diff --git a/CHANGELOG.md b/CHANGELOG.md
index e3a2fb9526d..7f9c9af4c7a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -54,6 +54,7 @@ Docs: https://docs.openclaw.ai
 - Release/CI/E2E: bound release candidate GitHub API calls so stalled network requests cannot wedge workflow and artifact polling.
 - Release/CI/E2E: bound Discord smoke API calls in cross-OS release checks so host-side round trips cannot hang on stalled fetches.
 - Release/CI/E2E: bound RPC RTT gateway readiness probes so a half-open local HTTP response cannot stall cleanup past the readiness deadline.
+- Release/CI/E2E: stop RPC RTT gateway process groups so pnpm wrapper children cannot survive measurement cleanup.
 - Scripts/UI: stop descendant processes from wrapped non-interactive commands when `run-with-env` receives shutdown signals.
 - Release/CI/E2E: write multi-node update Docker artifacts to unique per-run directories by default so parallel runs cannot overwrite evidence.
 - Release/CI/E2E: write package Telegram Docker artifacts to unique per-run directories by default so parallel live/RTT runs cannot overwrite evidence.
diff --git a/scripts/measure-rpc-rtt.mjs b/scripts/measure-rpc-rtt.mjs
index e657e16006a..565759bc5e5 100644
--- a/scripts/measure-rpc-rtt.mjs
+++ b/scripts/measure-rpc-rtt.mjs
@@ -11,6 +11,7 @@ const DEFAULT_METHODS = ["health", "config.get"];
 const DEFAULT_ITERATIONS = 10;
 export const READY_TIMEOUT_MS = 120_000;
 export const READY_PROBE_TIMEOUT_MS = 1_000;
+const PARENT_TERMINATION_SIGNALS = ["SIGHUP", "SIGINT", "SIGTERM"];
 const IS_DIRECT_RUN =
   typeof process.argv[1] === "string" &&
   path.resolve(process.argv[1]) === fileURLToPath(import.meta.url);
@@ -143,20 +144,117 @@ export async function waitForGatewayReady({
   throw new Error(`gateway did not become ready after ${readyTimeoutMs}ms\n${stderr.slice(-4000)}`);
 }
 
-async function stopGateway(child) {
-  if (child.exitCode !== null || child.signalCode !== null) {
+function isProcessAlreadyExitedError(error) {
+  return error && typeof error === "object" && error.code === "ESRCH";
+}
+
+function defaultKillProcess(pid, signal) {
+  return process.kill(pid, signal);
+}
+
+async function defaultOpen(filePath, flags) {
+  return await fs.open(filePath, flags);
+}
+
+export function signalGatewayProcess(child, signal, killProcess = defaultKillProcess) {
+  if (process.platform !== "win32" && typeof child.pid === "number") {
+    try {
+      killProcess(-child.pid, signal);
+      return true;
+    } catch (error) {
+      if (isProcessAlreadyExitedError(error)) {
+        return false;
+      }
+      throw error;
+    }
+  }
+  try {
+    return child.kill(signal);
+  } catch (error) {
+    if (isProcessAlreadyExitedError(error)) {
+      return false;
+    }
+    throw error;
+  }
+}
+
+export function isGatewayProcessAlive(child, killProcess = defaultKillProcess) {
+  if (process.platform !== "win32" && typeof child.pid === "number") {
+    try {
+      killProcess(-child.pid, 0);
+      return true;
+    } catch (error) {
+      if (isProcessAlreadyExitedError(error)) {
+        return false;
+      }
+      throw error;
+    }
+  }
+  return child.exitCode === null && child.signalCode === null;
+}
+
+function signalGatewayProcessForParentExit(child, signal, killProcess) {
+  try {
+    signalGatewayProcess(child, signal, killProcess);
+  } catch {
+    // Parent shutdown cleanup is best effort; the original signal should win.
+  }
+}
+
+export function installGatewayParentCleanup(
+  child,
+  { killProcess = defaultKillProcess, processLike = process } = {},
+) {
+  const signalHandlers = new Map();
+  const cleanup = (signal) => {
+    signalGatewayProcessForParentExit(child, signal, killProcess);
+    if (process.platform !== "win32") {
+      signalGatewayProcessForParentExit(child, "SIGKILL", killProcess);
+    }
+  };
+  const exitHandler = () => {
+    cleanup("SIGTERM");
+  };
+  const removeHandlers = () => {
+    processLike.off?.("exit", exitHandler);
+    for (const [signal, handler] of signalHandlers) {
+      processLike.off?.(signal, handler);
+    }
+    signalHandlers.clear();
+  };
+  processLike.once("exit", exitHandler);
+  for (const signal of PARENT_TERMINATION_SIGNALS) {
+    const handler = () => {
+      cleanup(signal);
+      removeHandlers();
+      processLike.kill?.(processLike.pid, signal);
+    };
+    signalHandlers.set(signal, handler);
+    processLike.once(signal, handler);
+  }
+  return removeHandlers;
+}
+
+async function waitForGatewayExit(child, timeoutMs, killProcess = defaultKillProcess) {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() <= deadline) {
+    if (!isGatewayProcessAlive(child, killProcess)) {
+      return true;
+    }
+    await sleep(Math.min(25, Math.max(0, deadline - Date.now())));
+  }
+  return !isGatewayProcessAlive(child, killProcess);
+}
+
+export async function stopGateway(child, options = {}) {
+  if (!isGatewayProcessAlive(child, options.killProcess)) {
     return;
   }
-  child.kill("SIGTERM");
-  const exited = await new Promise((resolve) => {
-    const timer = setTimeout(() => resolve(false), 1_500);
-    child.once("exit", () => {
-      clearTimeout(timer);
-      resolve(true);
-    });
-  });
-  if (!exited && child.exitCode === null && child.signalCode === null) {
-    child.kill("SIGKILL");
+  const killGraceMs = Math.max(0, options.killGraceMs ?? 1_500);
+  signalGatewayProcess(child, "SIGTERM", options.killProcess);
+  const exited = await waitForGatewayExit(child, killGraceMs, options.killProcess);
+  if (!exited) {
+    signalGatewayProcess(child, "SIGKILL", options.killProcess);
   }
 }
 
