diff --git a/client/src/components/settings/NineRouterUpdate.tsx b/client/src/components/settings/NineRouterUpdate.tsx
new file mode 100644
index 00000000..14acbb1f
--- /dev/null
+++ b/client/src/components/settings/NineRouterUpdate.tsx
@@ -0,0 +1,242 @@
+/**
+ * @file NineRouterUpdate.tsx
+ * @description **Update 9router** on the AI Proxy page (an admin's; beside
+ * Config 9router): a button — dotted when npm has a newer 9router — and a
+ * dialog that runs the server's three-step job (`server/lib/nine-router-update.js`):
+ * disconnect and shut 9router down, `npm install -g 9router@latest`, start it
+ * again hidden (tray, no browser) — the last only when it was running before.
+ * The dialog shows why an update cannot run right now (the server's `blocker`,
+ * with the command to run by hand when sudo needs a password) and follows the
+ * job by polling until it ends. Closing the dialog does not stop the job.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+import { useCallback, useEffect, useRef, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { ArrowUpCircle, Check, Circle, Copy, Loader2, MinusCircle, X } from "lucide-react";
+import { api, type NineRouterUpdateStatus, type NineRouterUpdateStep } from "../../lib/api";
+import { copyText } from "../../lib/clipboard";
+import { useDialog } from "../../hooks/useDialog";
+
+const POLL_MS = 1000;
+
+function StepIcon({ status }: { status: NineRouterUpdateStep["status"] }) {
+  if (status === "running") return <Loader2 className="h-3.5 w-3.5 animate-spin text-accent" />;
+  if (status === "done") return <Check className="h-3.5 w-3.5 text-status-success" />;
+  if (status === "failed") return <X className="h-3.5 w-3.5 text-status-danger" />;
+  if (status === "skipped") return <MinusCircle className="h-3.5 w-3.5 text-fg-muted" />;
+  return <Circle className="h-3.5 w-3.5 text-fg-muted" />;
+}
+
+export function NineRouterUpdate() {
+  const { t } = useTranslation("settings");
+  const [status, setStatus] = useState<NineRouterUpdateStatus | null>(null);
+  const [open, setOpen] = useState(false);
+  const [starting, setStarting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const dialogRef = useRef<HTMLDivElement>(null);
+  useDialog(open, dialogRef, () => setOpen(false));
+
+  const load = useCallback(async (fresh = false) => {
+    try {
+      setStatus(await api.aiProxies.nineRouterUpdateStatus(fresh));
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+    }
+  }, []);
+
+  useEffect(() => {
+    void load();
+  }, [load]);
+
+  const running = status?.job?.status === "running";
+  // Follow a running job — also one started from another tab.
+  useEffect(() => {
+    if (!running) return;
+    const timer = window.setInterval(() => void load(), POLL_MS);
+    return () => window.clearInterval(timer);
+  }, [running, load]);
+
+  const openDialog = () => {
+    setError(null);
+    setOpen(true);
+    void load(true);
+  };
+
+  const start = async () => {
+    setStarting(true);
+    setError(null);
+    try {
+      const job = await api.aiProxies.nineRouterUpdate();
+      setStatus((s) => (s ? { ...s, job } : s));
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+      void load(true);
+    } finally {
+      setStarting(false);
+    }
+  };
+
+  if (!status?.installed) return null;
+  const job = status.job;
+  const blocker = status.blocker;
+
+  return (
+    <>
+      <button
+        type="button"
+        onClick={openDialog}
+        className="relative inline-flex shrink-0 items-center gap-1.5 rounded-lg border border-border bg-surface-2 px-3 py-1.5 text-xs font-medium text-fg-secondary transition-colors hover:border-accent/30 hover:bg-accent/10 hover:text-accent"
+      >
+        {running ? (
+          <Loader2 className="h-3.5 w-3.5 animate-spin" />
+        ) : (
+          <ArrowUpCircle className="h-3.5 w-3.5" />
+        )}
+        {t("aiProxy.update9router")}
+        {status.updateAvailable && !running && (
+          <span
+            className="absolute -right-1 -top-1 h-2 w-2 rounded-full bg-accent-solid"
+            aria-label={t("aiProxy.update9routerAvailable")}
+          />
+        )}
+      </button>
+
+      {open && (
+        <div
+          className="fixed inset-0 z-50 flex items-center justify-center bg-surface-0/70 p-4"
+          role="presentation"
+        >
+          <div
+            ref={dialogRef}
+            role="dialog"
+            aria-modal="true"
+            aria-labelledby="nine-router-update-title"
+            className="max-h-[90vh] w-full max-w-md overflow-y-auto rounded-xl border border-border bg-surface-1 p-5 shadow-xl"
+          >
+            <h3
+              id="nine-router-update-title"
+              className="mb-3 text-sm font-semibold text-fg-primary"
+            >
+              {t("aiProxy.update9router")}
+            </h3>
+
+            <dl className="mb-3 grid grid-cols-[auto_1fr] gap-x-3 gap-y-1 text-xs">
+              <dt className="text-fg-muted">{t("aiProxy.update9routerCurrent")}</dt>
+              <dd className="font-mono text-fg-primary">{status.version ?? "—"}</dd>
+              <dt className="text-fg-muted">{t("aiProxy.update9routerLatest")}</dt>
+              <dd className="font-mono text-fg-primary">{status.latest ?? "—"}</dd>
+              <dt className="text-fg-muted">{t("aiProxy.update9routerState")}</dt>
+              <dd className="text-fg-primary">
+                {status.running
+                  ? status.managedBy === "systemd"
+                    ? t("aiProxy.update9routerRunningUnit")
+                    : t("aiProxy.update9routerRunning")
+                  : t("aiProxy.update9routerStopped")}
+              </dd>
+            </dl>
+
+            <p className="mb-3 text-[11px] text-fg-muted">
+              {status.running
+                ? t("aiProxy.update9routerExplain")
+                : t("aiProxy.update9routerExplainStopped")}
+            </p>
+
+            {job && (
+              <ol className="mb-3 space-y-1.5 rounded-md border border-border bg-surface-0 p-3">
+                {job.steps.map((s) => (
+                  <li key={s.id} className="flex items-start gap-2 text-xs">
+                    <span className="mt-0.5">
+                      <StepIcon status={s.status} />
+                    </span>
+                    <span className="min-w-0">
+                      <span className="text-fg-primary">
+                        {t(`aiProxy.update9routerStep.${s.id}`)}
+                      </span>
+                      {s.message && (
+                        <span className="block break-words text-[11px] text-fg-muted">
+                          {s.message}
+                        </span>
+                      )}
+                    </span>
+                  </li>
+                ))}
+              </ol>
+            )}
+            {job && job.status !== "running" && (
+              <p
+                className={`mb-3 text-xs ${
+                  job.status === "done" ? "text-status-success" : "text-status-danger"
+                }`}
+              >
+                {job.status !== "done"
+                  ? t("aiProxy.update9routerFailed")
+                  : job.steps.find((s) => s.id === "relaunch")?.status === "skipped"
+                    ? t("aiProxy.update9routerDoneStopped", { version: job.to ?? "—" })
+                    : t("aiProxy.update9routerDone", { version: job.to ?? "—" })}
+              </p>
+            )}
+            {job?.log && (
+              <details className="mb-3">
+                <summary className="cursor-pointer text-[11px] text-fg-muted">
+                  {t("aiProxy.update9routerLog")}
+                </summary>
+                <pre className="mt-1 max-h-48 overflow-auto whitespace-pre-wrap rounded-md bg-surface-0 p-2 font-mono text-[10px] text-fg-secondary">
+                  {job.log}
+                </pre>
+              </details>
+            )}
+
+            {blocker && !running && blocker.code !== "EUPTODATE" && (
+              <div className="mb-3 rounded-md border border-status-warning/40 bg-status-warning/10 px-3 py-2 text-xs text-fg-secondary">
