diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cd02195..a980e698 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ All notable changes to this project will be documented in this file.
 
 - **Usage/Claude:** Claude plan limits now work when you are signed in through Claude Code, without also signing into Anthropic in OpenCode; the account is read from Claude Code's own login on macOS, Linux, and WSL. The page shows your session and weekly limits again, adds per-model weekly limits and extra usage spending, and names your plan. Limits are kept on screen instead of disappearing when Anthropic temporarily blocks refreshes.
 - **Settings/Integrations:** a new Integrations settings page lists Claude Code, Command Code, and Cursor plugins with install, update, setup, and remove actions, plus Discord and Telegram Coming soon placeholders.
+- Chat: opening a busy subagent in the context panel now shows its history instead of only the working-status line (thanks to @makeittech).
 
 ## [1.18.4] - 2026-08-14
 
diff --git a/packages/ui/src/App.tsx b/packages/ui/src/App.tsx
index 1929683e..ad4bc2f4 100644
--- a/packages/ui/src/App.tsx
+++ b/packages/ui/src/App.tsx
@@ -209,6 +209,11 @@ const EmbeddedSessionChatContent: React.FC<{
       <OpenCodeUpdateToast />
       <ChatView
         active={embeddedBackgroundWorkEnabled}
+        // Always subscribe to message history in the mounted session-chat
+        // iframe. Visibility still gates composer focus and background work so
+        // a boot-inactive / lost-handshake race cannot leave a busy subagent
+        // showing only its status row (#2903 / #2892).
+        messagesEnabled={true}
         readOnly={embeddedSessionChat.readOnly}
         initialAllowPromptingSubagentSessions={embeddedSessionChat.allowPromptingSubagentSessions}
       />
diff --git a/packages/ui/src/components/chat/ChatContainer.tsx b/packages/ui/src/components/chat/ChatContainer.tsx
index ff38aeba..a50ea6e7 100644
--- a/packages/ui/src/components/chat/ChatContainer.tsx
+++ b/packages/ui/src/components/chat/ChatContainer.tsx
@@ -533,12 +533,27 @@ const DraftWelcome: React.FC = () => {
 
 type ChatContainerProps = {
     active?: boolean;
+    /**
+     * When set, controls message-history reads and session-message loads
+     * independently of `active`. Defaults to `active`. Embedded session-chat
+     * panels pass `true` so a delayed/lost visibility handshake cannot hide
+     * an already-materialized transcript (leaving only the working-status
+     * row — issue #2903).
+     */
+    messagesEnabled?: boolean;
     autoOpenDraft?: boolean;
     readOnly?: boolean;
     initialAllowPromptingSubagentSessions?: boolean;
 };
 
-export const ChatContainer: React.FC<ChatContainerProps> = ({ active = true, autoOpenDraft = true, readOnly = false, initialAllowPromptingSubagentSessions }) => {
+export const ChatContainer: React.FC<ChatContainerProps> = ({
+    active = true,
+    messagesEnabled: messagesEnabledProp,
+    autoOpenDraft = true,
+    readOnly = false,
+    initialAllowPromptingSubagentSessions,
+}) => {
+    const messagesEnabled = messagesEnabledProp ?? active;
     const { t } = useI18n();
     // Session UI state
     const currentSessionId = useSessionUIStore((s) => s.currentSessionId);
@@ -591,9 +606,11 @@ export const ChatContainer: React.FC<ChatContainerProps> = ({ active = true, aut
     );
     const sessionMessageCount = useSessionMessageCount(currentSessionId ?? '', effectiveSessionDirectory);
     const hasRenderableSessionSnapshot = useSessionRenderable(currentSessionId ?? '', effectiveSessionDirectory);
-    // Messages from sync system
+    // Messages from sync system. Keep this gated by `messagesEnabled`, not
+    // `active`, so embedded panels can show history while the composer stays
+    // inactive until the parent confirms visibility.
     const sessionMessageRecords = useSessionMessageRecords(currentSessionId ?? '', effectiveSessionDirectory, {
-        enabled: active,
+        enabled: messagesEnabled,
         suspendPartUpdates: Boolean(streamingMessageId),
         suspendPartUpdatesForMessageId: streamingMessageId,
     });
@@ -1042,9 +1059,9 @@ export const ChatContainer: React.FC<ChatContainerProps> = ({ active = true, aut
         Boolean(currentSessionId)
         && !hasRenderableSessionSnapshot;
     const retrySessionLoad = React.useCallback(() => {
-        if (!active || !currentSessionId) return;
+        if (!messagesEnabled || !currentSessionId) return;
         void sync.ensureSessionRenderable(currentSessionId, true, effectiveSessionDirectory);
-    }, [active, currentSessionId, effectiveSessionDirectory, sync]);
+    }, [currentSessionId, effectiveSessionDirectory, messagesEnabled, sync]);
 
