diff --git a/cmd/aicra/files.go b/cmd/aicra/files.go
index 79292f4..68d6f57 100644
--- a/cmd/aicra/files.go
+++ b/cmd/aicra/files.go
@@ -21,5 +21,5 @@ func getAbsPath(base string, path string) (string, error) {
 // Returns whether a directory exists for the path @path
 func dirExists(path string) bool {
 	stat, err := os.Stat(path)
-	return err != nil || !stat.IsDir()
+	return err == nil && stat.IsDir()
 }
diff --git a/internal/checker/public.go b/internal/checker/public.go
index a050d96..c361b3a 100644
--- a/internal/checker/public.go
+++ b/internal/checker/public.go
@@ -37,7 +37,7 @@ func CreateRegistry(loadDir ...string) *Registry {
 			continue
 		}
 
-		err := reg.Add(file.Name())
+		err := reg.add(file.Name())
 		if err != nil {
 			log.Fatalf("Cannot load plugin '%s'", file.Name())
 		}
@@ -47,10 +47,10 @@ func CreateRegistry(loadDir ...string) *Registry {
 	return reg
 }
 
-// Add adds a type to the registry; it must be a
+// add adds a type to the registry; it must be a
 // valid and existing plugin name with or without the .so extension
 // it must be located in the relative directory ./types
-func (reg *Registry) Add(pluginName string) error {
+func (reg *Registry) add(pluginName string) error {
 
 	/* (1) Check plugin name */
 	if len(pluginName) < 1 {
diff --git a/middleware/public.go b/middleware/public.go
index 8e96d67..58cc8f5 100644
--- a/middleware/public.go
+++ b/middleware/public.go
@@ -38,7 +38,7 @@ func CreateRegistry(loadDir ...string) *Registry {
 			continue
 		}
 
-		err := reg.Add(file.Name())
+		err := reg.add(file.Name())
 		if err != nil {
 			log.Fatalf("Cannot load plugin '%s'", file.Name())
 		}
@@ -48,10 +48,10 @@ func CreateRegistry(loadDir ...string) *Registry {
 	return reg
 }
 
-// Add adds a middleware to the registry; it must be a
+// add adds a middleware to the registry; it must be a
 // valid and existing plugin name with or without the .so extension
 // it must be located in the relative directory .build/middleware
-func (reg *Registry) Add(pluginName string) error {
+func (reg *Registry) add(pluginName string) error {
 
 	/* (1) Check plugin name */
 	if len(pluginName) < 1 {
diff --git a/server.go b/server.go
index 18113fd..bcd6ebc 100644
--- a/server.go
+++ b/server.go
@@ -27,7 +27,9 @@ func New(path string) (*Server, error) {
 
 	/* (1) Init instance */
 	var err error
-	var i *Server
+	var i = &Server{
+		controller: nil,
+	}
 
 	/* (2) Load configuration */
 	i.controller, err = controller.Load(path)
@@ -57,25 +59,25 @@ func (s *Server) Listen(port uint16) error {
 }
 
 // Router called for each request
-func (s *Server) manageRequest(res http.ResponseWriter, httpReq *http.Request) {
+func (s *Server) manageRequest(res http.ResponseWriter, req *http.Request) {
 
 	/* (1) Build request */
-	req, err := apirequest.BuildFromHTTPRequest(httpReq)
+	apiRequest, err := apirequest.BuildFromHTTPRequest(req)
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	/* (2) Middleware: authentication */
-	scope := s.middleware.Run(*httpReq)
+	/* (2) Launch middlewares to build the scope */
+	scope := s.middleware.Run(*req)
 
 	/* (3) Find a matching controller */
-	controller := s.findController(req)
+	controller := s.matchController(apiRequest)
 	if controller == nil {
 		return
 	}
 
 	/* (4) Check if matching method exists */
-	var method = controller.Method(httpReq.Method)
+	var method = controller.Method(req.Method)
 
 	if method == nil {
 		httpError(res, e.UnknownMethod)
@@ -90,7 +92,7 @@ func (s *Server) manageRequest(res http.ResponseWriter, httpReq *http.Request) {
 
 	/* (4) Check parameters
 	---------------------------------------------------------*/
-	parameters, paramError := s.extractParameters(req, method.Parameters)
+	parameters, paramError := s.extractParameters(apiRequest, method.Parameters)
 
 	// Fail if argument check failed
 	if paramError.Code != e.Success.Code {
@@ -100,7 +102,7 @@ func (s *Server) manageRequest(res http.ResponseWriter, httpReq *http.Request) {
 
 	/* (5) Load controller
 	---------------------------------------------------------*/
-	callable, callErr := req.LoadController(httpReq.Method)
+	controllerImplementation, callErr := apiRequest.LoadController(req.Method)
 	if callErr.Code != e.Success.Code {
 		httpError(res, callErr)
 		log.Printf("[err] %s\n", err)
@@ -110,16 +112,13 @@ func (s *Server) manageRequest(res http.ResponseWriter, httpReq *http.Request) {
 	/* (6) Execute and get response
 	---------------------------------------------------------*/
 	/* (1) Give Authorization header into controller */
-	authHeader := httpReq.Header.Get("Authorization")
-	if len(authHeader) > 0 {
-		parameters["_AUTHORIZATION_"] = authHeader
-	}
+	parameters["_AUTHORIZATION_"] = req.Header.Get("Authorization")
 
 	/* (2) Give Scope into controller */
 	parameters["_SCOPE_"] = scope
 
 	/* (3) Execute */
-	response := callable(parameters, response.New())
+	response := controllerImplementation(parameters, response.New())
 
 	/* (4) Extract http headers */
 	for k, v := range response.Dump() {
diff --git a/util.go b/util.go
index 345dfd0..f27fbc9 100644
--- a/util.go
+++ b/util.go
@@ -10,7 +10,7 @@ import (
 	"net/http"
 )
 
-func (s *Server) findController(req *apirequest.Request) *controller.Controller {
+func (s *Server) matchController(req *apirequest.Request) *controller.Controller {
 
 	/* (1) Try to browse by URI */
 	pathi, ctl := s.controller.Browse(req.URI)