+                <p>{blocker.message}</p>
+                {blocker.command && (
+                  <div className="mt-2 flex items-center gap-2">
+                    <code className="min-w-0 flex-1 truncate rounded bg-surface-0 px-2 py-1 font-mono text-[11px]">
+                      {blocker.command}
+                    </code>
+                    <button
+                      type="button"
+                      onClick={() => void copyText(blocker.command!)}
+                      className="shrink-0 rounded p-1 text-fg-muted hover:text-accent"
+                      aria-label={t("aiProxy.update9routerCopy")}
+                      title={t("aiProxy.update9routerCopy")}
+                    >
+                      <Copy className="h-3.5 w-3.5" />
+                    </button>
+                  </div>
+                )}
+              </div>
+            )}
+            {blocker?.code === "EUPTODATE" && !running && (
+              <p className="mb-3 text-xs text-fg-muted">{t("aiProxy.update9routerUpToDate")}</p>
+            )}
+            {error && (
+              <p className="mb-3 rounded-md border border-status-danger/40 bg-status-danger/10 px-3 py-2 text-xs text-status-danger">
+                {error}
+              </p>
+            )}
+
+            <div className="flex justify-end gap-2">
+              <button
+                type="button"
+                onClick={() => setOpen(false)}
+                className="rounded-lg border border-border px-3 py-1.5 text-xs text-fg-secondary hover:bg-surface-2"
+              >
+                {t("aiProxy.update9routerClose")}
+              </button>
+              <button
+                type="button"
+                onClick={() => void start()}
+                disabled={Boolean(blocker) || running || starting}
+                className="btn-primary inline-flex items-center gap-1.5 px-3 py-1.5 text-xs disabled:opacity-50"
+              >
+                {(running || starting) && <Loader2 className="h-3.5 w-3.5 animate-spin" />}
+                {t("aiProxy.update9routerStart")}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+    </>
+  );
+}
diff --git a/client/src/components/settings/__tests__/NineRouterUpdate.test.tsx b/client/src/components/settings/__tests__/NineRouterUpdate.test.tsx
new file mode 100644
index 00000000..ed8c1cea
--- /dev/null
+++ b/client/src/components/settings/__tests__/NineRouterUpdate.test.tsx
@@ -0,0 +1,95 @@
+/**
+ * @file Tests for **Update 9router** on the AI Proxy page: hidden without a
+ * 9router, a dialog that shows versions and starts the job, the server's
+ * blocker (with the manual command) disabling the start, and the job's steps.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { NineRouterUpdate } from "../NineRouterUpdate";
+import { api, type NineRouterUpdateJob, type NineRouterUpdateStatus } from "../../../lib/api";
+
+vi.mock("../../../lib/api", () => ({
+  api: { aiProxies: { nineRouterUpdateStatus: vi.fn(), nineRouterUpdate: vi.fn() } },
+}));
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+const statusMock = vi.mocked(api.aiProxies.nineRouterUpdateStatus);
+const startMock = vi.mocked(api.aiProxies.nineRouterUpdate);
+
+const base: NineRouterUpdateStatus = {
+  installed: true,
+  version: "0.5.104",
+  latest: "0.5.109",
+  updateAvailable: true,
+  running: true,
+  managedBy: "systemd",
+  blocker: null,
+  job: null,
+};
+
+const job: NineRouterUpdateJob = {
+  status: "running",
+  startedAt: "2026-10-26T00:00:00Z",
+  finishedAt: null,
+  from: "0.5.104",
+  to: null,
+  managedBy: "systemd",
+  install: "direct",
+  steps: [
+    { id: "shutdown", status: "done", message: null },
+    { id: "update", status: "running", message: null },
+    { id: "relaunch", status: "pending", message: null },
+  ],
+  log: "",
+};
+
+beforeEach(() => {
+  statusMock.mockReset();
+  startMock.mockReset();
+});
+
+describe("NineRouterUpdate", () => {
+  it("renders nothing when 9router is not installed", async () => {
+    statusMock.mockResolvedValue({ ...base, installed: false });
+    const { container } = render(<NineRouterUpdate />);
+    await waitFor(() => expect(statusMock).toHaveBeenCalled());
+    expect(container).toBeEmptyDOMElement();
+  });
+
+  it("opens with both versions and starts the three-step job", async () => {
+    statusMock.mockResolvedValue(base);
+    startMock.mockResolvedValue(job);
+    render(<NineRouterUpdate />);
+    await userEvent.click(await screen.findByRole("button", { name: /aiProxy.update9router/ }));
+    expect(statusMock).toHaveBeenLastCalledWith(true);
+    const dialog = await screen.findByRole("dialog");
+    expect(dialog).toHaveTextContent("0.5.104");
+    expect(dialog).toHaveTextContent("0.5.109");
+    await userEvent.click(screen.getByRole("button", { name: "aiProxy.update9routerStart" }));
+    expect(startMock).toHaveBeenCalledTimes(1);
+    expect(await screen.findByText("aiProxy.update9routerStep.shutdown")).toBeInTheDocument();
+    expect(screen.getByText("aiProxy.update9routerStep.update")).toBeInTheDocument();
+    expect(screen.getByText("aiProxy.update9routerStep.relaunch")).toBeInTheDocument();
+  });
+
+  it("shows the blocker with its manual command and keeps the start disabled", async () => {
+    statusMock.mockResolvedValue({
+      ...base,
+      blocker: {
+        code: "ENOPERM",
+        message: "/usr/local is not writable by this account and sudo needs a password",
+        command: "sudo npm install -g 9router@latest",
+      },
+    });
+    render(<NineRouterUpdate />);
+    await userEvent.click(await screen.findByRole("button", { name: /aiProxy.update9router/ }));
+    expect(await screen.findByText("sudo npm install -g 9router@latest")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "aiProxy.update9routerStart" })).toBeDisabled();
+  });
+});
diff --git a/client/src/i18n/locales/en/settings.json b/client/src/i18n/locales/en/settings.json
index 272074a1..df7257fb 100644
--- a/client/src/i18n/locales/en/settings.json
+++ b/client/src/i18n/locales/en/settings.json
@@ -759,6 +759,29 @@
     "description": "For example 9Router, OpenRouter or a self-hosted gateway. Save one here, then pick it for a session in the workspace prompt box.",
     "add": "Add profile",
     "config9router": "Config 9router",
+    "update9router": "Update 9router",
+    "update9routerAvailable": "A newer 9router is available",
+    "update9routerCurrent": "Installed",
+    "update9routerLatest": "Latest",
+    "update9routerState": "State",
+    "update9routerRunning": "Running",
+    "update9routerRunningUnit": "Running (9router.service)",
+    "update9routerStopped": "Not running",
+    "update9routerExplain": "Every session using 9router is disconnected while it updates: 9router is shut down, updated with npm, then started again hidden (tray, no browser).",
+    "update9routerExplainStopped": "9router is not running: it is updated with npm and left off.",
+    "update9routerStep": {
+      "shutdown": "Disconnect and shut down 9router",
+      "update": "Run the update (npm install -g 9router@latest)",
+      "relaunch": "Start 9router again, hidden"
+    },
+    "update9routerDone": "9router {{version}} is running.",
+    "update9routerDoneStopped": "9router {{version}} is installed and left off, as it was.",
+    "update9routerFailed": "The update did not finish — see the steps and the log.",
+    "update9routerLog": "npm output",
+    "update9routerUpToDate": "9router is already the latest version.",
+    "update9routerCopy": "Copy command",
+    "update9routerClose": "Close",
+    "update9routerStart": "Update now",
     "edit": "Edit",
     "remove": "Remove",
     "empty": "No proxy profile saved yet. Native runs against the vendor's own API.",
diff --git a/client/src/i18n/locales/vi/settings.json b/client/src/i18n/locales/vi/settings.json
index c09636f2..6d1f6b51 100644
--- a/client/src/i18n/locales/vi/settings.json
+++ b/client/src/i18n/locales/vi/settings.json
@@ -747,6 +747,29 @@
     "description": "Ví dụ 9Router, OpenRouter hoặc gateway tự dựng. Lưu ở đây rồi chọn cho từng session ở ô nhập prompt của workspace.",