     React.useEffect(() => {
         if (!active || !currentSessionId) return;
@@ -1069,10 +1086,10 @@ export const ChatContainer: React.FC<ChatContainerProps> = ({ active = true, aut
     }, [active, currentSessionId, currentSessionKey, releaseAutoFollow, restoreSnapshot]);
 
     React.useEffect(() => {
-        if (!active || !currentSessionId) return;
+        if (!messagesEnabled || !currentSessionId) return;
         if (hasRenderableSessionSnapshot) return;
         void ensureSessionRenderable(currentSessionId);
-    }, [active, currentSessionId, ensureSessionRenderable, hasRenderableSessionSnapshot]);
+    }, [currentSessionId, ensureSessionRenderable, hasRenderableSessionSnapshot, messagesEnabled]);
 
 	if (!currentSessionId && !draftOpen) {
 		// With auto-open, the draft welcome opens on the next tick (effect below),
diff --git a/packages/ui/src/components/chat/__tests__/issue-2903-subagent-status-line-only.test.tsx b/packages/ui/src/components/chat/__tests__/issue-2903-subagent-status-line-only.test.tsx
new file mode 100644
index 00000000..cd72ed46
--- /dev/null
+++ b/packages/ui/src/components/chat/__tests__/issue-2903-subagent-status-line-only.test.tsx
@@ -0,0 +1,249 @@
+/**
+ * Regression coverage for https://github.com/openchamber/openchamber/issues/2903
+ *
+ * Busy embedded session-chat panels were rendering only the working-status row
+ * ("…is running command") because ChatContainer gated message reads on the
+ * same visibility flag used to keep the composer from stealing focus. When the
+ * iframe booted inactive (or a visibility postMessage was lost),
+ * useSessionMessageRecords returned [] while session status stayed busy — so
+ * the empty-state branch was skipped and the transcript showed status only.
+ *
+ * Idle sessions hit the empty state instead (#2892). Same root cause.
+ *
+ * Fix: embedded session-chat keeps `messagesEnabled={true}` so history stays
+ * subscribed while `active={embeddedBackgroundWorkEnabled}` still gates
+ * composer focus and background work.
+ */
+import { describe, expect, mock, test } from 'bun:test';
+import { readFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import React, { act } from 'react';
+import { createRoot, type Root } from 'react-dom/client';
+import type { Message, Part } from '@opencode-ai/sdk/v2/client';
+
+mock.module('sonner', () => ({
+  toast: { dismiss: () => undefined, error: () => undefined, info: () => undefined, success: () => undefined },
+}));
+mock.module('@/components/ui', () => ({
+  toast: { info: () => undefined, error: () => undefined, success: () => undefined },
+}));
+mock.module('@/lib/opencode/client', () => ({
+  opencodeClient: {
+    getDirectory: () => '/repo',
+    setDirectory: () => undefined,
+    getSdkClient: () => ({}),
+    getScopedSdkClient: () => ({}),
+  },
+}));
+mock.module('@/stores/permissionStore', () => ({
+  usePermissionStore: { getState: () => ({ isSessionAutoAccepting: () => false, hydrate: async () => undefined }) },
+}));
+mock.module('@/stores/useConfigStore', () => ({
+  useConfigStore: {
+    getState: () => ({ isConnected: true, hasEverConnected: true, settingsMessageStreamTransport: 'auto' }),
+    setState: () => undefined,
+  },
+}));
+mock.module('@/stores/useTodosPersistStore', () => ({
+  useTodosPersistStore: { getState: () => ({ setSessionTodos: () => undefined }) },
+}));
+
+const { useSessionMessageRecords } = await import('@/sync/sync-context');
+const { ChildStoreManager } = await import('@/sync/child-store');
+const { getSessionMaterializationStatus } = await import('@/sync/materialization');
+import type { State } from '@/sync/types';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const appSource = readFileSync(join(__dirname, '..', '..', '..', 'App.tsx'), 'utf-8');
+const chatContainerSource = readFileSync(join(__dirname, '..', 'ChatContainer.tsx'), 'utf-8');
+const chatViewSource = readFileSync(join(__dirname, '..', '..', 'views', 'ChatView.tsx'), 'utf-8');
+const syncContextSource = readFileSync(join(__dirname, '..', '..', '..', 'sync', 'sync-context.tsx'), 'utf-8');
+
+const SESSION_ID = 'ses_subagent_2903';
