diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..21de5ac
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,437 @@
+import { ConnectionOptions } from "mongoose";
+
+export class BaseClass {
+  constructor(config?: WechatConfig);
+}
+
+export class Card extends BaseClass {
+  decryptCardCode(...args: any[]): void;
+
+  getApiTicket(...args: any[]): void;
+
+  getApiTicketRemotely(...args: any[]): void;
+
+  getCardExt(...args: any[]): void;
+
+  getCardSignature(...args: any[]): void;
+
+  getGlobalToken(...args: any[]): void;
+
+  sendDecodeRequest(...args: any[]): void;
+
+  static CARD_TYPE: {
+    CASH: string;
+    DISCOUNT: string;
+    GENERAL_COUPON: string;
+    GIFT: string;
+    GROUPON: string;
+  };
+
+  static CODE_TYPE: {
+    CODE_TYPE_BARCODE: string;
+    CODE_TYPE_NONE: string;
+    CODE_TYPE_ONLY_QRCODE: string;
+    CODE_TYPE_QRCODE: string;
+    CODE_TYPE_TEXT: string;
+  };
+}
+
+export class FileStore {
+  constructor(config?: FileStoreOptions);
+
+  destroy(...args: any[]): void;
+
+  flush(...args: any[]): void;
+
+  initFileStore(...args: any[]): void;
+
+  static StoreEvents: {
+    DESTROY: string;
+    DESTROYED: string;
+    FLUSH_STORE: string;
+    STORE_FLUSHED: string;
+  };
+
+  static defaultMaxListeners: number;
+
+  static init(): void;
+
+  static listenerCount(emitter: any, type: any): any;
+
+  static once(emitter: any, name: any): any;
+
+  static usingDomains: boolean;
+}
+
+export class JSSDK extends BaseClass {
+  createSignature(...args: any[]): void;
+
+  filterSignature(...args: any[]): void;
+
+  getAccessToken(...args: any[]): void;
+
+  getCachedSignature(...args: any[]): void;
+
+  getGlobalTokenAndTicket(...args: any[]): void;
+
+  getJsApiTicket(...args: any[]): void;
+
+  getSignature(...args: any[]): void;
+
+  prepareGlobalToken(...args: any[]): void;
+
+  saveSignature(...args: any[]): void;
+
+  updateAccessTokenOrTicketGlobally(...args: any[]): void;
+
+  updateSignature(...args: any[]): void;
+
+  verifySignature(...args: any[]): void;
+
+  static createNonceStr(...args: any[]): void;
+
+  static generateSignature(...args: any[]): void;
+
+  static isTokenExpired(...args: any[]): void;
+
+  static normalizeUrl(...args: any[]): void;
+}
+
+export class MiniProgram extends BaseClass {
+  decryptData(...args: any[]): void;
+
+  genSignature(...args: any[]): void;
+
+  getSession(...args: any[]): void;
+
+  verifySignature(...args: any[]): void;
+}
+
+export class MongoStore {
+  constructor(config?: MongoStoreOptions);
+
+  destroy(...args: any[]): void;
+
+  flush(...args: any[]): void;
+
+  flushCardTicket(...args: any[]): void;
+
+  flushGlobalToken(...args: any[]): void;
+
+  flushOAuthTokens(...args: any[]): void;
+
+  flushSignatures(...args: any[]): void;
+
+  getCardTicket(...args: any[]): void;
+
+  getGlobalToken(...args: any[]): void;
+
+  getOAuthAccessToken(...args: any[]): void;
+
+  getOAuthTokens(...args: any[]): void;
+
+  getSignature(...args: any[]): void;
+
+  getUrlSignatures(...args: any[]): void;
+
+  initializeTokenFromDB(...args: any[]): void;
+
+  saveOAuthAccessToken(...args: any[]): void;
+
+  saveSignature(...args: any[]): void;
+
+  toObject(...args: any[]): void;
+
+  updateCardTicket(...args: any[]): void;
+
+  updateGlobalToken(...args: any[]): void;
+
+  updateOAuthAccessToken(...args: any[]): void;
+
+  updateSignature(...args: any[]): void;
+