     "add": "Thêm profile",
     "config9router": "Config 9router",
+    "update9router": "Cập nhật 9router",
+    "update9routerAvailable": "Đã có bản 9router mới",
+    "update9routerCurrent": "Đang cài",
+    "update9routerLatest": "Mới nhất",
+    "update9routerState": "Trạng thái",
+    "update9routerRunning": "Đang chạy",
+    "update9routerRunningUnit": "Đang chạy (9router.service)",
+    "update9routerStopped": "Không chạy",
+    "update9routerExplain": "Mọi session đang dùng 9router sẽ bị ngắt kết nối trong lúc cập nhật: 9router được tắt, cập nhật bằng npm rồi mở lại ở chế độ ẩn (khay hệ thống, không mở trình duyệt).",
+    "update9routerExplainStopped": "9router đang không chạy: chỉ cập nhật bằng npm và giữ nguyên trạng thái tắt.",
+    "update9routerStep": {
+      "shutdown": "Ngắt kết nối và tắt 9router",
+      "update": "Chạy cập nhật (npm install -g 9router@latest)",
+      "relaunch": "Mở lại 9router ở chế độ ẩn"
+    },
+    "update9routerDone": "9router {{version}} đang chạy.",
+    "update9routerDoneStopped": "Đã cài 9router {{version}}, giữ nguyên trạng thái tắt như trước.",
+    "update9routerFailed": "Cập nhật chưa hoàn tất — xem các bước và log.",
+    "update9routerLog": "Output của npm",
+    "update9routerUpToDate": "9router đã là bản mới nhất.",
+    "update9routerCopy": "Sao chép lệnh",
+    "update9routerClose": "Đóng",
+    "update9routerStart": "Cập nhật ngay",
     "edit": "Sửa",
     "remove": "Xoá",
     "empty": "Chưa lưu profile proxy nào. Native là chạy thẳng vào API của hãng.",
diff --git a/client/src/lib/api.ts b/client/src/lib/api.ts
index fe15c7c3..38d72d35 100644
--- a/client/src/lib/api.ts
+++ b/client/src/lib/api.ts
@@ -3281,6 +3281,12 @@ export const api = {
     list: () => request<{ items: AiProxy[] }>("/ai-proxies"),
     /** GET /api/ai-proxies/9router - whether a `9router` binary is installed on the server. */
     nineRouter: () => request<{ installed: boolean }>("/ai-proxies/9router"),
+    /** GET /api/ai-proxies/9router/update - versions, whether it runs, why an update would be refused, the job. */
+    nineRouterUpdateStatus: (fresh = false) =>
+      request<NineRouterUpdateStatus>(`/ai-proxies/9router/update${fresh ? "?fresh=1" : ""}`),
+    /** POST /api/ai-proxies/9router/update - shut 9router down, update it, start it again hidden (admin). */
+    nineRouterUpdate: () =>
+      request<NineRouterUpdateJob>("/ai-proxies/9router/update", { method: "POST" }),
     /** POST /api/ai-proxies - save a new profile. */
     create: (body: AiProxyInput) =>
       request<AiProxy>("/ai-proxies", { method: "POST", body: JSON.stringify(body) }),
@@ -4836,6 +4842,38 @@ export interface AiProxy {
  *  error is still a successful HTTP call: `ok` is the PROXY's verdict, `status`
  *  is its HTTP code (null when nothing answered at all), and `message` is its
  *  own words — truncated server-side, never the key. */
+/** One step of the 9router update job, in order: shutdown → update → relaunch. */
+export interface NineRouterUpdateStep {
+  id: "shutdown" | "update" | "relaunch";
+  status: "pending" | "running" | "done" | "failed" | "skipped";
+  message: string | null;
+}
+
+/** The server's one 9router update job (in memory; null before the first). */
+export interface NineRouterUpdateJob {
+  status: "running" | "done" | "failed";
+  startedAt: string;
+  finishedAt: string | null;
+  from: string | null;
+  to: string | null;
+  managedBy: "systemd" | "process" | null;
+  install: "direct" | "sudo";
+  steps: NineRouterUpdateStep[];
+  log: string;
+}
+
+/** GET /api/ai-proxies/9router/update. `blocker` is why a start would be refused now. */
+export interface NineRouterUpdateStatus {
+  installed: boolean;
+  version: string | null;
+  latest: string | null;
+  updateAvailable: boolean;
+  running: boolean;
+  managedBy: "systemd" | "process" | null;
+  blocker: { code: string; message: string; command?: string } | null;
+  job: NineRouterUpdateJob | null;
+}
+
 export interface AiProxyProbe {
   ok: boolean;
   status: number | null;
diff --git a/client/src/pages/AiProxyConfig.tsx b/client/src/pages/AiProxyConfig.tsx
index 2393822a..cd8e6f2c 100644
--- a/client/src/pages/AiProxyConfig.tsx
+++ b/client/src/pages/AiProxyConfig.tsx
@@ -30,6 +30,8 @@
  * — on the DASHBOARD's host at `NINE_ROUTER_PORT` (`nineRouterUrl`), never the
  * viewer's own localhost: a teammate on the LAN has no 9router of their own.
  * It is shown only when the server finds a `9router` binary installed.
+ * Beside it an admin gets **Update 9router** (`NineRouterUpdate`): shut it
+ * down, `npm install -g 9router@latest`, start it again hidden.
  *
  * **Test** asks the endpoint itself, once as Claude Code would
  * (`/v1/messages`) and once as Codex would (`/v1/responses`), one line each.
@@ -54,6 +56,7 @@ import { confirmDialog } from "../lib/confirm";
 import { copyText } from "../lib/clipboard";
 import { useDialog } from "../hooks/useDialog";
 import { useAuth } from "../components/AuthGate";
+import { NineRouterUpdate } from "../components/settings/NineRouterUpdate";
 
 const NINE_ROUTER_PORT = 20128;
 
@@ -271,6 +274,7 @@ export function AiProxyConfig() {
               {t("aiProxy.config9router")}
             </a>
           )}
+          {nineRouter && isAdmin && <NineRouterUpdate />}
           <button
             type="button"
             onClick={startAdd}
diff --git a/docs/API.md b/docs/API.md
index 3978811e..4cbf0740 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -3033,6 +3033,8 @@ The login profiles of the AI tools other than Claude Code (`server/lib/tool-prof
 ```
 GET    /api/ai-proxies                Every saved profile, the built-in `native` one first
 GET    /api/ai-proxies/9router        `{ installed }` — is a `9router` binary on the server's PATH (nothing is run)
+GET    /api/ai-proxies/9router/update versions, running state, `blocker`, current job (`?fresh=1` re-asks npm)
+POST   /api/ai-proxies/9router/update shut down → npm update → start hidden; 202 + job (admin)
 POST   /api/ai-proxies                Create — Body: { label, baseUrl, apiKey?, model, models?, behavesAs?, scope? }
 POST   /api/ai-proxies/test           Probe an endpoint — Body: { baseUrl, model, apiKey?, name? }
 PATCH  /api/ai-proxies/:name          Update the same fields, all optional
@@ -3055,6 +3057,11 @@ A **proxy profile** is an endpoint that stands in front of Claude Code or Codex
 
 **`GET /api/ai-proxies/9router`** answers `{ installed: boolean }` from a PATH lookup only (the server's and the login shell's PATH); the AI Proxy page shows a **Config 9router** link beside **Add profile**, opening 9router's own UI in a new tab on the dashboard's own host, port 20128 (`http://<the host the page was opened on>:20128` — e.g. `http://10.1.13.7:20128` from a LAN browser, so the viewer needs no 9router of their own; 9router must listen beyond loopback for that), only when it is `true`.
 
+**Update 9router** (`server/lib/nine-router-update.js`; the AI Proxy page's button beside Config 9router, an admin's only — `/ai-proxies/9router` and `/ai-routers/9router` are in `ADMIN_WRITE_PREFIXES`). `GET /api/ai-proxies/9router/update` answers `{ installed, version, latest, updateAvailable, running, managedBy: "systemd"|"process"|null, blocker: {code, message, command?}|null, job }`. `POST` starts one job (202; `EBUSY` while one runs, else 409 with the blocker's code — checked BEFORE anything is stopped) of three steps, each `pending|running|done|failed|skipped`:
+1. **shutdown** — a running `9router.service` user unit is `systemctl --user stop`ped; otherwise this account's processes whose argv names the install's `cli.js` get SIGTERM, then they and their descendants SIGKILL after 5 s; the step waits until the port is free. Skipped when nothing ran.
+2. **update** — `npm install -g --prefix <the install's own prefix> --prefer-online 9router@latest`; a prefix this account cannot write runs it under `sudo -n`, only when `sudo -n <npm> --version` succeeds (else `ENOPERM` with `command: "sudo npm install -g 9router@latest"`).
