diff --git a/coffeelint.json b/coffeelint.json
index 23c2950..7309b68 100644
--- a/coffeelint.json
+++ b/coffeelint.json
@@ -38,10 +38,6 @@
     "level": "error",
     "limitComments": true
   },
-  "missing_fat_arrows": {
-    "name": "missing_fat_arrows",
-    "level": "warn"
-  },
   "newlines_after_classes": {
     "name": "newlines_after_classes",
     "value": 1,
diff --git a/core/billing-manager.coffee b/core/billing-manager.coffee
index e223808..7b64f28 100644
--- a/core/billing-manager.coffee
+++ b/core/billing-manager.coffee
@@ -64,7 +64,7 @@ class BillingPlan
   setupDefaultComponents: (account) ->
     Q.all _.values(@components).map ({type, defaults}) ->
       Q.all defaults.map (defaultOptions) ->
-        rp.components.byName(type).createComponent account, defaultOptions(account)
+        root.components.byName(type).createComponent account, defaultOptions(account)
 
   triggerTimeBilling: (account) ->
     unless @billing.time
diff --git a/core/i18n-manager.coffee b/core/i18n-manager.coffee
index e2556ac..bdf5aa4 100644
--- a/core/i18n-manager.coffee
+++ b/core/i18n-manager.coffee
@@ -79,8 +79,8 @@ module.exports = class I18nManager
 
     Return {Object}.
   ###
-  packClientLocale: (language) ->
-    return @packLocale @alternativeLanguages language
+  packTranslations: (language) ->
+    return @packTranslationsByLanguages @alternativeLanguages language
 
   ###
     Public: Get hash of packaged translations by language or request.
@@ -89,8 +89,8 @@ module.exports = class I18nManager
 
     Return {Object}.
   ###
-  localeHash: (language) ->
-    utils.sha256 jsonStableStringify @pickClientLocale language
+  translationsHash: (language) ->
+    utils.sha256 jsonStableStringify @packTranslations language
 
   ###
     Public: Translate name by languages.
@@ -135,9 +135,11 @@ module.exports = class I18nManager
 
     * `languages` {Array} of {String}
 
+    TODO: Cache.
+
     Return {Object}.
   ###
-  packLocale: (languages) ->
+  packTranslationsByLanguages: (languages) ->
     result = {}
 
     for language in languages
diff --git a/core/middleware.coffee b/core/middleware.coffee
index 0ee35d5..b78fc3c 100644
--- a/core/middleware.coffee
+++ b/core/middleware.coffee
@@ -1,11 +1,14 @@
 expressBunyanLogger = require 'express-bunyan-logger'
 expressSession = require 'express-session'
 redisStore = require 'connect-redis'
+moment = require 'moment-timezone'
+crypto = require 'crypto'
 csrf = require 'csrf'
+path = require 'path'
+fs = require 'fs'
+_ = require 'lodash'
 
-{config} = app
-{_, path, fs, moment, crypto} = app.libs
-{Account, SecurityLog} = app.models
+{Account, SecurityLog, config} = root
 
 exports.reqHelpers = (req, res, next) ->
   req.getCsrfToken = ->
@@ -36,10 +39,10 @@ exports.reqHelpers = (req, res, next) ->
     return req.cookies?.timezone ? config.i18n.default_timezone
 
   req.getTranslator = ->
-    return rp.translatorByReq req
+    return root.i18n.translator req
 
   req.getMoment = ->
-    return moment.apply(@, arguments).locale(req.getLanguage()).tz(req.getTimezone())
+    return moment.apply(arguments...).locale(req.getLanguage()).tz(req.getTimezone())
 
   req.createSecurityLog = (type, options, {account, token} = {}) ->
     SecurityLog.createLog (account ? req.account),
@@ -87,6 +90,7 @@ exports.renderHelpers = (req, res, next) ->
   next()
 
 exports.logger = ->
+  # TODO: refactor
   return expressBunyanLogger
     genReqId: (req) -> req.sessionID
     parseUA: false
@@ -122,7 +126,7 @@ exports.csrf = ->
       if req.path in app.getHooks('app.ignore_csrf', null, pluck: 'path')
         return next()
 
-      if req.method in ['GET', 'HEAD', 'OPTIONS']
+      if req.method in ['HEAD', 'OPTIONS']
         return next()
 
       unless provider.verify req.session.csrf_secret, req.getCsrfToken()
@@ -145,17 +149,15 @@ exports.authenticate = (req, res, next) ->
       _.extend req,
         token: token
         account: account
-
   .finally next
 
 exports.requireAuthenticate = (req, res, next) ->
   if req.account
     next()
+  else if req.method == 'GET'
+    res.redirect '/account/login/'
   else
-    if req.method == 'GET'
-      res.redirect '/account/login/'
-    else
-      res.error 403, 'auth_failed'
+    res.error 403, 'auth_failed'
 
 exports.requireAdminAuthenticate = (req, res, next) ->
   if req.account?.isAdmin()
diff --git a/core/model/coupon-code.coffee b/core/model/coupon-code.coffee
index 35d0699..ad158c4 100644
--- a/core/model/coupon-code.coffee
+++ b/core/model/coupon-code.coffee
@@ -53,6 +53,14 @@ CouponCode = mabolo.model 'CouponCode',
   # Public: Apply log of coupon
   apply_log: [ApplyLog]
 
+CouponCode.ensureIndex
+  code: 1
+,
+  unique: true
+
+CouponCode.findByCode = (code, options...) ->
+  @findOne code: code, options...
+
 ###
   Public: Create coupons.
 
