diff --git a/src/agent.ts b/src/agent.ts
index f151241..3b7ed9f 100644
--- a/src/agent.ts
+++ b/src/agent.ts
@@ -1,8 +1,9 @@
 import { debuglog } from 'node:util';
-import type { Agent, ILifecycleBoot } from 'egg';
+import type { ILifecycleBoot } from 'egg';
 import { WorkerStrategy } from './lib/strategy/worker.js';
 import { AllStrategy } from './lib/strategy/all.js';
 import { EggScheduleJobInfo } from './lib/types.js';
+import type Agent from './app/extend/agent.js';
 
 const debug = debuglog('@eggjs/schedule/agent');
 
@@ -30,7 +31,13 @@ export default class Boot implements ILifecycleBoot {
 
   async serverDidReady(): Promise<void> {
     // start schedule after worker ready
-    this.#agent.schedule.start();
+    await this.#agent.schedule.start();
     debug('serverDidReady, schedule start');
   }
+
+  async beforeClose(): Promise<void> {
+    // stop schedule before app close
+    await this.#agent.schedule.close();
+    debug('beforeClose, schedule close');
+  }
 }
diff --git a/src/app.ts b/src/app.ts
index 8912897..337d36b 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -1,8 +1,9 @@
 import { debuglog } from 'node:util';
 import type {
-  Application, ILifecycleBoot, EggLogger,
+  ILifecycleBoot, EggLogger,
 } from 'egg';
 import type { EggScheduleJobInfo } from './lib/types.js';
+import type Application from './app/extend/application.js';
 
 const debug = debuglog('@eggjs/schedule/app');
 
diff --git a/src/app/extend/agent.ts b/src/app/extend/agent.ts
index 81dd508..4c14902 100644
--- a/src/app/extend/agent.ts
+++ b/src/app/extend/agent.ts
@@ -1,30 +1,33 @@
+import { Agent as EggAgent } from 'egg';
 import { BaseStrategy } from '../../lib/strategy/base.js';
 import { TimerStrategy } from '../../lib/strategy/timer.js';
 import { Schedule } from '../../lib/schedule.js';
 
-const SCHEDULE = Symbol('agent#schedule');
+const SCHEDULE = Symbol('agent schedule');
 
-export default {
+export default class Agent extends EggAgent {
   /**
    * @member agent#ScheduleStrategy
    */
-  ScheduleStrategy: BaseStrategy,
+  get ScheduleStrategy() {
+    return BaseStrategy;
+  }
 
   /**
    * @member agent#TimerScheduleStrategy
    */
-  TimerScheduleStrategy: TimerStrategy,
+  get TimerScheduleStrategy() {
+    return TimerStrategy;
+  }
 
   /**
    * @member agent#schedule
    */
   get schedule() {
-    if (!this[SCHEDULE]) {
-      this[SCHEDULE] = new Schedule(this);
-      this.lifecycle.registerBeforeClose(() => {
-        return this[SCHEDULE].close();
-      });
+    let schedule = this[SCHEDULE] as Schedule;
+    if (!schedule) {
+      this[SCHEDULE] = schedule = new Schedule(this);
     }
-    return this[SCHEDULE];
-  },
-} as any;
+    return schedule;
+  }
+}
diff --git a/src/app/extend/application.ts b/src/app/extend/application.ts
index 0003596..87cd72b 100644
--- a/src/app/extend/application.ts
+++ b/src/app/extend/application.ts
@@ -1,16 +1,18 @@
+import { Application as EggApplication } from 'egg';
 import { ScheduleWorker } from '../../lib/schedule_worker.js';
 
-const SCHEDULE_WORKER = Symbol('application#scheduleWorker');
+const SCHEDULE_WORKER = Symbol('application scheduleWorker');
 
-export default {
+export default class Application extends EggApplication {
   /**
    * @member app#schedule
    */
   get scheduleWorker() {
-    if (!this[SCHEDULE_WORKER]) {
-      this[SCHEDULE_WORKER] = new ScheduleWorker(this);
+    let scheduleWorker = this[SCHEDULE_WORKER] as ScheduleWorker;
+    if (!scheduleWorker) {
+      this[SCHEDULE_WORKER] = scheduleWorker = new ScheduleWorker(this);
     }
-    return this[SCHEDULE_WORKER];
-  },
-} as any;
+    return scheduleWorker;
+  }
+}
 
diff --git a/src/app/extend/application.unittest.ts b/src/app/extend/application.unittest.ts
index ca6604c..85a535e 100644
--- a/src/app/extend/application.unittest.ts
+++ b/src/app/extend/application.unittest.ts
@@ -1,12 +1,12 @@
 import { debuglog } from 'node:util';
 import path from 'node:path';
 import { importResolve } from '@eggjs/utils';
-import type { ScheduleWorker } from '../../lib/schedule_worker.js';
 import type { EggScheduleItem } from '../../lib/types.js';
+import Application from './application.js';
 
 const debug = debuglog('@eggjs/schedule/app');
 