+3. **relaunch** — only when 9router was running before: `systemctl --user start 9router.service`, or `node cli.js --tray --no-browser --skip-update -p <old port> [-H <old host>]` detached in its own `systemd-run --user --scope` (plain detached spawn without one); done once the port answers. Runs even after a failed update.
+
 **`POST /api/ai-proxies/test`** answers the question saving cannot: does this endpoint, with this key, actually serve this model — for each CLI? It sends, in parallel and with a 15 s timeout each, one Anthropic-style message capped at a single output token to `<baseUrl>/v1/messages` (what Claude Code calls) and one OpenAI Responses call (`max_output_tokens: 16`) to `<baseUrl>/v1/responses` (what Codex calls). A proxy that answers is a `200` here whatever it replies: `{ claude: { ok, status, message }, codex: { ok, status, message } }`, each carrying the proxy's own words (truncated to 300 characters), `status` `null` when nothing answered at all. A proxy that serves only one wire shape shows one green line and one red. Only bad input is a 4xx.
 
 The stored key is only ever sent to the endpoint it was stored against. A blank `apiKey` falls back to the key of the profile named by `name`, but **only** while the submitted `baseUrl` still equals the saved one (both compared without `/v1`) — so testing a retyped endpoint needs a retyped key (`400 EBADKEY`). Without that rule this route would be a way to make the server POST a saved API key to any URL a browser names.
diff --git a/openapi.yaml b/openapi.yaml
index 83e5a5d0..5136043b 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -3,7 +3,7 @@
 openapi: 3.0.3
 info:
   title: Agent Dashboard for Claude Code API
-  version: 2.8.25
+  version: 2.8.26
   description: HTTP API for real-time Claude Code session monitoring, agent lifecycle tracking, analytics, pricing, hooks ingestion, and workflow intelligence.
   contact:
     name: Nguyễn Ngọc Trí Vĩ
@@ -19103,6 +19103,58 @@ paths:
                 properties:
                   installed:
                     type: boolean
+  /api/ai-proxies/9router/update:
+    get:
+      tags:
+        - AI Proxies
+      summary: 9router update status
+      description: 'Installed vs latest npm version of the host''s 9router, whether it runs (`managedBy`: the `9router.service` user unit or a plain process), `blocker` — why a start would be refused now (`ENOTINSTALLED`, `EUPTODATE`, `ENOLATEST`, `ENONPM`, `ENOPERM` with the `command` to run by hand, `EUNSUPPORTED`) — and the current/last job. `?fresh=1` re-asks the registry (cached 10 min).'
+      operationId: getAiProxy9routerUpdate
+      parameters:
+        - name: fresh
+          in: query
+          schema:
+            type: string
+            enum:
+              - '1'
+      responses:
+        '200':
+          description: Status.
+          content:
+            application/json:
+              schema:
+                type: object
+    post:
+      tags:
+        - AI Proxies
+      summary: Update 9router
+      description: 'Starts the one in-memory job: shut 9router down (stop the unit, or SIGTERM→SIGKILL its processes until the port is free), `npm install -g --prefix <its prefix> 9router@latest` (under `sudo -n` only when the prefix is not writable and sudo needs no password), then — only if it was running — start it again hidden (`--tray --no-browser --skip-update`). A failed update still relaunches. Admin only; same-origin guarded. Poll the GET for the steps.'
+      operationId: updateAiProxy9router
+      responses:
+        '202':
+          description: The job, running.
+          content:
+            application/json:
+              schema:
+                type: object
+        '403':
+          description: '`EADMIN`.'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '409':
+          description: '`EBUSY` or the status `blocker` code.'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '502':
+          description: '`ENOLATEST` — the npm registry did not answer.'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
   /api/ai-proxies/test:
     post:
       tags:
diff --git a/server/__tests__/nine-router-update.test.js b/server/__tests__/nine-router-update.test.js
new file mode 100644
index 00000000..8fa5467b
--- /dev/null
+++ b/server/__tests__/nine-router-update.test.js
@@ -0,0 +1,262 @@
+/**
+ * @file nine-router-update.test.js
+ * @description The **Update 9router** job (`server/lib/nine-router-update.js`)
+ * and its routes, against a FAKE 9router: a throwaway npm prefix whose `cli.js`
+ * listens on a free port and keeps a renamed child, and a fake `npm` that bumps
+ * its version. PATH is cut down so the machine's real 9router can never be
+ * found, let alone stopped — every test first checks the located install is
+ * the fake one. No systemd: the unit path is a seam turned off here.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const { describe, it, before, after, beforeEach } = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const net = require("node:net");
+const os = require("node:os");
+const path = require("node:path");
+const { spawn } = require("node:child_process");
+
+const TMP = fs.mkdtempSync(path.join(os.tmpdir(), "nine-router-update-"));
+process.env.CLAUDE_HOME = path.join(TMP, ".claude");
+const PREFIX = path.join(TMP, "prefix");
+const PKG_DIR = path.join(PREFIX, "lib", "node_modules", "9router");
+const BIN_DIR = path.join(PREFIX, "bin");
+const NPM_DIR = path.join(TMP, "npmbin");
+const ORIGINAL_PATH = process.env.PATH;
+
+const update = require("../lib/nine-router-update");
+const express = require("express");
+const router = require("../routes/ai-proxies");
+
+const CLI = `#!/usr/bin/env node
+const net = require("net");
+const { spawn } = require("child_process");
+const i = process.argv.indexOf("-p");
+const port = Number(process.argv[i + 1]);
+// A child that renames itself, like 9router's next-server.
+const child = spawn(process.execPath, ["-e", "process.title='fake-next-server'; setInterval(()=>{},1e6)"], { stdio: "ignore" });
+const srv = net.createServer((s) => s.end()).listen(port, "127.0.0.1");
+process.on("SIGTERM", () => { try { child.kill("SIGKILL"); } catch {} srv.close(); process.exit(0); });
+setInterval(() => {}, 1e6);
+`;
+
+const NPM = `#!/bin/sh
+# fake npm: --version, or install -g --prefix P ... 9router@latest
+if [ "$1" = "--version" ]; then echo 10.0.0; exit 0; fi
+while [ $# -gt 0 ]; do
+  if [ "$1" = "--prefix" ]; then P="$2"; shift; fi
+  shift
+done
+[ -f "${TMP}/npm-fail" ] && { echo "boom" >&2; exit 1; }
+echo '{"name":"9router","version":"9.9.9"}' > "$P/lib/node_modules/9router/package.json"
+echo installed
+`;
+
+function freePort() {
+  return new Promise((resolve) => {
+    const s = net.createServer().listen(0, "127.0.0.1", () => {
+      const { port } = s.address();
+      s.close(() => resolve(port));
+    });
+  });
+}
+
+const portOpen = (port) =>
+  new Promise((resolve) => {
+    const s = net.connect({ host: "127.0.0.1", port });
+    s.once("connect", () => (s.destroy(), resolve(true)));
+    s.once("error", () => resolve(false));
+  });
+
+async function until(fn, ms = 20000) {
+  const end = Date.now() + ms;
+  while (Date.now() < end) {
+    if (await fn()) return true;
+    await new Promise((r) => setTimeout(r, 100));
+  }
+  return false;
+}
+
+/** pids whose argv names the fake install — what a test must clean up. */
+function fakePids() {
+  const out = [];
+  for (const d of fs.readdirSync("/proc")) {
+    if (!/^\d+$/.test(d)) continue;
+    try {
+      const argv = fs.readFileSync(`/proc/${d}/cmdline`, "utf8");
+      if (argv.includes(TMP) || argv.includes("fake-next-server")) out.push(Number(d));
+    } catch {
+      /* gone */
+    }
+  }
+  return out.filter((p) => p !== process.pid);
+}
+
+function killFakes() {
+  for (const pid of fakePids()) {
+    try {
+      process.kill(pid, "SIGKILL");
+    } catch {
+      /* gone */
+    }
+  }
+}
+
+function startFake(port) {
+  const child = spawn(process.execPath, [path.join(PKG_DIR, "cli.js"), "--tray", "-p", String(port)], {
+    stdio: "ignore",
+    detached: true,
+  });
+  child.unref();
+  return child;
+}
+
+async function finished() {
+  await until(() => update.current()?.status !== "running", 60000);
+  return update.current();
+}
+
+let server;
+let BASE;
+
+before(async () => {
+  fs.mkdirSync(PKG_DIR, { recursive: true });
+  fs.mkdirSync(BIN_DIR, { recursive: true });
+  fs.mkdirSync(NPM_DIR, { recursive: true });
+  fs.writeFileSync(path.join(PKG_DIR, "cli.js"), CLI, { mode: 0o755 });
+  fs.symlinkSync("../lib/node_modules/9router/cli.js", path.join(BIN_DIR, "9router"));
+  fs.writeFileSync(path.join(NPM_DIR, "npm"), NPM, { mode: 0o755 });
+  // Only the fake bins, node's own dir and the basics — never /usr/local/bin.