@@ -171,7 +269,7 @@ async function closeFileHandles(handles) {
 export async function startGateway({
   configPath,
   env = process.env,
-  openImpl = fs.open,
+  openImpl = defaultOpen,
   port,
   repoRoot,
   spawnImpl = spawn,
@@ -207,6 +305,7 @@ export async function startGateway({
       ],
       {
         cwd: repoRoot,
+        detached: process.platform !== "win32",
         env: {
           ...env,
           HOME: path.join(tempRoot, "home"),
@@ -417,6 +516,7 @@ async function main() {
   const stdoutPath = path.join(tempRoot, "gateway.stdout.log");
   const stderrPath = path.join(tempRoot, "gateway.stderr.log");
   let gatewayChild;
+  let removeGatewayParentCleanup = () => {};
   let status = "fail";
   let details = "";
   let measurement;
@@ -449,6 +549,7 @@ async function main() {
       tempRoot,
       token,
     });
+    removeGatewayParentCleanup = installGatewayParentCleanup(gatewayChild);
     await waitForGatewayReady({ child: gatewayChild, port, stderrPath });
 
     const requireFromOpenClaw = createRequire(path.join(repoRoot, "package.json"));
@@ -534,8 +635,12 @@ async function main() {
   } catch (error) {
     details = error instanceof Error ? (error.stack ?? error.message) : String(error);
   } finally {
-    if (gatewayChild) {
-      await stopGateway(gatewayChild).catch(() => {});
+    try {
+      if (gatewayChild) {
+        await stopGateway(gatewayChild).catch(() => {});
+      }
+    } finally {
+      removeGatewayParentCleanup();
     }
     try {
       await cleanupTempRoot(tempRoot);
diff --git a/test/scripts/measure-rpc-rtt.test.ts b/test/scripts/measure-rpc-rtt.test.ts
index 07154ba201f..44f216df755 100644
--- a/test/scripts/measure-rpc-rtt.test.ts
+++ b/test/scripts/measure-rpc-rtt.test.ts
@@ -2,7 +2,11 @@ import { EventEmitter } from "node:events";
 import { describe, expect, it, vi } from "vitest";
 import {
   cleanupTempRoot,
+  installGatewayParentCleanup,
+  isGatewayProcessAlive,
+  signalGatewayProcess,
   startGateway,
+  stopGateway,
   waitForGatewayReady,
 } from "../../scripts/measure-rpc-rtt.mjs";
 
@@ -49,6 +53,7 @@ describe("scripts/measure-rpc-rtt.mjs", () => {
       ],
       expect.objectContaining({
         cwd: "/repo",
+        detached: process.platform !== "win32",
         env: expect.objectContaining({
           HOME: "/tmp/rpc-rtt/home",
           OPENCLAW_CONFIG_PATH: "/tmp/openclaw.json",
@@ -63,6 +68,162 @@ describe("scripts/measure-rpc-rtt.mjs", () => {
     expect(stderr.close).toHaveBeenCalledTimes(1);
   });
 
