diff --git a/Makefile b/Makefile
index 0b5b544..40167fe 100644
--- a/Makefile
+++ b/Makefile
@@ -31,7 +31,8 @@ TEST_BENCHMARK ?= no
 TOPLEVEL_PKG := github.com/nexocrew/3nigm4
 IMPL_LIST := authserver storageservice 3n4cli #<-- Implementation directories
 COMMON_LIST := lib/version lib/logo lib/itm lib/logger lib/crypto \
-	lib/messages lib/client lib/filemanager lib/s3 lib/auth \
+	lib/messages lib/client lib/filemanager lib/s3 \
+	lib/auth/client lib/auth/server lib/auth/types \
 	lib/storageclient
 
 # List building
diff --git a/authserver/database_test.go b/authserver/database_test.go
index d704331..84efd45 100644
--- a/authserver/database_test.go
+++ b/authserver/database_test.go
@@ -19,7 +19,7 @@ import (
 
 // Internal dependencies
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	"github.com/nexocrew/3nigm4/lib/auth/server"
 )
 
 // Third party libs
diff --git a/authserver/serve_cmd.go b/authserver/serve_cmd.go
index 18e23a4..3a26920 100644
--- a/authserver/serve_cmd.go
+++ b/authserver/serve_cmd.go
@@ -17,7 +17,8 @@ import (
 
 // Internal dependencies
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	auth "github.com/nexocrew/3nigm4/lib/auth/server"
+	db "github.com/nexocrew/3nigm4/lib/database/client"
 )
 
 // Third party libs
@@ -48,13 +49,13 @@ func init() {
 // in unit-tests, do not mess with it for other reasons.
 // The default, production targeting, implementation uses Mongodb
 // as backend database system.
-var databaseStartup func(*args) (auth.Database, error) = mgoStartup
+var databaseStartup func(*args) (db.Database, error) = mgoStartup
 
 // mgoStartup implement startup logic for a mongodb based database
 // connection.
-func mgoStartup(arguments *args) (auth.Database, error) {
+func mgoStartup(arguments *args) (db.Database, error) {
 	// startup db
-	mgodb, err := auth.MgoSession(&auth.DbArgs{
+	mgodb, err := db.MgoSession(&db.DbArgs{
 		Addresses: strings.Split(arguments.dbAddresses, ","),
 		User:      arguments.dbUsername,
 		Password:  arguments.dbPassword,
diff --git a/authserver/serve_test.go b/authserver/serve_test.go
index 9bed2da..490fdf1 100644
--- a/authserver/serve_test.go
+++ b/authserver/serve_test.go
@@ -20,7 +20,7 @@ import (
 
 // Internal dependencies.
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	"github.com/nexocrew/3nigm4/lib/auth/server"
 	"github.com/nexocrew/3nigm4/lib/itm"
 	"github.com/nexocrew/3nigm4/lib/logger"
 	wq "github.com/nexocrew/3nigm4/lib/workingqueue"
diff --git a/lib/auth/authclient.go b/lib/auth/client/authclient.go
similarity index 65%
rename from lib/auth/authclient.go
rename to lib/auth/client/authclient.go
index 1df3889..37d2cd6 100644
--- a/lib/auth/authclient.go
+++ b/lib/auth/client/authclient.go
@@ -3,7 +3,7 @@
 // Author: Guido Ronchetti <dyst0ni3@gmail.com>
 // v1.0 16/06/2016
 //
-package auth
+package authclient
 
 // Std golang packages
 import (
@@ -11,13 +11,18 @@ import (
 	"net/rpc"
 )
 
+// 3n4 libraries
+import (
+	t "github.com/nexocrew/3nigm4/lib/auth/types"
+)
+
 // AuthClient is the interface used to interact
 // with authentication services.
 type AuthClient interface {
-	Login(string, string) ([]byte, error)                     // manage user's login;
-	Logout([]byte) ([]byte, error)                            // manage user's logout;
-	AuthoriseAndGetInfo([]byte) (*UserInfoResponseArg, error) // returns authenticated user infos or an error;
-	Close() error                                             // closes eventual connections.
+	Login(string, string) ([]byte, error)                       // manage user's login;
+	Logout([]byte) ([]byte, error)                              // manage user's logout;
+	AuthoriseAndGetInfo([]byte) (*t.UserInfoResponseArg, error) // returns authenticated user infos or an error;
+	Close() error                                               // closes eventual connections.
 }
 