+const DIRECTORY = '/repo';
+
+const installMinimalDom = () => {
+  const descriptors = new Map<string, PropertyDescriptor | undefined>();
+  const setGlobal = (name: string, value: unknown) => {
+    descriptors.set(name, Object.getOwnPropertyDescriptor(globalThis, name));
+    Object.defineProperty(globalThis, name, { configurable: true, writable: true, value });
+  };
+  class ElementStub {}
+  const documentStub: Record<string, unknown> = {
+    nodeType: 9,
+    defaultView: globalThis,
+    activeElement: null,
+    addEventListener: () => undefined,
+    removeEventListener: () => undefined,
+  };
+  const container = {
+    nodeType: 1,
+    tagName: 'DIV',
+    nodeName: 'DIV',
+    namespaceURI: 'http://www.w3.org/1999/xhtml',
+    ownerDocument: documentStub,
+    addEventListener: () => undefined,
+    removeEventListener: () => undefined,
+  };
+  documentStub.documentElement = container;
+  documentStub.body = container;
+  setGlobal('document', documentStub);
+  setGlobal('window', globalThis);
+  setGlobal('location', { search: '', protocol: 'http:', hostname: 'localhost' });
+  setGlobal('Element', ElementStub);
+  setGlobal('HTMLElement', ElementStub);
+  setGlobal('HTMLIFrameElement', ElementStub);
+  setGlobal('IS_REACT_ACT_ENVIRONMENT', true);
+  setGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => setTimeout(() => callback(Date.now()), 0));
+  setGlobal('cancelAnimationFrame', (id: ReturnType<typeof setTimeout>) => clearTimeout(id));
+  return {
+    container: container as unknown as Element,
+    restore: () => {
+      for (const [name, descriptor] of descriptors) {
+        if (descriptor) Object.defineProperty(globalThis, name, descriptor);
+        else Reflect.deleteProperty(globalThis, name);
+      }
+    },
+  };
+};
+
+const createMessage = (id: string, role: 'user' | 'assistant', created: number): Message => ({
+  id,
+  sessionID: SESSION_ID,
+  role,
+  ...(role === 'assistant' ? { parentID: `u_${created}` } : {}),
+  time: { created },
+} as Message);
+
+const createPart = (id: string, messageID: string, text: string): Part => ({
+  id,
+  messageID,
+  sessionID: SESSION_ID,
+  type: 'text',
+  text,
+} as Part);
+
+/** 14-message subagent transcript, matching the issue reproduction fixture. */
+const buildMaterializedSubagentSession = () => {
+  const messages: Message[] = [];
+  const part: Record<string, Part[]> = {};
+  for (let index = 0; index < 14; index += 1) {
+    const created = index + 1;
+    const role: 'user' | 'assistant' = created % 2 === 1 ? 'user' : 'assistant';
+    const id = role === 'user' ? `u_${created}` : `a_${created}`;
+    messages.push(createMessage(id, role, created));
+    part[id] = [createPart(`prt_${id}`, id, role === 'user' ? `prompt ${created}` : `output ${created}`)];
+  }
+  return { messages, part };
+};
+
+const syncContext = (globalThis as unknown as {
+  __openchamber_sync_context__?: React.Context<unknown>;
+}).__openchamber_sync_context__;
+
+if (!syncContext) {
+  throw new Error('sync context was not published on globalThis by @/sync/sync-context');
+}
+
+describe('issue #2903 busy embedded subagent status-line-only', () => {
+  test('cold disabled reads hide a fully materialized 14-message subagent; enabled reads return all 14', async () => {
+    const dom = installMinimalDom();
+    const root: Root = createRoot(dom.container);
+    const childStores = new ChildStoreManager();
+    const store = childStores.ensureChild(DIRECTORY, { bootstrap: false });
+    const { messages, part } = buildMaterializedSubagentSession();
+    store.setState({
+      status: 'complete',
+      session: [{
+        id: SESSION_ID,
+        title: 'Audit Searchbar implementation',
+        time: { created: 1, updated: 1 },
+        version: '1',
+        directory: DIRECTORY,
+      } as State['session'][number]],
+      message: { [SESSION_ID]: messages },
+      part,
+    } as Partial<State>);
+
+    expect(getSessionMaterializationStatus(store.getState(), SESSION_ID)).toEqual({
+      hasMessages: true,
+      renderable: true,
+      missingPartMessageIDs: [],
