before and after sending and opens its source after reload", async ({
+    page,
+    seedForkWorkspace,
+  }, testInfo) => {
+    const initialPrompt = "emit 1 coalesced agent stream updates for readable fork history.";
+    const session = await seedForkWorkspace({
+      repoPrefix: "assistant-fork-readable-",
+      title: "Original conversation",
+      initialPrompt,
+      model: "ten-second-stream",
+    });
+    await openAgentRoute(page, session);
+    await expectComposerVisible(page);
+    await awaitAssistantMessage(page);
+    await session.client.waitForFinish(session.agentId, 45_000);
+    await forkMostRecentAssistantTurnToNewTab(page);
+    await openChatHistory(page, "draft", [initialPrompt]);
+    await captureChatHistory(page, testInfo, "history-wide.png");
+    await closeChatHistory(page);
+    await submitMessage(page, "emit 1 coalesced agent stream updates for the fork.");
+    const forkAgentId = await getActiveForkAgentId(page);
+    await session.client.waitForFinish(forkAgentId, 45_000);
+
+    await openAgentRoute(page, { workspaceId: session.workspaceId, agentId: forkAgentId });
+    await page.reload();
+    await setChatHistoryViewport(page, "compact");
+    await openChatHistory(page, "sent", [initialPrompt]);
+    await captureChatHistory(page, testInfo, "history-compact.png");
+    await followChatHistorySource(page);
+    await setChatHistoryViewport(page, "wide");
+    await expectActiveForkAgent(page, session.agentId);
+
+    await openAgentRoute(page, { workspaceId: session.workspaceId, agentId: forkAgentId });
+    await expectActiveForkAgent(page, forkAgentId);
+    await forkMostRecentAssistantTurnToNewTab(page);
+    await openChatHistory(page, "draft", [initialPrompt, "updates for the fork."]);
+    await followChatHistorySource(page);
+    await expectActiveForkAgent(page, forkAgentId);
+  });
+
+  for (const prompt of ["", "Continue the fork"]) {
+    test(`retains inherited context when rewinding the first fork prompt (${prompt || "history only"})`, async ({
+      page,
+      seedForkWorkspace,
+    }) => {
+      const initialPrompt = "emit 1 coalesced agent stream updates for rewindable fork history.";
+      const session = await seedForkWorkspace({
+        repoPrefix: "fork-rewind-",
+        title: "Rewind source",
+        initialPrompt,
+        model: "ten-second-stream",
+      });
+      await openAgentRoute(page, session);
+      await expectComposerVisible(page);
+      await awaitAssistantMessage(page);
+      await session.client.waitForFinish(session.agentId, 45_000);
+      await forkMostRecentAssistantTurnToNewTab(page);
+      await submitMessage(page, prompt);
+      const forkId = await getActiveForkAgentId(page);
+      await session.client.waitForFinish(forkId, 45_000);
+      await page.reload();
+      await openChatHistory(page, "sent", [initialPrompt]);
+      await closeChatHistory(page);
+      await rewindForkPrompt(page);
+      await expectRewoundHistoryIsPrivate(page, session.agentId, forkId);
+      await openChatHistory(page, "draft", [initialPrompt]);
+      await closeChatHistory(page);
+      await submitMessage(page, prompt);
+      await session.client.waitForFinish(forkId, 45_000);
+      await page.reload();
+      await openChatHistory(page, "sent", [initialPrompt]);
+    });
+  }
+
+  test("shows history sent from another connected client without reloading", async ({
+    page,
+    seedForkWorkspace,
+  }) => {
+    const session = await seedForkWorkspace({
+      repoPrefix: "assistant-fork-live-history-",
+      title: "Live history recipient",
+      model: "ten-second-stream",
+    });
+    await openAgentRoute(page, session);
+    await expectComposerVisible(page);
+    const history = "[User] Context inherited on another device.";
+    await sendChatHistoryFromAnotherClient(session, history);
+    await openChatHistory(page, "sent", [history]);
+    await session.client.waitForFinish(session.agentId, 45_000);
+  });
+
   test("forks a failed assistant turn that has no provider message id", async ({
     page,
     seedForkWorkspace,

packages/app/e2e/support/helpers/assistant-fork.ts

@@ -112,3 +112,21 @@ export async function expectLiveAssistantText(page: Page, text: string): Promise
     timeout: 60_000,
   });
 }
+
+export async function getActiveForkAgentId(page: Page): Promise<string> {
+  const selectedTab = page
+    .getByTestId("workspace-tabs-row")
+    .getByRole("button")
+    .and(page.locator('[aria-selected="true"]'));
+  await expect(selectedTab).toHaveAttribute("data-testid", /^workspace-tab-agent_/);
+  const tabId = await selectedTab.getAttribute("data-testid");
+  if (!tabId) throw new Error("Expected a selected agent tab");
+  return tabId.replace("workspace-tab-agent_", "");
+}
+
+export async function expectActiveForkAgent(page: Page, agentId: string) {
+  await expect(page.getByTestId(`workspace-tab-agent_${agentId}`)).toHaveAttribute(
+    "aria-selected",
+    "true",
+  );
+}

packages/app/e2e/support/helpers/chat-history.ts

@@ -0,0 +1,82 @@
+import { expect, type Page, type TestInfo } from "@playwright/test";
+import type { MockAgentWorkspace } from "./mock-agent";
+import { getServerId } from "./server-id";
+
+export function setChatHistoryViewport(page: Page, layout: "wide" | "compact") {
+  return page.setViewportSize(
+    layout === "wide" ? { width: 1280, height: 720 } : { width: 390, height: 844 },
+  );
+}
+
+export async function openChatHistory(page: Page, location: "draft" | "sent", contents: string[]) {
+  const testId =
+    location === "draft"
+      ? "composer-chat-history-attachment-pill"
+      : "message-chat-history-attachment";
+  const attachment = page.getByTestId(testId).filter({ visible: true }).last();
+  await expect(attachment).toBeVisible({ timeout: 10_000 });
+  await attachment.click();
+  for (const text of contents) {
+    await expect(page.getByTestId("chat-history-content")).toContainText(text);
+  }
+  await expect(page.getByRole("button", { name: "Open source chat" })).toBeVisible();
+}
+
+export async function closeChatHistory(page: Page) {
+  await page
+    .getByTestId("chat-history-preview")
+    .getByRole("button", { name: "Close", exact: true })
+    .click();
+}
+
+export async function followChatHistorySource(page: Page) {
+  await page.getByRole("button", { name: "Open source chat" }).click();
+  await expect(page.getByTestId("chat-history-preview")).not.toBeVisible();
+}
+
+export async function captureChatHistory(page: Page, testInfo: TestInfo, name: string) {
+  // Follow the existing QA helpers: settle spring animations and hide Expo-only chrome.
+  await page.waitForTimeout(600);
+  await page.addStyleTag({ content: ".__expo_fast_refresh { display: none !important; }" });
+  await page.screenshot({ path: testInfo.outputPath(name), animations: "disabled" });
+}
+
+export async function sendChatHistoryFromAnotherClient(
+  session: MockAgentWorkspace,
+  history: string,
+) {
+  const serverId = getServerId();
+  await session.client.sendAgentMessage(session.agentId, "", {
+    attachments: [
+      {
+        type: "text",
+        mimeType: "text/plain",
+        contextKind: "chat_history",
+        text: history,
+        chatHistorySource: { serverId, agentId: "source-agent", title: "Original conversation" },
+      },
+    ],
+  });
+}
+
+export async function rewindForkPrompt(page: Page) {
+  const prompt = page.getByTestId("user-message").filter({ visible: true }).last();
+  await prompt.hover();
+  const trigger = prompt.getByRole("button", { name: "Rewind to this message", exact: true });
+  await expect(trigger).toBeVisible({ timeout: 10_000 });
+  await trigger.click();
+  const option = page.getByRole("menuitem", { name: "Rewind conversation", exact: true });
+  await expect(option).toBeInViewport({ ratio: 1 });
+  await option.click();
+  await expect(option).not.toBeVisible();
+}
+
+export async function expectRewoundHistoryIsPrivate(page: Page, sourceId: string, forkId: string) {
+  await page.getByTestId(`workspace-tab-agent_${sourceId}`).click();
+  const history = page
+    .getByTestId("composer-chat-history-attachment-pill")
+    .filter({ visible: true });
+  await expect(history).toHaveCount(0);
+  await page.getByTestId(`workspace-tab-agent_${forkId}`).click();
+  await expect(history).toBeVisible();
+}

packages/app/e2e/support/helpers/seed-client.ts

@@ -157,7 +157,10 @@ export interface SeedDaemonClient {
   sendAgentMessage(
     agentId: string,
     text: string,
-    options?: { sourceAgentId?: string },
+    options?: {
+      sourceAgentId?: string;
+      attachments?: import("@getpaseo/protocol/messages").AgentAttachment[];
+    },
   ): Promise<void>;
   waitForFinish(
     agentId: string,