+  static StoreEvents: {
+    DESTROY: string;
+    DESTROYED: string;
+    FLUSH_STORE: string;
+    STORE_FLUSHED: string;
+  };
+
+  static defaultMaxListeners: number;
+
+  static init(): void;
+
+  static listenerCount(emitter: any, type: any): any;
+
+  static once(emitter: any, name: any): any;
+
+  static usingDomains: boolean;
+}
+
+export class OAuth extends BaseClass {
+  generateOAuthUrl(...args: any[]): void;
+
+  getAccessToken(...args: any[]): void;
+
+  getAccessTokenRemotely(...args: any[]): void;
+
+  getUserBaseInfo(...args: any[]): void;
+
+  getUserInfo(...args: any[]): void;
+
+  getUserInfoRemotely(...args: any[]): void;
+
+  isAccessTokenValid(...args: any[]): void;
+
+  refreshAccessToken(...args: any[]): void;
+
+  setDefaultOAuthUrl(...args: any[]): void;
+
+  static isAccessTokenExpired(...args: any[]): void;
+
+  static setAccessTokenExpirationTime(...args: any[]): void;
+}
+
+export class Payment extends BaseClass {
+  closeOrder(...args: any[]): void;
+
+  decryptRefundNotifyResult(...args: any[]): void;
+
+  download(...args: any[]): void;
+
+  downloadBill(...args: any[]): void;
+
+  downloadFundFlow(...args: any[]): void;
+
+  generateChooseWXPayInfo(...args: any[]): void;
+
+  generateGeneralPaymentSignature(...args: any[]): void;
+
+  generateSignature(...args: any[]): void;
+
+  getAPISignKey(...args: any[]): void;
+
+  getDownloadBillDate(...args: any[]): void;
+
+  getPaymentAgent(...args: any[]): void;
+
+  getSandboxSignKey(...args: any[]): void;
+
+  mergeParams(...args: any[]): void;
+
+  parseNotifyData(...args: any[]): void;
+
+  queryComments(...args: any[]): void;
+
+  queryExchangeRate(...args: any[]): void;
+
+  queryOrder(...args: any[]): void;
+
+  queryRefund(...args: any[]): void;
+
+  querySettlement(...args: any[]): void;
+
+  refund(...args: any[]): void;
+
+  replyData(...args: any[]): void;
+
+  reportToWechat(...args: any[]): void;
+
+  simpleRequest(...args: any[]): void;
+
+  simpleTradeNo(...args: any[]): void;
+
+  unifiedOrder(...args: any[]): void;
+
+  static COUPON_TYPE: {
+    CASH: string;
+    NO_CASH: string;
+  };
+
+  static DOWNLOAD_BILL_TYPE: {
+    ALL: string;
+    RECHARGE_REFUND: string;
+    REFUND: string;
+    SUCCESS: string;
+  };
+
+  static FUND_ACCOUNT_TYPE: {
+    BASIC: string;
+    FEES: string;
+    OPERATION: string;
+  };
+
+  static PAYMENT_TYPE: {
+    APP: string;
+    JSAPI: string;
+    MICROPAY: string;
+    NATIVE: string;
+  };
+
+  static REFUND_STATUS: {
+    CHANGE: string;
+    PROCESSING: string;
+    REFUNDCLOSE: string;
+    SUCCESS: string;
+  };
+
+  static SIGN_TYPE: {
+    HMAC_SHA256: string;
+    MD5: string;
+  };
+
+  static TRADE_STATE: {
+    CLOSED: string;
+    NOTPAY: string;
+    PAYERROR: string;
+    REFUND: string;
+    REVOKED: string;
+    SUCCESS: string;
+    USERPAYING: string;
+  };
+
+  static TRADE_TYPE: {
+    APP: string;
+    JSAPI: string;
+    MICROPAY: string;
+    NATIVE: string;
+  };
+
+  static fenToYuan(...args: any[]): void;
+
+  static formatCurrency(...args: any[]): void;
+
+  static yuanToFen(...args: any[]): void;
+}
+
+export class Store {
+  constructor(...args: any[]);
+
+  clearStore(...args: any[]): void;
+
+  destroy(...args: any[]): void;
+
+  flush(...args: any[]): void;
+
+  getCardTicket(...args: any[]): void;
+
+  getGlobalToken(...args: any[]): void;
+
+  getMPSession(...args: any[]): void;
