diff --git a/src/browser/pw-tools-core.downloads.ts b/src/browser/pw-tools-core.downloads.ts
index 1f029a483..a2884d4eb 100644
--- a/src/browser/pw-tools-core.downloads.ts
+++ b/src/browser/pw-tools-core.downloads.ts
@@ -1,8 +1,8 @@
 import type { Page } from "playwright-core";
 import crypto from "node:crypto";
 import fs from "node:fs/promises";
-import os from "node:os";
 import path from "node:path";
+import { resolvePreferredOpenClawTmpDir } from "../infra/tmp-openclaw-dir.js";
 import {
   ensurePageState,
   getPageForTargetId,
@@ -21,7 +21,7 @@ import {
 function buildTempDownloadPath(fileName: string): string {
   const id = crypto.randomUUID();
   const safeName = fileName.trim() ? fileName.trim() : "download.bin";
-  return path.join(os.tmpdir(), "openclaw", "downloads", `${id}-${safeName}`);
+  return path.join(resolvePreferredOpenClawTmpDir(), "downloads", `${id}-${safeName}`);
 }
 
 function createPageDownloadWaiter(page: Page, timeoutMs: number) {
diff --git a/src/browser/pw-tools-core.waits-next-download-saves-it.test.ts b/src/browser/pw-tools-core.waits-next-download-saves-it.test.ts
index e30d3ebfe..2e22749aa 100644
--- a/src/browser/pw-tools-core.waits-next-download-saves-it.test.ts
+++ b/src/browser/pw-tools-core.waits-next-download-saves-it.test.ts
@@ -29,6 +29,10 @@ const sessionMocks = vi.hoisted(() => ({
 }));
 
 vi.mock("./pw-session.js", () => sessionMocks);
+const tmpDirMocks = vi.hoisted(() => ({
+  resolvePreferredOpenClawTmpDir: vi.fn(() => "/tmp/openclaw"),
+}));
+vi.mock("../infra/tmp-openclaw-dir.js", () => tmpDirMocks);
 
 async function importModule() {
   return await import("./pw-tools-core.js");
@@ -47,6 +51,10 @@ describe("pw-tools-core", () => {
     for (const fn of Object.values(sessionMocks)) {
       fn.mockClear();
     }
+    for (const fn of Object.values(tmpDirMocks)) {
+      fn.mockClear();
+    }
+    tmpDirMocks.resolvePreferredOpenClawTmpDir.mockReturnValue("/tmp/openclaw");
   });
 
   it("waits for the next download and saves it", async () => {
@@ -125,6 +133,43 @@ describe("pw-tools-core", () => {
     expect(saveAs).toHaveBeenCalledWith(targetPath);
     expect(res.path).toBe(targetPath);
   });
+  it("uses preferred tmp dir when waiting for download without explicit path", async () => {
+    let downloadHandler: ((download: unknown) => void) | undefined;
+    const on = vi.fn((event: string, handler: (download: unknown) => void) => {
+      if (event === "download") {
+        downloadHandler = handler;
+      }
+    });
+    const off = vi.fn();
+
+    const saveAs = vi.fn(async () => {});
+    const download = {
+      url: () => "https://example.com/file.bin",
+      suggestedFilename: () => "file.bin",
+      saveAs,
+    };
+
+    tmpDirMocks.resolvePreferredOpenClawTmpDir.mockReturnValue("/tmp/openclaw-preferred");
+    currentPage = { on, off };
+
+    const mod = await importModule();
+    const p = mod.waitForDownloadViaPlaywright({
+      cdpUrl: "http://127.0.0.1:18792",
+      targetId: "T1",
+      timeoutMs: 1000,
+    });
+
+    await Promise.resolve();
+    downloadHandler?.(download);
+
+    const res = await p;
+    const outPath = vi.mocked(saveAs).mock.calls[0]?.[0];
+    expect(typeof outPath).toBe("string");
+    expect(String(outPath)).toContain("/tmp/openclaw-preferred/downloads/");
+    expect(String(outPath)).toContain("-file.bin");
+    expect(res.path).toContain("/tmp/openclaw-preferred/downloads/");
+    expect(tmpDirMocks.resolvePreferredOpenClawTmpDir).toHaveBeenCalled();
+  });
   it("waits for a matching response and returns its body", async () => {
     let responseHandler: ((resp: unknown) => void) | undefined;
     const on = vi.fn((event: string, handler: (resp: unknown) => void) => {
diff --git a/src/browser/routes/agent.debug.ts b/src/browser/routes/agent.debug.ts
index ec4c944c9..7ba0ed52a 100644
--- a/src/browser/routes/agent.debug.ts
+++ b/src/browser/routes/agent.debug.ts
@@ -1,12 +1,14 @@
 import crypto from "node:crypto";
 import fs from "node:fs/promises";
-import os from "node:os";
 import path from "node:path";
 import type { BrowserRouteContext } from "../server-context.js";
 import type { BrowserRouteRegistrar } from "./types.js";
+import { resolvePreferredOpenClawTmpDir } from "../../infra/tmp-openclaw-dir.js";
 import { handleRouteError, readBody, requirePwAi, resolveProfileContext } from "./agent.shared.js";
 import { toBoolean, toStringOrEmpty } from "./utils.js";
 