-export default {
+export default class ApplicationUnittest extends Application {
   async runSchedule(schedulePath: string, ...args: any[]) {
     debug('[runSchedule] start schedulePath: %o, args: %o', schedulePath, args);
     // for test purpose
@@ -32,10 +32,9 @@ export default {
     }
 
     debug('[runSchedule] resolve schedulePath: %o', schedulePath);
-    const scheduleWorker: ScheduleWorker = this.scheduleWorker;
     let schedule: EggScheduleItem;
     try {
-      schedule = scheduleWorker.scheduleItems[schedulePath];
+      schedule = this.scheduleWorker.scheduleItems[schedulePath];
       if (!schedule) {
         throw new TypeError(`Cannot find schedule ${schedulePath}`);
       }
@@ -52,6 +51,6 @@ export default {
     return await this.ctxStorage.run(ctx, async () => {
       return await schedule.task(ctx, ...args);
     });
-  },
-} as any;
+  }
+}
 
diff --git a/src/index.ts b/src/index.ts
index f6ebe91..d6bd499 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1 +1,9 @@
+import Agent from './app/extend/agent.js';
+import Application from './app/extend/application.js';
+import ApplicationUnittest from './app/extend/application.unittest.js';
+
+export { Agent, Application, ApplicationUnittest };
+export { ScheduleWorker } from './lib/schedule_worker.js';
+export { Schedule } from './lib/schedule.js';
+
 export * from './lib/types.js';
diff --git a/src/lib/schedule.ts b/src/lib/schedule.ts
index 3c28d18..0628762 100644
--- a/src/lib/schedule.ts
+++ b/src/lib/schedule.ts
@@ -1,8 +1,9 @@
 import { debuglog } from 'node:util';
-import type { Agent, EggLogger } from 'egg';
+import type { EggLogger } from 'egg';
 import { loadSchedule } from './load_schedule.js';
 import type { EggScheduleItem, EggScheduleJobInfo } from './types.js';
 import type { BaseStrategy } from './strategy/base.js';
+import type Agent from '../app/extend/agent.js';
 
 const debug = debuglog('@eggjs/schedule/lib/schedule');
 
@@ -30,7 +31,7 @@ export class Schedule {
   }
 
   /**
-   * load all schedule jobs, then initialize and register speical strategy
+   * load all schedule jobs, then initialize and register special strategy
    */
   async init() {
     const scheduleItems = await loadSchedule(this.#agent);
@@ -82,7 +83,7 @@ export class Schedule {
   /**
    * start schedule
    */
-  start() {
+  async start() {
     debug('start');
     this.closed = false;
     for (const instance of this.#strategyInstanceMap.values()) {
@@ -90,10 +91,10 @@ export class Schedule {
     }
   }
 
-  close() {
+  async close() {
     this.closed = true;
     for (const instance of this.#strategyInstanceMap.values()) {
-      instance.close();
+      await instance.close();
     }
     debug('close');
   }
diff --git a/src/lib/schedule_worker.ts b/src/lib/schedule_worker.ts
index 415ea20..3467262 100644
--- a/src/lib/schedule_worker.ts
+++ b/src/lib/schedule_worker.ts
@@ -1,6 +1,6 @@
-import type { Application } from 'egg';
 import { loadSchedule } from './load_schedule.js';
 import type { EggScheduleItem } from './types.js';
+import type Application from '../app/extend/application.js';
 
 export class ScheduleWorker {
   #app: Application;
diff --git a/src/lib/strategy/base.ts b/src/lib/strategy/base.ts
index 8b83834..3e70541 100644
--- a/src/lib/strategy/base.ts
+++ b/src/lib/strategy/base.ts
@@ -1,5 +1,6 @@
-import type { Agent, EggLogger } from 'egg';
+import type { EggLogger } from 'egg';
 import type { EggScheduleConfig, EggScheduleJobInfo } from '../types.js';
+import type Agent from '../../app/extend/agent.js';
 
 export class BaseStrategy {
   protected agent: Agent;
@@ -21,11 +22,11 @@ export class BaseStrategy {
     return this.scheduleConfig;
   }
 
-  start() {
+  async start() {
     // empty loop by default
   }
 
-  close() {
+  async close() {
     this.closed = true;
   }
 
diff --git a/src/lib/strategy/timer.ts b/src/lib/strategy/timer.ts
index 99b024d..7114a82 100644
--- a/src/lib/strategy/timer.ts
+++ b/src/lib/strategy/timer.ts
@@ -4,9 +4,9 @@ import cronParser from 'cron-parser';
 import { ms } from 'humanize-ms';
 import safeTimers from 'safe-timers';
 import { logDate } from 'utility';
-import type { Agent } from 'egg';
 import type { EggScheduleConfig } from '../types.js';
 import { BaseStrategy } from './base.js';
+import type Agent from '../../app/extend/agent.js';
 
 export abstract class TimerStrategy extends BaseStrategy {
   protected cronInstance?: CronExpression;
@@ -34,8 +34,7 @@ export abstract class TimerStrategy extends BaseStrategy {
     throw new TypeError(`[@eggjs/schedule] ${this.key} strategy should override \`handler()\` method`);
   }
 
-
-  start() {
+  async start() {
     /* istanbul ignore next */
     if (this.agent.schedule.closed) return;
 
diff --git a/src/lib/types.ts b/src/lib/types.ts
index 36d8e38..d2eb19c 100644
--- a/src/lib/types.ts
+++ b/src/lib/types.ts
@@ -1,6 +1,4 @@
 import type { ParserOptions as CronOptions } from 'cron-parser';
-import type { Schedule } from './schedule.js';
-import type { ScheduleWorker } from './schedule_worker.js';
 
 /**
  * Schedule Config
@@ -34,25 +32,3 @@ export interface EggScheduleJobInfo {
   message?: string;
   rt?: number;
 }
-
-declare module 'egg' {
-  export interface EggScheduleAgent {
-    schedule: Schedule;
-  }
-  export interface Agent extends EggScheduleAgent {}
-
-  export interface EggScheduleApplication {
-    scheduleWorker: ScheduleWorker;
-    /** runSchedule in unittest */
-    runSchedule: (schedulePath: string, ...args: any[]) => Promise<void>;
-  }
-  export interface Application extends EggScheduleApplication {}
-
-  export interface EggScheduleAppConfig {
-    schedule: {
-      directory: string[];
-    };
-  }
-
-  export interface EggAppConfig extends EggScheduleAppConfig {}
-}