+  process.env.PATH = [BIN_DIR, NPM_DIR, path.dirname(process.execPath), "/bin", "/usr/bin"].join(":");
+  const app = express();
+  app.use(express.json());
+  app.use("/api/ai-proxies", router);
+  await new Promise((resolve) => {
+    server = app.listen(0, "127.0.0.1", resolve);
+  });
+  BASE = `http://127.0.0.1:${server.address().port}`;
+});
+
+beforeEach(() => {
+  killFakes();
+  update.__reset();
+  fs.writeFileSync(path.join(PKG_DIR, "package.json"), JSON.stringify({ name: "9router", version: "1.0.0" }));
+  fs.rmSync(path.join(TMP, "npm-fail"), { force: true });
+  update.__setSeams({
+    useSystemd: false,
+    fetchLatest: async () => "2.0.0",
+    timing: { termGraceMs: 2000, portFreeMs: 5000, portUpMs: 15000 },
+  });
+  const loc = update.locate();
+  assert.ok(loc && loc.pkgDir.startsWith(TMP), `refusing to run against ${loc?.pkgDir}`);
+});
+
+after(() => {
+  killFakes();
+  process.env.PATH = ORIGINAL_PATH;
+  server?.close();
+  fs.rmSync(TMP, { recursive: true, force: true });
+});
+
+describe("nine-router-update", () => {
+  it("reports the install, the latest version and that nothing runs", async () => {
+    const s = await update.status();
+    assert.equal(s.installed, true);
+    assert.equal(s.version, "1.0.0");
+    assert.equal(s.latest, "2.0.0");
+    assert.equal(s.updateAvailable, true);
+    assert.equal(s.running, false);
+    assert.equal(s.blocker, null);
+  });
+
+  it("refuses when already on the latest version", async () => {
+    update.__setSeams({ fetchLatest: async () => "1.0.0" });
+    const s = await update.status();
+    assert.equal(s.blocker.code, "EUPTODATE");
+    await assert.rejects(update.start(), { code: "EUPTODATE" });
+  });
+
+  it("refuses with a manual command when the prefix is not writable and sudo asks", async () => {
+    fs.chmodSync(path.join(PREFIX, "lib", "node_modules"), 0o555);
+    update.__setSeams({
+      exec: async (file, args) =>
+        file === "sudo" ? { code: 1, stdout: "", stderr: "a password is required" } : { code: 0, stdout: "", stderr: "" },
+    });
+    try {
+      if (process.getuid?.() === 0) return; // root writes anyway
+      await assert.rejects(update.start(), (e) => e.code === "ENOPERM" && /sudo npm install -g 9router@latest/.test(e.command));
+      assert.equal(update.current(), null, "no job, so 9router was never stopped");
+    } finally {
+      fs.chmodSync(path.join(PREFIX, "lib", "node_modules"), 0o755);
+    }
+  });
+
+  it("stops a running 9router (child included), updates it, and starts it again hidden", async () => {
+    const port = await freePort();
+    startFake(port);
+    assert.ok(await until(() => portOpen(port)), "fake 9router came up");
+    assert.ok(await until(() => fakePids().length >= 2), "with its child");
+    const before = fakePids();
+
+    const job = await update.start();
+    assert.equal(job.status, "running");
+    assert.equal(job.managedBy, "process");
+    const done = await finished();
+    assert.equal(done.status, "done", done.log + JSON.stringify(done.steps));
+    assert.deepEqual(done.steps.map((s) => s.status), ["done", "done", "done"]);
+    assert.equal(done.from, "1.0.0");
+    assert.equal(done.to, "9.9.9");
+    for (const pid of before) assert.ok(!fakePids().includes(pid), `old pid ${pid} is gone`);
+    assert.ok(await portOpen(port), "relaunched on the same port");
+    // Relaunched hidden: tray mode, no browser, no self-update.
+    const argv = fakePids()
+      .map((p) => fs.readFileSync(`/proc/${p}/cmdline`, "utf8").split("\0"))
+      .find((a) => a.includes(path.join(PKG_DIR, "cli.js")));
+    for (const flag of ["--tray", "--no-browser", "--skip-update"]) assert.ok(argv.includes(flag), flag);
+  });
+
+  it("leaves 9router off when it was not running", async () => {
+    await update.start();
+    const done = await finished();
+    assert.equal(done.status, "done");
+    assert.deepEqual(done.steps.map((s) => s.status), ["skipped", "done", "skipped"]);
+    assert.equal(fakePids().length, 0);
+  });
+
+  it("still relaunches the old version when npm fails", async () => {
+    fs.writeFileSync(path.join(TMP, "npm-fail"), "");
+    const port = await freePort();
+    startFake(port);
+    assert.ok(await until(() => portOpen(port)));
+    await update.start();
+    const done = await finished();
+    assert.equal(done.status, "failed");
+    assert.deepEqual(done.steps.map((s) => s.status), ["done", "failed", "done"]);
+    assert.match(done.log, /boom/);
+    assert.ok(await portOpen(port));
+  });
+
+  it("refuses a second start while one runs", async () => {
+    const port = await freePort();
+    startFake(port);
+    assert.ok(await until(() => portOpen(port)));
+    await update.start();
+    await assert.rejects(update.start(), { code: "EBUSY" });
+    await finished();
+  });
+});
+
+describe("routes /api/ai-proxies/9router/update", () => {
+  it("GET reports status, POST starts and answers 202, a refusal is a 409", async () => {
+    const s = await (await fetch(`${BASE}/api/ai-proxies/9router/update`)).json();
+    assert.equal(s.version, "1.0.0");
+    const r = await fetch(`${BASE}/api/ai-proxies/9router/update`, { method: "POST" });
+    assert.equal(r.status, 202);
+    await finished();
+    update.__setSeams({ fetchLatest: async () => "9.9.9" });
+    const again = await fetch(`${BASE}/api/ai-proxies/9router/update`, { method: "POST" });
+    assert.equal(again.status, 409);
+    assert.equal((await again.json()).error.code, "EUPTODATE");
+  });
+});
diff --git a/server/lib/auth.js b/server/lib/auth.js
index 6752607a..a6405fb8 100644
--- a/server/lib/auth.js
+++ b/server/lib/auth.js
@@ -80,6 +80,9 @@ const ADMIN_WRITE_PREFIXES = [
   "/accounts",
   // Alert rules and budgets fire for every user's sessions.
   "/alerts/rules",
+  // Stopping, updating and restarting the host's 9router (both mounts).
+  "/ai-proxies/9router",
+  "/ai-routers/9router",
 ];
 
 /**
diff --git a/server/lib/nine-router-update.js b/server/lib/nine-router-update.js
new file mode 100644
index 00000000..5f35fee9
--- /dev/null
+++ b/server/lib/nine-router-update.js
@@ -0,0 +1,507 @@
+/**
+ * @file nine-router-update.js
+ * @description The **Update 9router** button of Settings → AI Proxy: one
+ * in-memory job that shuts the host's 9router down, updates its npm package and
+ * starts it again hidden — in that order, because 9router's own updater relaunches
+ * through `npx` and kills by `ps aux | grep`, which neither respects a
+ * `9router.service` user unit (`Restart=always` would fight it) nor leaves a
+ * pane alone.
+ *
+ * Steps:
+ *   1. **shutdown** — disconnect every client by stopping 9router: a running
+ *      `9router.service` user unit is `systemctl --user stop`ped; otherwise the
+ *      9router processes of THIS account (matched by the install's own path in
+ *      their argv, never by name) get SIGTERM — its CLI kills its server and tray
+ *      icon on that — then SIGKILL after a grace period, until the port is free.
