fix: preserve inherited fork context and live history attachments

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

@@ -1,6 +1,16 @@
+import {
+  captureChatHistory,
+  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,
@@ -54,62 +64,45 @@ test.describe("Assistant fork menu", () => {
     await awaitAssistantMessage(page);
     await session.client.waitForFinish(session.agentId, 45_000);
     await forkMostRecentAssistantTurnToNewTab(page);
-    await page.getByTestId("composer-chat-history-attachment-pill").click();
-    const preview = page.getByTestId("chat-history-preview");
-    await expect(page.getByTestId("chat-history-content")).toContainText(initialPrompt);
-    await expect(page.getByRole("button", { name: "Open source chat" })).toBeVisible();
-    // Settle the sheet's spring animation and hide Expo's development-only overlay for QA.
-    await page.waitForTimeout(600);
-    await page.addStyleTag({ content: ".__expo_fast_refresh { display: none !important; }" });
-    await page.screenshot({
-      path: testInfo.outputPath("history-wide.png"),
-      animations: "disabled",
-    });
-    await preview.getByRole("button", { name: "Close", exact: true }).click();
+    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.");
-    await expect(page.getByTestId("message-chat-history-attachment")).toBeVisible();
-    const selectedTab = page
-      .getByTestId("workspace-tabs-row")
-      .getByRole("button")
-      .and(page.locator('[aria-selected="true"]'));
-    const tabId = await selectedTab.getAttribute("data-testid");
-    expect(tabId).toMatch(/^workspace-tab-agent_/);
-    const forkAgentId = tabId!.replace("workspace-tab-agent_", "");
+    const forkAgentId = await getActiveForkAgentId(page);
     await session.client.waitForFinish(forkAgentId, 45_000);
+
     await openAgentRoute(page, { workspaceId: session.workspaceId, agentId: forkAgentId });
     await page.reload();
-    await page.setViewportSize({ width: 390, height: 844 });
-    await page.getByTestId("message-chat-history-attachment").click();
-    await expect(page.getByTestId("chat-history-content")).toContainText(initialPrompt);
-    // Settle the sheet's spring animation and hide Expo's development-only overlay for QA.
-    await page.waitForTimeout(600);
-    await page.addStyleTag({ content: ".__expo_fast_refresh { display: none !important; }" });
-    await page.screenshot({
-      path: testInfo.outputPath("history-compact.png"),
-      animations: "disabled",
-    });
-    await page.getByRole("button", { name: "Open source chat" }).click();
-    await expect(preview).not.toBeVisible();
-    await page.setViewportSize({ width: 1280, height: 720 });
-    await expect(page.getByTestId(`workspace-tab-agent_${session.agentId}`)).toHaveAttribute(
-      "aria-selected",
-      "true",
-    );
+    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);
 
-    // Fork the fork, then follow its immediate source rather than guessing by title.
     await openAgentRoute(page, { workspaceId: session.workspaceId, agentId: forkAgentId });
-    await expect(page.getByTestId(`workspace-tab-agent_${forkAgentId}`)).toHaveAttribute(
-      "aria-selected",
-      "true",
-    );
+    await expectActiveForkAgent(page, forkAgentId);
     await forkMostRecentAssistantTurnToNewTab(page);
-    await page.getByTestId("composer-chat-history-attachment-pill").click();
-    await expect(page.getByTestId("chat-history-content")).toContainText("updates for the fork.");
-    await page.getByRole("button", { name: "Open source chat" }).click();
-    await expect(page.getByTestId(`workspace-tab-agent_${forkAgentId}`)).toHaveAttribute(
-      "aria-selected",
-      "true",
-    );
+    await openChatHistory(page, "draft", [initialPrompt, "updates for the fork."]);
+    await followChatHistorySource(page);
+    await expectActiveForkAgent(page, forkAgentId);
+  });
+
+  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 ({

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 +1,58 @@
+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";
+  await page.getByTestId(testId).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" },
+      },
+    ],
+  });
+}

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/chat-history/index.tsx

@@ -1,3 +1,4 @@
+import { extractChatHistoryBody } from "@getpaseo/protocol/chat-history";
 import { useCallback, useMemo, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { Text } from "react-native";
@@ -53,15 +54,7 @@ export function ChatHistoryAttachment({
       ) : undefined,
     [source, openSource, t],
   );
-  const history = useMemo(() => {
-    const text = attachment.text;
-    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;
-  }, [attachment.text]);
+  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} />

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

@@ -182,6 +182,47 @@ describe("user message identity", () => {
     },
   );
 
+  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

@@ -891,6 +891,18 @@ 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,
@@ -902,8 +914,8 @@ function appendUserMessage(
   turnId?: string,
   chatHistory?: Extract<AgentTimelineItem, { type: "user_message" }>["chatHistory"],
 ): StreamItem[] {
-  const { chunk, hasContent } = normalizeChunk(text);
-  if (!hasContent && !chatHistory) {
+  const { chunk, hasContent, attachments } = normalizeUserMessageContent(text, chatHistory);
+  if (!hasContent) {
     return state;
   }
 
@@ -915,7 +927,7 @@ function appendUserMessage(
     timelineCursor,
     turnId,
     text: chunk,
-    ...(chatHistory ? { attachments: [chatHistory] } : {}),
+    attachments,
     timestamp,
   });
   return upsertUserMessage(state, nextItem);
@@ -1877,7 +1889,7 @@ 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;
@@ -1890,6 +1902,7 @@ function applyCanonicalUserMessageEvent(params: {
     turnId: event.turnId,
     timelineCursor,
     text: normalized.chunk,
+    attachments: normalized.attachments,
     timestamp,
   });
   if (unmatchedInsert === "head") {

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/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,