+  it("signals the gateway process group on POSIX so pnpm children do not leak", () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: null,
+      kill: vi.fn(),
+      pid: 12345,
+      signalCode: null,
+    });
+    const kill = vi.fn(() => true);
+
+    expect(signalGatewayProcess(child, "SIGTERM", kill)).toBe(true);
+
+    if (process.platform === "win32") {
+      expect(child.kill).toHaveBeenCalledWith("SIGTERM");
+    } else {
+      expect(kill).toHaveBeenCalledWith(-12345, "SIGTERM");
+      expect(child.kill).not.toHaveBeenCalled();
+    }
+  });
+
+  it("treats missing gateway process groups as already exited", () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: null,
+      kill: vi.fn(() => false),
+      pid: 12345,
+      signalCode: null,
+    });
+    const kill = vi.fn(() => {
+      throw Object.assign(new Error("no such process"), { code: "ESRCH" });
+    });
+
+    expect(signalGatewayProcess(child, "SIGTERM", kill)).toBe(false);
+  });
+
+  it("checks process group liveness instead of only the pnpm wrapper", () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: 0,
+      kill: vi.fn(),
+      pid: 12345,
+      signalCode: null,
+    });
+    const kill = vi.fn(() => true);
+
+    if (process.platform === "win32") {
+      expect(isGatewayProcessAlive(child, kill)).toBe(false);
+    } else {
+      expect(isGatewayProcessAlive(child, kill)).toBe(true);
+      expect(kill).toHaveBeenCalledWith(-12345, 0);
+    }
+  });
+
+  it("force-kills the gateway process group after the graceful stop window", async () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: null,
+      kill: vi.fn(),
+      pid: 12346,
+      signalCode: null,
+    });
+    const kill = vi.fn(() => true);
+
+    await stopGateway(child, { killGraceMs: 1, killProcess: kill });
+
+    if (process.platform === "win32") {
+      expect(child.kill).toHaveBeenNthCalledWith(1, "SIGTERM");
+      expect(child.kill).toHaveBeenNthCalledWith(2, "SIGKILL");
+    } else {
+      expect(kill).toHaveBeenNthCalledWith(1, -12346, 0);
+      expect(kill).toHaveBeenNthCalledWith(2, -12346, "SIGTERM");
+      expect(kill).toHaveBeenLastCalledWith(-12346, "SIGKILL");
+      expect(child.kill).not.toHaveBeenCalled();
+    }
+  });
+
+  it("does not trust a finished pnpm wrapper while the process group is alive", async () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: 0,
+      kill: vi.fn(),
+      pid: 12347,
+      signalCode: null,
+    });
+    const kill = vi.fn(() => true);
+
+    await stopGateway(child, { killGraceMs: 1, killProcess: kill });
+
+    if (process.platform === "win32") {
+      expect(child.kill).not.toHaveBeenCalled();
+    } else {
+      expect(kill).toHaveBeenNthCalledWith(1, -12347, 0);
+      expect(kill).toHaveBeenNthCalledWith(2, -12347, "SIGTERM");
+      expect(kill).toHaveBeenLastCalledWith(-12347, "SIGKILL");
+      expect(child.kill).not.toHaveBeenCalled();
+    }
+  });
+
+  it("cleans up the gateway process group before re-raising parent signals", () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: null,
+      kill: vi.fn(),
+      pid: 12348,
+      signalCode: null,
+    });
+    const processLike = Object.assign(new EventEmitter(), {
+      kill: vi.fn(),
+      pid: 98765,
+    });
+    const kill = vi.fn(() => true);
+
+    const removeCleanup = installGatewayParentCleanup(child, {
+      killProcess: kill,
+      processLike,
+    });
+    processLike.emit("SIGTERM");
+
+    if (process.platform === "win32") {
+      expect(child.kill).toHaveBeenCalledWith("SIGTERM");
+    } else {
+      expect(kill).toHaveBeenNthCalledWith(1, -12348, "SIGTERM");
+      expect(kill).toHaveBeenNthCalledWith(2, -12348, "SIGKILL");
+      expect(child.kill).not.toHaveBeenCalled();
+    }
+    expect(processLike.kill).toHaveBeenCalledWith(98765, "SIGTERM");
+    expect(processLike.listenerCount("SIGTERM")).toBe(0);
+
+    removeCleanup();
+  });
+
+  it("cleans up the gateway process group on parent exit", () => {
+    const child = Object.assign(new EventEmitter(), {
+      exitCode: null,
+      kill: vi.fn(),
+      pid: 12349,
+      signalCode: null,
+    });
+    const processLike = Object.assign(new EventEmitter(), {
+      kill: vi.fn(),
+      pid: 98766,
+    });
+    const kill = vi.fn(() => true);
+
+    const removeCleanup = installGatewayParentCleanup(child, {
+      killProcess: kill,
+      processLike,
+    });
+    processLike.emit("exit");
+
+    if (process.platform === "win32") {
+      expect(child.kill).toHaveBeenCalledWith("SIGTERM");
+    } else {
+      expect(kill).toHaveBeenNthCalledWith(1, -12349, "SIGTERM");
+      expect(kill).toHaveBeenNthCalledWith(2, -12349, "SIGKILL");
+      expect(child.kill).not.toHaveBeenCalled();
+    }
+    expect(processLike.kill).not.toHaveBeenCalled();
+
+    removeCleanup();
+  });
+
   it("fails readiness immediately when the gateway already exited", async () => {
     const child = Object.assign(new EventEmitter(), {
       exitCode: 1,