packages/app/src/attachments/attachment-pill-content.tsx

@@ -49,7 +49,7 @@ function getTextAttachmentSubtitle(
   t: TFunction,
 ): string {
   if (attachment.contextKind === "chat_history") {
-    return "Previous conversation";
+    return attachment.chatHistorySource?.title ?? t("message.chatHistory.previousConversation");
   }
   return t("message.attachments.text");
 }
@@ -87,6 +87,13 @@ export function getAgentAttachmentPillContent(
         subtitle: `Issue #${attachment.number}`,
       };
     case "text":
+      if (attachment.contextKind === "chat_history") {
+        return {
+          icon: attachmentFileIcon,
+          title: t("message.chatHistory.title"),
+          subtitle: getTextAttachmentSubtitle(attachment, t),
+        };
+      }
       if (attachment.externalResource) {
         return {
           icon: attachmentGithubIssueIcon,

packages/app/src/attachments/chat-history/index.tsx

@@ -0,0 +1,125 @@
+import { generateMessageId } from "@/types/stream";
+import { useWorkspaceAttachmentsStore } from "@/attachments/workspace-attachments-store";
+import type { ChatHistoryAttachment as HistoryAttachment } from "@getpaseo/protocol/messages";
+import { extractChatHistoryBody } from "@getpaseo/protocol/chat-history";
+import { useCallback, useMemo, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { Text } from "react-native";
+import { StyleSheet } from "react-native-unistyles";
+import { ArrowUpRight } from "lucide-react-native";
+import type { AgentAttachment } from "@getpaseo/protocol/messages";
+import { getAgentAttachmentPillContent } from "@/attachments/attachment-pill-content";
+import { AttachmentFrame, AttachmentLabel, AttachmentPill } from "@/components/attachment-pill";
+import { AdaptiveModalSheet, FULL_SHEET_SNAP_POINTS } from "@/components/adaptive-modal-sheet";
+import { Button } from "@/components/ui/button";
+import { navigateToAgent } from "@/utils/navigate-to-agent";
+
+interface ChatHistoryAttachmentProps {
+  attachment: Extract<AgentAttachment, { type: "text" }>;
+  onRemove?: () => void;
+  disabled?: boolean;
+  testID?: string;
+}
+
+export function ChatHistoryAttachment({
+  attachment,
+  onRemove,
+  disabled = false,
+  testID,
+}: ChatHistoryAttachmentProps) {
+  const { t } = useTranslation();
+  const [visible, setVisible] = useState(false);
+  const open = useCallback(() => setVisible(true), []);
+  const close = useCallback(() => setVisible(false), []);
+  const source = attachment.chatHistorySource;
+  const openSource = useCallback(() => {
+    if (!source) return;
+    close();
+    navigateToAgent({ serverId: source.serverId, agentId: source.agentId });
+  }, [close, source]);
+  const header = useMemo(
+    () => ({
+      title: t("message.chatHistory.title"),
+      subtitle: source?.title ? (
+        <Text style={styles.description} numberOfLines={1}>
+          {source.title}
+        </Text>
+      ) : undefined,
+    }),
+    [source?.title, t],
+  );
+  const footer = useMemo(
+    () =>
+      source ? (
+        <Button variant="outline" size="sm" leftIcon={ArrowUpRight} onPress={openSource}>
+          {t("message.chatHistory.openSource")}
+        </Button>
+      ) : undefined,
+    [source, openSource, t],
+  );
+  const history = useMemo(() => extractChatHistoryBody(attachment.text), [attachment.text]);
+  const content = getAgentAttachmentPillContent(attachment, t);
+  const label = (
+    <AttachmentLabel icon={content.icon} title={content.title} subtitle={content.subtitle} />
+  );
+  const openLabel = t("message.chatHistory.open");
+
+  return (
+    <>
+      {onRemove ? (
+        <AttachmentPill
+          testID={testID}
+          onOpen={open}
+          onRemove={onRemove}
+          disabled={disabled}
+          openAccessibilityLabel={openLabel}
+          removeAccessibilityLabel={t("message.chatHistory.remove")}
+        >
+          {label}
+        </AttachmentPill>
+      ) : (
+        <AttachmentFrame testID={testID} onPress={open} accessibilityLabel={openLabel}>
+          {label}
+        </AttachmentFrame>
+      )}
+      <AdaptiveModalSheet
+        visible={visible}
+        onClose={close}
+        header={header}
+        snapPoints={FULL_SHEET_SNAP_POINTS}
+        desktopMaxWidth={720}
+        desktopHeight="75%"
+        testID="chat-history-preview"
+        contentStyle={styles.content}
+        footer={footer}
+      >
+        <Text style={styles.description}>{t("message.chatHistory.description")}</Text>
+        <Text selectable testID="chat-history-content" style={styles.history}>
+          {history}
+        </Text>
+      </AdaptiveModalSheet>
+    </>
+  );
+}
+
+const styles = StyleSheet.create((theme) => ({
+  content: { gap: theme.spacing[4] },
+  description: { fontSize: theme.fontSize.sm, color: theme.colors.foregroundMuted },
+  history: {
+    fontSize: theme.fontSize.content,
+    lineHeight: theme.fontSize.content * 1.6,
+    color: theme.colors.foreground,
+  },
+}));
+
+export function restoreChatHistoryAttachment(scopeKey: string, attachment: HistoryAttachment) {
+  useWorkspaceAttachmentsStore.getState().addWorkspaceAttachment({
+    scopeKey,
+    attachment: {
+      kind: "chat_history",
+      id: generateMessageId(),
+      attachment,
+      source: attachment.chatHistorySource,
+    },
+  });
+}

packages/app/src/attachments/types.ts

@@ -1,5 +1,6 @@
 import type {
   AgentAttachment,
+  ChatHistorySource,
   ForgeSearchItem,
   UploadedFileAttachment,
 } from "@getpaseo/protocol/messages";
@@ -82,9 +83,7 @@ export interface ChatHistoryContextAttachment {
   kind: "chat_history";
   id: string;
   attachment: Extract<AgentAttachment, { type: "text" }>;
-  source: {
-    serverId: string;
-    agentId: string;
+  source?: ChatHistorySource & {
     boundaryMessageId?: string | null;
     boundaryCursor?: { epoch: string; seq: number } | null;
     itemCount?: number;

packages/app/src/attachments/workspace-attachment-utils.test.ts

@@ -21,6 +21,29 @@ function contextAttachment(
 }
 
 describe("workspace attachment utilities", () => {
+  it("submits chat history with its source host and agent", () => {
+    const source = { serverId: "original-host", agentId: "original-agent", title: "Original" };
+    expect(
+      workspaceAttachmentToSubmitAttachment({
+        kind: "chat_history",
+        id: "history-draft",
+        attachment: {
+          type: "text",
+          mimeType: "text/plain",
+          contextKind: "chat_history",
+          text: "Earlier context",
+        },
+        source,
+      }),
+    ).toEqual({
+      type: "text",
+      mimeType: "text/plain",
+      contextKind: "chat_history",
+      text: "Earlier context",
+      chatHistorySource: source,
+    });
+  });
+
   it("treats pull request context as a workspace attachment", () => {
     expect(isWorkspaceAttachment(contextAttachment())).toBe(true);
   });

packages/app/src/attachments/workspace-attachment-utils.ts

@@ -62,7 +62,12 @@ export function workspaceAttachmentToSubmitAttachment(
     };
   }
   if (attachment.kind === "chat_history") {
-    return attachment.attachment;
+    if (!attachment.source) return attachment.attachment;
+    const { serverId, agentId, title } = attachment.source;
+    return {
+      ...attachment.attachment,
+      chatHistorySource: { serverId, agentId, ...(title ? { title } : {}) },
+    };
   }
   return attachment.kind === "review" ? attachment.attachment : null;
 }

packages/app/src/attachments/workspace-attachments-store.ts

@@ -178,6 +178,19 @@ export function useWorkspaceAttachmentScopeKey(input: WorkspaceAttachmentScope):
   }, [cwd, draftId, isDraftScope, serverId, workspaceId]);
 }
 
