diff --git a/packages/connector-alipay-native/src/index.test.ts b/packages/connector-alipay-native/src/index.test.ts
index 11f584307..93e879976 100644
--- a/packages/connector-alipay-native/src/index.test.ts
+++ b/packages/connector-alipay-native/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import AlipayNativeConnector from '.';
 import { alipayEndpoint } from './constant';
 import { mockedAlipayNativeConfig, mockedAlipayNativeConfigWithValidPrivateKey } from './mock';
+import { AlipayNativeConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -25,21 +26,21 @@ describe('validateConfig', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = alipayNativeMethods.validateConfig;
+    const validator: ValidateConfig<AlipayNativeConfig> = alipayNativeMethods.validateConfig;
     expect(() => {
       validator(mockedAlipayNativeConfig);
     }).not.toThrow();
   });
 
   it('should fail on empty config', async () => {
-    const validator: ValidateConfig = alipayNativeMethods.validateConfig;
+    const validator: ValidateConfig<AlipayNativeConfig> = alipayNativeMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
   });
 
   it('should fail when missing required properties', async () => {
-    const validator: ValidateConfig = alipayNativeMethods.validateConfig;
+    const validator: ValidateConfig<AlipayNativeConfig> = alipayNativeMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId' });
     }).toThrow();
diff --git a/packages/connector-alipay-web/src/index.test.ts b/packages/connector-alipay-web/src/index.test.ts
index d6fff86bc..262906ee3 100644
--- a/packages/connector-alipay-web/src/index.test.ts
+++ b/packages/connector-alipay-web/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import AlipayConnector from '.';
 import { alipayEndpoint, authorizationEndpoint } from './constant';
 import { mockedAlipayConfig, mockedAlipayConfigWithValidPrivateKey } from './mock';
+import { AlipayConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -25,7 +26,7 @@ describe('validateConfig', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = alipayMethods.validateConfig;
+    const validator: ValidateConfig<AlipayConfig> = alipayMethods.validateConfig;
     expect(() => {
       validator({
         appId: 'appId',
@@ -36,14 +37,14 @@ describe('validateConfig', () => {
   });
 
   it('should fail on empty config', async () => {
-    const validator: ValidateConfig = alipayMethods.validateConfig;
+    const validator: ValidateConfig<AlipayConfig> = alipayMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
   });
 
   it('should fail when missing required properties', async () => {
-    const validator: ValidateConfig = alipayMethods.validateConfig;
+    const validator: ValidateConfig<AlipayConfig> = alipayMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId' });
     }).toThrow();
diff --git a/packages/connector-aliyun-dm/src/index.test.ts b/packages/connector-aliyun-dm/src/index.test.ts
index 76a667066..f1b0c4b42 100644
--- a/packages/connector-aliyun-dm/src/index.test.ts
+++ b/packages/connector-aliyun-dm/src/index.test.ts
@@ -3,6 +3,7 @@ import { GetConnectorConfig, ValidateConfig } from '@logto/connector-types';
 import AliyunDmConnector from '.';
 import { mockedConfig } from './mock';
 import { singleSendMail } from './single-send-mail';
+import { AliyunDmConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -34,7 +35,7 @@ describe('validateConfig()', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = aliyunDmMethods.validateConfig;
+    const validator: ValidateConfig<AliyunDmConfig> = aliyunDmMethods.validateConfig;
     expect(() => {
       validator({
         accessKeyId: 'accessKeyId',
@@ -46,7 +47,7 @@ describe('validateConfig()', () => {
   });
 
   it('should fail if config is invalid', async () => {
-    const validator: ValidateConfig = aliyunDmMethods.validateConfig;
+    const validator: ValidateConfig<AliyunDmConfig> = aliyunDmMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-aliyun-sms/src/index.test.ts b/packages/connector-aliyun-sms/src/index.test.ts
index 31840ac73..908145f78 100644
--- a/packages/connector-aliyun-sms/src/index.test.ts
+++ b/packages/connector-aliyun-sms/src/index.test.ts
@@ -3,6 +3,7 @@ import { GetConnectorConfig, ValidateConfig } from '@logto/connector-types';
 import AliyunSmsConnector from '.';
 import { mockedConnectorConfig, mockedValidConnectorConfig, phoneTest, codeTest } from './mock';
 import { sendSms } from './single-send-text';
+import { AliyunSmsConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -30,14 +31,14 @@ describe('validateConfig()', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = aliyunSmsMethods.validateConfig;
+    const validator: ValidateConfig<AliyunSmsConfig> = aliyunSmsMethods.validateConfig;
     expect(() => {
       validator(mockedValidConnectorConfig);
     }).not.toThrow();
   });
 
