diff --git a/package.json b/package.json
index 39edd03..6f4e6fa 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,8 @@
     "@nestjs/core": "^11.0.1",
     "@nestjs/platform-express": "^11.0.1",
     "@nestjs/swagger": "^11.2.5",
+    "class-transformer": "^0.5.1",
+    "class-validator": "^0.14.3",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1"
   },
diff --git a/src/core/app.module.ts b/src/core/app.module.ts
index e414bd1..9cb9e2f 100644
--- a/src/core/app.module.ts
+++ b/src/core/app.module.ts
@@ -1,11 +1,13 @@
 import { Module } from '@nestjs/common'
 import { ConfigModule } from '@nestjs/config'
 
+import { AuthModule } from '../modules/auth/auth.module'
+
 import { AppController } from './app.controller'
 import { AppService } from './app.service'
 
 @Module({
-  imports: [ConfigModule.forRoot({ isGlobal: true })],
+  imports: [ConfigModule.forRoot({ isGlobal: true }), AuthModule],
   controllers: [AppController],
   providers: [AppService]
 })
diff --git a/src/core/config/cors.config.ts b/src/core/config/cors.config.ts
new file mode 100644
index 0000000..f067c04
--- /dev/null
+++ b/src/core/config/cors.config.ts
@@ -0,0 +1,9 @@
+import { CorsOptions } from '@nestjs/common/interfaces/external/cors-options.interface'
+import { ConfigService } from '@nestjs/config'
+
+export function getCorsConfig(configService: ConfigService): CorsOptions {
+  return {
+    origin: configService.getOrThrow<string>('HTTP_CORS').split(','),
+    credentials: true
+  }
+}
diff --git a/src/core/config/index.ts b/src/core/config/index.ts
new file mode 100644
index 0000000..635ba52
--- /dev/null
+++ b/src/core/config/index.ts
@@ -0,0 +1,3 @@
+export * from './cors.config'
+export * from './swagger.config'
+export * from './validation-pipe.config'
diff --git a/src/core/config/swagger.config.ts b/src/core/config/swagger.config.ts
new file mode 100644
index 0000000..b681442
--- /dev/null
+++ b/src/core/config/swagger.config.ts
@@ -0,0 +1,8 @@
+import { DocumentBuilder } from '@nestjs/swagger'
+
+export const swaggerConfig = new DocumentBuilder()
+  .setTitle('Teacinema API')
+  .setDescription('API Gateway for Teacinema microservices')
+  .setVersion('1.0.0')
+  .addBearerAuth()
+  .build()
diff --git a/src/core/config/validation-pipe.config.ts b/src/core/config/validation-pipe.config.ts
new file mode 100644
index 0000000..45e2b33
--- /dev/null
+++ b/src/core/config/validation-pipe.config.ts
@@ -0,0 +1,6 @@
+import { ValidationPipe } from '@nestjs/common'
+
+export const validationPipe = new ValidationPipe({
+  transform: true,
+  whitelist: true
+})
diff --git a/src/main.ts b/src/main.ts
index e31cff1..54e6b28 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,9 +1,10 @@
 import { Logger } from '@nestjs/common'
 import { ConfigService } from '@nestjs/config'
 import { NestFactory } from '@nestjs/core'
-import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger'
+import { SwaggerModule } from '@nestjs/swagger'
 
 import { AppModule } from './core/app.module'
+import { getCorsConfig, swaggerConfig, validationPipe } from './core/config'
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule)
@@ -11,17 +12,9 @@ async function bootstrap() {
   const logger = new Logger()
   const config = app.get(ConfigService)
 
-  app.enableCors({
-    origin: config.getOrThrow<string>('HTTP_CORS').split(','),
-    credentials: true
-  })
+  app.useGlobalPipes(validationPipe)
 