+export function useAgentAttachmentScopeKey(input: { serverId: string; agentId: string }): string {
+  const { serverId, agentId } = input;
+  return useMemo(
+    () =>
+      [
+        "agent-attachments",
+        `server=${encodeScopePart(serverId)}`,
+        `agent=${encodeScopePart(agentId)}`,
+      ].join(":"),
+    [serverId, agentId],
+  );
+}
+
 export function useDraftWorkspaceAttachmentScopeKey(draftId: string | null | undefined): string {
   const normalizedDraftId = useMemo(() => draftId?.trim() ?? "", [draftId]);
   return useMemo(

packages/app/src/components/message.tsx

@@ -1,3 +1,4 @@
+import { ChatHistoryAttachment } from "@/attachments/chat-history";
 import { useDisclosureHold } from "@/agent-stream/disclosure";
 import { MessagePreview, MessageSender } from "@/components/user-message";
 import { useStableEvent } from "@/hooks/use-stable-event";
@@ -33,7 +34,10 @@ import { useTargetAgentTitle } from "@/tool-calls/use-target-agent-title";
 import type { DaemonClient } from "@getpaseo/client/internal/daemon-client";
 import type { AgentMessage } from "@getpaseo/protocol/agent-message";
 import type { AgentCapabilityFlags, ToolCallDetail } from "@getpaseo/protocol/agent-types";
-import type { AgentAttachment } from "@getpaseo/protocol/messages";
+import type {
+  AgentAttachment,
+  ChatHistoryAttachment as ChatHistorySnapshot,
+} from "@getpaseo/protocol/messages";
 import MaskedView from "@react-native-masked-view/masked-view";
 import {
   Check,
@@ -419,7 +423,12 @@ export const UserMessage = memo(function UserMessage({
   const hasText = message.trim().length > 0;
   const hasImages = images.length > 0;
   const hasAttachments = attachments.length > 0;
-  const showTrailingRow = !isPending && hasText && (isCompact || isNative || isHovered);
+  const chatHistory = attachments.find(
+    (attachment): attachment is ChatHistorySnapshot =>
+      attachment.type === "text" && attachment.contextKind === "chat_history",
+  );
+  const showTrailingRow =
+    !isPending && (hasText || Boolean(chatHistory)) && (isCompact || isNative || isHovered);
   const formattedTimestamp = useMemo(
     () => formatMessageTimestamp(new Date(timestamp)),
     [timestamp],
@@ -428,9 +437,12 @@ export const UserMessage = memo(function UserMessage({
 
   const handlePointerEnter = useCallback(() => setIsHovered(true), []);
   const handlePointerLeave = useCallback(() => setIsHovered(false), []);
-  const getMessageContent = useCallback(() => message, [message]);
+  const getMessageContent = useCallback(
+    () => message || chatHistory?.text || "",
+    [message, chatHistory],
+  );
   const handleRewind = useCallback(
-    (input: { mode: RewindMode; rewoundText: string }) => {
+    (input: { mode: RewindMode; rewoundText: string; chatHistory?: ChatHistorySnapshot }) => {
       return rewindMutation.rewindAgent(input);
     },
     [rewindMutation],
@@ -496,11 +508,19 @@ export const UserMessage = memo(function UserMessage({
             {hasAttachments ? (
               <View style={attachmentPreviewContainerStyle}>
                 {attachments.map((attachment, index) => {
+                  const key = `${attachment.type}:${"number" in attachment ? attachment.number : index}`;
+                  if (attachment.type === "text" && attachment.contextKind === "chat_history") {
+                    return (
+                      <ChatHistoryAttachment
+                        key={key}
+                        attachment={attachment}
+                        testID="message-chat-history-attachment"
+                      />
+                    );
+                  }
                   const content = getAgentAttachmentPillContent(attachment, t);
                   return (
-                    <AttachmentFrame
-                      key={`${attachment.type}:${"number" in attachment ? attachment.number : index}`}
-                    >
+                    <AttachmentFrame key={key}>
                       <AttachmentLabel
                         icon={content.icon}
                         title={content.title}
@@ -518,7 +538,7 @@ export const UserMessage = memo(function UserMessage({
             ) : null}
           </MessagePreview>
         </View>
-        {hasText ? (
+        {hasText || chatHistory ? (
           <View
             style={trailingRowStyle}
             pointerEvents={showTrailingRow ? "auto" : "none"}
@@ -532,6 +552,7 @@ export const UserMessage = memo(function UserMessage({
                 capabilities={capabilities}
                 isPending={rewindMutation.isPending}
                 rewoundText={message}
+                chatHistory={chatHistory}
                 onRewind={handleRewind}
               />
             ) : null}

packages/app/src/components/rewind/composer-restore.test.ts

@@ -1,27 +1,45 @@
 import { describe, expect, test } from "vitest";
-import { restoreComposerTextIfEmpty } from "./composer-restore";
+import { restoreComposerPromptIfEmpty } from "./composer-restore";
 import { shouldRestoreComposerForRewindMode } from "./rewind-mode";
 
-describe("restoreComposerTextIfEmpty", () => {
+describe("restoreComposerPromptIfEmpty", () => {
   test("restores the rewound message when the composer is empty", () => {
     expect(
-      restoreComposerTextIfEmpty({
+      restoreComposerPromptIfEmpty({
         currentText: "",
-        rewoundText: "message before rewind",
+        rewoundPrompt: { text: "message before rewind" },
       }),
-    ).toBe("message before rewind");
+    ).toEqual({ text: "message before rewind" });
   });
 
   test("preserves an existing composer draft", () => {
     expect(
-      restoreComposerTextIfEmpty({
+      restoreComposerPromptIfEmpty({
         currentText: "keep this draft",
-        rewoundText: "message before rewind",
+        rewoundPrompt: { text: "message before rewind" },
       }),
-    ).toBe("keep this draft");
+    ).toEqual({ text: "keep this draft" });
   });
 });
 
+test.each(["", "Continue here"])("restores inherited history with rewound prompt %s", (text) => {
+  const chatHistory = {
+    type: "text",
+    mimeType: "text/plain",
+    contextKind: "chat_history",
+    text: "Earlier context",
+  } as const;
+  expect(
+    restoreComposerPromptIfEmpty({ currentText: "", rewoundPrompt: { text, chatHistory } }),
+  ).toEqual({ text, chatHistory });
+  expect(
+    restoreComposerPromptIfEmpty({
+      currentText: "Existing draft",
+      rewoundPrompt: { text, chatHistory },
+    }),
+  ).toEqual({ text: "Existing draft" });
+});
+
 describe("shouldRestoreComposerForRewindMode", () => {
   test("restores only conversation-mutating rewind modes", () => {
     expect(shouldRestoreComposerForRewindMode("conversation")).toBe(true);

packages/app/src/components/rewind/composer-restore.tsx

@@ -1,11 +1,14 @@
+import type { ChatHistoryAttachment } from "@getpaseo/protocol/messages";
+import { restoreChatHistoryAttachment } from "@/attachments/chat-history";
 import type { ComposerTextSource } from "@/composer/text-source";
 import { createContext, useCallback, useContext, useMemo, type ReactNode } from "react";
 
 interface RewindComposerRestoreContextValue {
-  completeRewind: (text: string) => void;
+  completeRewind: (prompt: { text: string; chatHistory?: ChatHistoryAttachment }) => void;
 }
 
 interface RewindComposerRestoreProviderProps {
+  attachmentScopeKey: string;
   textSource: ComposerTextSource;
   setText: (text: string) => void;
   onRewindComplete: () => void;
@@ -14,35 +17,34 @@ interface RewindComposerRestoreProviderProps {
 
 const RewindComposerRestoreContext = createContext<RewindComposerRestoreContextValue | null>(null);
 
-export function restoreComposerTextIfEmpty(input: {
+export function restoreComposerPromptIfEmpty(input: {
   currentText: string;
-  rewoundText: string;
-}): string {
-  if (input.currentText.length > 0) {
-    return input.currentText;
-  }
-  return input.rewoundText;
+  rewoundPrompt: { text: string; chatHistory?: ChatHistoryAttachment };
+}): { text: string; chatHistory?: ChatHistoryAttachment } {
+  if (input.currentText.length > 0) return { text: input.currentText };
+  return input.rewoundPrompt;
 }
 
 export function RewindComposerRestoreProvider({
+  attachmentScopeKey,
   textSource,
   setText,
   onRewindComplete,
   children,
 }: RewindComposerRestoreProviderProps) {
   const completeRewind = useCallback(
-    (rewoundText: string) => {
+    (prompt: { text: string; chatHistory?: ChatHistoryAttachment }) => {
       const currentText = textSource.getSnapshot();
-      const nextText = restoreComposerTextIfEmpty({
-        currentText: currentText,
-        rewoundText,
-      });
-      if (nextText !== currentText) {
-        setText(nextText);
+      const restored = restoreComposerPromptIfEmpty({ currentText, rewoundPrompt: prompt });
+      if (restored.chatHistory) {
+        restoreChatHistoryAttachment(attachmentScopeKey, restored.chatHistory);
+      }
+      if (restored.text !== currentText) {
+        setText(restored.text);
       }
       onRewindComplete();
     },
-    [onRewindComplete, setText, textSource],
+    [attachmentScopeKey, onRewindComplete, setText, textSource],
   );
 
   const value = useMemo(() => ({ completeRewind }), [completeRewind]);

