diff --git a/extensions/bluebubbles/src/test-harness.ts b/extensions/bluebubbles/src/test-harness.ts
index a9e3bcb5375..627b04197ba 100644
--- a/extensions/bluebubbles/src/test-harness.ts
+++ b/extensions/bluebubbles/src/test-harness.ts
@@ -1,3 +1,4 @@
+import type { Mock } from "vitest";
 import { afterEach, beforeEach, vi } from "vitest";
 
 export function resolveBlueBubblesAccountFromConfig(params: {
@@ -19,7 +20,11 @@ export function createBlueBubblesAccountsMockModule() {
   };
 }
 
-export function createBlueBubblesProbeMockModule() {
+type BlueBubblesProbeMockModule = {
+  getCachedBlueBubblesPrivateApiStatus: Mock<() => boolean | null>;
+};
+
+export function createBlueBubblesProbeMockModule(): BlueBubblesProbeMockModule {
   return {
     getCachedBlueBubblesPrivateApiStatus: vi.fn().mockReturnValue(null),
   };
diff --git a/src/agents/models-config.e2e-harness.ts b/src/agents/models-config.e2e-harness.ts
index eb6e8cfe38d..a35e9108990 100644
--- a/src/agents/models-config.e2e-harness.ts
+++ b/src/agents/models-config.e2e-harness.ts
@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, vi } from "vitest";
 import type { OpenClawConfig } from "../config/config.js";
+import type { MockFn } from "../test-utils/vitest-mock-fn.js";
 import { withTempHome as withTempHomeBase } from "../../test/helpers/temp-home.js";
 
 export async function withModelsTempHome<T>(fn: (home: string) => Promise<T>): Promise<T> {
@@ -57,7 +58,7 @@ export async function withUnsetCopilotTokenEnv<T>(fn: () => Promise<T>): Promise
   });
 }
 
-export function mockCopilotTokenExchangeSuccess() {
+export function mockCopilotTokenExchangeSuccess(): MockFn {
   const fetchMock = vi.fn().mockResolvedValue({
     ok: true,
     status: 200,
diff --git a/src/agents/openclaw-tools.subagents.test-harness.ts b/src/agents/openclaw-tools.subagents.test-harness.ts
index e996e88d237..44b6ea79118 100644
--- a/src/agents/openclaw-tools.subagents.test-harness.ts
+++ b/src/agents/openclaw-tools.subagents.test-harness.ts
@@ -1,8 +1,9 @@
 import { vi } from "vitest";
+import type { MockFn } from "../test-utils/vitest-mock-fn.js";
 
 export type LoadedConfig = ReturnType<(typeof import("../config/config.js"))["loadConfig"]>;
 
-export const callGatewayMock = vi.fn();
+export const callGatewayMock: MockFn = vi.fn();
 
 const defaultConfig: LoadedConfig = {
   session: {
diff --git a/src/commands/test-runtime-config-helpers.ts b/src/commands/test-runtime-config-helpers.ts
index be5c64e1b81..4890ea999d7 100644
--- a/src/commands/test-runtime-config-helpers.ts
+++ b/src/commands/test-runtime-config-helpers.ts
@@ -1,4 +1,5 @@
 import { vi } from "vitest";
+import type { MockFn } from "../test-utils/vitest-mock-fn.js";
 
 export const baseConfigSnapshot = {
   path: "/tmp/openclaw.json",
@@ -11,7 +12,13 @@ export const baseConfigSnapshot = {
   legacyIssues: [],
 };
 
-export function createTestRuntime() {
+export type TestRuntime = {
+  log: MockFn;
+  error: MockFn;
+  exit: MockFn;
+};
+
+export function createTestRuntime(): TestRuntime {
   return {
     log: vi.fn(),
     error: vi.fn(),
diff --git a/src/cron/service.test-harness.ts b/src/cron/service.test-harness.ts
index 211620148b9..05db703d6cb 100644
--- a/src/cron/service.test-harness.ts
+++ b/src/cron/service.test-harness.ts
@@ -91,7 +91,12 @@ export function createFinishedBarrier() {
 export function createStartedCronServiceWithFinishedBarrier(params: {
   storePath: string;
   logger: ReturnType<typeof createNoopLogger>;
-}) {
+}): {
+  cron: CronService;
+  enqueueSystemEvent: MockFn;
+  requestHeartbeatNow: MockFn;
+  finished: ReturnType<typeof createFinishedBarrier>;
+} {
   const enqueueSystemEvent = vi.fn();
   const requestHeartbeatNow = vi.fn();
   const finished = createFinishedBarrier();
diff --git a/src/discord/monitor.tool-result.test-harness.ts b/src/discord/monitor.tool-result.test-harness.ts
index 01b2b5e9635..bdea448526b 100644
--- a/src/discord/monitor.tool-result.test-harness.ts
+++ b/src/discord/monitor.tool-result.test-harness.ts
@@ -1,11 +1,12 @@
 import { vi } from "vitest";
+import type { MockFn } from "../test-utils/vitest-mock-fn.js";
 
-export const sendMock = vi.fn();
-export const reactMock = vi.fn();
-export const updateLastRouteMock = vi.fn();
-export const dispatchMock = vi.fn();
-export const readAllowFromStoreMock = vi.fn();
-export const upsertPairingRequestMock = vi.fn();
+export const sendMock: MockFn = vi.fn();
+export const reactMock: MockFn = vi.fn();
+export const updateLastRouteMock: MockFn = vi.fn();
+export const dispatchMock: MockFn = vi.fn();
+export const readAllowFromStoreMock: MockFn = vi.fn();
+export const upsertPairingRequestMock: MockFn = vi.fn();
 
 vi.mock("./send.js", () => ({
   sendMessageDiscord: (...args: unknown[]) => sendMock(...args),