diff --git a/server/src/app.ts b/server/src/app.ts
index 9095eaa..aab9032 100644
--- a/server/src/app.ts
+++ b/server/src/app.ts
@@ -1,4 +1,3 @@
-import path from 'path'
 import http from 'http'
 
 import express, { Application } from 'express'
@@ -11,24 +10,31 @@ import usersRouter from './routes/users'
 
 import { normalizePort } from './helpers/port'
 import { getErrorCb, getListeningCb } from './helpers/server-callbacks'
+import { WEBUI_DIR } from './helpers/paths'
 
-const ROOT_DIR = path.resolve('../')
 const PORT = normalizePort(process.env.PORT || '6595')
+
 const debug = initDebug('deemix-gui:server')
 const app: Application = express()
 const server = http.createServer(app)
 
+/* === Middlewares === */
 app.use(logger('dev'))
 app.use(express.json())
 app.use(express.urlencoded({ extended: false }))
 app.use(cookieParser())
-app.use(express.static(path.join(ROOT_DIR, 'webui', 'public')))
+app.use(express.static(WEBUI_DIR))
 
+/* === Routes === */
 app.use('/', indexRouter)
 app.use('/users', usersRouter)
 
+/* === Other === */
 app.set('port', PORT)
 
+/* === Server port === */
 server.listen(PORT)
+
+/* === Server callbacks === */
 server.on('error', getErrorCb(PORT))
 server.on('listening', getListeningCb(server, debug))
diff --git a/server/src/helpers/paths.ts b/server/src/helpers/paths.ts
new file mode 100644
index 0000000..87d1218
--- /dev/null
+++ b/server/src/helpers/paths.ts
@@ -0,0 +1,4 @@
+import path from 'path'
+
+export const ROOT_DIR = path.resolve('../')
+export const WEBUI_DIR = path.join(ROOT_DIR, 'webui', 'public')
diff --git a/server/src/helpers/port.ts b/server/src/helpers/port.ts
index 0b8eb8b..3035c4c 100644
--- a/server/src/helpers/port.ts
+++ b/server/src/helpers/port.ts
@@ -1,8 +1,11 @@
+import { Port } from '../types'
+
 /**
  * Normalize a port into a number, string, or false.
+ *
+ * @since	0.0.0
  */
-
-export function normalizePort (portString:string) {
+export function normalizePort (portString:string): Port {
   const port = parseInt(portString, 10)
 
   if (isNaN(port)) {
diff --git a/server/src/helpers/server-callbacks.ts b/server/src/helpers/server-callbacks.ts
index 84e1ee5..18fb1f0 100644
--- a/server/src/helpers/server-callbacks.ts
+++ b/server/src/helpers/server-callbacks.ts
@@ -3,6 +3,8 @@ import type { Debugger } from 'debug'
 
 /**
  * Event listener for HTTP server "error" event.
+ *
+ * @since	0.0.0
  */
 export function getErrorCb (port: number | string | boolean) {
   return (error: any) => {
@@ -32,6 +34,8 @@ export function getErrorCb (port: number | string | boolean) {
 
 /**
  * Event listener for HTTP server "listening" event.
+ *
+ * @since	0.0.0
  */
 export function getListeningCb (server: http.Server, debug: Debugger) {
   return () => {
diff --git a/server/src/routes/index.ts b/server/src/routes/index.ts
index 7cf3089..be2ba5e 100644
--- a/server/src/routes/index.ts
+++ b/server/src/routes/index.ts
@@ -2,7 +2,11 @@ import express from 'express'
 
 const router = express.Router()
 
-/* GET home page. */
+/**
+ * GET home page
+ *
+ * @since	0.0.0
+ */
 router.get('/', (_, res) => {
   res.render('index', { title: 'Express' })
 })
diff --git a/server/src/routes/users.ts b/server/src/routes/users.ts
index 02c7a6a..ba5cc06 100644
--- a/server/src/routes/users.ts
+++ b/server/src/routes/users.ts
@@ -2,8 +2,12 @@ import express from 'express'
 
 const router = express.Router()
 
-/* GET users listing. */
-router.get('/', function (_, res) {
+/**
+ * GET users listing.
+ *
+ * @since	0.0.0
+ */
+router.get('/', (_, res) => {
   res.send('respond with a resource')
 })
 
diff --git a/server/src/types.ts b/server/src/types.ts
new file mode 100644
index 0000000..b166801
--- /dev/null
+++ b/server/src/types.ts
@@ -0,0 +1 @@
+export type Port = number | string | boolean