packages/app/src/components/rewind/rewind-menu.tsx

@@ -1,3 +1,4 @@
+import type { ChatHistoryAttachment } from "@getpaseo/protocol/messages";
 import { memo, useCallback, useMemo, useState, type ReactElement } from "react";
 import { useTranslation } from "react-i18next";
 import { Text, View } from "react-native";
@@ -19,7 +20,12 @@ export type { RewindMode };
 interface RewindMenuProps {
   capabilities: AgentCapabilityFlags;
   rewoundText: string;
-  onRewind: (input: { mode: RewindMode; rewoundText: string }) => Promise<void> | void;
+  chatHistory?: ChatHistoryAttachment;
+  onRewind: (input: {
+    mode: RewindMode;
+    rewoundText: string;
+    chatHistory?: ChatHistoryAttachment;
+  }) => Promise<void> | void;
   isPending?: boolean;
   testID?: string;
 }
@@ -38,6 +44,7 @@ function getIcon(mode: RewindMode, color: string): ReactElement {
 export const RewindMenu = memo(function RewindMenu({
   capabilities,
   rewoundText,
+  chatHistory,
   onRewind,
   isPending: isPendingProp = false,
   testID = "rewind-menu",
@@ -70,7 +77,7 @@ export const RewindMenu = memo(function RewindMenu({
       if (isLocked) return;
       setPendingMode(mode);
       try {
-        await onRewind({ mode, rewoundText });
+        await onRewind({ mode, rewoundText, chatHistory });
       } catch {
         // useRewindAgentMutation owns the toast; the menu only owns flow state.
       } finally {
@@ -78,7 +85,7 @@ export const RewindMenu = memo(function RewindMenu({
         setIsOpen(false);
       }
     },
-    [isLocked, onRewind, rewoundText],
+    [isLocked, onRewind, rewoundText, chatHistory],
   );
 
   const triggerStyle = useCallback(

packages/app/src/components/rewind/use-rewind-agent-mutation.ts

@@ -1,3 +1,4 @@
+import type { ChatHistoryAttachment } from "@getpaseo/protocol/messages";
 import { planTimelineTailFetch } from "@/timeline/timeline-sync-plan";
 import { useCallback } from "react";
 import { useTranslation } from "react-i18next";
@@ -20,6 +21,7 @@ interface UseRewindAgentMutationInput {
 interface RewindAgentInput {
   mode: RewindMode;
   rewoundText: string;
+  chatHistory?: ChatHistoryAttachment;
 }
 
 export function useRewindAgentMutation(input: UseRewindAgentMutationInput): {
@@ -52,7 +54,10 @@ export function useRewindAgentMutation(input: UseRewindAgentMutationInput): {
       if (!shouldRestoreComposerForRewindMode(variables.mode)) {
         return;
       }
-      composerRestore?.completeRewind(variables.rewoundText);
+      composerRestore?.completeRewind({
+        text: variables.rewoundText,
+        chatHistory: variables.chatHistory,
+      });
     },
     onError: (error) => {
       toast.error(error instanceof Error ? error.message : t("rewind.errors.failed"));

packages/app/src/composer/attachments/workspace.tsx

@@ -1,3 +1,4 @@
+import { ChatHistoryAttachment } from "@/attachments/chat-history";
 import { useCallback, useEffect, useMemo, useState, type ReactElement } from "react";
 import { useTranslation } from "react-i18next";
 import type {
@@ -255,12 +256,28 @@ function WorkspaceAttachmentPill({
 }: WorkspaceAttachmentPillProps) {
   const { t } = useTranslation();
   const content = getWorkspaceAttachmentPillContent(attachment, t);
+  const chatHistory = useMemo(() => {
+    if (attachment.kind !== "chat_history") return null;
+    if (!attachment.source) return attachment.attachment;
+    const { serverId, agentId, title } = attachment.source;
+    return { ...attachment.attachment, chatHistorySource: { serverId, agentId, title } };
+  }, [attachment]);
   const handleOpen = useCallback(() => {
     onOpen(attachment);
   }, [onOpen, attachment]);
   const handleRemove = useCallback(() => {
     onRemove(index);
   }, [onRemove, index]);
+  if (chatHistory) {
+    return (
+      <ChatHistoryAttachment
+        attachment={chatHistory}
+        onRemove={handleRemove}
+        disabled={disabled}
+        testID={getPillTestID(attachment)}
+      />
+    );
+  }
   return (
     <AttachmentPill
       testID={getPillTestID(attachment)}

packages/app/src/composer/draft/create-flow.test.ts

@@ -242,10 +242,10 @@ describe("useDraftAgentCreateFlow", () => {
     expect(createRequest).toHaveBeenCalledWith({
       attempt: expect.objectContaining({
         text: "",
-        attachments: [attachment.attachment],
+        attachments: [{ ...attachment.attachment, chatHistorySource: attachment.source }],
       }),
       text: "",
-      attachments: [attachment.attachment],
+      attachments: [{ ...attachment.attachment, chatHistorySource: attachment.source }],
       cwd: "/repo",
     });
     expect(onCreateSuccess).toHaveBeenCalledTimes(1);

packages/app/src/hooks/use-fork-agent.ts

@@ -68,6 +68,7 @@ export interface UseForkAgentInput {
 
 function buildChatHistoryAttachment(input: {
   draftId: string;
+  title: string | null;
   serverId: string;
   agentId: string;
   payload: Awaited<ReturnType<DaemonClient["buildAgentForkContext"]>>;
@@ -83,6 +84,7 @@ function buildChatHistoryAttachment(input: {
     source: {
       serverId: input.serverId,
       agentId: input.agentId,
+      ...(input.title ? { title: input.title } : {}),
       boundaryMessageId: input.payload.boundaryMessageId,
       boundaryCursor: input.payload.boundaryCursor,
       itemCount: input.payload.itemCount,
@@ -147,6 +149,7 @@ export function useForkAgent(
         const payload = await client.buildAgentForkContext(agentId, boundary);
         const attachment = buildChatHistoryAttachment({
           draftId,
+          title: useSessionStore.getState().sessions[serverId]?.agents.get(agentId)?.title ?? null,
           serverId,
           agentId,
           payload,

packages/app/src/i18n/resources/ar.ts

@@ -342,6 +342,14 @@ export const ar: TranslationResources = {
       openFile: "افتح الملف",
       copied: "منقول",
     },
+    chatHistory: {
+      title: "سجل المحادثة",
+      previousConversation: "المحادثة السابقة",
+      open: "فتح مرفق سجل المحادثة",
+      remove: "إزالة مرفق سجل المحادثة",
+      openSource: "فتح المحادثة الأصلية",
+      description: "السياق المنسوخ عند تفريع هذه المحادثة.",
+    },
     attachments: {
       dismissImage: "تجاهل الصورة",
       closeImage: "إغلاق الصورة",

packages/app/src/i18n/resources/en.ts

@@ -339,6 +339,14 @@ export const en = {
       openFile: "Open file",
       copied: "Copied",
     },
+    chatHistory: {
+      title: "Chat history",
+      previousConversation: "Previous conversation",
+      open: "Open chat history attachment",
+      remove: "Remove chat history attachment",
+      openSource: "Open source chat",
+      description: "Context copied when this chat was forked.",
+    },
     attachments: {
       dismissImage: "Dismiss image",
       closeImage: "Close image",

packages/app/src/i18n/resources/es.ts

@@ -347,6 +347,14 @@ export const es: TranslationResources = {
       openFile: "Abrir archivo",
       copied: "Copiado",
     },
+    chatHistory: {
+      title: "Historial del chat",
+      previousConversation: "Conversación anterior",
+      open: "Abrir el historial adjunto",
+      remove: "Quitar el historial adjunto",
+      openSource: "Abrir el chat de origen",
+      description: "Contexto copiado al bifurcar este chat.",
+    },
     attachments: {
       dismissImage: "Descartar imagen",
       closeImage: "Cerrar imagen",

packages/app/src/i18n/resources/fr.ts

@@ -347,6 +347,14 @@ export const fr: TranslationResources = {
       openFile: "Ouvrir le fichier",
       copied: "Copié",
     },
+    chatHistory: {
+      title: "Historique du chat",
+      previousConversation: "Conversation précédente",
+      open: "Ouvrir l’historique joint",
+      remove: "Retirer l’historique joint",
+      openSource: "Ouvrir le chat d’origine",
+      description: "Contexte copié lors de la bifurcation de ce chat.",
+    },
     attachments: {
       dismissImage: "Ignorer l’image",
       closeImage: "Fermer l’image",

packages/app/src/i18n/resources/ja.ts

@@ -347,6 +347,14 @@ export const ja: TranslationResources = {
       openFile: "ファイルを開く",
       copied: "コピーしました",
     },
+    chatHistory: {
+      title: "チャット履歴",
+      previousConversation: "以前の会話",
+      open: "チャット履歴の添付を開く",
+      remove: "チャット履歴の添付を削除",
+      openSource: "元のチャットを開く",
+      description: "このチャットを分岐した時点でコピーされたコンテキストです。",
+    },
     attachments: {
       dismissImage: "画像を閉じる",
       closeImage: "画像を閉じる",

packages/app/src/i18n/resources/ko.ts

@@ -343,6 +343,14 @@ export const ko: TranslationResources = {
       openFile: "파일 열기",
       copied: "복사됨",
     },
+    chatHistory: {
+      title: "채팅 기록",
+      previousConversation: "이전 대화",
+      open: "채팅 기록 첨부 열기",
+      remove: "채팅 기록 첨부 제거",
+      openSource: "원본 채팅 열기",
+      description: "이 채팅을 분기할 때 복사된 컨텍스트입니다.",
+    },
     attachments: {
       dismissImage: "이미지 닫기",
       closeImage: "이미지 닫기",

