diff --git a/package.json b/package.json
index 7f18233..579f50e 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
     "version": "0.1.0",
     "description": "Programmatically install NPM dependencies to the project!",
     "repository": "nuxt/lmify",
+    "typings": "types/lmify.d.ts",
     "main": "dist/lmify.js",
     "files": [
         "dist"
@@ -23,6 +24,7 @@
     "devDependencies": {
         "@babel/preset-env": "^7.4.2",
         "@nuxtjs/eslint-config": "^0.0.1",
+        "@types/execa": "^0.9.0",
         "babel-jest": "^24.5.0",
         "bili": "^4.7.2",
         "codecov": "^3.2.0",
diff --git a/types/lmify.d.ts b/types/lmify.d.ts
new file mode 100644
index 0000000..c818582
--- /dev/null
+++ b/types/lmify.d.ts
@@ -0,0 +1,23 @@
+import * as execa from 'execa'
+
+declare class Lmify {
+
+  // for initalize
+  init(): void
+  private _init(): Promise<void>
+  
+  // options
+  setPackageManager(name: 'npm' | 'yarn'): void
+  setRootDir(): void
+
+  // permissions
+  addGranter(granter: () => Promise<boolean>): void
+  _grant(packages: string): Promise<boolean>
+
+  // commands
+  install(packages: string[]): Promise<void> | execa.ExecaReturns
+}
+
+declare module 'lmify' {
+  export default Lmify
+}
diff --git a/yarn.lock b/yarn.lock
index 9a10cb9..f8376d1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -836,6 +836,13 @@
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
   integrity sha512-EYNwp3bU+98cpU4lAWYYL7Zz+2gryWH1qbdDTidVd6hkiR6weksdbMadyXKXNPEkQFhXM+hVO9ZygomHXp+AIw==
 
+"@types/execa@^0.9.0":
+  version "0.9.0"
+  resolved "https://registry.yarnpkg.com/@types/execa/-/execa-0.9.0.tgz#9b025d2755f17e80beaf9368c3f4f319d8b0fb93"
+  integrity sha512-mgfd93RhzjYBUHHV532turHC2j4l/qxsF/PbfDmprHDEUHmNZGlDn1CEsulGK3AfsPdhkWzZQT/S/k0UGhLGsA==
+  dependencies:
+    "@types/node" "*"
+
 "@types/istanbul-lib-coverage@^1.1.0":
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/@types/istanbul-lib-coverage/-/istanbul-lib-coverage-1.1.0.tgz#2cc2ca41051498382b43157c8227fea60363f94a"