diff --git a/ui/src/ui/app-chat.test.ts b/ui/src/ui/app-chat.test.ts
index b0df28cd947..f5d54c5bbfd 100644
--- a/ui/src/ui/app-chat.test.ts
+++ b/ui/src/ui/app-chat.test.ts
@@ -2,6 +2,40 @@
 
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { handleSendChat, refreshChatAvatar, type ChatHost } from "./app-chat.ts";
+import { sendChatMessage } from "./controllers/chat.ts";
+import { saveSettings, type UiSettings } from "./storage.ts";
+
+vi.mock("./controllers/chat.ts", () => ({
+  abortChatRun: vi.fn(),
+  loadChatHistory: vi.fn(),
+  sendChatMessage: vi.fn(),
+}));
+
+vi.mock("./storage.ts", async () => {
+  const actual = await vi.importActual<typeof import("./storage.ts")>("./storage.ts");
+  return {
+    ...actual,
+    saveSettings: vi.fn(),
+  };
+});
+
+vi.mock("./app-scroll.ts", async () => {
+  const actual = await vi.importActual<typeof import("./app-scroll.ts")>("./app-scroll.ts");
+  return {
+    ...actual,
+    resetChatScroll: vi.fn(),
+    scheduleChatScroll: vi.fn(),
+  };
+});
+
+vi.mock("./app-tool-stream.ts", async () => {
+  const actual =
+    await vi.importActual<typeof import("./app-tool-stream.ts")>("./app-tool-stream.ts");
+  return {
+    ...actual,
+    resetToolStream: vi.fn(),
+  };
+});
 
 function makeHost(overrides?: Partial<ChatHost>): ChatHost {
   return {
@@ -71,6 +105,7 @@ describe("refreshChatAvatar", () => {
 describe("handleSendChat", () => {
   afterEach(() => {
     vi.unstubAllGlobals();
+    vi.clearAllMocks();
   });
 
   it("keeps slash-command model changes in sync with the chat header cache", async () => {
@@ -128,4 +163,48 @@ describe("handleSendChat", () => {
       value: "openai/gpt-5-mini",
     });
   });
+
+  it("persists the last active session key without depending on app-settings", async () => {
+    vi.mocked(sendChatMessage).mockResolvedValueOnce("run-1");
+
+    const settings: UiSettings = {
+      gatewayUrl: "ws://localhost:18789",
+      token: "",
+      sessionKey: "main",
+      lastActiveSessionKey: "main",
+      theme: "claw",
+      themeMode: "system",
+      chatFocusMode: false,
+      chatShowThinking: true,
+      chatShowToolCalls: true,
+      splitRatio: 0.6,
+      navCollapsed: false,
+      navWidth: 220,
+      navGroupsCollapsed: {},
+      borderRadius: 50,
+    };
+    const host = Object.assign(
+      makeHost({
+        chatMessage: "hello",
+        sessionKey: "agent:ops:main",
+      }),
+      {
+        applySessionKey: "main",
+        settings,
+      },
+    ) as ChatHost & { applySessionKey: string; settings: UiSettings };
+
+    await handleSendChat(host);
+
+    expect(vi.mocked(sendChatMessage)).toHaveBeenCalledWith(
+      host as unknown as Parameters<typeof sendChatMessage>[0],
+      "hello",
+      undefined,
+    );
+    expect(host.settings.lastActiveSessionKey).toBe("agent:ops:main");
+    expect(host.applySessionKey).toBe("agent:ops:main");
+    expect(vi.mocked(saveSettings)).toHaveBeenCalledWith(
+      expect.objectContaining({ lastActiveSessionKey: "agent:ops:main" }),
+    );
+  });
 });
diff --git a/ui/src/ui/app-chat.ts b/ui/src/ui/app-chat.ts
index dc8eaf39be6..4478e5abca0 100644
--- a/ui/src/ui/app-chat.ts
+++ b/ui/src/ui/app-chat.ts
@@ -1,6 +1,5 @@
 import { parseAgentSessionKey } from "../../../src/sessions/session-key-utils.js";
 import { scheduleChatScroll, resetChatScroll } from "./app-scroll.ts";
-import { setLastActiveSessionKey } from "./app-settings.ts";
 import { resetToolStream } from "./app-tool-stream.ts";
 import type { OpenClawApp } from "./app.ts";
 import { executeSlashCommand } from "./chat/slash-command-executor.ts";
@@ -10,6 +9,7 @@ import { loadModels } from "./controllers/models.ts";
 import { loadSessions } from "./controllers/sessions.ts";
 import type { GatewayBrowserClient, GatewayHelloOk } from "./gateway.ts";
 import { normalizeBasePath } from "./navigation.ts";
+import { saveSettings, type UiSettings } from "./storage.ts";
 import type { ChatModelOverride, ModelCatalogEntry } from "./types.ts";
 import type { ChatAttachment, ChatQueueItem } from "./ui-types.ts";
 import { generateUUID } from "./uuid.ts";
@@ -38,6 +38,11 @@ export type ChatHost = {
   onSlashAction?: (action: string) => void;
 };
 
+type ChatSessionSettingsHost = {
+  settings: UiSettings;
+  applySessionKey: string;
+};
+
 export const CHAT_SESSIONS_ACTIVE_MINUTES = 120;
 
 export function isChatBusy(host: ChatHost) {
@@ -82,6 +87,33 @@ export async function handleAbortChat(host: ChatHost) {
   await abortChatRun(host as unknown as OpenClawApp);
 }
 
+function isChatSessionSettingsHost(host: ChatHost): host is ChatHost & ChatSessionSettingsHost {
+  return (
+    "settings" in host &&
+    typeof host.settings === "object" &&
+    host.settings !== null &&
+    "applySessionKey" in host &&
+    typeof host.applySessionKey === "string"
+  );
+}
+
+function persistLastActiveSessionKey(host: ChatHost, next: string) {
+  if (!isChatSessionSettingsHost(host)) {
+    return;
+  }
+  const trimmed = next.trim();
+  if (!trimmed || host.settings.lastActiveSessionKey === trimmed) {
+    return;
+  }
+  const settings = {
+    ...host.settings,
+    lastActiveSessionKey: trimmed,
+  };
+  host.settings = settings;
+  host.applySessionKey = settings.lastActiveSessionKey;
+  saveSettings(settings);
+}
+
 function enqueueChatMessage(
   host: ChatHost,
   text: string,
@@ -132,10 +164,7 @@ async function sendChatMessageNow(
     host.chatAttachments = opts.previousAttachments;
   }
   if (ok) {
-    setLastActiveSessionKey(
-      host as unknown as Parameters<typeof setLastActiveSessionKey>[0],
-      host.sessionKey,
-    );
+    persistLastActiveSessionKey(host, host.sessionKey);
   }
   if (ok && opts?.restoreDraft && opts.previousDraft?.trim()) {
     host.chatMessage = opts.previousDraft;