+ *   2. **update** — `npm install -g --prefix <its own prefix> 9router@latest`, so
+ *      the copy that is updated is the one that runs. A prefix this account
+ *      cannot write runs the same argv under `sudo -n`, and only when sudoers
+ *      already allows that npm without a password (probed BEFORE step 1 with
+ *      `sudo -n <npm> --version`, so a refused update never leaves 9router
+ *      down); otherwise
+ *      the start is refused with the command to run by hand.
+ *   3. **relaunch** — only when 9router was running before step 1: the unit is
+ *      started again, or `cli.js --tray --no-browser --skip-update -p <port>` is
+ *      spawned detached (inside its own `systemd-run --user --scope` on Linux, so
+ *      a dashboard restart never takes it along). A failed update still
+ *      relaunches — the old version is better than none.
+ *
+ * Nothing here takes a command, path or package name from a request: the
+ * package is always `9router`, its location comes from PATH.
+ *
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const fs = require("node:fs");
+const net = require("node:net");
+const path = require("node:path");
+const { execFile, spawn } = require("node:child_process");
+
+const aiTools = require("./ai-tools");
+const versions = require("./ai-tool-versions");
+const { compareVersions } = require("./update-check");
+const { desktopEnv } = require("./desktop-env");
+
+const PKG = "9router";
+const UNIT = "9router.service";
+const DEFAULT_PORT = 20128;
+const LATEST_CACHE_MS = 10 * 60 * 1000;
+const LOG_CAP = 128 * 1024;
+const STEPS = ["shutdown", "update", "relaunch"];
+
+const timing = {
+  installTimeoutMs: 10 * 60 * 1000,
+  termGraceMs: 5000,
+  portFreeMs: 15000,
+  portUpMs: 45000,
+};
+
+const makeErr = (code, message, extra = {}) =>
+  Object.assign(new Error(message), { code }, extra);
+
+/** execFile as a promise that never rejects: `{code, stdout, stderr}`. */
+const realExec = (file, args, opts = {}) =>
+  new Promise((resolve) => {
+    execFile(file, args, { encoding: "utf8", timeout: 10000, ...opts }, (err, stdout, stderr) =>
+      resolve({
+        code: err ? (typeof err.code === "number" ? err.code : 1) : 0,
+        stdout: String(stdout || ""),
+        stderr: String(stderr || err?.message || ""),
+      })
+    );
+  });
+
+// Seams (tests): command runner, the systemd user manager, the latest-version
+// lookup, and whether a relaunch may use systemd-run.
+let exec = realExec;
+let useSystemd = process.platform === "linux";
+let fetchLatestImpl = async () => {
+  const r = await fetch(`https://registry.npmjs.org/${PKG}/latest`, {
+    signal: AbortSignal.timeout(5000),
+  });
+  if (!r.ok) return null;
+  const v = (await r.json())?.version;
+  return typeof v === "string" ? v : null;
+};
+
+let job = null;
+let latestCache = null; // { at, version }
+
+/** The env a `systemctl --user` needs; a server started outside a login lacks XDG_RUNTIME_DIR. */
+function userEnv() {
+  const env = { ...process.env, PATH: versions.jobPath() };
+  if (!env.XDG_RUNTIME_DIR && typeof process.getuid === "function") {
+    const dir = `/run/user/${process.getuid()}`;
+    if (fs.existsSync(dir)) env.XDG_RUNTIME_DIR = dir;
+  }
+  return env;
+}
+
+/**
+ * Where 9router is installed: `{bin, cli, pkgDir, prefix, version}`, or null.
+ * `prefix` is null for a layout that is not an npm global install
+ * (`<prefix>/lib/node_modules/9router`), which this updater does not touch.
+ */
+function locate() {
+  const bin = aiTools.which(PKG, versions.jobPath());
+  if (!bin) return null;
+  let cli;
+  try {
+    cli = fs.realpathSync(bin);
+  } catch {
+    return null;
+  }
+  const pkgDir = path.dirname(cli);
+  let version = null;
+  try {
+    const pkg = JSON.parse(fs.readFileSync(path.join(pkgDir, "package.json"), "utf8"));
+    if (pkg.name !== PKG) return null;
+    version = typeof pkg.version === "string" ? pkg.version : null;
+  } catch {
+    return null;
+  }
+  const nm = path.dirname(pkgDir);
+  const lib = path.dirname(nm);
+  const prefix =
+    path.basename(nm) === "node_modules" && path.basename(lib) === "lib" ? path.dirname(lib) : null;
+  return { bin, cli, pkgDir, prefix, version };
+}
+
+/** Whether this account can write `dir`. */
+function canWrite(dir) {
+  try {
+    fs.accessSync(dir, fs.constants.W_OK);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+const npmArgs = (prefix) => ["install", "-g", "--prefix", prefix, "--prefer-online", `${PKG}@latest`];
+
+/** `direct` (we can write the prefix), `sudo` (passwordless sudo allows it), or null. */
+async function installMode(loc, npm) {
+  if (canWrite(path.join(loc.prefix, "lib", "node_modules")) && canWrite(path.join(loc.prefix, "bin")))
+    return "direct";
+  // `sudo -l` would answer yes for a rule that still asks for a password, so
+  // the probe is a harmless real run of the same npm.
+  const r = await exec("sudo", ["-n", "--", npm, "--version"], { timeout: 10000 });
+  return r.code === 0 ? "sudo" : null;
+}
+
+/** Whether the `9router.service` user unit is running. */
+async function unitActive() {
+  if (!useSystemd) return false;
+  const r = await exec("systemctl", ["--user", "is-active", "--quiet", UNIT], {
+    env: userEnv(),
+    timeout: 5000,
+  });
+  return r.code === 0;
+}
+
+/**
+ * This account's 9router processes — those whose argv names the install itself.
+ * `roots` are its CLI (argv carries cli.js or the bin link): SIGTERM lets each
+ * stop its own server and tray; `all` adds their descendants, for the SIGKILL.
+ */
+async function findProcesses(loc) {
+  const uid = typeof process.getuid === "function" ? String(process.getuid()) : null;
+  const r = await exec("ps", ["-ww", ...(uid ? ["-U", uid] : ["-e"]), "-o", "pid=,ppid=,args="], {
+    timeout: 5000,
+  });
+  const rows = [];
+  for (const line of r.stdout.split("\n")) {
+    const m = line.trim().match(/^(\d+)\s+(\d+)\s+(.*)$/);
+    if (m && Number(m[1]) !== process.pid)
+      rows.push({ pid: Number(m[1]), ppid: Number(m[2]), argv: m[3].split(/\s+/) });
+  }
+  const roots = [];
+  let port = null;
+  let host = null;
+  for (const { pid, argv } of rows) {
+    if (!argv.some((a) => a === loc.cli || a === loc.bin)) continue;
+    roots.push(pid);
+    const pi = argv.findIndex((a) => a === "-p" || a === "--port");
+    if (pi >= 0 && /^\d{2,5}$/.test(argv[pi + 1] || "")) port = Number(argv[pi + 1]);
+    const hi = argv.findIndex((a) => a === "-H" || a === "--host");
+    if (hi >= 0 && /^[\w.:-]+$/.test(argv[hi + 1] || "")) host = argv[hi + 1];
+  }
+  // Its server renames itself (`next-server`), so children are found by parent,
+  // plus anything still running from inside the install.
