diff --git a/src/tui/tui-auth-child-pty.e2e.test.ts b/src/tui/tui-auth-child-pty.e2e.test.ts
new file mode 100644
index 000000000000..a1ebeab2bec9
--- /dev/null
+++ b/src/tui/tui-auth-child-pty.e2e.test.ts
@@ -0,0 +1,107 @@
+import { chmod, mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { sleep } from "../utils/sleep.js";
+import {
+  disposeActiveTuiFixtures,
+  startTuiFixture,
+} from "./tui-pty-harness-fixture-test-support.js";
+
+const STARTUP_TIMEOUT_MS = 60_000;
+const EXIT_TIMEOUT_MS = 4_000;
+const tempDirs: string[] = [];
+
+async function createCodexFixture(exitMs?: number) {
+  const dir = await mkdtemp(path.join(tmpdir(), "openclaw-tui-auth-"));
+  tempDirs.push(dir);
+  const scriptPath = path.join(dir, "codex-fixture.cjs");
+  await writeFile(
+    scriptPath,
+    [
+      'console.log("AUTH_CHILD_STARTED:" + process.pid);',
+      exitMs === undefined
+        ? "setInterval(() => {}, 1000);"
+        : `setTimeout(() => process.exit(0), ${String(exitMs)});`,
+    ].join("\n"),
+    "utf8",
+  );
+  if (process.platform === "win32") {
+    await writeFile(
+      path.join(dir, "codex.cmd"),
+      `@"${process.execPath}" "${scriptPath}" %*\r\n`,
+      "utf8",
+    );
+  } else {
+    const launcherPath = path.join(dir, "codex");
+    await writeFile(launcherPath, `#!/bin/sh\nexec "${process.execPath}" "${scriptPath}" "$@"\n`);
+    await chmod(launcherPath, 0o755);
+  }
+  return {
+    pathEnv: `${dir}${path.delimiter}${process.env.PATH ?? ""}`,
+  };
+}
+
+async function waitForProcessExit(pid: number, timeoutMs: number): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    try {
+      process.kill(pid, 0);
+    } catch {
+      return;
+    }
+    await sleep(10);
+  }
+  throw new Error(`auth child ${String(pid)} remained alive`);
+}
+
+describe.sequential("TUI auth child lifecycle", () => {
+  afterEach(async () => {
+    await disposeActiveTuiFixtures();
+    for (const dir of tempDirs.splice(0)) {
+      await rm(dir, { recursive: true, force: true });
+    }
+  });
+
+  it.skipIf(process.platform === "win32")(
+    "terminates the foreground auth child when SIGTERM exits the TUI",
+    async () => {
+      const auth = await createCodexFixture();
+      const fixture = await startTuiFixture({
+        env: {
+          PATH: auth.pathEnv,
+        },
+      });
+      await fixture.run.waitForOutput("local ready", STARTUP_TIMEOUT_MS);
+      await fixture.run.write("/auth openai\r", { delay: false });
+      await fixture.run.waitForOutput("AUTH_CHILD_STARTED:", STARTUP_TIMEOUT_MS);
+      const pidMatch = fixture.run.visibleOutput().match(/AUTH_CHILD_STARTED:(\d+)/u);
+      expect(pidMatch).not.toBeNull();
+      const authPid = Number(pidMatch?.[1]);
+
+      process.kill(fixture.run.pid, "SIGTERM");
+
+      await expect(fixture.run.waitForExit(EXIT_TIMEOUT_MS)).resolves.toBeDefined();
+      await expect(waitForProcessExit(authPid, 750)).resolves.toBeUndefined();
+    },
+    STARTUP_TIMEOUT_MS + EXIT_TIMEOUT_MS,
+  );
+
+  it(
+    "resumes the TUI after normal auth completion",
+    async () => {
+      const auth = await createCodexFixture(50);
+      const fixture = await startTuiFixture({
+        env: {
+          PATH: auth.pathEnv,
+        },
+      });
+      await fixture.run.waitForOutput("local ready", STARTUP_TIMEOUT_MS);
+      await fixture.run.write("/auth openai\r", { delay: false });
+      await fixture.run.waitForOutput("auth flow finished for openai", STARTUP_TIMEOUT_MS);
+      await fixture.run.write("/gateway-status\r", { delay: false });
+      await fixture.run.waitForOutput("fixture gateway ok", STARTUP_TIMEOUT_MS);
+    },
+    STARTUP_TIMEOUT_MS * 2,
+  );
+});
diff --git a/src/tui/tui-auth-child.test.ts b/src/tui/tui-auth-child.test.ts
new file mode 100644
index 000000000000..d7bcd79f31d6
--- /dev/null
+++ b/src/tui/tui-auth-child.test.ts
@@ -0,0 +1,98 @@
+import type { ChildProcess } from "node:child_process";
+import { EventEmitter } from "node:events";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+const killTreeMocks = vi.hoisted(() => ({ signalProcessTree: vi.fn() }));