+
+  getMPSessionKey(...args: any[]): void;
+
+  getOAuthAccessToken(...args: any[]): void;
+
+  getSignature(...args: any[]): void;
+
+  isSignatureExisting(...args: any[]): void;
+
+  saveOAuthAccessToken(...args: any[]): void;
+
+  saveSignature(...args: any[]): void;
+
+  setMPSession(...args: any[]): void;
+
+  updateCardTicket(...args: any[]): void;
+
+  updateGlobalToken(...args: any[]): void;
+
+  updateOAuthAccessToken(...args: any[]): void;
+
+  updateSignature(...args: any[]): void;
+
+  static StoreEvents: {
+    DESTROY: string;
+    DESTROYED: string;
+    FLUSH_STORE: string;
+    STORE_FLUSHED: string;
+  };
+
+  static defaultMaxListeners: number;
+
+  static init(): void;
+
+  static listenerCount(emitter: any, type: any): any;
+
+  static once(emitter: any, name: any): any;
+
+  static usingDomains: boolean;
+}
+
+export class Wechat extends BaseClass {
+  jssdk: JSSDK
+  oauth: OAuth
+  card?: Card
+  payment?: Payment
+  miniProgram?: MiniProgram
+  store: Store
+}
+
+export interface WechatConfigPaymentUrls {
+  UNIFIED_ORDER?: string;
+  QUERY_ORDER?: string;
+  CLOSE_ORDER?: string;
+  REFUND?: string;
+  QUERY_REFUND?: string;
+  DOWNLOAD_BILL?: string;
+  SHORT_URL?: string;
+  REPORT?: string;
+  SIGN_KEY?: string;
+  DOWNLOAD_FUND_FLOW?: string;
+  BATCH_QUERY_COMMENT?: string;
+  QUERY_SETTLEMENT?: string;
+  // yes this is correct, spelling "exchange" correctly is difficult 🤷️
+  QUERY_EXCHANGE_RATE?: string;
+}
+
+export interface WetchatConfigMiniProgram {
+  //your mini program appId
+  appId: string;
+  // your mini program appSecret
+  appSecret: string;
+  GET_SESSION_KEY_URL?: string;
+}
+
+export interface WechatConfig {
+  //redirect host in oauth redirect
+  wechatRedirectHost?: string;
+  //full redirect url in oauth redirect, e.g http://127.0.0.1/wechat/oauth-callback
+  wechatRedirectUrl?: string;
+  //your wechat token set in your
+  // https://mp.weixin.qq.com/advanced/advanced?action=dev&t=advanced/dev&token=1244756112&lang=zh_CN
+  wechatToken?: string;
+  //your wechat appId
+  appId: string;
+  // your wechat appSecret
+  appSecret: string;
+  ticketUrl?: string;
+  accessTokenUrl?: string;
+  oAuthUrl?: string;
+  apiUrl?: string;
+  //state in oauth callback query
+  oAuthState?: string;
+  paymentNotifyUrl?: string;
+  paymentSandBox?: false;
+  paymentKey?: string;
+  PAYMENT_HOST?: string;
+  PAYMENT_HOST_PORT?: 443;
+  paymentUrls?: WechatConfigPaymentUrls;
+  decodeCardCodeUrl?: string;
+  miniProgram?: WetchatConfigMiniProgram;
+  storeOptions?: FileStoreOptions;
+  store?: Store;
+}
+
+export interface MongoStoreOptions {
+  dbHost?: string; //default?: "127.0.0.1"
+  dbPort?: string; //default?: "27017"
+  dbName?: string; //default?: "wechat"
+  dbAddress?: string; //pass your full uri, the three options above will be ignored.
+  dbOptions?: ConnectionOptions; //extra options passed to mongoose
+  limit?: 10; //how many url signature and oauth token items should be initialized from db, default?: 20
+}
+
+export interface FileStoreOptions {
+  fileStorePath?: string;
+}
diff --git a/package.json b/package.json
index 149ed26..10c2a3a 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
   "engines": {
     "node": ">= 8.6"
   },
+  "types": "index.d.ts",
   "scripts": {
     "start": "DEBUG=wechat* node ./demo/index.js",
     "dev": "DEBUG=wechat* nodemon -w ./lib -w ./demo ./demo/index.js",