+  const all = new Set(roots);
+  for (const { pid, argv } of rows) if (argv.some((a) => a.startsWith(loc.pkgDir + path.sep))) all.add(pid);
+  for (let grew = true; grew; ) {
+    grew = false;
+    for (const { pid, ppid } of rows)
+      if (all.has(ppid) && !all.has(pid)) {
+        all.add(pid);
+        grew = true;
+      }
+  }
+  return { roots, all: [...all], port, host };
+}
+
+/** Whether something answers on 127.0.0.1:`port`. */
+const portOpen = (port) =>
+  new Promise((resolve) => {
+    const s = net.connect({ host: "127.0.0.1", port });
+    const done = (v) => {
+      s.destroy();
+      resolve(v);
+    };
+    s.setTimeout(1000, () => done(false));
+    s.once("connect", () => done(true));
+    s.once("error", () => done(false));
+  });
+
+async function waitFor(check, ms) {
+  const until = Date.now() + ms;
+  for (;;) {
+    if (await check()) return true;
+    if (Date.now() >= until) return false;
+    await new Promise((r) => setTimeout(r, 300));
+  }
+}
+
+const alive = (pid) => {
+  try {
+    process.kill(pid, 0);
+    return true;
+  } catch {
+    return false;
+  }
+};
+
+const signal = (pids, sig) => {
+  for (const pid of pids) {
+    try {
+      process.kill(pid, sig);
+    } catch {
+      /* gone already */
+    }
+  }
+};
+
+async function latestVersion({ fresh = false } = {}) {
+  if (!fresh && latestCache && Date.now() - latestCache.at < LATEST_CACHE_MS) return latestCache.version;
+  let version = null;
+  try {
+    version = await fetchLatestImpl();
+  } catch {
+    version = null;
+  }
+  latestCache = { at: Date.now(), version };
+  return version;
+}
+
+/** The public view of the job (a copy). */
+const view = (j) => (j ? JSON.parse(JSON.stringify(j)) : null);
+
+/**
+ * What the page shows: `{installed, version, latest, updateAvailable, running,
+ * managedBy, blocker, job}`. `blocker` (`{code, message, command?}`) is why a
+ * start would be refused right now; `command` is the one to run by hand.
+ */
+async function status({ fresh = false } = {}) {
+  const loc = locate();
+  if (!loc) {
+    return { installed: false, version: null, latest: null, updateAvailable: false, running: false, managedBy: null, blocker: { code: "ENOTINSTALLED", message: "9router is not installed on this machine" }, job: view(job) };
+  }
+  const [latest, unit, procs] = await Promise.all([
+    latestVersion({ fresh }),
+    unitActive(),
+    findProcesses(loc),
+  ]);
+  const updateAvailable = Boolean(latest && loc.version && compareVersions(latest, loc.version) > 0);
+  const manual = `sudo npm install -g ${PKG}@latest`;
+  let blocker = null;
+  if (process.platform === "win32") {
+    blocker = { code: "EUNSUPPORTED", message: "updating 9router from AgentHub is not supported on Windows" };
+  } else if (!loc.prefix) {
+    blocker = { code: "EUNSUPPORTED", message: `9router at ${loc.pkgDir} is not an npm global install` };
+  } else if (!updateAvailable) {
+    blocker = latest
+      ? { code: "EUPTODATE", message: `9router ${loc.version} is the latest version` }
+      : { code: "ENOLATEST", message: "the npm registry could not be reached" };
+  } else {
+    const npm = versions.npmBin();
+    if (!npm) blocker = { code: "ENONPM", message: "npm was not found on the login shell's PATH" };
+    else if (!(await installMode(loc, npm)))
+      blocker = {
+        code: "ENOPERM",
+        message: `${loc.prefix} is not writable by this account and sudo needs a password`,
+        command: manual,
+      };
+  }
+  return {
+    installed: true,
+    version: loc.version,
+    latest,
+    updateAvailable,
+    running: unit || procs.roots.length > 0,
+    managedBy: unit ? "systemd" : procs.roots.length ? "process" : null,
+    blocker,
+    job: view(job),
+  };
+}
+
+function step(id) {
+  return job.steps.find((s) => s.id === id);
+}
+
+function log(text) {
+  job.log = (job.log + text).slice(-LOG_CAP);
+}
+
+function setStep(id, state, message) {
+  const s = step(id);
+  s.status = state;
+  if (message !== undefined) s.message = message;
+}
+
+async function doShutdown(loc, unit, procs) {
+  if (unit) {
+    const r = await exec("systemctl", ["--user", "stop", UNIT], { env: userEnv(), timeout: 30000 });
+    if (r.code !== 0) throw makeErr("ESTOP", `systemctl --user stop ${UNIT}: ${r.stderr.trim()}`);
+  } else {
+    signal(procs.roots, "SIGTERM");
+    await waitFor(async () => !procs.roots.some(alive), timing.termGraceMs);
+    // Whatever survived (and any child the CLI did not take down), by force.
+    const left = (await findProcesses(loc)).all;
+    signal([...new Set([...procs.all, ...left])].filter(alive), "SIGKILL");
+  }
+  const port = procs.port || DEFAULT_PORT;
+  if (!(await waitFor(async () => !(await portOpen(port)), timing.portFreeMs)))
+    throw makeErr("EPORTBUSY", `port ${port} is still in use after 9router stopped`);
+}
+
+/** Run npm, streaming its output into the job log. Resolves its exit code. */
+function runInstall(argv) {
+  return new Promise((resolve) => {
+    log(`$ ${argv.join(" ")}\n`);
+    const child = spawn(argv[0], argv.slice(1), {
+      stdio: ["ignore", "pipe", "pipe"],
+      env: { ...process.env, PATH: versions.jobPath() },
+      detached: true,
+    });
+    const timer = setTimeout(() => {
+      log("\n[agenthub] npm timed out\n");
+      try {
+        process.kill(-child.pid, "SIGKILL");
+      } catch {
+        /* gone */
+      }
+    }, timing.installTimeoutMs);
+    child.stdout.on("data", (d) => log(String(d)));
+    child.stderr.on("data", (d) => log(String(d)));
+    child.on("error", (e) => {
+      clearTimeout(timer);
+      log(`\n${e.message}\n`);
+      resolve(1);
+    });
+    child.on("close", (code) => {
+      clearTimeout(timer);
+      resolve(code ?? 1);
+    });
+  });
+}
+
+/** Start 9router hidden, detached from this server. */
+async function launchHidden(loc, procs) {
+  const node = aiTools.which("node", versions.jobPath()) || process.execPath;
+  const port = procs.port || DEFAULT_PORT;
+  const args = ["--dns-result-order=ipv4first", loc.cli, "--tray", "--no-browser", "--skip-update", "-p", String(port)];
+  if (procs.host) args.push("-H", procs.host);
+  const env = { ...userEnv(), ...desktopEnv() };
+  delete env.TRAY_MODE;
+  const spawnDetached = (file, argv) => {
+    const child = spawn(file, argv, { detached: true, stdio: "ignore", env, cwd: loc.pkgDir });
+    child.unref();
+    return child;
+  };
+  const systemdRun = useSystemd && env.XDG_RUNTIME_DIR && aiTools.which("systemd-run", env.PATH);
+  if (systemdRun) {
+    const child = spawnDetached(systemdRun, ["--user", "--scope", "--quiet", "--collect", "--description=9Router", "--", node, ...args]);
+    // A scope that cannot be created exits at once; anything else is 9router running.
+    const failed = await new Promise((resolve) => {
+      const t = setTimeout(() => resolve(false), 1500);
+      child.once("exit", (code) => {
+        clearTimeout(t);
+        resolve(code !== 0);
+      });
+      child.once("error", () => {
+        clearTimeout(t);
+        resolve(true);
+      });
+    });
+    if (!failed) return port;
+    log("[agenthub] systemd-run --user --scope failed; starting 9router directly\n");
+  }
+  spawnDetached(node, args);
+  return port;
+}
+
+async function doRelaunch(loc, unit, procs) {
+  let port = procs.port || DEFAULT_PORT;
+  if (unit) {
+    const r = await exec("systemctl", ["--user", "start", UNIT], { env: userEnv(), timeout: 30000 });
+    if (r.code !== 0) throw makeErr("ESTART", `systemctl --user start ${UNIT}: ${r.stderr.trim()}`);
+  } else {
+    port = await launchHidden(loc, procs);
+  }
+  if (!(await waitFor(() => portOpen(port), timing.portUpMs)))
+    throw makeErr("ENOTUP", `9router did not answer on port ${port}`);
+}
+
+async function runJob(loc, npm, mode, unit, procs) {
+  const wasRunning = unit || procs.roots.length > 0;
+  let failed = false;
+  if (!wasRunning) setStep("shutdown", "skipped", "9router was not running");
+  else {
+    setStep("shutdown", "running");
+    try {
+      await doShutdown(loc, unit, procs);
+      setStep("shutdown", "done");
+    } catch (e) {
+      // Still running (or unknown): updating underneath it is not safe.