   it('should fail if config is invalid', async () => {
-    const validator: ValidateConfig = aliyunSmsMethods.validateConfig;
+    const validator: ValidateConfig<AliyunSmsConfig> = aliyunSmsMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-apple/src/index.test.ts b/packages/connector-apple/src/index.test.ts
index 190bf903e..6126d74b1 100644
--- a/packages/connector-apple/src/index.test.ts
+++ b/packages/connector-apple/src/index.test.ts
@@ -9,6 +9,7 @@ import { jwtVerify } from 'jose';
 import AppleConnector from '.';
 import { authorizationEndpoint } from './constant';
 import { mockedConfig } from './mock';
+import { AppleConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -50,14 +51,14 @@ describe('validateConfig', () => {
    */
 
   it('should be true on valid config', async () => {
-    const validator: ValidateConfig = appleMethods.validateConfig;
+    const validator: ValidateConfig<AppleConfig> = appleMethods.validateConfig;
     expect(() => {
       validator({ clientId: 'clientId' });
     }).not.toThrow();
   });
 
   it('should be false on empty config', async () => {
-    const validator: ValidateConfig = appleMethods.validateConfig;
+    const validator: ValidateConfig<AppleConfig> = appleMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-facebook/src/index.test.ts b/packages/connector-facebook/src/index.test.ts
index b2cd7f503..96dc270ab 100644
--- a/packages/connector-facebook/src/index.test.ts
+++ b/packages/connector-facebook/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import FacebookConnector from '.';
 import { accessTokenEndpoint, authorizationEndpoint, userInfoEndpoint } from './constant';
 import { clientId, clientSecret, code, dummyRedirectUri, fields, mockedConfig } from './mock';
+import { FacebookConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -30,14 +31,14 @@ describe('facebook connector', () => {
      */
 
     it('should pass on valid config', async () => {
-      const validator: ValidateConfig = facebookMethods.validateConfig;
+      const validator: ValidateConfig<FacebookConfig> = facebookMethods.validateConfig;
       expect(() => {
         validator({ clientId, clientSecret });
       }).not.toThrow();
     });
 
     it('should fail on invalid config', async () => {
-      const validator: ValidateConfig = facebookMethods.validateConfig;
+      const validator: ValidateConfig<FacebookConfig> = facebookMethods.validateConfig;
       expect(() => {
         validator({});
       }).toThrow();
diff --git a/packages/connector-github/src/index.test.ts b/packages/connector-github/src/index.test.ts
index 31939be71..1f22a8b30 100644
--- a/packages/connector-github/src/index.test.ts
+++ b/packages/connector-github/src/index.test.ts
@@ -10,6 +10,7 @@ import * as qs from 'query-string';
 import GithubConnector from '.';
 import { accessTokenEndpoint, authorizationEndpoint, userInfoEndpoint } from './constant';
 import { mockedConfig } from './mock';
+import { GithubConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -77,21 +78,21 @@ describe('validateConfig', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = githubMethods.validateConfig;
+    const validator: ValidateConfig<GithubConfig> = githubMethods.validateConfig;
     expect(() => {
       validator({ clientId: 'clientId', clientSecret: 'clientSecret' });
     }).not.toThrow();
   });
 
   it('should fail on empty config', async () => {
-    const validator: ValidateConfig = githubMethods.validateConfig;
+    const validator: ValidateConfig<GithubConfig> = githubMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
   });
 
   it('should fail when missing clientSecret', async () => {
-    const validator: ValidateConfig = githubMethods.validateConfig;
+    const validator: ValidateConfig<GithubConfig> = githubMethods.validateConfig;
     expect(() => {
       validator({ clientId: 'clientId' });
     }).toThrow();
diff --git a/packages/connector-google/src/index.test.ts b/packages/connector-google/src/index.test.ts
index 4766725d6..c5451d3dc 100644
--- a/packages/connector-google/src/index.test.ts
+++ b/packages/connector-google/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import GoogleConnector from '.';
 import { accessTokenEndpoint, authorizationEndpoint, userInfoEndpoint } from './constant';
 import { mockedConfig } from './mock';
+import { GoogleConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -30,14 +31,14 @@ describe('google connector', () => {
      */
 