+    });
+
+    const system = { childStores, messageLoader: {}, sdk: {}, runtimeKey: 'test', directory: DIRECTORY };
+    const Provider = syncContext.Provider as React.Provider<unknown>;
+    let inactiveCount = -1;
+    let activeCount = -1;
+    let enabled = false;
+
+    const Harness = () => {
+      const records = useSessionMessageRecords(SESSION_ID, DIRECTORY, { enabled });
+      if (enabled) {
+        activeCount = records.length;
+      } else {
+        inactiveCount = records.length;
+      }
+      return null;
+    };
+
+    try {
+      await act(async () => {
+        root.render(React.createElement(Provider, { value: system }, React.createElement(Harness)));
+      });
+      expect(inactiveCount).toBe(0);
+
+      enabled = true;
+      await act(async () => {
+        root.render(React.createElement(Provider, { value: system }, React.createElement(Harness)));
+      });
+      expect(activeCount).toBe(14);
+    } finally {
+      await act(async () => root.unmount());
+      dom.restore();
+    }
+  });
+
+  test('sync gate still returns empty on cold disabled reads', () => {
+    const hookStart = syncContextSource.indexOf('export function useSessionMessageRecords(');
+    const hookBody = syncContextSource.slice(hookStart, hookStart + 1800);
+    expect(hookBody).toContain('if (options?.enabled === false)');
+    expect(hookBody).toContain('EMPTY_SESSION_MESSAGE_RECORDS');
+    expect(hookBody).toContain('snapshotRef.current.sessionID === sessionID ? snapshotRef.current.list');
+  });
+
+  test('embedded session-chat keeps message history enabled while visibility gates active', () => {
+    expect(appSource).toContain('messagesEnabled={true}');
+    expect(appSource).toContain('active={embeddedBackgroundWorkEnabled}');
+    expect(appSource).toContain('const [isEmbeddedVisible, setIsEmbeddedVisible] = React.useState(false);');
+    expect(chatViewSource).toContain('messagesEnabled?: boolean');
+    expect(chatContainerSource).toContain('messagesEnabled: messagesEnabledProp');
+    expect(chatContainerSource).toContain('const messagesEnabled = messagesEnabledProp ?? active;');
+    expect(chatContainerSource).toContain('enabled: messagesEnabled');
+    expect(chatContainerSource.includes('enabled: active')).toBe(false);
+    expect(chatContainerSource).toContain('if (!messagesEnabled || !currentSessionId) return;');
+    expect(chatContainerSource).toContain('void ensureSessionRenderable(currentSessionId);');
+  });
+
+  test('empty+busy branch skips empty state so StatusRowContainer can stand alone', () => {
+    expect(chatContainerSource).toContain('if (sessionMessages.length === 0 && !sessionIsWorking)');
+    expect(chatContainerSource).toContain('<ChatEmptyState');
+    expect(chatContainerSource).toContain('<StatusRowContainer />');
+
+    const emptyBusyGuard = 'if (sessionMessages.length === 0 && !sessionIsWorking)';
+    const emptyStateReturn = chatContainerSource.indexOf(emptyBusyGuard);
+    expect(emptyStateReturn).toBeGreaterThan(-1);
+    const emptyStateBlock = chatContainerSource.slice(
+      emptyStateReturn,
+      emptyStateReturn + 1600,
+    );
+    expect(emptyStateBlock).toContain('<ChatEmptyState');
+    expect(emptyStateBlock).not.toContain('<StatusRowContainer />');
+  });
+
+  test('visibility handshake remains as defense-in-depth for background work', () => {
+    expect(appSource).toContain('requestEmbeddedSessionVisibility();');
+    expect(appSource).toContain('EMBEDDED_VISIBILITY_UPDATE');
+  });
+});
diff --git a/packages/ui/src/components/layout/__tests__/issue-2815-sessionChatIframesMountAllTabs.test.ts b/packages/ui/src/components/layout/__tests__/issue-2815-sessionChatIframesMountAllTabs.test.ts
index ccb2fea0..619a8cd2 100644
--- a/packages/ui/src/components/layout/__tests__/issue-2815-sessionChatIframesMountAllTabs.test.ts
+++ b/packages/ui/src/components/layout/__tests__/issue-2815-sessionChatIframesMountAllTabs.test.ts
@@ -147,11 +147,12 @@ describe('issue #2815 active-only chat iframe source guard', () => {
     expect(requestIndex).toBeGreaterThan(listenerIndex);
   });
 