 // AuthRpc implements the RPC default client for
@@ -42,8 +47,8 @@ func NewAuthRpc(addr string, port int) (*AuthRpc, error) {
 // Login grant access to users, over RPC, using username and password.
 func (a *AuthRpc) Login(username string, password string) ([]byte, error) {
 	// perform login on RPC service
-	var loginResponse LoginResponseArg
-	err := a.client.Call("Login.Login", &LoginRequestArg{
+	var loginResponse t.LoginResponseArg
+	err := a.client.Call("Login.Login", &t.LoginRequestArg{
 		Username: username,
 		Password: password,
 	}, &loginResponse)
@@ -55,8 +60,8 @@ func (a *AuthRpc) Login(username string, password string) ([]byte, error) {
 
 // Logout remove actual active sessions over RPC.
 func (a *AuthRpc) Logout(token []byte) ([]byte, error) {
-	var logoutResponse LogoutResponseArg
-	err := a.client.Call("Login.Logout", &LogoutRequestArg{
+	var logoutResponse t.LogoutResponseArg
+	err := a.client.Call("Login.Logout", &t.LogoutRequestArg{
 		Token: token,
 	}, &logoutResponse)
 	if err != nil {
@@ -67,10 +72,10 @@ func (a *AuthRpc) Logout(token []byte) ([]byte, error) {
 
 // AuthoriseAndGetInfo if the token is valid returns info about
 // the associated user over RPC service.
-func (a *AuthRpc) AuthoriseAndGetInfo(token []byte) (*UserInfoResponseArg, error) {
+func (a *AuthRpc) AuthoriseAndGetInfo(token []byte) (*t.UserInfoResponseArg, error) {
 	// verify token and retrieve user infos
-	var authResponse UserInfoResponseArg
-	err := a.client.Call("SessionAuth.UserInfo", &AuthenticateRequestArg{
+	var authResponse t.UserInfoResponseArg
+	err := a.client.Call("SessionAuth.UserInfo", &t.AuthenticateRequestArg{
 		Token: token,
 	}, &authResponse)
 	if err != nil {
diff --git a/lib/auth/authclient_mock.go b/lib/auth/mock/client_mock.go
similarity index 99%
rename from lib/auth/authclient_mock.go
rename to lib/auth/mock/client_mock.go
index b1d5eb1..26f4c61 100644
--- a/lib/auth/authclient_mock.go
+++ b/lib/auth/mock/client_mock.go
@@ -9,7 +9,7 @@
 // optimisation logic.
 //
 
-package auth
+package authmock
 
 // Std golang libs
 import (
diff --git a/lib/auth/global.go b/lib/auth/server/global.go
similarity index 82%
rename from lib/auth/global.go
rename to lib/auth/server/global.go
index cbb12e0..73d20fc 100644
--- a/lib/auth/global.go
+++ b/lib/auth/server/global.go
@@ -7,23 +7,27 @@
 // db client (that will be copyied by all functions).
 //
 
-package auth
+package authserver
 
 import (
 	"sync"
 )
 
+import (
+	db "github.com/nexocrew/3nigm4/lib/database/client"
+)
+
 // Global vars protecting mutex.
 var mtx sync.Mutex
 
 // Runtime allocated global base database instance.
-var dbclient Database
+var dbclient db.Database
 