@@ -76,6 +84,9 @@ CouponCode.createCoupons = ({type, options, expired_at, available_times}, count)
       expired_at: expired_at
       available_times: available_times
 
+CouponCode::pick = ->
+  return _.omit @, 'apply_log'
+
 ###
   Public: Check availability for specified account.
 
@@ -84,10 +95,13 @@ CouponCode.createCoupons = ({type, options, expired_at, available_times}, count)
   Return {Promise} resolve with {Boolean}.
 ###
 CouponCode::validate = (account) ->
-  if @available_times <= 0
-    return Q false
-
   @populate().then ->
+    if @available_times != undefined and @available_times <= 0
+      return false
+
+    if @expired and new Date() > @expired
+      return false
+
     @provider.validate account, @
 
 ###
@@ -98,18 +112,19 @@ CouponCode::validate = (account) ->
   Return {Promise}.
 ###
 CouponCode::apply = (account) ->
-  if @available_times <= 0
-    throw new Error 'coupon_unavailable'
-
-  @populate().then ->
-    @provider.apply(account, @).then =>
-      @update
-        $inc:
-          available_times: -1
-        $push:
-          apply_log:
-            account_id: account._id
-            created_at: new Date()
+  @validate(account).then (available) ->
+    unless available
+      throw new Error 'coupon_unavailable'
+  .then =>
+    @provider.apply account, @
+  .then =>
+    @update
+      $inc:
+        available_times: -1
+      $push:
+        apply_log:
+          account_id: account._id
+          created_at: new Date()
 
 ###
   Public: Populate.
diff --git a/core/registry/view.coffee b/core/registry/view.coffee
index d45e5ac..32a2656 100644
--- a/core/registry/view.coffee
+++ b/core/registry/view.coffee
@@ -58,9 +58,9 @@ module.exports = class ViewRegistry
 
     async.detect([
       view
-      rp.resolve view
-      rp.resolve 'core', view
-      rp.resolve 'core/view', view
+      root.resolve view
+      root.resolve 'core', view
+      root.resolve 'core/view', view
     ], fs.exists).then (filename) ->
       fs.read(filename).then (source) ->
         return jade.compile extendSource(source),
diff --git a/core/router/account.coffee b/core/router/account.coffee
index 6cf2673..ba65a0c 100644
--- a/core/router/account.coffee
+++ b/core/router/account.coffee
@@ -1,38 +1,69 @@
-{_, express} = app.libs
-{requireAuthenticate} = app.middleware
-{Account, SecurityLog, CouponCode} = app.models
-{config, utils, logger, i18n} = app
+express = require 'express'
+_ = require 'lodash'
 
-module.exports = exports = express.Router()
+utils = require '../utils'
 
-exports.get '/register', (req, res) ->
+{i18n, Account, CouponCode} = root
+{requireAuthenticate} = root.middleware
+
+module.router = router = express.Router()
+
+###
+  Router: GET /account/register
+
+  Response HTML.
+###
+router.get '/register', (req, res) ->
   res.render 'account/register'
 
-exports.get '/login', (req, res) ->
+###
+  Router: GET /account/login
+
+  Response HTML.
+###
+router.get '/login', (req, res) ->
   res.render 'account/login'
 
-exports.get '/locale/:language?', (req, res) ->
-  if req.params['language']
-    req.cookies['language'] = req.params['language']
+###
+  Router: GET /account/translations/:language?
 
-  res.json i18n.pickClientLocale i18n.getLanguagesByReq req
+  Response {Object}.
+###
+router.get '/translations/:language?', (req, res) ->
+  if req.params.language
+    res.json i18n.packTranslations req.params.language
+  else
+    res.json i18n.packTranslations req
 
-exports.get '/preferences', requireAuthenticate, (req, res) ->
+###
+  Router: GET /account/preferences/edit
+
+  Response HTML.
+###
+router.get '/preferences/edit', requireAuthenticate, (req, res) ->
   res.render 'account/preferences'
 
-exports.get '/session_info/', (req, res) ->
-  response =
-    csrf_token: req.session.csrf_token
+###
+  Router: GET /account/self
 
-  if req.account
-    _.extend response,
-      account_id: req.account._id
-      username: req.account.username
-      preferences: req.account.preferences
+  Response {Account} from {Account::pick}
+###
+router.get '/self', requireAuthenticate, (req, res) ->
+  res.json req.account.pick 'self'
 
