diff --git a/packages/harmony-contract/src/contractFactory.ts b/packages/harmony-contract/src/contractFactory.ts
index 71bc84a..87e7e1b 100644
--- a/packages/harmony-contract/src/contractFactory.ts
+++ b/packages/harmony-contract/src/contractFactory.ts
@@ -3,9 +3,9 @@ import { Contract } from './contract';
 import { ContractOptions } from './utils/options';
 
 export class ContractFactory {
-  wallet: Wallet;
+  wallet: Wallet | any;
 
-  constructor(wallet: Wallet) {
+  constructor(wallet: Wallet | any) {
     this.wallet = wallet;
   }
   createContract(abi: any[], address?: string, options?: ContractOptions) {
diff --git a/packages/harmony-core/src/harmonyExtension.ts b/packages/harmony-core/src/harmonyExtension.ts
new file mode 100644
index 0000000..330ecaa
--- /dev/null
+++ b/packages/harmony-core/src/harmonyExtension.ts
@@ -0,0 +1,89 @@
+import { HttpProvider, WSProvider, Messenger, Provider } from '@harmony-js/network';
+
+import * as crypto from '@harmony-js/crypto';
+import * as utils from '@harmony-js/utils';
+
+import { Transaction, TransactionFactory } from '@harmony-js/transaction';
+import { Blockchain } from './blockchain';
+import { ContractFactory } from '@harmony-js/contract';
+
+export enum ExtensionType {
+  MathWallet = 'MathWallet',
+}
+
+export interface ExtensionAccount {
+  address: 'string';
+  name: 'string';
+}
+
+export interface ExtensionNetwork {
+  chain_url: string;
+  net_version: number;
+}
+
+export interface ExtensionInterface {
+  signTransaction: (
+    transaction: Transaction,
+    updateNonce: boolean,
+    encodeMode: string,
+    blockNumber: string,
+  ) => Promise<Transaction>;
+  getAccount: () => Promise<ExtensionAccount>;
+  messenger?: Messenger;
+  version: string;
+  isMathWallet?: boolean;
+  network: ExtensionNetwork;
+}
+
+const Extendsion: ExtensionInterface = (<any>window).harmony;
+
+export class HarmonyExtension {
+  extensionType: ExtensionType | null;
+  wallet: ExtensionInterface;
+  provider: HttpProvider | WSProvider;
+  messenger: Messenger;
+  blockchain: Blockchain;
+  transactions: TransactionFactory;
+  contracts: ContractFactory;
+  crypto: any;
+  utils: any;
+
+  constructor(wallet: ExtensionInterface = Extendsion) {
+    this.extensionType = null;
+    this.wallet = wallet;
+    // check if it is mathwallet
+    this.isExtension(this.wallet);
+    this.provider = new Provider(wallet.network.chain_url).provider;
+    this.messenger = new Messenger(this.provider, utils.ChainType.Harmony, utils.ChainID.Default);
+    this.wallet.messenger = this.messenger;
+    this.blockchain = new Blockchain(this.messenger);
+    this.transactions = new TransactionFactory(this.messenger);
+    this.contracts = new ContractFactory(this.wallet);
+    this.crypto = crypto;
+    this.utils = utils;
+  }
+  public setProvider(provider: string | HttpProvider | WSProvider): void {
+    this.provider = new Provider(provider).provider;
+    this.messenger.setProvider(this.provider);
+    this.blockchain.setMessenger(this.messenger);
+    this.wallet.messenger = this.messenger;
+    this.transactions.setMessenger(this.messenger);
+  }
+  public isExtension(wallet: ExtensionInterface) {
+    let isExtension = false;
+    this.extensionType = null;
+    if (wallet.isMathWallet) {
+      isExtension = true;
+      this.extensionType = ExtensionType.MathWallet;
+    }
+    if (!isExtension) {
+      throw new Error('Extension is not found');
+    }
+    return;
+  }
+  public async login() {
+    const account = await this.wallet.getAccount();
+    // Use address
+    return account;
+  }
+}
diff --git a/packages/harmony-core/src/index.ts b/packages/harmony-core/src/index.ts
index 2a9e2a5..16b483d 100644
--- a/packages/harmony-core/src/index.ts
+++ b/packages/harmony-core/src/index.ts
@@ -1,4 +1,5 @@
 export * from './harmony';
 export * from './blockchain';
 export * from './truffleProvider';
+export * from './harmonyExtension';
 export * from './types';