     it('should pass on valid config', async () => {
-      const validator: ValidateConfig = googleMethods.validateConfig;
+      const validator: ValidateConfig<GoogleConfig> = googleMethods.validateConfig;
       expect(() => {
         validator({ clientId: 'clientId', clientSecret: 'clientSecret' });
       }).not.toThrow();
     });
 
     it('should fail on invalid config', async () => {
-      const validator: ValidateConfig = googleMethods.validateConfig;
+      const validator: ValidateConfig<GoogleConfig> = googleMethods.validateConfig;
       expect(() => {
         validator({});
       }).toThrow();
diff --git a/packages/connector-sendgrid-mail/src/index.test.ts b/packages/connector-sendgrid-mail/src/index.test.ts
index 2154b2c4e..860f26778 100644
--- a/packages/connector-sendgrid-mail/src/index.test.ts
+++ b/packages/connector-sendgrid-mail/src/index.test.ts
@@ -2,7 +2,7 @@ import { GetConnectorConfig, ValidateConfig } from '@logto/connector-types';
 
 import SendGridMailConnector from '.';
 import { mockedConfig } from './mock';
-import { ContextType } from './types';
+import { ContextType, SendGridMailConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -25,7 +25,7 @@ describe('validateConfig()', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = sendGridMailMethods.validateConfig;
+    const validator: ValidateConfig<SendGridMailConfig> = sendGridMailMethods.validateConfig;
     expect(() => {
       validator({
         apiKey: 'apiKey',
@@ -44,7 +44,7 @@ describe('validateConfig()', () => {
   });
 
   it('should be false if config is invalid', async () => {
-    const validator: ValidateConfig = sendGridMailMethods.validateConfig;
+    const validator: ValidateConfig<SendGridMailConfig> = sendGridMailMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-smtp/src/index.test.ts b/packages/connector-smtp/src/index.test.ts
index 24d504d1c..783282960 100644
--- a/packages/connector-smtp/src/index.test.ts
+++ b/packages/connector-smtp/src/index.test.ts
@@ -1,6 +1,7 @@
 import { GetConnectorConfig, ValidateConfig } from '@logto/connector-types';
 
 import SmtpConnector from '.';
+import { SmtpConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -17,7 +18,7 @@ describe('validateConfig()', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = smtpMethods.validateConfig;
+    const validator: ValidateConfig<SmtpConfig> = smtpMethods.validateConfig;
     expect(() => {
       validator({
         host: 'smtp.testing.com',
@@ -56,7 +57,7 @@ describe('validateConfig()', () => {
   });
 
   it('should be false if config is invalid', async () => {
-    const validator: ValidateConfig = smtpMethods.validateConfig;
+    const validator: ValidateConfig<SmtpConfig> = smtpMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-twilio-sms/src/index.test.ts b/packages/connector-twilio-sms/src/index.test.ts
index 703cafd01..5ea339723 100644
--- a/packages/connector-twilio-sms/src/index.test.ts
+++ b/packages/connector-twilio-sms/src/index.test.ts
@@ -2,6 +2,7 @@ import { GetConnectorConfig, ValidateConfig } from '@logto/connector-types';
 
 import TwilioSmsConnector from '.';
 import { mockedConfig } from './mock';
+import { TwilioSmsConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -18,14 +19,14 @@ describe('validateConfig()', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = twilioSmsMethods.validateConfig;
+    const validator: ValidateConfig<TwilioSmsConfig> = twilioSmsMethods.validateConfig;
     expect(() => {
       validator(mockedConfig);
     }).not.toThrow();
   });
 
   it('throws if config is invalid', async () => {
-    const validator: ValidateConfig = twilioSmsMethods.validateConfig;
+    const validator: ValidateConfig<TwilioSmsConfig> = twilioSmsMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
diff --git a/packages/connector-wechat-native/src/index.test.ts b/packages/connector-wechat-native/src/index.test.ts
index bffa3286e..27e0144b2 100644
--- a/packages/connector-wechat-native/src/index.test.ts
+++ b/packages/connector-wechat-native/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import WechatNativeConnector from '.';
 import { accessTokenEndpoint, authorizationEndpoint, userInfoEndpoint } from './constant';
 import { mockedConfig } from './mock';
+import { WechatNativeConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -102,21 +103,21 @@ describe('validateConfig', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = wechatNativeMethods.validateConfig;
+    const validator: ValidateConfig<WechatNativeConfig> = wechatNativeMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId', appSecret: 'appSecret' });
     }).not.toThrow();
   });
 