 // SetGlobalDbClient must be called to set the global db client,
 // that implements the Database interface, to be used by RPC
 // exposed functions. This function must be always invoked before
 // proceeding registering other fucntions.
-func SetGlobalDbClient(database Database) {
+func SetGlobalDbClient(database db.Database) {
 	mtx.Lock()
 	dbclient = database
 	mtx.Unlock()
diff --git a/lib/auth/session_model.go b/lib/auth/server/session_model.go
similarity index 71%
rename from lib/auth/session_model.go
rename to lib/auth/server/session_model.go
index 9d7dd5c..8ad16d5 100644
--- a/lib/auth/session_model.go
+++ b/lib/auth/server/session_model.go
@@ -4,7 +4,7 @@
 // v1.0 16/06/2016
 //
 
-package auth
+package authserver
 
 // Golang std libs
 import (
@@ -13,6 +13,10 @@ import (
 	"time"
 )
 
+import (
+	ty "github.com/nexocrew/3nigm4/lib/auth/types"
+)
+
 const (
 	kTimeToLive = 15 // minutes to live for a session between accesses.
 )
@@ -20,20 +24,6 @@ const (
 // SessionAuth RPC required custom type (using int arbitrarely).
 type SessionAuth int
 
-// VoidResponseArg empty return value.
-type VoidResponseArg struct{}
-
-// AuthenticateRequestArg define the RPC request struct
-type AuthenticateRequestArg struct {
-	Token []byte // the authentication token.
-}
-
-// AuthenticateResponseArg the returned auth structure.
-type AuthenticateResponseArg struct {
-	Username     string    // the session related username;
-	LastSeenTime time.Time // last connection from the user.
-}
-
 // sessionTimeValid verify the time range between last seen
 // time and now, if it exceed the session expiration time (15 min)
 // it returns true otherwise false.
@@ -47,7 +37,7 @@ func sessionTimeValid(now, lastSeen *time.Time, timeToLive time.Duration) bool {
 // Authenticate RPC exposed functions verify a session token
 // and returns the userid to authenticate user required
 // operations.
-func (s *SessionAuth) Authenticate(args *AuthenticateRequestArg, response *AuthenticateResponseArg) error {
+func (s *SessionAuth) Authenticate(args *ty.AuthenticateRequestArg, response *ty.AuthenticateResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -87,21 +77,11 @@ func (s *SessionAuth) Authenticate(args *AuthenticateRequestArg, response *Authe
 	return nil
 }
 
-// UserInfoResponseArg the returned authenticated  user
-// data.
-type UserInfoResponseArg struct {
-	Username    string       // the session related username;
-	FullName    string       // the user full name;
-	Email       string       // the user email address;
-	Permissions *Permissions // user associated permissions;
-	LastSeen    time.Time    // last seen info.
-}
-
 // UserInfo RPC exposed function verify a session token
 // and returns the user associated data (from the User struct).
 // Notice that this function will update the "last seen" time
 // stamp as the Authenticate do.
-func (s *SessionAuth) UserInfo(args *AuthenticateRequestArg, response *UserInfoResponseArg) error {
+func (s *SessionAuth) UserInfo(args *ty.AuthenticateRequestArg, response *ty.UserInfoResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -115,7 +95,7 @@ func (s *SessionAuth) UserInfo(args *AuthenticateRequestArg, response *UserInfoR
 		return fmt.Errorf("invalid nil token data")
 	}
 
-	userResponse := AuthenticateResponseArg{}
+	userResponse := ty.AuthenticateResponseArg{}
 	err := s.Authenticate(args, &userResponse)
 	if err != nil {
 		return err
@@ -136,23 +116,11 @@ func (s *SessionAuth) UserInfo(args *AuthenticateRequestArg, response *UserInfoR
 	return nil
 }
 
-//
-// Superadmin behaviour: the following functions are intended to
-// implement administrative tasks like creating or removing users,
-// update user's permissions or logout all users.
-//
-
-// UpserUserRequestArg request to upsert user data.
-type UpserUserRequestArg struct {
-	Token []byte // the authentication token;
-	User  User   // the user record to be updated.
-}
-
 // UpsertUser is an RPC exposed function used to add or update a user in
 // the authentication database. If the user is not already present it'll
 // be added, otherwise it will be updated. Only Super-Admins will be able
 // to use this function.
-func (s *SessionAuth) UpsertUser(args *UpserUserRequestArg, response *VoidResponseArg) error {
+func (s *SessionAuth) UpsertUser(args *ty.UpserUserRequestArg, response *ty.VoidResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -166,8 +134,8 @@ func (s *SessionAuth) UpsertUser(args *UpserUserRequestArg, response *VoidRespon
 		return fmt.Errorf("invalid nil token data")
 	}
 