+const DEFAULT_TRACE_DIR = resolvePreferredOpenClawTmpDir();
+
 export function registerBrowserAgentDebugRoutes(
   app: BrowserRouteRegistrar,
   ctx: BrowserRouteContext,
@@ -132,7 +134,7 @@ export function registerBrowserAgentDebugRoutes(
         return;
       }
       const id = crypto.randomUUID();
-      const dir = path.join(os.tmpdir(), "openclaw");
+      const dir = DEFAULT_TRACE_DIR;
       await fs.mkdir(dir, { recursive: true });
       const tracePath = out.trim() || path.join(dir, `browser-trace-${id}.zip`);
       await pw.traceStopViaPlaywright({
diff --git a/src/cli/browser-cli-actions-input/register.files-downloads.ts b/src/cli/browser-cli-actions-input/register.files-downloads.ts
index 316faae3e..0827079ba 100644
--- a/src/cli/browser-cli-actions-input/register.files-downloads.ts
+++ b/src/cli/browser-cli-actions-input/register.files-downloads.ts
@@ -57,7 +57,10 @@ export function registerBrowserFilesAndDownloadsCommands(
   browser
     .command("waitfordownload")
     .description("Wait for the next download (and save it)")
-    .argument("[path]", "Save path (default: os.tmpdir()/openclaw/downloads/...)")
+    .argument(
+      "[path]",
+      "Save path (default: /tmp/openclaw/downloads/...; fallback: os.tmpdir()/openclaw/downloads/...)",
+    )
     .option("--target-id <id>", "CDP target id (or unique prefix)")
     .option(
       "--timeout-ms <ms>",
diff --git a/src/infra/tmp-openclaw-dir.test.ts b/src/infra/tmp-openclaw-dir.test.ts
new file mode 100644
index 000000000..1eea9a1bb
--- /dev/null
+++ b/src/infra/tmp-openclaw-dir.test.ts
@@ -0,0 +1,64 @@
+import path from "node:path";
+import { describe, expect, it, vi } from "vitest";
+import { POSIX_OPENCLAW_TMP_DIR, resolvePreferredOpenClawTmpDir } from "./tmp-openclaw-dir.js";
+
+describe("resolvePreferredOpenClawTmpDir", () => {
+  it("prefers /tmp/openclaw when it already exists and is writable", () => {
+    const accessSync = vi.fn();
+    const statSync = vi.fn(() => ({ isDirectory: () => true }));
+    const tmpdir = vi.fn(() => "/var/fallback");
+
+    const resolved = resolvePreferredOpenClawTmpDir({ accessSync, statSync, tmpdir });
+
+    expect(statSync).toHaveBeenCalledTimes(1);
+    expect(accessSync).toHaveBeenCalledTimes(1);
+    expect(resolved).toBe(POSIX_OPENCLAW_TMP_DIR);
+    expect(tmpdir).not.toHaveBeenCalled();
+  });
+
+  it("prefers /tmp/openclaw when it does not exist but /tmp is writable", () => {
+    const accessSync = vi.fn();
+    const statSync = vi.fn(() => {
+      const err = new Error("missing") as Error & { code?: string };
+      err.code = "ENOENT";
+      throw err;
+    });
+    const tmpdir = vi.fn(() => "/var/fallback");
+
+    const resolved = resolvePreferredOpenClawTmpDir({ accessSync, statSync, tmpdir });
+
+    expect(resolved).toBe(POSIX_OPENCLAW_TMP_DIR);
+    expect(accessSync).toHaveBeenCalledWith("/tmp", expect.any(Number));
+    expect(tmpdir).not.toHaveBeenCalled();
+  });
+
+  it("falls back to os.tmpdir()/openclaw when /tmp/openclaw is not a directory", () => {
+    const accessSync = vi.fn();
+    const statSync = vi.fn(() => ({ isDirectory: () => false }));
+    const tmpdir = vi.fn(() => "/var/fallback");
+
+    const resolved = resolvePreferredOpenClawTmpDir({ accessSync, statSync, tmpdir });
+
+    expect(resolved).toBe(path.join("/var/fallback", "openclaw"));
+    expect(tmpdir).toHaveBeenCalledTimes(1);
+  });
+
+  it("falls back to os.tmpdir()/openclaw when /tmp is not writable", () => {
+    const accessSync = vi.fn((target: string) => {
+      if (target === "/tmp") {
+        throw new Error("read-only");
+      }
+    });
+    const statSync = vi.fn(() => {
+      const err = new Error("missing") as Error & { code?: string };
+      err.code = "ENOENT";
+      throw err;
+    });
+    const tmpdir = vi.fn(() => "/var/fallback");
