diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6209b30..8fba060 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1 +1,19 @@
-RELEASE 1.0.0
\ No newline at end of file
+## RELEASE 1.1.0
+### Feature
+* Add full support for useClass and useExisting
+* Add more docs
+### Bug Fixes
+* Fix minor bugs
+
+## RELEASE 1.0.5
+### Feature
+* Update package.json
+* Add more docs
+### Bug Fixes
+* Fix minor bugs
+
+## RELEASE 1.0.1
+### Feature
+* Initial support for About currency conversion module for nestjs
+### Bug Fixes
+* Fix minor bugs
\ No newline at end of file
diff --git a/example/src/app.module.ts b/example/src/app.module.ts
index 1b44fc9..c38b4b8 100644
--- a/example/src/app.module.ts
+++ b/example/src/app.module.ts
@@ -12,7 +12,6 @@ const rates = {
 
 @Module({
   imports: [
-    ConfigModule.forRoot(),
     // CashifyModule.forRoot({base: 'EUR', rates}),
     CashifyModule.forRootAsync({
       imports: [ConfigModule],
@@ -20,7 +19,12 @@ const rates = {
         base: configService.get<string>('BASE'), rates
       }),
       inject: [ConfigService]
-    })
+    }),
+    // CashifyModule.forRootAsync({
+    //   useClass: CashifyConfigService,
+    //   import: [ConfigModule],
+    //   extraProviders: [ConfigService],
+    // })
   ],
   controllers: [AppController],
   providers: [AppService],
diff --git a/example/src/cashify-config.service.ts b/example/src/cashify-config.service.ts
new file mode 100644
index 0000000..7f09437
--- /dev/null
+++ b/example/src/cashify-config.service.ts
@@ -0,0 +1,20 @@
+import { Injectable } from "@nestjs/common";
+import { ConfigService } from "@nestjs/config";
+import { CashifyOptionsFactory } from 'nestjs-cashify';
+
+@Injectable()
+export class CashifyConfigService implements CashifyOptionsFactory {
+  constructor(private configService: ConfigService) {}
+
+  createCashifyOptions() {
+    const rates = {
+      GBP: 0.92,
+      EUR: 1.00,
+      USD: 1.12
+    };
+    return {
+      base: this.configService.get<string>('BASE'),
+      rates
+    };
+  }
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index e3d97dc..bcccfa1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "nestjs-cashify",
-  "version": "1.0.5",
+  "version": "1.1.0",
   "description": "Currency conversion module for nest",
   "author": "Vahid Najafi <vahid.vdn@gmail.com>",
   "license": "MIT",
@@ -22,7 +22,14 @@
     "test:e2e": "jest --config ./test/jest-e2e.json"
   },
   "keywords": [
-    "nestjs"
+    "nestjs",
+    "nodejs",
+    "cashify",
+    "nestjs-cashify",
+    "currency-exchange",
+    "conversion",
+    "money",
+    "exchange-rates"
   ],
   "publishConfig": {
     "access": "public"
diff --git a/src/cashify.module.ts b/src/cashify.module.ts
index 1d6b3a4..a0e0e46 100644
--- a/src/cashify.module.ts
+++ b/src/cashify.module.ts
@@ -1,10 +1,23 @@
-import { DynamicModule, Module } from '@nestjs/common';
+import { DynamicModule, Module, Provider } from '@nestjs/common';
 import { Cashify } from 'cashify';
 import { CASHIFY, CashifyService, CASHIFY_OPTIONS } from './';
+import { CashifyOptionsFactory } from './interfaces/cashify-module.interface';
 