-	userinfo := UserInfoResponseArg{}
-	err := s.UserInfo(&AuthenticateRequestArg{
+	userinfo := ty.UserInfoResponseArg{}
+	err := s.UserInfo(&ty.AuthenticateRequestArg{
 		Token: args.Token,
 	}, &userinfo)
 	if err != nil {
@@ -186,16 +154,9 @@ func (s *SessionAuth) UpsertUser(args *UpserUserRequestArg, response *VoidRespon
 	return nil
 }
 
-// RemoveUserRequestArg request for remove an existing
-// user.
-type RemoveUserRequestArg struct {
-	Token    []byte // the authentication token;
-	Username string // the user to be removed.
-}
-
 // RemoveUser is an RPC exposed function that removes an existing user
 // from the authentication db.
-func (s *SessionAuth) RemoveUser(args *RemoveUserRequestArg, response *VoidResponseArg) error {
+func (s *SessionAuth) RemoveUser(args *ty.RemoveUserRequestArg, response *ty.VoidResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -213,8 +174,8 @@ func (s *SessionAuth) RemoveUser(args *RemoveUserRequestArg, response *VoidRespo
 		return fmt.Errorf("invalid username: unable to process requesto for nil username")
 	}
 	// get user infos
-	userinfo := UserInfoResponseArg{}
-	err := s.UserInfo(&AuthenticateRequestArg{
+	userinfo := ty.UserInfoResponseArg{}
+	err := s.UserInfo(&ty.AuthenticateRequestArg{
 		Token: args.Token,
 	}, &userinfo)
 	if err != nil {
@@ -235,7 +196,7 @@ func (s *SessionAuth) RemoveUser(args *RemoveUserRequestArg, response *VoidRespo
 
 // KickOutAllSessions is an RPC exposed function that remove all active sessions from
 // the authentication database.
-func (s *SessionAuth) KickOutAllSessions(args *AuthenticateRequestArg, response *VoidResponseArg) error {
+func (s *SessionAuth) KickOutAllSessions(args *ty.AuthenticateRequestArg, response *ty.VoidResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -249,8 +210,8 @@ func (s *SessionAuth) KickOutAllSessions(args *AuthenticateRequestArg, response
 		return fmt.Errorf("invalid nil token data")
 	}
 	// get user infos
-	userinfo := UserInfoResponseArg{}
-	err := s.UserInfo(&AuthenticateRequestArg{
+	userinfo := ty.UserInfoResponseArg{}
+	err := s.UserInfo(&ty.AuthenticateRequestArg{
 		Token: args.Token,
 	}, &userinfo)
 	if err != nil {
diff --git a/lib/auth/session_test.go b/lib/auth/server/session_test.go
similarity index 99%
rename from lib/auth/session_test.go
rename to lib/auth/server/session_test.go
index 4b11f8c..e62d2f1 100644
--- a/lib/auth/session_test.go
+++ b/lib/auth/server/session_test.go
@@ -4,7 +4,7 @@
 // v1.0 16/06/2016
 //
 
-package auth
+package authserver
 
 // Golang std libs
 import (
diff --git a/lib/auth/user_model.go b/lib/auth/server/user_model.go
similarity index 79%
rename from lib/auth/user_model.go
rename to lib/auth/server/user_model.go
index 8858f97..9468aea 100644
--- a/lib/auth/user_model.go
+++ b/lib/auth/server/user_model.go
@@ -4,7 +4,7 @@
 // v1.0 16/06/2016
 //
 
-package auth
+package authserver
 
 // Golang std libs
 import (
@@ -16,6 +16,10 @@ import (
 	"time"
 )
 