+
+vi.mock("../process/kill-tree.js", () => ({
+  signalProcessTree: killTreeMocks.signalProcessTree,
+}));
+
+import { createTuiAuthChildOwner } from "./tui-auth-child.js";
+
+function createChild(pid: number): ChildProcess {
+  return Object.assign(new EventEmitter(), {
+    exitCode: null,
+    kill: vi.fn(),
+    pid,
+    signalCode: null,
+  }) as unknown as ChildProcess;
+}
+
+function emitExit(
+  child: ChildProcess,
+  exitCode: number | null,
+  signal: NodeJS.Signals | null,
+): void {
+  Object.assign(child, { exitCode, signalCode: signal });
+  child.emit("exit", exitCode, signal);
+}
+
+describe("TUI auth child owner", () => {
+  afterEach(() => {
+    killTreeMocks.signalProcessTree.mockReset();
+  });
+
+  it("does not spawn after terminal close", async () => {
+    const owner = createTuiAuthChildOwner();
+    const spawnChild = vi.fn(() => createChild(101));
+    owner.close();
+
+    await expect(owner.spawnAndWait(spawnChild)).rejects.toThrow("owner is closed");
+    expect(spawnChild).not.toHaveBeenCalled();
+    expect(owner.running).toBe(false);
+  });
+
+  it("waits for normal completion and releases the exact child", async () => {
+    const owner = createTuiAuthChildOwner();
+    const child = createChild(102);
+    const result = owner.spawnAndWait(() => child);
+    expect(owner.running).toBe(true);
+    const secondSpawn = vi.fn(() => createChild(202));
+    await expect(owner.spawnAndWait(secondSpawn)).rejects.toThrow("already running");
+    expect(secondSpawn).not.toHaveBeenCalled();
+
+    emitExit(child, 0, null);
+
+    await expect(result).resolves.toEqual({ exitCode: 0, signal: null });
+    expect(owner.running).toBe(false);
+    expect(killTreeMocks.signalProcessTree).not.toHaveBeenCalled();
+  });
+
+  it("cancels gracefully, then force-kills only the still-active child", async () => {
+    const owner = createTuiAuthChildOwner();
+    const child = createChild(103);
+    const result = owner.spawnAndWait(() => child);
+
+    owner.close();
+    owner.close();
+
+    expect(killTreeMocks.signalProcessTree).toHaveBeenCalledTimes(1);
+    expect(killTreeMocks.signalProcessTree).toHaveBeenCalledWith(103, "SIGTERM", {
+      detached: false,
+    });
+    await new Promise((resolve) => {
+      setTimeout(resolve, 1_050);
+    });
+    expect(killTreeMocks.signalProcessTree).toHaveBeenLastCalledWith(103, "SIGKILL", {
+      detached: false,
+    });
+
+    emitExit(child, null, "SIGKILL");
+    await expect(result).resolves.toEqual({ exitCode: null, signal: "SIGKILL" });
+  });
+
+  it("clears force escalation when the owned child exits", async () => {
+    const owner = createTuiAuthChildOwner();
+    const child = createChild(104);
+    const result = owner.spawnAndWait(() => child);
+    owner.close();
+    emitExit(child, null, "SIGTERM");
+
+    await expect(result).resolves.toEqual({ exitCode: null, signal: "SIGTERM" });
+    await new Promise((resolve) => {
+      setTimeout(resolve, 1_050);
+    });
+    expect(killTreeMocks.signalProcessTree).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/src/tui/tui-auth-child.ts b/src/tui/tui-auth-child.ts
new file mode 100644
index 000000000000..2d19a8b0c644
--- /dev/null
+++ b/src/tui/tui-auth-child.ts
@@ -0,0 +1,95 @@
+import type { ChildProcess } from "node:child_process";
+import { signalProcessTree } from "../process/kill-tree.js";
+
+const AUTH_CHILD_FORCE_EXIT_MS = 1_000;
+
+type TuiAuthChildResult = {
+  exitCode: number | null;
+  signal: NodeJS.Signals | null;
+};
+
+type ActiveAuthChild = {
+  child: ChildProcess;
+  forceTimer?: ReturnType<typeof setTimeout>;
+};
+
+function isChildRunning(child: ChildProcess): boolean {
+  return child.exitCode === null && child.signalCode === null;
+}
+
+function signalAuthChild(child: ChildProcess, signal: "SIGTERM" | "SIGKILL"): void {
+  if (child.pid) {
+    // Auth shares the TUI foreground process group. POSIX must target only this PID;
+    // Windows uses taskkill /T here so a cmd.exe launcher cannot strand its CLI child.
