diff --git a/src/alice.ts b/src/alice.ts
index b15ff83..d539cb1 100644
--- a/src/alice.ts
+++ b/src/alice.ts
@@ -21,7 +21,7 @@ import {
 
 import aliceStateMiddleware from './middlewares/aliceStateMiddleware'
 
-import { IConfig } from './types/alice'
+import { IConfig, IAlice } from './types/alice'
 import { ICommand } from './types/command'
 import { IContext } from './types/context'
 import { WebhookResponse, WebhookRequest } from './types/webhook'
@@ -39,7 +39,7 @@ import {
 const DEFAULT_SESSIONS_LIMIT: number = 1000
 const DEFAULT_RESPONSE_TIMEOUT = 1200
 
-export default class Alice {
+export default class Alice implements IAlice {
   public scenes: Scene[]
 
   protected anyCallback: (ctx: IContext) => void
@@ -86,7 +86,7 @@ export default class Alice {
    * @param {Function} middleware - function, that receives {context}
    * and makes some modifications with it.
    */
-  public use(middleware) {
+  public use(middleware: (IContext: IContext) => IContext): void {
     if (!isFunction(middleware)) {
       throw new Error('Any middleware could only be a function.')
     }
@@ -98,14 +98,14 @@ export default class Alice {
    * @param {string | Array<string> | regex} name — Trigger for the command
    * @param {Function} callback — Handler for the command
    */
-  public command(name, callback) {
+  public command(name: ICommand, callback: (IContext) => void) {
     this.commands.add(name, callback)
   }
 
   /*
   * Стартовая команда на начало сессии
   */
-  public welcome(callback) {
+  public welcome(callback: (IContext) => void): void {
     this.welcomeCallback = callback
   }
 
@@ -114,7 +114,7 @@ export default class Alice {
    * которую запросил пользователь,
    * вызывается этот колбек
    */
-  public any(callback) {
+  public any(callback: (IContext) => void): void {
     this.anyCallback = callback
   }
 
diff --git a/src/types/alice.d.ts b/src/types/alice.d.ts
index 4592a1a..e790b39 100644
--- a/src/types/alice.d.ts
+++ b/src/types/alice.d.ts
@@ -1,3 +1,6 @@
+import { IContext } from './context'
+import { ICommand } from './command'
+
 export interface IConfig {
   fuseOptions?: {}
   sessionsLimit?: number
@@ -6,3 +9,8 @@ export interface IConfig {
   devServerUrl?: string
   responseTimeout?: number
 }
+
+export interface IAlice {
+  command(name: ICommand, callback: (IContext) => void): void
+  use(middleware: (IContext: IContext) => IContext): void
+}
diff --git a/src/utils/index.ts b/src/utils/index.ts
index ef028c4..09ad0f1 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -46,7 +46,7 @@ export const selectCommand = (req): string => req.request.command
 export const selectSession = (req) => req.session
 export const selectSessionId = (req) => selectSession(req).session_id
 export const selectUserId = (req) => selectSession(req).user_id
-export const isFunction = (fn: () => void) => fn && typeof fn === 'function'
+export const isFunction = (fn: (args: any) => any) => fn && typeof fn === 'function'
 export const delay = (ms: number): Promise<void> => new Promise((resolve) => setTimeout(resolve, ms))
 export const rejectsIn = (ms: number) => new Promise((resolve, reject) => setTimeout(reject, ms))