+import (
+	ty "github.com/nexocrew/3nigm4/lib/auth/types"
+)
+
 // Third party libs
 import (
 	"golang.org/x/crypto/bcrypt"
@@ -66,22 +70,10 @@ func generateSessionToken(username string) ([]byte, error) {
 // Login the RPC required custom type.
 type Login int
 
-// LoginRequestArg define the RPC request struct
-type LoginRequestArg struct {
-	Username string // the authenticating username;
-	Password string // plaintext password.
-}
-
-// LoginResponseArg the returned login structure
-// having the user assigned session token.
-type LoginResponseArg struct {
-	Token []byte // the session token to be used, from now on, to communicate with server.
-}
-
 // Login RPC exposed functions it's create a session token
 // after verifying that the username and password are already
 // registered in the system.
-func (t *Login) Login(args *LoginRequestArg, response *LoginResponseArg) error {
+func (t *Login) Login(args *ty.LoginRequestArg, response *ty.LoginResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
@@ -116,7 +108,7 @@ func (t *Login) Login(args *LoginRequestArg, response *LoginResponseArg) error {
 	}
 	// save to the database
 	now := time.Now()
-	err = client.SetSession(&Session{
+	err = client.SetSession(&ty.Session{
 		Token:        token,
 		Username:     reference.Username,
 		LoginTime:    now,
@@ -131,21 +123,9 @@ func (t *Login) Login(args *LoginRequestArg, response *LoginResponseArg) error {
 	return nil
 }
 
-// LogoutRequestArg is the request passed to logout the
-// user's sessions.
-type LogoutRequestArg struct {
-	Token []byte // the session token used to identify the user.
-}
-
-// LogoutResponseArg is the structure used to return the
-// list of invalidated sessions.
-type LogoutResponseArg struct {
-	Invalidated []byte
-}
-
 // Logout RPC exposed function logout a user, starting from a valid active
 // session and remove all opened session related to that user.
-func (t *Login) Logout(args *LogoutRequestArg, response *LogoutResponseArg) error {
+func (t *Login) Logout(args *ty.LogoutRequestArg, response *ty.LogoutResponseArg) error {
 	// check for session
 	if dbclient == nil {
 		return fmt.Errorf("invalid db session, unable to proceed")
diff --git a/lib/auth/user_test.go b/lib/auth/server/user_test.go
similarity index 99%
rename from lib/auth/user_test.go
rename to lib/auth/server/user_test.go
index 3ffde48..a1ae748 100644
--- a/lib/auth/user_test.go
+++ b/lib/auth/server/user_test.go
@@ -4,7 +4,7 @@
 // v1.0 16/06/2016
 //
 
