diff --git a/internal/base/base.go b/internal/base/base.go
index dc87bca3f..415936078 100644
--- a/internal/base/base.go
+++ b/internal/base/base.go
@@ -1,3 +1,4 @@
+// Package base provides base support.
 package base
 
 import (
diff --git a/internal/browser/browser.go b/internal/browser/browser.go
index b74293455..73d527186 100644
--- a/internal/browser/browser.go
+++ b/internal/browser/browser.go
@@ -1,3 +1,4 @@
+// Package browser support open a url in browser.
 package browser
 
 import (
diff --git a/internal/build/build.go b/internal/build/build.go
index feda83a33..2ea34fa7c 100644
--- a/internal/build/build.go
+++ b/internal/build/build.go
@@ -1,3 +1,4 @@
+// Package build implements the command build.
 package build
 
 import (
diff --git a/internal/clean/clean.go b/internal/clean/clean.go
index 809bc7a36..4f86b89ca 100644
--- a/internal/clean/clean.go
+++ b/internal/clean/clean.go
@@ -1,3 +1,4 @@
+// Package clean implements the command clean.
 package clean
 
 import (
diff --git a/internal/client/client.go b/internal/client/client.go
index d049eb01e..73eb1af85 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -1,3 +1,4 @@
+// Package client provides support for http request.
 package client
 
 import (
diff --git a/internal/description/description.go b/internal/description/description.go
index 4fe251965..ba819943d 100644
--- a/internal/description/description.go
+++ b/internal/description/description.go
@@ -1,3 +1,4 @@
+// Package description implements the command description.
 package description
 
 import (
diff --git a/internal/help/help.go b/internal/help/help.go
index e6c5ca76a..d4e9d4873 100644
--- a/internal/help/help.go
+++ b/internal/help/help.go
@@ -1,3 +1,4 @@
+// Package help implements the command help.
 package help
 
 import (
diff --git a/internal/helper/helper.go b/internal/helper/helper.go
index 8447032c2..ca76c5b5f 100644
--- a/internal/helper/helper.go
+++ b/internal/helper/helper.go
@@ -1,3 +1,4 @@
+// Package helper implements the command helper.
 package helper
 
 import (
diff --git a/internal/kit/doc.go b/internal/kit/doc.go
new file mode 100644
index 000000000..8f0b630f8
--- /dev/null
+++ b/internal/kit/doc.go
@@ -0,0 +1,2 @@
+// Package kit contain the predefined type.
+package kit
diff --git a/internal/leetcode/doc.go b/internal/leetcode/doc.go
new file mode 100644
index 000000000..77d4a5503
--- /dev/null
+++ b/internal/leetcode/doc.go
@@ -0,0 +1,2 @@
+// Package leetcode implements access to leetcode.com.
+package leetcode
diff --git a/internal/open/open.go b/internal/open/open.go
index f3b921a93..c9f568321 100644
--- a/internal/open/open.go
+++ b/internal/open/open.go
@@ -1,3 +1,4 @@
+// Package open implements the command open.
 package open
 
 import (
diff --git a/internal/page/page.go b/internal/page/page.go
index 08df58925..00868e4e1 100644
--- a/internal/page/page.go
+++ b/internal/page/page.go
@@ -1,3 +1,4 @@
+// Package page implements the command page.
 package page
 
 import (
diff --git a/internal/post/post.go b/internal/post/post.go
index 77989cbf0..8c014609f 100644
--- a/internal/post/post.go
+++ b/internal/post/post.go
@@ -1,3 +1,4 @@
+// Package post implements the command post.
 package post
 
 import (
diff --git a/internal/question/question.go b/internal/question/question.go
index 5c62a8e9e..4bae967ac 100644
--- a/internal/question/question.go
+++ b/internal/question/question.go
@@ -1,3 +1,4 @@
+// Package question implements the command question.
 package question
 
 import (
diff --git a/internal/readme/readme.go b/internal/readme/readme.go
index 0dd79efff..a57bf8d8e 100644
--- a/internal/readme/readme.go
+++ b/internal/readme/readme.go
@@ -1,3 +1,4 @@
+// Package readme implements the command readme.
 package readme
 
 import (
diff --git a/internal/tag/tag.go b/internal/tag/tag.go
index 90e35f563..edd4c102d 100644
--- a/internal/tag/tag.go
+++ b/internal/tag/tag.go
@@ -1,3 +1,4 @@
+// Package tag implements the command tag.
 package tag
 
 import (
diff --git a/internal/test/test.go b/internal/test/test.go
index 9cc2e330f..b3622677a 100644
--- a/internal/test/test.go
+++ b/internal/test/test.go
@@ -1,3 +1,4 @@
+// Package test implements the command test.
 package test
 
 import (
diff --git a/internal/update/update.go b/internal/update/update.go
index 5dd515062..09d00f1aa 100644
--- a/internal/update/update.go
+++ b/internal/update/update.go
@@ -1,3 +1,4 @@
+// Package update implements the command update.
 package update
 
 import (
diff --git a/internal/version/version.go b/internal/version/version.go
index 8f4c00a9e..cad261ed8 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -1,3 +1,4 @@
+// Package version implements the command version.
 package version
 
 import (
diff --git a/main.go b/main.go
index ff4c9e6ba..f5307068e 100644
--- a/main.go
+++ b/main.go
@@ -1,3 +1,4 @@
+// leetcode is a tool for managing leetcode source code.
 package main
 
 import (