diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..d680812
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License
+
+Copyright (c) 2017 NHN Entertainment Corp.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/README.md b/README.md
index 631401e..a45cfb5 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,35 @@
-# tui-release-notes
\ No newline at end of file
+# tui-release-notes
+
+Gather commits on tag
+
+## Installation
+```json
+// package.json
+devDependencies: {
+    ...
+    "tui-release-notes": "git+https://github.com/nhnent/tui.release-notes.git"
+    ...
+}
+```
+
+## Usage
+Register `TUI_GITHUB_TOKEN` as a environment variables
+
+**Mac OS**
+```sh
+# ~/.bash_profile
+export TUI_GITHUB_TOKEN=github-personal-access-toke
+```
+
+Execute `tuie` on your `project root`
+```bash
+# latest tag
+npm run release
+# specific tag
+npm run release --tag={specific-tag}
+# enterprise
+npm run release --apiUrl={github.your-enterprise-url.com/api/v3}
+```
+
+## License
+This software is licensed under the [MIT License](https://github.com/nhnent/tui.release-notes/blob/master/LICENSE).
diff --git a/src/github-release.js b/src/github-release.js
index c020ebe..726a2ae 100755
--- a/src/github-release.js
+++ b/src/github-release.js
@@ -31,11 +31,11 @@ let githubHelper;
  * Get target tags
  * Collect commits
  * Make release note
- * Post Github release 
+ * Post Github release
  */
 function release() {
     /* check could use github-api */
-    if (!isValidRepositoryUrl(pkgJson) || !hasGitHubAccessToken()) {
+    if (!isValidRepositoryUrl(pkg) || !hasGitHubAccessToken()) {
         throw new Error();
     }
 
@@ -54,7 +54,7 @@ function release() {
 
 /**
  * Get Repository configured with access token, base url
- * @returns {Repository} - repository 
+ * @returns {Repository} - repository
  * @see https://github.com/github-tools/github/blob/22b889cd48cd281812b020d85f8ea502af69ddfd/lib/Repository.js
  */
 function getRepo() {
@@ -69,6 +69,7 @@ function getRepo() {
 
 /**
  * Get repository url from package.json
+ * @param {JSON} pkgJson - json object defined in package.json
  * @returns {string} - repository url
  */
 function getRepositoryUrl(pkgJson) {
@@ -87,6 +88,7 @@ function getRepositoryUrl(pkgJson) {
 
 /**
  * Get Repository username, repository name
+ * @param {JSON} pkgJson - json object defined in package.json
  * @returns {Object} - username and repository name
  */
 function getRepositoryInfo(pkgJson) {
@@ -100,12 +102,13 @@ function getRepositoryInfo(pkgJson) {
 
 /**
  * test repository url on package.json is valid
+ * @param {JSON} pkgJson - json object defined in package.json
  * @returns {boolean} - url validity
  */
 function isValidRepositoryUrl(pkgJson) {
     const pass = GIT_REPO_REGEXP.test(getRepositoryUrl(pkgJson));
     if (!pass) {
-        console.error('Wrong repository url on package.json');
+        console.error('Invalid repository url on package.json');
     }
 
     return pass;
@@ -157,7 +160,7 @@ function getCommitLogsUntilTag(tag) {
 }
 
 /**
- * Change to CommitObject 
+ * Change to CommitObject
  * @param {Array} commits - commits
  * @returns {Array} - filtered commits
  */
@@ -178,6 +181,7 @@ function filterCommits(commits) {
 /**
  * Filter commit matches commit message conventions
  * @param {string} commitMessage - commit's first line
+ * @returns {Array} - filtered commit objects
  */
 function matchCommitMessage(commitMessage) {
     const captureGroup = commitMessage.match(COMMIT_LOG_REGEXP);
@@ -242,7 +246,7 @@ function makeReleaseNote(commits) {
 /**
  * check commit type by regular expression of available types
  * @param {string} type - commit type
- * @returns {number} 
+ * @returns {number}
  *  - index: when commit type is matched by some type's
  *  - -1: matches nothing
  */