-  const swaggerConfig = new DocumentBuilder()
-    .setTitle('Teacinema API')
-    .setDescription('API Gateway for Teacinema microservices')
-    .setVersion('1.0.0')
-    .addBearerAuth()
-    .build()
+  app.enableCors(getCorsConfig(config))
 
   const swaggerDocument = SwaggerModule.createDocument(app, swaggerConfig)
   SwaggerModule.setup('docs', app, swaggerDocument, {
diff --git a/src/modules/auth/auth.controller.ts b/src/modules/auth/auth.controller.ts
new file mode 100644
index 0000000..c345856
--- /dev/null
+++ b/src/modules/auth/auth.controller.ts
@@ -0,0 +1,19 @@
+import { Body, Controller, HttpCode, HttpStatus, Post } from '@nestjs/common'
+import { ApiOperation } from '@nestjs/swagger'
+
+import { SendOtpRequestDto } from './dto'
+
+@Controller('auth')
+export class AuthController {
+  @ApiOperation({
+    summary: 'Send OTP',
+    description: 'Send verification code to the user phone or email'
+  })
+  @Post('otp/send')
+  @HttpCode(HttpStatus.OK)
+  public sendOtp(@Body() dto: SendOtpRequestDto) {
+    console.log('data', dto)
+
+    return { ok: true }
+  }
+}
diff --git a/src/modules/auth/auth.module.ts b/src/modules/auth/auth.module.ts
new file mode 100644
index 0000000..d928ab5
--- /dev/null
+++ b/src/modules/auth/auth.module.ts
@@ -0,0 +1,7 @@
+import { Module } from '@nestjs/common';
+import { AuthController } from './auth.controller';
+
+@Module({
+  controllers: [AuthController]
+})
+export class AuthModule {}
diff --git a/src/modules/auth/dto/index.ts b/src/modules/auth/dto/index.ts
new file mode 100644
index 0000000..66d0236
--- /dev/null
+++ b/src/modules/auth/dto/index.ts
@@ -0,0 +1 @@
+export * from './rq'
diff --git a/src/modules/auth/dto/rq/index.ts b/src/modules/auth/dto/rq/index.ts
new file mode 100644
index 0000000..060b2b8
--- /dev/null
+++ b/src/modules/auth/dto/rq/index.ts
@@ -0,0 +1 @@
+export * from './send-otp.request.dto'
diff --git a/src/modules/auth/dto/rq/send-otp.request.dto.ts b/src/modules/auth/dto/rq/send-otp.request.dto.ts
new file mode 100644
index 0000000..a231c72
--- /dev/null
+++ b/src/modules/auth/dto/rq/send-otp.request.dto.ts
@@ -0,0 +1,22 @@
+import { ApiProperty } from '@nestjs/swagger'
+import { IsEnum, IsString, Validate } from 'class-validator'
+
+import { IdentifierValidator } from '../../../../shared/validators'
+
+export class SendOtpRequestDto {
+  @ApiProperty({
+    description: 'User phone or email',
+    example: '+791234567890'
+  })
+  @Validate(IdentifierValidator)
+  @IsString()
+  public identifier: string
+
+  @ApiProperty({
+    description: 'Type of identifier',
+    example: 'phone',
+    enum: ['phone', 'email']
+  })
+  @IsEnum(['phone', 'email'])
+  public type: 'phone' | 'email'
+}
diff --git a/src/shared/validators/identifier.validator.ts b/src/shared/validators/identifier.validator.ts
new file mode 100644
index 0000000..4aca647
--- /dev/null
+++ b/src/shared/validators/identifier.validator.ts
@@ -0,0 +1,35 @@
+import {
+  isEmail,
+  isPhoneNumber,
+  ValidationArguments,
+  ValidatorConstraint,
+  ValidatorConstraintInterface
+} from 'class-validator'
+
+import { SendOtpRequestDto } from '../../modules/auth/dto'
+
+@ValidatorConstraint({ name: 'IdentifierValidator', async: false })
+export class IdentifierValidator implements ValidatorConstraintInterface {
+  public validate(value: string, args: ValidationArguments) {
+    const object = args.object as SendOtpRequestDto
+    if (object.type === 'email') {
+      return typeof value === 'string' && isEmail(value)
+    } else if (object.type === 'phone') {
+      return typeof value === 'string' && isPhoneNumber(value)
+    }
+
+    return false
+  }
+
+  public defaultMessage(args: ValidationArguments) {
+    const object = args.object as SendOtpRequestDto
+
+    if (object.type === 'email') {
+      return 'identifier must be a valid email'
+    } else if (object.type === 'phone') {
+      return 'identifier must be a valid phone number'
+    }
+
+    return 'Invalid identifier'
+  }
+}
diff --git a/src/shared/validators/index.ts b/src/shared/validators/index.ts
new file mode 100644
index 0000000..21bad3b
--- /dev/null
+++ b/src/shared/validators/index.ts
@@ -0,0 +1 @@
+export * from './identifier.validator'
diff --git a/yarn.lock b/yarn.lock
index 4fa934b..70c7e5d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1359,6 +1359,11 @@
     "@types/methods" "^1.1.4"
     "@types/superagent" "^8.1.0"
 