packages/app/src/i18n/resources/pt-BR.ts

@@ -346,6 +346,14 @@ export const ptBR: TranslationResources = {
       openFile: "Abrir arquivo",
       copied: "Copiado",
     },
+    chatHistory: {
+      title: "Histórico do chat",
+      previousConversation: "Conversa anterior",
+      open: "Abrir histórico anexado",
+      remove: "Remover histórico anexado",
+      openSource: "Abrir chat de origem",
+      description: "Contexto copiado ao ramificar este chat.",
+    },
     attachments: {
       dismissImage: "Dispensar imagem",
       closeImage: "Fechar imagem",

packages/app/src/i18n/resources/ru.ts

@@ -346,6 +346,14 @@ export const ru: TranslationResources = {
       openFile: "Открыть файл",
       copied: "Скопировано",
     },
+    chatHistory: {
+      title: "История чата",
+      previousConversation: "Предыдущий разговор",
+      open: "Открыть вложенную историю чата",
+      remove: "Удалить вложенную историю чата",
+      openSource: "Открыть исходный чат",
+      description: "Контекст, скопированный при создании этой ветки чата.",
+    },
     attachments: {
       dismissImage: "Закрыть изображение",
       closeImage: "Закрыть изображение",

packages/app/src/i18n/resources/zh-CN.ts

@@ -342,6 +342,14 @@ export const zhCN: TranslationResources = {
       openFile: "打开文件",
       copied: "已复制",
     },
+    chatHistory: {
+      title: "聊天历史",
+      previousConversation: "之前的对话",
+      open: "打开聊天历史附件",
+      remove: "移除聊天历史附件",
+      openSource: "打开来源对话",
+      description: "创建此分叉时复制的上下文。",
+    },
     attachments: {
       dismissImage: "关闭图片",
       closeImage: "关闭图片",

packages/app/src/panels/agent-panel.tsx

@@ -43,7 +43,10 @@ import { RewindComposerRestoreProvider } from "@/components/rewind/composer-rest
 import { useAgentDescriptor } from "@/agent-presentation";
 import { useToastHost, type ToastApi, type ToastState } from "@/components/toast-host";
 import type { WorkspaceComposerAttachment } from "@/attachments/types";
-import { useWorkspaceAttachmentScopeKey } from "@/attachments/workspace-attachments-store";
+import {
+  useWorkspaceAttachmentScopeKey,
+  useAgentAttachmentScopeKey,
+} from "@/attachments/workspace-attachments-store";
 import { COMPACT_CONTENT_WIDTH, useIsCompactFormFactor } from "@/constants/layout";
 import { isNative, isWeb } from "@/constants/platform";
 import { useAgentAttentionClear } from "@/hooks/use-agent-attention-clear";
@@ -1112,6 +1115,7 @@ const ChatAgentReadyContent = memo(function ChatAgentReadyContent({
   const parentAgentId = useParentAgentId(serverId, agentId);
   // With a composer the parent is a pill above it; without one, the box takes the composer's place.
   const parentPillAgentId = showsComposer ? parentAgentId : null;
+  const rewindAttachmentScopeKey = useAgentAttachmentScopeKey({ serverId, agentId });
   const rawAgentInputDraft = useAgentInputDraft({
     draftKey: buildDraftStoreKey({
       serverId,
@@ -1245,6 +1249,7 @@ const ChatAgentReadyContent = memo(function ChatAgentReadyContent({
 
   const content = (
     <RewindComposerRestoreProvider
+      attachmentScopeKey={rewindAttachmentScopeKey}
       textSource={agentInputDraft.textSource}
       setText={agentInputDraft.replaceText}
       onRewindComplete={handleRewindComplete}
@@ -1541,9 +1546,10 @@ function ActiveAgentComposer({
     cwd,
     workspaceId,
   });
+  const agentAttachmentScopeKey = useAgentAttachmentScopeKey({ serverId, agentId });
   const attachmentScopeKeys = useMemo(
-    () => [workspaceAttachmentScopeKey],
-    [workspaceAttachmentScopeKey],
+    () => [workspaceAttachmentScopeKey, agentAttachmentScopeKey],
+    [workspaceAttachmentScopeKey, agentAttachmentScopeKey],
   );
   const handleOpenWorkspaceAttachment = useCallback(
     (attachment: WorkspaceComposerAttachment) => {

packages/app/src/types/stream.test.ts

@@ -9,6 +9,7 @@ import {
   hydrateStreamState,
   mergeToolCallDetail,
   reduceStreamUpdate,
+  replaceWithCanonicalStream,
   streamTimelineItemIdentity,
   type AgentToolCallItem,
   type StreamItem,
@@ -158,6 +159,104 @@ describe("plugin timeline rows", () => {
 });
 
 describe("user message identity", () => {
+  it.each(["", "Continue here"])(
+    "restores fork history onto a cached user message (%s)",
+    (text) => {
+      const cached = createUserMessage({
+        clientMessageId: "fork-client",
+        messageId: "fork-provider",
+        text,
+        timestamp: new Date(0),
+        timelineCursor: { epoch: "timeline", seq: 1 },
+      });
+      const history = {
+        type: "text",
+        mimeType: "text/plain",
+        contextKind: "chat_history",
+        text: "[User] Earlier question\n[Assistant] Earlier answer",
+      } as const;
+      const canonical = createUserMessage({
+        ...cached,
+        attachments: [history],
+      });
+      const result = replaceWithCanonicalStream({
+        canonical: [canonical],
+        previousTail: [cached],
+        previousHead: [],
+        sendingClientMessageIds: [],
+        preserveContinuity: true,
+        canonicalCoverage: { epoch: "timeline", endSeq: 1 },
+      });
+      expect(result.tail).toHaveLength(1);
+      expect(result.tail[0]).toMatchObject({ text, attachments: [history] });
+    },
+  );
+
+  it.each(["", "Continue from here"])(
+    "hydrates fork history without optimistic state: %s",
+    (text) => {
+      const chatHistory = {
+        type: "text",
+        mimeType: "text/plain",
+        contextKind: "chat_history",
+        text: "[User] Earlier question\n[Assistant] Earlier answer",
+        chatHistorySource: { serverId: "source-host", agentId: "source-agent", title: "Original" },
+      } as const;
+      const result = reduceStreamUpdate(
+        [],
+        {
+          type: "timeline",
+          provider: "codex",
+          item: { type: "user_message", text, messageId: "fork-prompt", chatHistory },
+        },
+        new Date(0),
+      );
+      expect(result).toHaveLength(1);
+      expect(result[0]).toMatchObject({ kind: "user_message", text, attachments: [chatHistory] });
+    },
+  );
+
+  it.each([
+    { text: "", insert: "tail" },
+    { text: "Continue", insert: "tail" },
+    { text: "", insert: "head" },
+    { text: "Continue", insert: "head" },
+  ] as const)("delivers fork history to a live viewer ($insert, $text)", ({ text, insert }) => {
+    const chatHistory = {
+      type: "text",
+      mimeType: "text/plain",
+      contextKind: "chat_history",
+      text: "[User] Original question",
+      chatHistorySource: { serverId: "source-host", agentId: "source-agent" },
+    } as const;
+    const event = {
+      type: "timeline",
+      provider: "codex",
+      item: { type: "user_message", text, messageId: "fork-message", chatHistory },
+    } as const;
+    const first = applyStreamEvent({
+      tail: [],
+      head: [],
+      event,
+      timestamp: new Date(0),
+      unmatchedUserMessageInsert: insert,
+    });
+    expect(first[insert]).toHaveLength(1);
+    expect(first[insert][0]).toMatchObject({
+      kind: "user_message",
+      text,
+      attachments: [chatHistory],
+    });
+    const repeated = applyStreamEvent({
+      ...first,
+      event,
+      timestamp: new Date(0),
+      unmatchedUserMessageInsert: insert,
+    });
+    expect([...repeated.tail, ...repeated.head]).toHaveLength(1);
+    expect([...repeated.tail, ...repeated.head][0]).toMatchObject({ attachments: [chatHistory] });
+  });
+
   it("replaces provisional optimistic turn membership with canonical membership", () => {
     const optimistic = createUserMessage({
       clientMessageId: "hello-client",

packages/app/src/types/stream.ts

@@ -263,6 +263,7 @@ function produceUserMessage(
     clientMessageId: incoming.clientMessageId ?? existing.clientMessageId,
     messageId: incoming.messageId ?? existing.messageId,
     timelineCursor: incoming.timelineCursor ?? existing.timelineCursor,
+    attachments: presentation.attachments ?? incoming.attachments,
   });
   if (
     existing.id === merged.id &&
@@ -891,6 +892,18 @@ export function handoffCreatedAgentUserMessageToStream(params: {
   });
 }
 
