diff --git a/index.d.ts b/index.d.ts
index 79a6f6609b..1997f2b5a6 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -10,6 +10,7 @@ import { EggLogger, EggLoggers, LoggerLevel as EggLoggerLevel, EggContextLogger
 import { HttpClient2, RequestOptions } from 'urllib';
 import {
   EggCoreBase,
+  FileLoaderOption,
   EggLoader as CoreLoader, 
   EggCoreOptions as CoreOptions, 
   EggLoaderOptions as CoreLoaderOptions, 
@@ -183,6 +184,18 @@ declare module 'egg' {
   type IgnoreItem = string | RegExp | ((ctx: Context) => boolean);
   type IgnoreOrMatch = IgnoreItem | IgnoreItem[];
 
+  /** Custom Loader Configuration */
+  export interface CustomLoaderConfig extends RemoveSpecProp<FileLoaderOption, 'inject' | 'target'> {
+    /**
+     * an object you wanner load to, value can only be 'ctx' or 'app'. default to app
+     */
+    inject?: 'ctx' | 'app';
+    /**
+     * whether need to load files in plugins or framework, default to false
+     */
+    loadunit?: boolean;
+  }
+
   export interface EggAppConfig {
     workerStartTimeout: number;
     baseDir: string;
@@ -295,6 +308,14 @@ declare module 'egg' {
        */
       reloadPattern: string[] | string;
     };
+
+    /**
+     * customLoader config
+     */
+    customLoader: {
+      [key: string]: CustomLoaderConfig;
+    };
+
     /**
      * It will ignore special keys when dumpConfig
      */
diff --git a/test/fixtures/apps/app-ts-type-check/error.ts b/test/fixtures/apps/app-ts-type-check/error.ts
index 840df1c626..ab1a99c80a 100644
--- a/test/fixtures/apps/app-ts-type-check/error.ts
+++ b/test/fixtures/apps/app-ts-type-check/error.ts
@@ -5,6 +5,9 @@ import {
   Agent,
   Controller,
   Service,
+  EggAppConfig,
+  PowerPartial,
+  Singleton,
 } from 'egg';
 
 new BaseContextClass({} as Context).ctx;
@@ -46,3 +49,18 @@ const yadan = new YadanApplication({ baseDir: __dirname, plugins: {}, type: 'app
 new yadan.ContextHttpClient();
 new yadan.HttpClient();
 new YadanAgent(undefined, 1123);
+
+// config
+const config = {} as EggAppConfig;
+config.customLoader = {
+  model: {
+  }
+}
+
+// partial config
+const config2 = {} as PowerPartial<EggAppConfig>;
+console.info(config2.security.csrf);
+
+// singleton
+const redis = {} as Singleton<{ test(): void; }>;
+redis.get('123').checkSingleTon();
diff --git a/test/fixtures/apps/app-ts-type-check/normal.ts b/test/fixtures/apps/app-ts-type-check/normal.ts
index 45212b475d..c64b064a9c 100644
--- a/test/fixtures/apps/app-ts-type-check/normal.ts
+++ b/test/fixtures/apps/app-ts-type-check/normal.ts
@@ -6,6 +6,9 @@ import {
   Controller,
   Service,
   Subscription,
+  EggAppConfig,
+  PowerPartial,
+  Singleton,
 } from 'egg';
 
 // base context class
@@ -86,6 +89,37 @@ class MySubscription extends Subscription {
 }
 new MySubscription({} as Context);
 
+// config
+const config = {} as EggAppConfig;
+config.keys = '123123';
+config.customLoader = {
+  model: {
+    directory: 'app/model',
+    inject: 'app',
+  }
+}
+
+// partial config
+const config2 = {} as PowerPartial<EggAppConfig>;
+config2.keys = '123123';
+config2.customLoader = {
+  model: {
+    directory: 'app/model',
+  }
+}
+config2.customLoader = {
+  model: {
+    inject: 'app',
+  }
+}
+config2.security = {
+  csrf: false,
+}
+
+// singleton
+const redis = {} as Singleton<{ test(): void; }>;
+redis.get('123').test();
+
 // extends egg
 app.config.mySpecConfig.substring(0);
 declare module 'egg' {
diff --git a/test/fixtures/apps/app-ts/app/model/test.ts b/test/fixtures/apps/app-ts/app/model/test.ts
new file mode 100644
index 0000000000..f94081b083
--- /dev/null
+++ b/test/fixtures/apps/app-ts/app/model/test.ts
@@ -0,0 +1 @@
+export default class Test {}
diff --git a/test/fixtures/apps/app-ts/config/config.ts b/test/fixtures/apps/app-ts/config/config.ts
index 0ec84155ab..183eeb2483 100644
--- a/test/fixtures/apps/app-ts/config/config.ts
+++ b/test/fixtures/apps/app-ts/config/config.ts
@@ -1,4 +1,18 @@
-export default {
-  keys: 'foo',
-  serverTimeout: 2 * 60 * 1000,
+import { EggAppConfig } from 'egg';
+
+export default () => {
+  const config = {} as EggAppConfig;
+
+  config.keys = 'foo';
+
+  config.serverTimeout = 2 * 60 * 1000;
+
+  config.customLoader = {
+    model: {
+      directory: 'app/model',
+      inject: 'ctx',
+    },
+  };
+
+  return config;
 }
diff --git a/test/ts/index.test.js b/test/ts/index.test.js
index 5ef83b4fbc..9d2a590ad9 100644
--- a/test/ts/index.test.js
+++ b/test/ts/index.test.js
@@ -78,7 +78,7 @@ describe('test/ts/index.test.js', () => {
         require.resolve('typescript/bin/tsc'),
         [ '-p', path.resolve(__dirname, '../fixtures/apps/app-ts-type-check/tsconfig-error.json') ]
       )
-        .debug()
+        // .debug()
         .expect('stdout', /Property 'ctx' is protected/)
         .expect('stdout', /Property 'localsCheckAny' does not exist on type 'string'/)
         .expect('stdout', /Property 'configKeysCheckAny' does not exist on type 'string'/)
@@ -86,7 +86,10 @@ describe('test/ts/index.test.js', () => {
         .expect('stdout', /Property 'serviceLocalCheckAny' does not exist on type 'string'/)
         .expect('stdout', /Property 'serviceConfigCheckAny' does not exist on type 'string'/)
         .expect('stdout', /Property 'serviceAppCheckAny' does not exist on type 'Application'/)
+        .expect('stdout', /Property 'checkSingleTon' does not exist/)
+        .expect('stdout', /Property 'directory' is missing in type '{}' but required in type 'CustomLoaderConfig'/)
         .notExpect('stdout', /Cannot find module 'yadan'/)
+        .expect('stdout', /Object is possibly 'undefined'\./)
         .expect('stdout', /Expected 1 arguments, but got 0\./)
         .expect('stdout', /Expected 0-1 arguments, but got 2\./)
         .expect('code', 2)