diff --git a/.github/workflows/ci-cd.yml b/.github/workflows/ci-cd.yml
index 20a63c8..899d1c2 100644
--- a/.github/workflows/ci-cd.yml
+++ b/.github/workflows/ci-cd.yml
@@ -46,6 +46,12 @@ jobs:
         echo "BACKGROUND_BUCKET=${{ vars.BACKGROUND_BUCKET }}" >> .env
         echo "COMPONENT_BUCKET=${{ vars.COMPONENT_BUCKET }}" >> .env
         echo "LETTER_BUCKET=${{ vars.LETTER_BUCKET }}" >> .env
+        echo "DB_TYPE=${{ vars.DB_TYPE }}" >> .env
+        echo "DB_HOST=${{ secrets.DB_HOST }}" >> .env
+        echo "DB_NAME=${{ secrets.DB_NAME }}" >> .env
+        echo "DB_PORT=${{ secrets.DB_PORT}}" >> .env
+        echo "DB_PWD=${{ secrets.DB_PWD }}" >> .env
+        echo "DB_USER=${{ secrets.DB_USER }}" >> .env
     - name: docker create
       run : docker buildx create --use
 
diff --git a/src/database/database.module.ts b/src/database/database.module.ts
index 62bd51e..463f2cd 100644
--- a/src/database/database.module.ts
+++ b/src/database/database.module.ts
@@ -1,17 +1,32 @@
 import { Global, Module } from '@nestjs/common';
-import { ConfigModule } from '@nestjs/config';
+import { ConfigModule, ConfigService } from '@nestjs/config';
 import { TypeOrmModule } from '@nestjs/typeorm';
-import { ConfigService } from 'aws-sdk';
 import { LetterDataSource } from './datasource/letter.datasource';
+import { Enviroments } from '@app/domain/dto/env';
+import { plainToClass, plainToInstance } from 'class-transformer';
+import { validateSync } from 'class-validator';
 
 @Global()
 @Module({
   imports: [
     TypeOrmModule.forRootAsync({
       imports: [ConfigModule],
-      useFactory: async () => {
-        await LetterDataSource.initialize();
-        return LetterDataSource.options;
+      useFactory: async (config:ConfigService) => {
+
+        const env = plainToInstance(Enviroments,process.env, {
+            enableImplicitConversion : true,
+        });
+        const ds = LetterDataSource({ 
+            type: env.DB_TYPE,
+            host: env.DB_HOST,
+            port: env.DB_PORT,
+            database: env.DB_NAME,
+            username: env.DB_USER,
+            password: env.DB_PWD,
+            synchronize : false,
+        })
+        await ds.initialize(); 
+        return ds.options;
       },
       inject: [ConfigService],
     }),
diff --git a/src/database/datasource/letter.datasource.ts b/src/database/datasource/letter.datasource.ts
index 3b1a414..05f1f1f 100644
--- a/src/database/datasource/letter.datasource.ts
+++ b/src/database/datasource/letter.datasource.ts
@@ -1,14 +1,15 @@
 import { DataSource } from 'typeorm';
-import 'dotenv/config';
 
-export const LetterDataSource = new DataSource({
-  type: process.env.DB_TYPE as any,
-  host: process.env.DB_HOST,
-  port: Number(process.env.DB_PORT),
-  username: process.env.DB_USER,
-  password: process.env.DB_PWD,
-  database: process.env.DB_NAME,
+export const LetterDataSource =(param : {
+  type : any,
+  host : string,
+  port : number,
+  username : string,
+  password : string,
+  database : string,
+  synchronize : boolean
+}) => new DataSource({
+  ...param,
   entities: [__dirname + '/../entity/*.{ts,js}'],
   migrations: [__dirname + '/../migration/*.{ts,js}'],
-  synchronize: process.env.DB_SYNC === 'true' || false,
 });
diff --git a/src/database/entity/letter.ts b/src/database/entity/letter.ts
index ea1d3c7..fdfc907 100644
--- a/src/database/entity/letter.ts
+++ b/src/database/entity/letter.ts
@@ -29,7 +29,6 @@ export class LetterEntity extends DefaultEntity {
   @Column({
     name: UserColumn.userId,
     type: 'char',
-    length: 36,
     nullable: false,
   })
   userId: string;
diff --git a/src/domain/dto/env.ts b/src/domain/dto/env.ts
index c4658d8..1cae6b1 100644
--- a/src/domain/dto/env.ts
+++ b/src/domain/dto/env.ts
@@ -1,35 +1,61 @@
-import { IsString, IsUrl, IsNotEmpty } from 'class-validator';
+import { Transform } from 'class-transformer';
+import { IsString, IsUrl, IsNotEmpty, IsNumber } from 'class-validator';
 
 export class Enviroments {
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   WASABI_ACCESS_KEY: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   WASABI_SECRET_KEY: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   WASABI_REGION: string;
 
-  @IsUrl()
   @IsNotEmpty()
+  @IsUrl()
   WASABI_ENDPOINT: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   THUMB_BUCKET: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   BACKGROUND_BUCKET: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   COMPONENT_BUCKET: string;
 
-  @IsString()
   @IsNotEmpty()
+  @IsString()
   LETTER_BUCKET: string;
+
+  @IsNotEmpty()
+  @IsString()
+  DB_TYPE : string;
+
+  @IsNotEmpty()
+  @IsString()
+  DB_HOST : string;
+
+  @Transform(({value}) => Number(value))
+  @IsNotEmpty()
+  @IsNumber()
+  DB_PORT : number;
+
+  @IsNotEmpty()
+  @IsString()
+  DB_NAME : string;
+
+  @IsNotEmpty()
+  @IsString()
+  DB_USER : string;
+
+  @IsNotEmpty()
+  @IsString()
+  DB_PWD : string; 
 }
diff --git a/src/domain/letter/dto/request/add.letter.ts b/src/domain/letter/dto/request/add.letter.ts
new file mode 100644
index 0000000..c295cd5
--- /dev/null
+++ b/src/domain/letter/dto/request/add.letter.ts
@@ -0,0 +1,20 @@
+import { LetterCategory, LetterCategoryCode } from "@util/category";
+import { Transform } from "class-transformer";
+import { IsDefined, IsIn, IsOptional, IsString, MaxLength } from "class-validator";
+
+export class AddLetterRequest {
+    @IsDefined()
+    @IsString()
+    @IsIn(Object.values(LetterCategoryCode))
+    category : LetterCategoryCode
+
+    @IsDefined()
+    @IsString()
+    @MaxLength(20)
+    title : string
+
+    @IsOptional()
+    @IsString()
+    @MaxLength(255)
+    body : string;
+}
\ No newline at end of file