+function normalizeUserMessageContent(
+  text: string,
+  chatHistory?: Extract<AgentTimelineItem, { type: "user_message" }>["chatHistory"],
+) {
+  const normalized = normalizeChunk(text);
+  return {
+    ...normalized,
+    hasContent: normalized.hasContent || chatHistory !== undefined,
+    attachments: chatHistory ? [chatHistory] : undefined,
+  };
+}
+
 function appendUserMessage(
   state: StreamItem[],
   text: string,
@@ -900,8 +913,9 @@ function appendUserMessage(
   clientMessageId?: string,
   timelineCursor?: TimelinePosition,
   turnId?: string,
+  chatHistory?: Extract<AgentTimelineItem, { type: "user_message" }>["chatHistory"],
 ): StreamItem[] {
-  const { chunk, hasContent } = normalizeChunk(text);
+  const { chunk, hasContent, attachments } = normalizeUserMessageContent(text, chatHistory);
   if (!hasContent) {
     return state;
   }
@@ -914,6 +928,7 @@ function appendUserMessage(
     timelineCursor,
     turnId,
     text: chunk,
+    attachments,
     timestamp,
   });
   return upsertUserMessage(state, nextItem);
@@ -1523,6 +1538,7 @@ function reduceTimelineEvent(
         item.clientMessageId,
         timelineCursor,
         event.turnId,
+        item.chatHistory,
       );
     case "assistant_message":
       return appendAssistantMessage(
@@ -1874,7 +1890,7 @@ function applyCanonicalUserMessageEvent(params: {
 }): ApplyStreamEventResult | null {
   const { tail, head, event, timestamp, timelineCursor, unmatchedInsert = "tail" } = params;
   if (event.type !== "timeline" || event.item.type !== "user_message") return null;
-  const normalized = normalizeChunk(event.item.text);
+  const normalized = normalizeUserMessageContent(event.item.text, event.item.chatHistory);
 
   const flushedTail = head.length > 0 ? flushHeadToTail(tail, head) : tail;
   const flushedHead = head.length > 0 ? [] : head;
@@ -1887,6 +1903,7 @@ function applyCanonicalUserMessageEvent(params: {
     turnId: event.turnId,
     timelineCursor,
     text: normalized.chunk,
+    attachments: normalized.attachments,
     timestamp,
   });
   if (unmatchedInsert === "head") {

packages/protocol/src/agent-types.ts

@@ -1,5 +1,5 @@
 import type { AgentMessage } from "./agent-message.js";
-import type { AgentAttachment } from "./messages.js";
+import type { AgentAttachment, ChatHistoryAttachment } from "./messages.js";
 
 export type AgentProvider = string;
 
@@ -373,7 +373,13 @@ export interface AgentTaskItem {
 }
 
 export type AgentTimelineItem =
-  | { type: "user_message"; text: string; messageId?: string; clientMessageId?: string }
+  | {
+      type: "user_message";
+      text: string;
+      messageId?: string;
+      clientMessageId?: string;
+      chatHistory?: ChatHistoryAttachment;
+    }
   | { type: "assistant_message"; text: string; messageId?: string }
   | { type: "reasoning"; text: string }
   | ToolCallTimelineItem

packages/protocol/src/chat-history.ts

@@ -0,0 +1,9 @@
+/** Remove the fork prompt envelope while preserving the snapshot body verbatim. */
+export function extractChatHistoryBody(text: string): string {
+  const bodyStart = text.indexOf("\n\n");
+  return text.startsWith("<chat-history-summary>\n") &&
+    text.endsWith("\n</chat-history-summary>") &&
+    bodyStart !== -1
+    ? text.slice(bodyStart + 2, -"\n</chat-history-summary>".length)
+    : text;
+}

packages/protocol/src/messages.attachments.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 
 import {
+  AgentTimelineItemPayloadSchema,
   AgentForkContextRequestMessageSchema,
   AgentForkContextResponseMessageSchema,
   CreateAgentRequestMessageSchema,
@@ -9,6 +10,24 @@ import {
 } from "./messages.js";
 
 describe("shared messages attachments", () => {
+  it("round-trips fork history on a timeline row and accepts rows without it", () => {
+    const row = {
+      type: "user_message",
+      text: "",
+      messageId: "fork-prompt",
+      chatHistory: {
+        type: "text",
+        mimeType: "text/plain",
+        contextKind: "chat_history",
+        text: "Earlier context",
+        chatHistorySource: { serverId: "source-host", agentId: "source-agent", title: "Original" },
+      },
+    };
+    expect(AgentTimelineItemPayloadSchema.parse(row)).toEqual(row);
+    const legacy = { type: "user_message", text: "Earlier message" };
+    expect(AgentTimelineItemPayloadSchema.parse(legacy)).toEqual(legacy);
+  });
+
   it("preserves an optional timeline cursor on fork-context messages", () => {
     const boundaryCursor = { epoch: "timeline-1", seq: 42 };
     const request = AgentForkContextRequestMessageSchema.parse({
@@ -269,6 +288,29 @@ describe("shared messages attachments", () => {
     ]);
   });
 
+  it("preserves the source of a fork across message submission", () => {
+    const attachment = {
+      type: "text",
+      mimeType: "text/plain",
+      contextKind: "chat_history",
+      title: "Chat history",
+      text: "Earlier context",
+      chatHistorySource: {
+        serverId: "source-host",
+        agentId: "source-agent",
+        title: "Original conversation",
+      },
+    };
+    const parsed = SendAgentMessageRequestSchema.parse({
+      type: "send_agent_message_request",
+      requestId: "req-fork-source",
+      agentId: "fork-agent",
+      text: "Continue",
+      attachments: [attachment],
+    });
+    expect(parsed.attachments).toEqual([attachment]);
+  });
+
   it("keeps known text attachment context kinds and ignores future ones", () => {
     const parsed = SendAgentMessageRequestSchema.parse({
       type: "send_agent_message_request",

packages/protocol/src/messages.ts

@@ -712,6 +712,25 @@ const ToolCallTimelineItemPayloadSchema: z.ZodType<ToolCallTimelineItem, unknown
     ToolCallCanceledPayloadSchema,
   ]);
 
+export const ChatHistorySourceSchema = z.object({
+  serverId: z.string(),
+  agentId: z.string(),
+  title: z.string().optional(),
+});
+
+export type ChatHistorySource = z.infer<typeof ChatHistorySourceSchema>;
+
+export const ChatHistoryAttachmentSchema = z.object({
+  type: z.literal("text"),
+  mimeType: z.literal("text/plain"),
+  contextKind: z.literal("chat_history"),
+  title: z.string().nullable().optional(),
+  text: z.string(),
+  chatHistorySource: ChatHistorySourceSchema.optional(),
+});
+
+export type ChatHistoryAttachment = z.infer<typeof ChatHistoryAttachmentSchema>;
+
 // zod-aot 0.20.4 miscompiles this as a nested discriminated union by omitting
 // the inner tool_call branch from the generated outer dispatch.
 export const AgentTimelineItemPayloadSchema: z.ZodType<AgentTimelineItem, unknown> = z.union([
@@ -720,6 +739,7 @@ export const AgentTimelineItemPayloadSchema: z.ZodType<AgentTimelineItem, unknow
     text: z.string(),
     messageId: z.string().optional(),
     clientMessageId: z.string().optional(),
+    chatHistory: ChatHistoryAttachmentSchema.optional(),
   }),
   z.object({
     type: z.literal("assistant_message"),
@@ -1180,6 +1200,7 @@ export const TextAttachmentSchema = z
     title: z.string().nullable().optional(),
     text: z.string(),
     externalResource: ExternalResourceAttachmentMetadataSchema.optional(),
+    chatHistorySource: ChatHistorySourceSchema.optional(),
   })
   .transform(({ contextKind, ...attachment }) => ({
     ...attachment,

packages/server/src/server/agent/activity-curator.test.ts

@@ -572,3 +572,57 @@ it("preserves every message in fork history below the character budget", () => {
     `<chat-history-summary>\nChat history from a previous Paseo agent.\n\n[User] ${text}\n</chat-history-summary>`,
   );
 });
+
+it.each(["", "Continue in B"])("carries inherited history through repeated forks (%s)", (text) => {
+  const original = buildAgentForkContextAttachment({
+    rows: [
+      row(1, { type: "user_message", text: "Question in A" }),
+      row(2, { type: "assistant_message", text: "Answer in A" }),
+    ],
+  });
+  const child = buildAgentForkContextAttachment({
+    rows: [
+      row(1, {
+        type: "user_message",
+        text,
+        chatHistory: { ...original.attachment, contextKind: "chat_history" },
+      }),
+      row(2, { type: "assistant_message", text: "Answer in B" }),
+    ],
+  });
+  const grandchild = buildAgentForkContextAttachment({
+    rows: [
+      row(1, {
+        type: "user_message",
+        text: "Continue in C",
+        chatHistory: { ...child.attachment, contextKind: "chat_history" },
+      }),
+      row(2, { type: "assistant_message", text: "Answer in C" }),
+    ],
+  });
+  expect(grandchild.attachment.text).toContain("[User] Question in A\n[Assistant] Answer in A");
+  expect(grandchild.attachment.text).toContain("[Assistant] Answer in B");
+  expect(grandchild.attachment.text).toContain("[User] Continue in C\n[Assistant] Answer in C");
+  expect(grandchild.attachment.text.match(/<chat-history-summary>/g)).toHaveLength(1);
+});
+
+it("keeps the fork budget when inherited history exceeds the remaining space", () => {
+  const result = buildAgentForkContextAttachment({
+    rows: [
+      row(1, {
+        type: "user_message",
+        text: "Current question",
+        chatHistory: {
+          type: "text",
+          mimeType: "text/plain",
+          contextKind: "chat_history",
+          text: "Old ".repeat(30_000),
+        },
+      }),
+      row(2, { type: "assistant_message", text: "Latest answer" }),
+    ],
+  });
+  expect(result.attachment.text.length).toBeLessThanOrEqual(100_000);
+  expect(result.attachment.text).toContain("[Earlier chat history omitted]");
+  expect(result.attachment.text).toContain("[User] Current question\n[Assistant] Latest answer");
+});