+    signalProcessTree(child.pid, signal, { detached: false });
+    return;
+  }
+  child.kill(signal);
+}
+
+export function createTuiAuthChildOwner() {
+  let active: ActiveAuthChild | null = null;
+  let closed = false;
+
+  const clearActive = (owned: ActiveAuthChild): void => {
+    if (owned.forceTimer) {
+      clearTimeout(owned.forceTimer);
+      owned.forceTimer = undefined;
+    }
+    if (active === owned) {
+      active = null;
+    }
+  };
+
+  const cancel = (owned: ActiveAuthChild): void => {
+    if (!isChildRunning(owned.child)) {
+      return;
+    }
+    signalAuthChild(owned.child, "SIGTERM");
+    owned.forceTimer = setTimeout(() => {
+      if (active !== owned || !isChildRunning(owned.child)) {
+        return;
+      }
+      signalAuthChild(owned.child, "SIGKILL");
+    }, AUTH_CHILD_FORCE_EXIT_MS);
+    owned.forceTimer.unref?.();
+  };
+
+  return {
+    get running(): boolean {
+      return active !== null && isChildRunning(active.child);
+    },
+    spawnAndWait: async (spawnChild: () => ChildProcess): Promise<TuiAuthChildResult> => {
+      if (closed) {
+        throw new Error("TUI auth child owner is closed");
+      }
+      if (active) {
+        throw new Error("TUI auth child is already running");
+      }
+      const owned: ActiveAuthChild = { child: spawnChild() };
+      active = owned;
+      return await new Promise<TuiAuthChildResult>((resolve, reject) => {
+        let settled = false;
+        const settle = (complete: () => void): void => {
+          if (settled) {
+            return;
+          }
+          settled = true;
+          clearActive(owned);
+          complete();
+        };
+        owned.child.once("error", (error) => settle(() => reject(error)));
+        owned.child.once("exit", (exitCode, signal) => settle(() => resolve({ exitCode, signal })));
+      });
+    },
+    close: (): void => {
+      if (closed) {
+        return;
+      }
+      closed = true;
+      if (active) {
+        cancel(active);
+      }
+    },
+  };
+}
diff --git a/src/tui/tui-pty-local-test-support.test.ts b/src/tui/tui-pty-local-test-support.test.ts
index eac5c93b1a41..fb7a9e559dfb 100644
--- a/src/tui/tui-pty-local-test-support.test.ts
+++ b/src/tui/tui-pty-local-test-support.test.ts
@@ -124,6 +124,7 @@ describe("local TUI PTY fixture support", () => {
     const run = {
       cols: 100,
       output: () => output,
+      pid: 123,
       rows: 30,
       visibleOutput: () => output.replace(/\s+/gu, " "),
       write: async (data: string) => {
diff --git a/src/tui/tui-pty-test-support.ts b/src/tui/tui-pty-test-support.ts
index 4f5f6707a42b..0e956ca649dd 100644
--- a/src/tui/tui-pty-test-support.ts
+++ b/src/tui/tui-pty-test-support.ts
@@ -15,6 +15,7 @@ type PtyExitEvent = Parameters<Parameters<IPty["onExit"]>[0]>[0];
 export type PtyRun = {
   cols: number;
   output: () => string;
+  pid: number;
   rows: number;
   visibleOutput: () => string;
   write: (data: string, opts?: { delay?: boolean }) => Promise<void>;
@@ -370,6 +371,7 @@ export function startPty(
   const run: PtyRun = {
     cols,
     output: () => output,
+    pid: pty.pid,
     rows,
     visibleOutput: () => visibleOutput,
     write: async (data, writeOpts) => await writePtyInput(pty, data, ptyEnv, writeOpts),
diff --git a/src/tui/tui.ts b/src/tui/tui.ts
index fe7bbd0a734f..7598a5a2be51 100644
--- a/src/tui/tui.ts
+++ b/src/tui/tui.ts
@@ -49,6 +49,7 @@ import { ChatLog } from "./components/chat-log.js";
 import { CustomEditor } from "./components/custom-editor.js";
 import { resolveLocalRunShutdownGraceMs } from "./local-run-shutdown.js";
 import { editorTheme, tuiTheme as theme } from "./theme/theme.js";
+import { createTuiAuthChildOwner } from "./tui-auth-child.js";
 import { sanitizeAutocompleteProvider } from "./tui-autocomplete.js";
 import type { TuiBackend } from "./tui-backend.js";
 import { createCommandHandlers } from "./tui-command-handlers.js";
@@ -800,6 +801,7 @@ async function runTuiUnlocked(opts: RunTuiOptions): Promise<TuiResult> {
   let dynamicSlashCommandsRefreshTimer: ReturnType<typeof setTimeout> | null = null;
   let exitRequested = false;
   let exitResult: TuiResult = { exitReason: "exit" };
+  const authChild = createTuiAuthChildOwner();
   let statusTimer: NodeJS.Timeout | null = null;