   it('should fail on empty config', async () => {
-    const validator: ValidateConfig = wechatNativeMethods.validateConfig;
+    const validator: ValidateConfig<WechatNativeConfig> = wechatNativeMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
   });
 
   it('should fail when missing appSecret', async () => {
-    const validator: ValidateConfig = wechatNativeMethods.validateConfig;
+    const validator: ValidateConfig<WechatNativeConfig> = wechatNativeMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId' });
     }).toThrow();
diff --git a/packages/connector-wechat-web/src/index.test.ts b/packages/connector-wechat-web/src/index.test.ts
index c4539899c..69146af89 100644
--- a/packages/connector-wechat-web/src/index.test.ts
+++ b/packages/connector-wechat-web/src/index.test.ts
@@ -9,6 +9,7 @@ import nock from 'nock';
 import WechatConnector from '.';
 import { accessTokenEndpoint, authorizationEndpoint, userInfoEndpoint } from './constant';
 import { mockedConfig } from './mock';
+import { WechatConfig } from './types';
 
 const getConnectorConfig = jest.fn() as GetConnectorConfig;
 
@@ -102,21 +103,21 @@ describe('validateConfig', () => {
    */
 
   it('should pass on valid config', async () => {
-    const validator: ValidateConfig = wechatMethods.validateConfig;
+    const validator: ValidateConfig<WechatConfig> = wechatMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId', appSecret: 'appSecret' });
     }).not.toThrow();
   });
 
   it('should fail on empty config', async () => {
-    const validator: ValidateConfig = wechatMethods.validateConfig;
+    const validator: ValidateConfig<WechatConfig> = wechatMethods.validateConfig;
     expect(() => {
       validator({});
     }).toThrow();
   });
 
   it('should fail when missing appSecret', async () => {
-    const validator: ValidateConfig = wechatMethods.validateConfig;
+    const validator: ValidateConfig<WechatConfig> = wechatMethods.validateConfig;
     expect(() => {
       validator({ appId: 'appId' });
     }).toThrow();
diff --git a/packages/core/src/routes/connector.ts b/packages/core/src/routes/connector.ts
index f96dfc456..f87346f11 100644
--- a/packages/core/src/routes/connector.ts
+++ b/packages/core/src/routes/connector.ts
@@ -1,5 +1,4 @@
 import {
-  ValidateConfig,
   ConnectorInstance,
   EmailConnectorInstance,
   SmsConnectorInstance,
@@ -89,6 +88,7 @@ export default function connectorRoutes<T extends AuthedRouter>(router: T) {
       const connectorInstance = await getConnectorInstanceById(id);
       const {
         connector: { config },
+        validateConfig,
         metadata,
       } = connectorInstance;
 
@@ -96,8 +96,7 @@ export default function connectorRoutes<T extends AuthedRouter>(router: T) {
        * Assertion functions always need explicit annotations.
        * See https://github.com/microsoft/TypeScript/issues/36931#issuecomment-589753014
        */
-      // eslint-disable-next-line unicorn/consistent-destructuring
-      const validator: ValidateConfig = connectorInstance.validateConfig;
+      const validator: typeof validateConfig = validateConfig;
 
       if (enabled) {
         validator(config);
@@ -145,15 +144,13 @@ export default function connectorRoutes<T extends AuthedRouter>(router: T) {
         body,
       } = ctx.guard;
 
-      const connectorInstance = await getConnectorInstanceById(id);
-      const { metadata } = connectorInstance;
+      const { metadata, validateConfig } = await getConnectorInstanceById(id);
 
       /**
        * Assertion functions always need explicit annotations.
        * See https://github.com/microsoft/TypeScript/issues/36931#issuecomment-589753014
        */
-      // eslint-disable-next-line unicorn/consistent-destructuring
-      const validator: ValidateConfig = connectorInstance.validateConfig;
+      const validator: typeof validateConfig = validateConfig;
 
       if (body.config) {
         validator(body.config);