+      setStep("shutdown", "failed", e.message);
+      setStep("update", "skipped");
+      failed = true;
+    }
+  }
+  if (!failed) {
+    setStep("update", "running");
+    const argv = [npm, ...npmArgs(loc.prefix)];
+    const code = await runInstall(mode === "sudo" ? ["sudo", "-n", "--", ...argv] : argv);
+    const after = locate();
+    job.to = after?.version || null;
+    if (code === 0) setStep("update", "done", job.to ? `${job.from} → ${job.to}` : undefined);
+    else {
+      setStep("update", "failed", `npm exited with code ${code}`);
+      failed = true;
+    }
+  }
+  if (!wasRunning) setStep("relaunch", "skipped", "9router was not running before the update");
+  else {
+    setStep("relaunch", "running");
+    try {
+      await doRelaunch(locate() || loc, unit, procs);
+      setStep("relaunch", "done");
+    } catch (e) {
+      setStep("relaunch", "failed", e.message);
+      failed = true;
+    }
+  }
+  job.status = failed ? "failed" : "done";
+  job.finishedAt = new Date().toISOString();
+  latestCache = null;
+}
+
+/** Start the update; refuses (with the status blocker's code) when it cannot run. */
+async function start() {
+  if (job?.status === "running") throw makeErr("EBUSY", "a 9router update is already running");
+  const s = await status({ fresh: true });
+  if (job?.status === "running") throw makeErr("EBUSY", "a 9router update is already running");
+  if (s.blocker) throw makeErr(s.blocker.code, s.blocker.message, s.blocker.command ? { command: s.blocker.command } : {});
+  const loc = locate();
+  const npm = versions.npmBin();
+  const mode = await installMode(loc, npm);
+  if (!mode) throw makeErr("ENOPERM", "the npm prefix is not writable and sudo needs a password");
+  const unit = await unitActive();
+  const procs = await findProcesses(loc);
+  job = {
+    status: "running",
+    startedAt: new Date().toISOString(),
+    finishedAt: null,
+    from: loc.version,
+    to: null,
+    managedBy: unit ? "systemd" : procs.roots.length ? "process" : null,
+    install: mode,
+    steps: STEPS.map((id) => ({ id, status: "pending", message: null })),
+    log: "",
+  };
+  runJob(loc, npm, mode, unit, procs).catch((e) => {
+    job.status = "failed";
+    job.finishedAt = new Date().toISOString();
+    log(`\n${e.message}\n`);
+  });
+  return view(job);
+}
+
+const current = () => view(job);
+
+function __setSeams({ exec: e, useSystemd: u, fetchLatest, timing: t } = {}) {
+  if (e) exec = e;
+  if (u !== undefined) useSystemd = u;
+  if (fetchLatest) fetchLatestImpl = fetchLatest;
+  if (t) Object.assign(timing, t);
+  latestCache = null;
+}
+
+function __reset() {
+  job = null;
+  latestCache = null;
+  exec = realExec;
+}
+
+module.exports = { status, start, current, locate, STEPS, __setSeams, __reset };
diff --git a/server/openapi-extra/tools-more.js b/server/openapi-extra/tools-more.js
index 26d8951c..47408fd0 100644
--- a/server/openapi-extra/tools-more.js
+++ b/server/openapi-extra/tools-more.js
@@ -324,6 +324,30 @@ const paths = {
       },
     },
   },
+  "/api/ai-proxies/9router/update": {
+    get: {
+      tags: ["AI Proxies"],
+      summary: "9router update status",
+      description:
+        "Installed vs latest npm version of the host's 9router, whether it runs (`managedBy`: the `9router.service` user unit or a plain process), `blocker` — why a start would be refused now (`ENOTINSTALLED`, `EUPTODATE`, `ENOLATEST`, `ENONPM`, `ENOPERM` with the `command` to run by hand, `EUNSUPPORTED`) — and the current/last job. `?fresh=1` re-asks the registry (cached 10 min).",
+      operationId: "getAiProxy9routerUpdate",
+      parameters: [{ name: "fresh", in: "query", schema: { type: "string", enum: ["1"] } }],
+      responses: { 200: json({ type: "object" }, "Status.") },
+    },
+    post: {
+      tags: ["AI Proxies"],
+      summary: "Update 9router",
+      description:
+        "Starts the one in-memory job: shut 9router down (stop the unit, or SIGTERM→SIGKILL its processes until the port is free), `npm install -g --prefix <its prefix> 9router@latest` (under `sudo -n` only when the prefix is not writable and sudo needs no password), then — only if it was running — start it again hidden (`--tray --no-browser --skip-update`). A failed update still relaunches. Admin only; same-origin guarded. Poll the GET for the steps.",
+      operationId: "updateAiProxy9router",
+      responses: {
+        202: json({ type: "object" }, "The job, running."),
+        403: errResp("`EADMIN`."),
+        409: errResp("`EBUSY` or the status `blocker` code."),
+        502: errResp("`ENOLATEST` — the npm registry did not answer."),
+      },
+    },
+  },
   "/api/ai-proxies/test": {
     post: {
       tags: ["AI Proxies"],
diff --git a/server/routes/ai-proxies.js b/server/routes/ai-proxies.js
index 6314cfd2..b07eea14 100644
--- a/server/routes/ai-proxies.js
+++ b/server/routes/ai-proxies.js
@@ -24,6 +24,9 @@
  *
  * `GET /9router` only says whether a `9router` binary is on the server's PATH,
  * so the page can offer a link to its own config UI; it never runs it.
+ * `GET|POST /9router/update` reports on / starts the **Update 9router** job
+ * (`server/lib/nine-router-update.js`: shut down, `npm install -g`, start again
+ * hidden) — the host's own 9router, so starting one is an admin's only.
  *
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
@@ -36,6 +39,7 @@ const { refreshProfileFiles, removeProfileFiles } = require("../lib/proxy-apply"
 const { sameOriginGuard } = require("../lib/same-origin");
 const { which } = require("../lib/ai-tools");
 const { shellPath } = require("../lib/shell-path");
+const nineRouterUpdate = require("../lib/nine-router-update");
 
 const router = express.Router();
 
@@ -49,6 +53,13 @@ const ERR_TO_STATUS = {
   EBUILTIN: 409,
   ENOTFOUND: 404,
   EADMIN: 403,
+  EBUSY: 409,
+  ENOTINSTALLED: 409,
+  EUPTODATE: 409,
+  ENOLATEST: 502,
+  ENONPM: 409,
+  ENOPERM: 409,
+  EUNSUPPORTED: 409,
 };
 
 const notFound = (name) =>
@@ -68,7 +79,9 @@ function assertMayWrite(req, name) {
 
 function fail(res, e) {
   const status = ERR_TO_STATUS[e.code] || 500;
-  return res.status(status).json({ error: { code: e.code || "EINTERNAL", message: e.message } });
+  const error = { code: e.code || "EINTERNAL", message: e.message };
+  if (e.command) error.command = e.command;
+  return res.status(status).json({ error });
 }
 
 // GET /api/ai-proxies — every profile, built-in `native` first. Never a key.
@@ -87,6 +100,29 @@ router.get("/9router", (_req, res) => {
   res.json({ installed: Boolean(which("9router", pathStr)) });
 });
 
+// GET /api/ai-proxies/9router/update — installed vs latest version, whether
+// it runs (and under what), why an update would be refused now (`blocker`),
+// and the last/current update job. `?fresh=1` re-asks the npm registry.
+router.get("/9router/update", async (req, res) => {
+  try {
+    res.json(await nineRouterUpdate.status({ fresh: req.query.fresh === "1" }));
+  } catch (e) {
+    return fail(res, e);
+  }
+});
+
+// POST /api/ai-proxies/9router/update — start the job; 202 with it. Poll the
+// GET above for its steps. Admin only (also in auth.js ADMIN_WRITE_PREFIXES).
+router.post("/9router/update", sameOriginGuard, async (req, res) => {
+  try {
+    if (req.user && req.user.role !== "admin")
+      throw Object.assign(new Error("only an admin may update 9router"), { code: "EADMIN" });
+    res.status(202).json(await nineRouterUpdate.start());
+  } catch (e) {
+    return fail(res, e);
+  }
+});
+
 // POST /api/ai-proxies — body: { label, baseUrl, apiKey?, model, models?,
 // behavesAs?, scope? }. `scope` is "shared" (an admin's default) or "personal"
 // (a member's only choice); local mode has no user and always writes shared.