   let statusStartedAt: number | null = null;
   let lastActivityStatus = "idle";
@@ -1319,14 +1321,16 @@ async function runTuiUnlocked(opts: RunTuiOptions): Promise<TuiResult> {
     try {
       return await work();
     } finally {
-      if (isLocalMode) {
-        setConsoleSubsystemFilter(["__openclaw_tui_quiet__"]);
+      if (!exitRequested) {
+        if (isLocalMode) {
+          setConsoleSubsystemFilter(["__openclaw_tui_quiet__"]);
+        }
+        tui.start();
+        tui.setFocus(editor);
+        updateHeader();
+        updateFooter();
+        tui.requestRender(true);
       }
-      tui.start();
-      tui.setFocus(editor);
-      updateHeader();
-      updateFooter();
-      tui.requestRender(true);
     }
   };
 
@@ -1342,32 +1346,26 @@ async function runTuiUnlocked(opts: RunTuiOptions): Promise<TuiResult> {
               ? await resolveCodexCliBin()
               : null;
 
-          return await new Promise<{ exitCode: number | null; signal: NodeJS.Signals | null }>(
-            (resolve, reject) => {
-              let command: string;
-              let args: string[];
-              let cwd: string;
-              if (codexBin) {
-                command = codexBin;
-                args = ["login"];
-                cwd = resolveUsableCwd();
-              } else {
-                const invocation = resolveTuiLocalAuthCliInvocation({ provider });
-                ({ command, args, cwd } = invocation);
-              }
+          let command: string;
+          let args: string[];
+          let cwd: string;
+          if (codexBin) {
+            command = codexBin;
+            args = ["login"];
+            cwd = resolveUsableCwd();
+          } else {
+            const invocation = resolveTuiLocalAuthCliInvocation({ provider });
+            ({ command, args, cwd } = invocation);
+          }
 
-              const invocation = resolveLocalAuthSpawnInvocation({ command, args });
-              const child = spawn(invocation.command, invocation.args, {
-                cwd,
-                env: process.env,
-                stdio: "inherit",
-                ...invocation.options,
-              });
-              child.once("error", reject);
-              child.once("exit", (exitCode, signal) => {
-                resolve({ exitCode, signal });
-              });
-            },
+          const invocation = resolveLocalAuthSpawnInvocation({ command, args });
+          return await authChild.spawnAndWait(() =>
+            spawn(invocation.command, invocation.args, {
+              cwd,
+              env: process.env,
+              stdio: "inherit",
+              ...invocation.options,
+            }),
           );
         })
     : undefined;
@@ -1521,6 +1519,7 @@ async function runTuiUnlocked(opts: RunTuiOptions): Promise<TuiResult> {
       return;
     }
     exitRequested = true;
+    authChild.close();
     // Exit owns the input boundary before transport teardown can race a buffered submit.
     disposeSubmitBurst();
     connectionGeneration += 1;
diff --git a/test/vitest/vitest.tui-pty.config.ts b/test/vitest/vitest.tui-pty.config.ts
index aa81c60a77d4..d6885cc447ec 100644
--- a/test/vitest/vitest.tui-pty.config.ts
+++ b/test/vitest/vitest.tui-pty.config.ts
@@ -5,11 +5,13 @@ import { resolveRepoRootPath, sharedVitestConfig } from "./vitest.shared.config.
 
 const targetableIncludes = [
   "src/tui/tui-pty-harness-assertion-test-support.test.ts",
+  "src/tui/tui-auth-child-pty.e2e.test.ts",
   "src/tui/tui-pty-harness.e2e.test.ts",
   "src/tui/tui-session-identity-pty.e2e.test.ts",
   "src/tui/tui-pty-local.e2e.test.ts",
   "src/tui/tui-reset-transition-pty.e2e.test.ts",
   "tui/tui-pty-harness-assertion-test-support.test.ts",
+  "tui/tui-auth-child-pty.e2e.test.ts",
   "tui/tui-pty-harness.e2e.test.ts",
   "tui/tui-session-identity-pty.e2e.test.ts",
   "tui/tui-pty-local.e2e.test.ts",
@@ -26,6 +28,7 @@ function createTuiPtyVitestConfig(env?: Record<string, string | undefined>) {
   const configEnv = env ?? process.env;
   const includeLocal = configEnv.OPENCLAW_TUI_PTY_INCLUDE_LOCAL === "1";
   const include = [
+    "tui/tui-auth-child-pty.e2e.test.ts",
     "tui/tui-pty-harness.e2e.test.ts",
     "tui/tui-session-identity-pty.e2e.test.ts",
     "tui/tui-reset-transition-pty.e2e.test.ts",