 @Module({})
 export class CashifyModule {
+
+  /**
+   * @param options a simple configuration object
+   * @returns DynamicModule object
+   */
   public static forRoot(options): DynamicModule {
+
+    /**
+    * To have access to the Cashify's instance by CASHIFY token injection
+    * The reason we export it too, is that we can have direct access in consumer module,
+    * so if there is a new method added in future for core module by it's author,
+    * consumer module can have access to it
+     */
     const CashifyProvider = {
       provide: CASHIFY,
       useValue: new Cashify(options),
@@ -18,13 +31,19 @@ export class CashifyModule {
       ]
     }
   }
+  
+  /**
+   * @param optionsAsync this is not a simple object of main options
+   * this is an async configuration with useFactory passed from consumer module
+   * @returns DynamicModule object
+   */
   public static forRootAsync(optionsAsync): DynamicModule {
-    const CashifyOptionProvider = {
-      provide: CASHIFY_OPTIONS,
-      useFactory: optionsAsync.useFactory,
-      inject: optionsAsync.inject || []
-    };
-    const CashifyProvider = {
+
+    /**
+    * This is our main provider that is accessible within the service
+    * The same one in forRoot method (but resolve the options in an async way)
+     */
+    const CashifyProvider =  {
       provide: CASHIFY,
       useFactory: (options) => new Cashify(options),
       inject: [CASHIFY_OPTIONS],
@@ -35,10 +54,53 @@ export class CashifyModule {
       imports: optionsAsync.imports,
       exports: [CashifyService, CashifyProvider],
       providers: [
+        ...this.createAsyncProviders(optionsAsync),
         CashifyProvider,
-        CashifyOptionProvider,
-        CashifyService
-      ]
+        CashifyService,
+        ...(optionsAsync.extraProviders || []),
+      ],
     }
   }
+
+  private static createAsyncProviders(options): Provider[] {
+    if (options.useExisting || options.useFactory) {
+      return [this.createAsyncOptionsProvider(options)];
+    }
+    return [
+      this.createAsyncOptionsProvider(options),
+      {
+        provide: options.useClass,
+        useClass: options.useClass,
+      },
+    ];
+  }
+
+  private static createAsyncOptionsProvider(optionsAsync): Provider {
+
+    /**
+    * This is going to be a factory provider and import in the list of providers
+    * This provider make the options value available in CashifyProvider. Since it's a provider,
+    * it can be injected in CashifyProvider
+     */
+    if (optionsAsync.useFactory) {
+      return {
+        provide: CASHIFY_OPTIONS,
+        useFactory: optionsAsync.useFactory,
+        inject: optionsAsync.inject || []
+      };
+    }
+
+    /**
+     * In consumer module, if we use useClass, the give class may have some dependencies,
+     * like ConfigService (and it's module). But they are not available in this module's context.
+     * So, we have an 'imports' object and extraProviders in forRootAsync method.
+     * Then we can dynamically add them from consumer module. See example in example folder.
+     */
+    return {
+      provide: CASHIFY_OPTIONS,
+      useFactory: async (optionsFactory: CashifyOptionsFactory) =>
+        optionsFactory.createCashifyOptions(),
+      inject: [optionsAsync.useExisting || optionsAsync.useClass],
+    };
+  }
 }
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index 4c382b4..22f40f6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -2,4 +2,5 @@
 export * from './cashify.const';
 export * from './cashify.module';
 export * from './cashify.service';
+export * from './interfaces';
 
diff --git a/src/interfaces/cashify-module.interface.ts b/src/interfaces/cashify-module.interface.ts
new file mode 100644
index 0000000..fe117ed
--- /dev/null
+++ b/src/interfaces/cashify-module.interface.ts
@@ -0,0 +1,11 @@
+/**
+ * Interface describing a `CashifyOptionsFactory`.  Providers supplying configuration
+ * options for the Cashify module must implement this interface.
+ *
+ * @see [Async configuration](https://docs.nestjs.com/techniques/caching#async-configuration)
+ *
+ * @publicApi
+ */
+ export interface CashifyOptionsFactory {
+    createCashifyOptions();
+  }
\ No newline at end of file
diff --git a/src/interfaces/index.ts b/src/interfaces/index.ts
new file mode 100644
index 0000000..a656222
--- /dev/null
+++ b/src/interfaces/index.ts
@@ -0,0 +1 @@
+export * from './cashify-module.interface';