packages/server/src/server/agent/activity-curator.ts

@@ -1,3 +1,4 @@
+import { extractChatHistoryBody } from "@getpaseo/protocol/chat-history";
 import type { AgentTimelineItem } from "./agent-sdk-types.js";
 import type { AgentMessage } from "@getpaseo/protocol/agent-message";
 import type { AgentAttachment } from "@getpaseo/protocol/messages";
@@ -21,6 +22,7 @@ const FORK_CONTEXT_KINDS: readonly AgentTimelineItem["type"][] = [
 ];
 
 interface ActivityCuratorOptions {
+  includeChatHistory?: boolean;
   maxItems?: number;
   labelAssistantMessages?: boolean;
   includeKinds?: readonly AgentTimelineItem["type"][];
@@ -37,6 +39,17 @@ function activityEntry(text: string): ActivityEntry {
   return { text };
 }
 
+function appendUserEntry(
+  entries: ActivityEntry[],
+  item: Extract<AgentTimelineItem, { type: "user_message" }>,
+  options?: ActivityCuratorOptions,
+) {
+  if (options?.includeChatHistory && item.chatHistory) {
+    entries.push(activityEntry(extractChatHistoryBody(item.chatHistory.text)));
+  }
+  entries.push(activityEntry(`[User] ${item.text.trim()}`));
+}
+
 function appendTextEntry(
   entries: ActivityEntry[],
   item: Extract<AgentTimelineItem, { type: "assistant_message" | "reasoning" }>,
@@ -158,7 +171,7 @@ function curateProjectedActivityEntries(
 
     switch (item.type) {
       case "user_message":
-        entries.push(activityEntry(`[User] ${item.text.trim()}`));
+        appendUserEntry(entries, item, options);
         break;
       case "assistant_message":
       case "reasoning":
@@ -361,6 +374,7 @@ export function buildAgentForkContextAttachment(input: {
   });
   const entries = curateProjectedActivityEntries(selected.items, {
     maxItems: 0,
+    includeChatHistory: true,
     labelAssistantMessages: true,
     includeKinds: FORK_CONTEXT_KINDS,
     includeExternalToolInput: false,

packages/server/src/server/agent/agent-manager.test.ts

@@ -729,6 +729,159 @@ test("uses an injected timeline store without making it a production requirement
   }
 });
 
+test.each([true, false])(
+  "fork history survives storage-backed replay (provider echo: %s)",
+  async (echo) => {
+    const workdir = mkdtempSync(join(tmpdir(), "agent-manager-fork-history-"));
+    const storagePath = join(workdir, "agents");
+    const attachment = {
+      type: "text",
+      mimeType: "text/plain",
+      contextKind: "chat_history",
+      text: "<chat-history-summary>\nChat history from a previous Paseo agent.\n\n[User] Original question\n[Assistant] Original answer\n</chat-history-summary>",
+      chatHistorySource: { serverId: "source-host", agentId: "source-agent", title: "Original" },
+    } as const;
+    const clientMessageId = "fork-prompt";
+    let hasHistory = false;
+    let includeFork = true;
+    class HistorySession extends TestAgentSession {
+      override async startTurn(): Promise<{ turnId: string }> {
+        hasHistory = true;
+        if (echo)
+          this.pushEvent({
+            type: "timeline",
+            provider: "codex",
+            item: {
+              type: "user_message",
+              text: attachment.text,
+              messageId: "native-fork",
+              clientMessageId,
+            },
+          });
+        return super.startTurn();
+      }
+      override async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
+        if (!hasHistory) return;
+        if (includeFork)
+          yield {
+            type: "timeline",
+            provider: "codex",
+            item: { type: "user_message", text: attachment.text, messageId: "native-fork" },
+          };
+        yield {
+          type: "timeline",
+          provider: "codex",
+          item: { type: "user_message", text: attachment.text, messageId: "native-later" },
+        };
+      }
+    }
+    class HistoryClient extends TestAgentClient {
+      override async createSession(config: AgentSessionConfig): Promise<AgentSession> {
+        return new HistorySession(config);
+      }
+      override async resumeSession(): Promise<AgentSession> {
+        return new HistorySession({ provider: "codex", cwd: workdir });
+      }
+    }
+    const client = new HistoryClient();
+    let storage = new AgentStorage(storagePath, logger);
+    let manager = new AgentManager({ clients: { codex: client }, registry: storage, logger });
+    const agent = await manager.createAgent({ provider: "codex", cwd: workdir }, undefined, {
+      workspaceId: undefined,
+    });
+    onTestFinished(async () => {
+      await manager.closeAgent(agent.id);
+      await manager.flush();
+      rmSync(workdir, { recursive: true, force: true });
+    });
+    await drainAsyncGenerator(manager.streamAgent(agent.id, [attachment], { clientMessageId }));
+    expect((await manager.getTimelineRows(agent.id))[0]?.item).toMatchObject({
+      type: "user_message",
+      text: "",
+      chatHistory: attachment,
+    });
+    await manager.closeAgent(agent.id);
+    await manager.flush();
+
+    storage = new AgentStorage(storagePath, logger);
+    manager = new AgentManager({ clients: { codex: client }, registry: storage, logger });
+    await ensureAgentLoaded(agent.id, { agentManager: manager, agentStorage: storage, logger });
+    await manager.hydrateTimelineFromProvider(agent.id);
+    expect((await manager.getTimelineRows(agent.id)).map((row) => row.item)).toEqual([
+      { type: "user_message", text: "", messageId: "native-fork", chatHistory: attachment },
+      { type: "user_message", text: attachment.text, messageId: "native-later" },
+    ]);
+    // A provider rewind must not recreate a removed fork prompt.
+    includeFork = false;
+    await manager.hydrateTimelineFromProvider(agent.id, { force: true });
+    expect((await manager.getTimelineRows(agent.id)).map((row) => row.item)).toEqual([
+      { type: "user_message", text: attachment.text, messageId: "native-later" },
+    ]);
+  },
+);
+
+test.each([undefined, "native-replay-id"])(
+  "restores fork history after a local submission echo and replay ID %s",
+  async (replayId) => {
+    const workdir = mkdtempSync(join(tmpdir(), "fork-local-echo-"));
+    const clientMessageId = "local-fork-prompt";
+    const attachment = {
+      type: "text",
+      mimeType: "text/plain",
+      contextKind: "chat_history",
+      text: "[User] Original question",
+    } as const;
+    class LocalEchoSession extends TestAgentSession {
+      override async startTurn(): Promise<{ turnId: string }> {
+        this.pushEvent({
+          type: "timeline",
+          provider: "codex",
+          item: {
+            type: "user_message",
+            text: attachment.text,
+            messageId: clientMessageId,
+            clientMessageId,
+          },
+        });
+        return super.startTurn();
+      }
+      override async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
+        yield {
+          type: "timeline",
+          provider: "codex",
+          item: {
+            type: "user_message",
+            text: attachment.text,
+            ...(replayId ? { messageId: replayId } : {}),
+          },
+        };
+      }
+    }
+    class LocalEchoClient extends TestAgentClient {
+      override async createSession(config: AgentSessionConfig): Promise<AgentSession> {
+        return new LocalEchoSession(config);
+      }
+    }
+    const manager = new AgentManager({ clients: { codex: new LocalEchoClient() }, logger });
+    const agent = await manager.createAgent({ provider: "codex", cwd: workdir }, undefined, {
+      workspaceId: undefined,
+    });
+    try {
+      await drainAsyncGenerator(manager.streamAgent(agent.id, [attachment], { clientMessageId }));
+      await manager.hydrateTimelineFromProvider(agent.id, { force: true });
+      expect((await manager.getTimelineRows(agent.id))[0]?.item).toMatchObject({
+        type: "user_message",
+        text: "",
+        chatHistory: attachment,
+      });
+    } finally {
+      await manager.closeAgent(agent.id);
+      await manager.flush();
+      rmSync(workdir, { recursive: true, force: true });
+    }
+  },
+);
+
 test("refreshing an agent replaces the injected timeline store instead of appending a second copy", async () => {
   const workdir = mkdtempSync(join(tmpdir(), "agent-manager-timeline-rehydrate-"));
   const store = new RecordingTimelineStore();

packages/server/src/server/agent/agent-manager.ts

@@ -441,6 +441,7 @@ interface HandleStreamEventOptions {
 }
 
 interface ManagedAgentBase {
+  forkContext?: StoredAgentRecord["forkContext"];
   id: string;
   provider: AgentProvider;
   cwd: string;
@@ -2701,11 +2702,15 @@ export class AgentManager {
       if (event.type === "timeline") {
         this.touchUpdatedAt(agent);
         const row = this.recordTimeline(agent.id, event.item);
-        this.dispatchStream(agent.id, event, {
-          seq: row.seq,
-          epoch: this.timelineStore.getEpoch(agent.id),
-          timestamp: row.timestamp,
-        });
+        this.dispatchStream(
+          agent.id,
+          { ...event, item: row.item },
+          {
+            seq: row.seq,
+            epoch: this.timelineStore.getEpoch(agent.id),
+            timestamp: row.timestamp,
+          },
+        );
         return;
       }
       this.dispatchStream(agent.id, event, { timestamp: new Date().toISOString() });
@@ -3919,6 +3924,8 @@ export class AgentManager {
         options,
       });
 