-  test('gates embedded chat subscriptions and background work on visibility', () => {
+  test('gates embedded chat background work on visibility but keeps message history enabled', () => {
     expect(appSource).toContain(
       'const embeddedBackgroundWorkEnabled = !embeddedSessionChat || isEmbeddedVisible;',
     );
     expect(appSource).toContain('active={embeddedBackgroundWorkEnabled}');
+    expect(appSource).toContain('messagesEnabled={true}');
     expect(appSource).toContain(
       'useWebNotificationStream({ enabled: embeddedBackgroundWorkEnabled });',
     );
diff --git a/packages/ui/src/components/views/ChatView.tsx b/packages/ui/src/components/views/ChatView.tsx
index bcba8dc7..29d83cff 100644
--- a/packages/ui/src/components/views/ChatView.tsx
+++ b/packages/ui/src/components/views/ChatView.tsx
@@ -5,17 +5,29 @@ import { useSessionUIStore } from '@/sync/session-ui-store';
 
 type ChatViewProps = {
     active?: boolean;
+    /**
+     * Controls message-history subscription independently of `active`.
+     * Embedded session-chat panels keep this true so history stays visible
+     * while composer focus / background work remain gated by visibility.
+     */
+    messagesEnabled?: boolean;
     readOnly?: boolean;
     initialAllowPromptingSubagentSessions?: boolean;
 };
 
-export const ChatView: React.FC<ChatViewProps> = ({ active = true, readOnly = false, initialAllowPromptingSubagentSessions }) => {
+export const ChatView: React.FC<ChatViewProps> = ({
+    active = true,
+    messagesEnabled,
+    readOnly = false,
+    initialAllowPromptingSubagentSessions,
+}) => {
     const currentSessionId = useSessionUIStore((state) => state.currentSessionId);
 
     return (
         <ChatErrorBoundary sessionId={currentSessionId || undefined}>
             <ChatContainer
                 active={active}
+                messagesEnabled={messagesEnabled}
                 readOnly={readOnly}
                 initialAllowPromptingSubagentSessions={initialAllowPromptingSubagentSessions}
             />
diff --git a/packages/ui/src/stores/DOCUMENTATION.md b/packages/ui/src/stores/DOCUMENTATION.md
index 14df83a7..4f17d6e4 100644
--- a/packages/ui/src/stores/DOCUMENTATION.md
+++ b/packages/ui/src/stores/DOCUMENTATION.md
@@ -45,7 +45,10 @@ its message listener, the iframe requests its authoritative visibility from the
 parent. The parent accepts requests only from a currently mounted chat frame and
 answers from the current active tab. Do not rely only on a parent `onLoad`
 notification: it can arrive before the iframe listener exists and leave a
-visible chat with background work and message subscriptions disabled.
+visible chat with background work disabled. Message-history subscriptions in the
+mounted session-chat iframe stay enabled independently of that visibility flag
+so a delayed or lost handshake cannot hide an already-materialized transcript
+(busy subagents would otherwise show only the working-status row).
 
 ### Session / project coordination stores