+"@types/validator@^13.15.3":
+  version "13.15.10"
+  resolved "https://registry.yarnpkg.com/@types/validator/-/validator-13.15.10.tgz#742b77ec34d58554b94a76a14cef30d59e3c16b9"
+  integrity sha512-T8L6i7wCuyoK8A/ZeLYt1+q0ty3Zb9+qbSSvrIVitzT3YjZqkTZ40IbRsPanlB4h1QB3JVL1SYCdR6ngtFYcuA==
+
 "@types/yargs-parser@*":
   version "21.0.3"
   resolved "https://registry.yarnpkg.com/@types/yargs-parser/-/yargs-parser-21.0.3.tgz#815e30b786d2e8f0dcd85fd5bcf5e1a04d008f15"
@@ -2112,6 +2117,20 @@ cjs-module-lexer@^2.1.0:
   resolved "https://registry.yarnpkg.com/cjs-module-lexer/-/cjs-module-lexer-2.2.0.tgz#b3ca5101843389259ade7d88c77bd06ce55849ca"
   integrity sha512-4bHTS2YuzUvtoLjdy+98ykbNB5jS0+07EvFNXerqZQJ89F7DI6ET7OQo/HJuW6K0aVsKA9hj9/RVb2kQVOrPDQ==
 
+class-transformer@^0.5.1:
+  version "0.5.1"
+  resolved "https://registry.yarnpkg.com/class-transformer/-/class-transformer-0.5.1.tgz#24147d5dffd2a6cea930a3250a677addf96ab336"
+  integrity sha512-SQa1Ws6hUbfC98vKGxZH3KFY0Y1lm5Zm0SY8XX9zbK7FJCyVEac3ATW0RIpwzW+oOfmHE5PMPufDG9hCfoEOMw==
+
+class-validator@^0.14.3:
+  version "0.14.3"
+  resolved "https://registry.yarnpkg.com/class-validator/-/class-validator-0.14.3.tgz#834a4caafa8359aed73d7708badb4cf271be50fe"
+  integrity sha512-rXXekcjofVN1LTOSw+u4u9WXVEUvNBVjORW154q/IdmYWy1nMbOU9aNtZB0t8m+FJQ9q91jlr2f9CwwUFdFMRA==
+  dependencies:
+    "@types/validator" "^13.15.3"
+    libphonenumber-js "^1.11.1"
+    validator "^13.15.20"
+
 cli-cursor@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/cli-cursor/-/cli-cursor-3.1.0.tgz#264305a7ae490d1d03bf0c9ba7c925d1753af307"
@@ -3666,6 +3685,11 @@ levn@^0.4.1:
     prelude-ls "^1.2.1"
     type-check "~0.4.0"
 
+libphonenumber-js@^1.11.1:
+  version "1.12.34"
+  resolved "https://registry.yarnpkg.com/libphonenumber-js/-/libphonenumber-js-1.12.34.tgz#20ed9da39e930e98eff4b6e24a8d8480303658af"
+  integrity sha512-v/Ip8k8eYdp7bINpzqDh46V/PaQ8sK+qi97nMQgjZzFlb166YFqlR/HVI+MzsI9JqcyyVWCOipmmretiaSyQyw==
+
 lines-and-columns@^1.1.6:
   version "1.2.4"
   resolved "https://registry.yarnpkg.com/lines-and-columns/-/lines-and-columns-1.2.4.tgz#eca284f75d2965079309dc0ad9255abb2ebc1632"
@@ -4953,6 +4977,11 @@ v8-to-istanbul@^9.0.1:
     "@types/istanbul-lib-coverage" "^2.0.1"
     convert-source-map "^2.0.0"
 
+validator@^13.15.20:
+  version "13.15.26"
+  resolved "https://registry.yarnpkg.com/validator/-/validator-13.15.26.tgz#36c3deeab30e97806a658728a155c66fcaa5b944"
+  integrity sha512-spH26xU080ydGggxRyR1Yhcbgx+j3y5jbNXk/8L+iRvdIEQ4uTRH2Sgf2dokud6Q4oAtsbNvJ1Ft+9xmm6IZcA==
+
 vary@^1, vary@^1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/vary/-/vary-1.1.2.tgz#2299f02c6ded30d4a5961b0b9f74524a18f634fc"