-package auth
+package authserver
 
 // Golang std libs
 import (
diff --git a/lib/auth/types.go b/lib/auth/types.go
deleted file mode 100644
index ef20015..0000000
--- a/lib/auth/types.go
+++ /dev/null
@@ -1,51 +0,0 @@
-//
-// 3nigm4 auth package
-// Author: Guido Ronchetti <dyst0ni3@gmail.com>
-// v1.0 16/06/2016
-//
-
-package auth
-
-import (
-	"time"
-)
-
-// Level type describe available user's permission
-// levels.
-type Level uint
-
-// Common levels used to identify tipical figures
-// that can access a service, this list can be expanded.
-const (
-	LevelUser  Level = iota // common user, will not be able to administer a service;
-	LevelAdmin Level = iota // administrator will be able to perform maintainance tasks.
-)
-
-// Permissions struct describe user's permisisons
-// on a service basis, if the user is a sper-admin
-// a special bool flag will be setted.
-type Permissions struct {
-	SuperAdmin bool             `bson:"superadmin,omitempty"` // special user that have all permissions on all services;
-	Services   map[string]Level `bson:"services"`             // permissions organised per service, the "all" can be used for generalised behaviour.
-}
-
-// User struct identify a registered
-// user to the service.
-type User struct {
-	Username       string      `bson:"username"`           // user name;
-	FullName       string      `bson:"fullname,omitempty"` // complete full name;
-	HashedPassword []byte      `bson:"pwdhash"`            // hashed password;
-	Email          string      `bson:"email,omitempty"`    // user's verified email;
-	Permissions    Permissions `bson:"permissions"`        // the permissions associated to the user;
-	IsDisabled     bool        `bson:"disabled"`           // user active (true) or not (false).
-}
-
-// Session contains information about loggedin
-// for authenticated users.
-type Session struct {
-	Token        []byte        `bson:"token"`       // token for the session;
-	Username     string        `bson:"username"`    // username associated to session;
-	LoginTime    time.Time     `bson:"login_ts"`    // timestamp of login time for this session;
-	LastSeenTime time.Time     `bson:"lastseen_ts"` // last call to an API done by the user;
-	TimeToLive   time.Duration `bson:"timetolive"`  // time of validity of the session.
-}
diff --git a/lib/auth/types/types.go b/lib/auth/types/types.go
new file mode 100644
index 0000000..91d30bf
--- /dev/null
+++ b/lib/auth/types/types.go
@@ -0,0 +1,118 @@
+//
+// 3nigm4 auth package
+// Author: Guido Ronchetti <dyst0ni3@gmail.com>
+// v1.0 16/06/2016
+//
+
+package authserver
+
+import (
+	"time"
+)
+
+// Level type describe available user's permission
+// levels.
+type Level uint
+
+// Common levels used to identify tipical figures
+// that can access a service, this list can be expanded.
+const (
+	LevelUser  Level = iota // common user, will not be able to administer a service;
+	LevelAdmin Level = iota // administrator will be able to perform maintainance tasks.
+)
+
+// Permissions struct describe user's permisisons
+// on a service basis, if the user is a sper-admin
+// a special bool flag will be setted.
+type Permissions struct {
+	SuperAdmin bool             `bson:"superadmin,omitempty"` // special user that have all permissions on all services;
+	Services   map[string]Level `bson:"services"`             // permissions organised per service, the "all" can be used for generalised behaviour.
+}
+
+// User struct identify a registered
+// user to the service.
+type User struct {
+	Username       string      `bson:"username"`           // user name;
+	FullName       string      `bson:"fullname,omitempty"` // complete full name;
+	HashedPassword []byte      `bson:"pwdhash"`            // hashed password;
+	Email          string      `bson:"email,omitempty"`    // user's verified email;
+	Permissions    Permissions `bson:"permissions"`        // the permissions associated to the user;
+	IsDisabled     bool        `bson:"disabled"`           // user active (true) or not (false).
+}
+
+// Session contains information about loggedin
+// for authenticated users.
+type Session struct {
+	Token        []byte        `bson:"token"`       // token for the session;
+	Username     string        `bson:"username"`    // username associated to session;
+	LoginTime    time.Time     `bson:"login_ts"`    // timestamp of login time for this session;
+	LastSeenTime time.Time     `bson:"lastseen_ts"` // last call to an API done by the user;
+	TimeToLive   time.Duration `bson:"timetolive"`  // time of validity of the session.
+}
+
+// VoidResponseArg empty return value.
+type VoidResponseArg struct{}
+
+// AuthenticateRequestArg define the RPC request struct
+type AuthenticateRequestArg struct {
+	Token []byte // the authentication token.
+}
+
+// AuthenticateResponseArg the returned auth structure.
+type AuthenticateResponseArg struct {
+	Username     string    // the session related username;
+	LastSeenTime time.Time // last connection from the user.
+}
+
+// UserInfoResponseArg the returned authenticated  user
+// data.
+type UserInfoResponseArg struct {
+	Username    string       // the session related username;
+	FullName    string       // the user full name;
+	Email       string       // the user email address;
+	Permissions *Permissions // user associated permissions;
+	LastSeen    time.Time    // last seen info.
+}
+
+//
+// Superadmin behaviour: the following functions are intended to
+// implement administrative tasks like creating or removing users,
+// update user's permissions or logout all users.
+//
+
+// UpserUserRequestArg request to upsert user data.
+type UpserUserRequestArg struct {
+	Token []byte // the authentication token;
+	User  User   // the user record to be updated.
+}
+
+// RemoveUserRequestArg request for remove an existing
+// user.
+type RemoveUserRequestArg struct {
+	Token    []byte // the authentication token;
+	Username string // the user to be removed.
+}
+
+// LoginRequestArg define the RPC request struct
+type LoginRequestArg struct {
+	Username string // the authenticating username;
+	Password string // plaintext password.
+}
+
+// LoginResponseArg the returned login structure
+// having the user assigned session token.
+type LoginResponseArg struct {
+	Token []byte // the session token to be used, from now on, to communicate with server.
+}
+
+// LogoutRequestArg is the request passed to logout the
+// user's sessions.
+type LogoutRequestArg struct {
+	Token []byte // the session token used to identify the user.
+}
+
+// LogoutResponseArg is the structure used to return the
+// list of invalidated sessions.
+type LogoutResponseArg struct {
+	Invalidated []byte
+}
diff --git a/lib/auth/database.go b/lib/database/client/database.go
similarity index 88%
rename from lib/auth/database.go
rename to lib/database/client/database.go
index eb47efb..7e61b2d 100644
--- a/lib/auth/database.go
+++ b/lib/database/client/database.go
@@ -11,7 +11,7 @@
 // offline tests.
 // In production this file is a simple wrapper around
 // mgo package.
-package auth
+package database
 