-  res.json response
+###
+  Router: POST /account/register
 
-exports.post '/register', (req, res) ->
+  Request {Object}
+
+    * `username` {String}
+    * `email` {String}
+    * `password` {String}
+
+  Response {Token}.
+  Set-Cookie: token.
+###
+router.post '/register', (req, res) ->
   Account.register(req.body).then (account) ->
     res.createToken account
   .catch (err) ->
@@ -43,7 +74,18 @@ exports.post '/register', (req, res) ->
     else
       res.error err
 
-exports.post '/login', (req, res) ->
+###
+  Router: POST /account/login
+
+  Request {Object}
+
+    * `username` {String} Username, email or account_id.
+    * `password` {String}
+
+  Response {Token}.
+  Set-Cookie: token, language.
+###
+router.post '/login', (req, res) ->
   Account.search(req.body.username).then (account) ->
     unless account?.matchPassword req.body.password
       throw new Error 'wrong_password'
@@ -61,14 +103,28 @@ exports.post '/login', (req, res) ->
     else
       res.error err
 
-exports.post '/logout', requireAuthenticate, (req, res) ->
-  req.token.revoke().then ->
+###
+  Router: POST /account/logout
+
+  Set-Cookie: token.
+###
+router.post '/logout', requireAuthenticate, (req, res) ->
+  req.token.revoke().done ->
     req.createSecurityLog('revoke_token').then ->
       res.clearCookie('token').sendStatus 204
-  .catch res.error
+  , res.error
 
-exports.post '/update_password', requireAuthenticate, (req, res) ->
-  Q().then ->
+###
+  Router: PUT /account/password
+
+  Request {Object}
+
+    * `original_password` {String}
+    * `password` {String}
+
+###
+router.put '/password', requireAuthenticate, (req, res) ->
+  Q().done ->
     unless req.account.matchPassword req.body.original_password
       throw new Error 'wrong_password'
 
@@ -77,10 +133,20 @@ exports.post '/update_password', requireAuthenticate, (req, res) ->
 
     req.account.setPassword(req.body.password).then ->
       req.createSecurityLog 'update_password'
+      res.sendStatus 204
 
-  .catch res.error
+  , res.error
 
-exports.post '/update_email', requireAuthenticate, (req, res) ->
+###
+  Router: PUT /email
+
+  Request {Object}
+
+    * `email` {String}
+    * `password` {String}
+
+###
+router.post '/update_email', requireAuthenticate, (req, res) ->
   Q().done ->
     unless req.account.matchPassword req.body.password
       throw new Error 'wrong_password'
@@ -95,46 +161,47 @@ exports.post '/update_email', requireAuthenticate, (req, res) ->
         original_email: original_email
         current_email: req.account.email
 
+      res.sendStatus 204
+
   , req.error
 
-exports.post '/update_preferences', requireAuthenticate, (req, res) ->
+###
+  Router: PATCH /account/preferences
 
-exports.use do ->
-  router = new express.Router()
+  Request {Preferences}.
 
-  router.use requireAuthenticate
+  Response {Preferences}.
+###
+router.patch '/preferences', requireAuthenticate, (req, res) ->
+  req.account.updatePreferences(req.body).done (preferences) ->
+    res.json preferences
+  , res.error
 
-  router.get '/info', (req, res) ->
-    CouponCode.findOne
-      code: req.query.code
-    , (err, coupon) ->
-      unless coupon
-        return res.error 'code_not_exist'
+router.use '/coupons', do (router = express.Router()) ->
+  ###
+    Router: GET /account/coupons/:code
 
-      coupon.validateCode req.account, (is_available) ->
-        unless is_available
-          return res.error 'code_not_available'
+    Response {CouponCode}.
+  ###
+  router.get '/:code', (req, res) ->
+    CouponCode.findByCode(req.params.code).done (coupon) ->
+      if coupon
+        coupon.populate(req: req).then ->
+          coupon.validate(req.account).then (available) ->
+            res.json _.extend coupon.pick(),
+              available: available
+      else
+        throw new Error 'coupon_not_found'
+    , res.error
 
-        coupon.getMessage req, (message) ->
-          res.json
-            message: message
-
-  router.post '/apply', (req, res) ->
-    CouponCode.findOne
-      code: req.body.code
-    , (err, coupon) ->
-      unless coupon
-        return res.error 'code_not_exist'
-
-      if coupon.expired and Date.now() > coupon.expired.getTime()
-        return res.error 'code_expired'
-
-      if coupon.available_times and coupon.available_times < 0
-        return res.error 'code_not_available'
-
-      coupon.validateCode req.account, (is_available) ->
-        unless is_available
-          return res.error 'code_not_available'
-
-        coupon.applyCode req.account, ->
-          res.json {}
+  ###
+    Router: POST /account/coupons/:code/apply
+  ###
+  router.post '/:code/apply', requireAuthenticate, (req, res) ->
+    CouponCode.findByCode(req.params.code).done (coupon) ->
+      if coupon
+        coupon.apply(account).then ->
+          res.sendStatus 204
+      else
+        throw new Error 'coupon_not_found'
+    , res.error