+      await this.restoreForkContext(managed);
+
       // Read history before publishing the agent: a provider failure must leave the
       // session unregistered so the registration catch closes it.
       const startupHistory: AgentStreamEvent[] = [];
@@ -4491,11 +4498,15 @@ export class AgentManager {
         event.timestamp ? { timestamp: event.timestamp } : undefined,
       );
       if (broadcastTimeline) {
-        this.dispatchStream(agent.id, event, {
-          seq: row.seq,
-          epoch: this.timelineStore.getEpoch(agent.id),
-          timestamp: row.timestamp,
-        });
+        this.dispatchStream(
+          agent.id,
+          { ...event, item: row.item },
+          {
+            seq: row.seq,
+            epoch: this.timelineStore.getEpoch(agent.id),
+            timestamp: row.timestamp,
+          },
+        );
       }
     }
     this.touchUpdatedAt(agent);
@@ -4560,13 +4571,17 @@ export class AgentManager {
         event.timestamp ? { timestamp: event.timestamp } : undefined,
       );
       if (deferredBroadcast) {
-        timelineEvents.push({ event, row });
+        timelineEvents.push({ event: { ...event, item: row.item }, row });
       } else if (broadcast) {
-        this.dispatchStream(agent.id, event, {
-          seq: row.seq,
-          epoch: this.timelineStore.getEpoch(agent.id),
-          timestamp: row.timestamp,
-        });
+        this.dispatchStream(
+          agent.id,
+          { ...event, item: row.item },
+          {
+            seq: row.seq,
+            epoch: this.timelineStore.getEpoch(agent.id),
+            timestamp: row.timestamp,
+          },
+        );
       }
     }
     agent.historyPrimed = true;
@@ -5101,7 +5116,7 @@ export class AgentManager {
     const row = this.recordTimeline(agentId, item, { ...options, turnId });
     const event: AgentStreamEvent = {
       type: "timeline",
-      item,
+      item: row.item,
       provider,
       ...(turnId !== undefined ? { turnId } : {}),
     };
@@ -5133,9 +5148,25 @@ export class AgentManager {
     outcome: "accepted" | "rejected",
     options?: { messageId?: string; providerMessageId?: string; turnId?: string },
   ): void {
+    const text = submittedPromptText(prompt);
+    if (typeof prompt !== "string") {
+      const attachment = prompt.find(
+        (block) =>
+          block.type === "text" && "contextKind" in block && block.contextKind === "chat_history",
+      );
+      if (attachment?.type === "text" && "mimeType" in attachment) {
+        agent.forkContext = {
+          clientMessageId,
+          providerMessageId:
+            options?.providerMessageId !== clientMessageId ? options?.providerMessageId : undefined,
+          text,
+          attachment: { ...attachment, contextKind: "chat_history" },
+        };
+      }
+    }
     const items = projectAgentMessages({
       type: "user_message",
-      text: submittedPromptText(prompt),
+      text,
       clientMessageId,
       ...(options?.messageId ? { messageId: options.messageId } : {}),
     });
@@ -5183,6 +5214,10 @@ export class AgentManager {
     }
     if (!existing || existing.item.type !== "user_message") return null;
     if (messageId) {
+      if (agent.forkContext?.clientMessageId === clientMessageId && messageId !== clientMessageId) {
+        agent.forkContext.providerMessageId = messageId;
+        this.enqueueBackgroundPersist(agent);
+      }
       const enriched = this.timelineStore.enrichSubmittedUserMessage(
         agent.id,
         clientMessageId,
@@ -5247,6 +5282,10 @@ export class AgentManager {
     return parts.join("\n\n");
   }
 
+  private async restoreForkContext(agent: ManagedAgent): Promise<void> {
+    agent.forkContext = (await this.registry?.get(agent.id))?.forkContext;
+  }
+
   private recordTimeline(
     agentId: string,
     item: AgentTimelineItem,
@@ -5256,6 +5295,29 @@ export class AgentManager {
       turnId?: string;
     },
   ): AgentTimelineRow {
+    const agent = this.agents.get(agentId);
+    const context = agent?.forkContext;
+    if (
+      context &&
+      item.type === "user_message" &&
+      (item.clientMessageId === context.clientMessageId ||
+        (context.providerMessageId
+          ? item.messageId === context.providerMessageId
+          : context.attachment.text.length > 0 && item.text.includes(context.attachment.text)))
+    ) {
+      // Providers without client IDs can be matched once by the exact snapshot.
+      // Remember their native ID so a later quotation is not mistaken for the fork.
+      if (
+        agent &&
+        !context.providerMessageId &&
+        item.messageId &&
+        item.messageId !== context.clientMessageId
+      ) {
+        context.providerMessageId = item.messageId;
+        this.enqueueBackgroundPersist(agent);
+      }
+      item = { ...item, text: context.text, chatHistory: context.attachment };
+    }
     item = limitAgentTimelineItemContent(item);
     const row = this.timelineStore.append(agentId, item, options);
     this.enqueueDurableTimelineAppend(agentId, row);

packages/server/src/server/agent/agent-projections.ts

@@ -92,6 +92,7 @@ export function toStoredAgentRecord(
     lastUserMessageAt: agent.lastUserMessageAt ? agent.lastUserMessageAt.toISOString() : null,
     title: options?.title ?? null,
     labels: agent.labels,
+    forkContext: agent.forkContext,
     lastStatus: agent.lifecycle,
     lastModeId: agent.currentModeId ?? config?.modeId ?? null,
     config: config ?? null,

packages/server/src/server/agent/agent-sdk-types.ts

@@ -9,7 +9,7 @@ import type {
   ToolPolicy,
 } from "@getpaseo/protocol/agent-types";
 import type { AgentMessage } from "@getpaseo/protocol/agent-message";
-import type { AgentAttachment } from "@getpaseo/protocol/messages";
+import type { AgentAttachment, ChatHistoryAttachment } from "@getpaseo/protocol/messages";
 import type { PaseoToolCatalog } from "./tools/types.js";
 
 export type {
@@ -398,7 +398,13 @@ export interface PluginTimelineItem {
 }
 
 export type AgentTimelineItem =
-  | { type: "user_message"; text: string; messageId?: string; clientMessageId?: string }
+  | {
+      type: "user_message";
+      text: string;
+      messageId?: string;
+      clientMessageId?: string;
+      chatHistory?: ChatHistoryAttachment;
+    }
   | { type: "assistant_message"; text: string; messageId?: string }
   | { type: "reasoning"; text: string }
   | ToolCallTimelineItem

packages/server/src/server/agent/agent-storage.ts

@@ -4,7 +4,7 @@ import { z } from "zod";
 import type { Logger } from "pino";
 
 import { writeJsonFileAtomic } from "../atomic-file.js";
-import { AgentFeatureSchema, AgentStatusSchema } from "../messages.js";
+import { AgentFeatureSchema, AgentStatusSchema, ChatHistoryAttachmentSchema } from "../messages.js";
 import { toStoredAgentRecord } from "./agent-projections.js";
 import type { ManagedAgent } from "./agent-manager.js";
 import type { AgentSessionConfig } from "./agent-sdk-types.js";
@@ -53,6 +53,15 @@ const STORED_AGENT_SCHEMA = z.object({
   lastUserMessageAt: z.string().nullable().optional(),
   title: z.string().nullable().optional(),
   labels: z.record(z.string(), z.string()).default({}),
+  // Provider transcripts retain the rendered prompt, not attachment metadata.
+  forkContext: z
+    .object({
+      clientMessageId: z.string(),
+      providerMessageId: z.string().optional(),
+      text: z.string(),
+      attachment: ChatHistoryAttachmentSchema,
+    })
+    .optional(),
   lastStatus: AgentStatusSchema.default("closed"),
   resumeOnStartup: z.boolean().optional(),
   lastModeId: z.string().nullable().optional(),