+
+    const resolved = resolvePreferredOpenClawTmpDir({ accessSync, statSync, tmpdir });
+
+    expect(resolved).toBe(path.join("/var/fallback", "openclaw"));
+    expect(tmpdir).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/src/infra/tmp-openclaw-dir.ts b/src/infra/tmp-openclaw-dir.ts
new file mode 100644
index 000000000..ab4038b7c
--- /dev/null
+++ b/src/infra/tmp-openclaw-dir.ts
@@ -0,0 +1,50 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+export const POSIX_OPENCLAW_TMP_DIR = "/tmp/openclaw";
+
+type ResolvePreferredOpenClawTmpDirOptions = {
+  accessSync?: (path: string, mode?: number) => void;
+  statSync?: (path: string) => { isDirectory(): boolean };
+  tmpdir?: () => string;
+};
+
+type MaybeNodeError = { code?: string };
+
+function isNodeErrorWithCode(err: unknown, code: string): err is MaybeNodeError {
+  return (
+    typeof err === "object" &&
+    err !== null &&
+    "code" in err &&
+    (err as MaybeNodeError).code === code
+  );
+}
+
+export function resolvePreferredOpenClawTmpDir(
+  options: ResolvePreferredOpenClawTmpDirOptions = {},
+): string {
+  const accessSync = options.accessSync ?? fs.accessSync;
+  const statSync = options.statSync ?? fs.statSync;
+  const tmpdir = options.tmpdir ?? os.tmpdir;
+
+  try {
+    const preferred = statSync(POSIX_OPENCLAW_TMP_DIR);
+    if (!preferred.isDirectory()) {
+      return path.join(tmpdir(), "openclaw");
+    }
+    accessSync(POSIX_OPENCLAW_TMP_DIR, fs.constants.W_OK | fs.constants.X_OK);
+    return POSIX_OPENCLAW_TMP_DIR;
+  } catch (err) {
+    if (!isNodeErrorWithCode(err, "ENOENT")) {
+      return path.join(tmpdir(), "openclaw");
+    }
+  }
+
+  try {
+    accessSync("/tmp", fs.constants.W_OK | fs.constants.X_OK);
+    return POSIX_OPENCLAW_TMP_DIR;
+  } catch {
+    return path.join(tmpdir(), "openclaw");
+  }
+}
diff --git a/src/logging/logger.import-side-effects.test.ts b/src/logging/logger.import-side-effects.test.ts
new file mode 100644
index 000000000..712892e8c
--- /dev/null
+++ b/src/logging/logger.import-side-effects.test.ts
@@ -0,0 +1,20 @@
+import fs from "node:fs";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+describe("logger import side effects", () => {
+  beforeEach(() => {
+    vi.resetModules();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("does not mkdir at import time", async () => {
+    const mkdirSpy = vi.spyOn(fs, "mkdirSync");
+
+    await import("./logger.js");
+
+    expect(mkdirSpy).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/logging/logger.ts b/src/logging/logger.ts
index eef171fa0..63de56aed 100644
--- a/src/logging/logger.ts
+++ b/src/logging/logger.ts
@@ -1,26 +1,15 @@
 import fs from "node:fs";
 import { createRequire } from "node:module";
-import os from "node:os";
 import path from "node:path";
 import { Logger as TsLogger } from "tslog";
 import type { OpenClawConfig } from "../config/types.js";
 import type { ConsoleStyle } from "./console.js";
+import { resolvePreferredOpenClawTmpDir } from "../infra/tmp-openclaw-dir.js";
 import { readLoggingConfig } from "./config.js";
 import { type LogLevel, levelToMinLevel, normalizeLogLevel } from "./levels.js";
 import { loggingState } from "./state.js";
 
-// Prefer /tmp/openclaw so macOS Debug UI and docs match, but fall back to
-// os.tmpdir() on platforms where /tmp is read-only (e.g. Termux/Android).
-function resolveDefaultLogDir(): string {
-  try {
-    fs.mkdirSync("/tmp/openclaw", { recursive: true });
-    return "/tmp/openclaw";
-  } catch {
-    return path.join(os.tmpdir(), "openclaw");
-  }
-}
-
-export const DEFAULT_LOG_DIR = resolveDefaultLogDir();
+export const DEFAULT_LOG_DIR = resolvePreferredOpenClawTmpDir();
 export const DEFAULT_LOG_FILE = path.join(DEFAULT_LOG_DIR, "openclaw.log"); // legacy single-file path
 
 const LOG_PREFIX = "openclaw";