 // Golang std libs
 import (
@@ -20,6 +20,10 @@ import (
 	"time"
 )
 
+import (
+	ty "github.com/nexocrew/3nigm4/lib/auth/types"
+)
+
 // Third party libs
 import (
 	"gopkg.in/mgo.v2"
@@ -53,14 +57,14 @@ type Database interface {
 	Copy() Database // retain the db client in a multi-coroutine environment;
 	Close()         // release the client;
 	// user behaviour
-	GetUser(string) (*User, error) // gets a user struct from an argument username;
-	SetUser(*User) error           // creates a new user in the db;
-	RemoveUser(string) error       // remove an user from the db;
+	GetUser(string) (*ty.User, error) // gets a user struct from an argument username;
+	SetUser(*ty.User) error           // creates a new user in the db;
+	RemoveUser(string) error          // remove an user from the db;
 	// session behaviour
-	GetSession([]byte) (*Session, error) // search for a session in the db;
-	SetSession(*Session) error           // insert a session in the db;
-	RemoveSession([]byte) error          // remove an existing session;
-	RemoveAllSessions() error            // remove all sessions in the db.
+	GetSession([]byte) (*ty.Session, error) // search for a session in the db;
+	SetSession(*ty.Session) error           // insert a session in the db;
+	RemoveSession([]byte) error             // remove an existing session;
+	RemoveAllSessions() error               // remove all sessions in the db.
 }
 
 // Mongodb database, wrapping mgo session
@@ -136,13 +140,13 @@ func (d *Mongodb) Close() {
 
 // GetUser get user strucutre from a given username, if
 // something wrong returns an error.
-func (d *Mongodb) GetUser(username string) (*User, error) {
+func (d *Mongodb) GetUser(username string) (*ty.User, error) {
 	// build query
 	selector := bson.M{
 		"username": bson.M{"$eq": username},
 	}
 	// perform db query
-	var user User
+	var user ty.User
 	err := d.session.DB(d.database).C(d.usersCollection).Find(selector).One(&user)
 	if err != nil {
 		return nil, err
@@ -152,7 +156,7 @@ func (d *Mongodb) GetUser(username string) (*User, error) {
 
 // SetUser adds an argument User struct to the database,
 // returns an error if something went wrong.
-func (d *Mongodb) SetUser(user *User) error {
+func (d *Mongodb) SetUser(user *ty.User) error {
 	selector := bson.M{
 		"username": user.Username,
 	}
@@ -183,13 +187,13 @@ func (d *Mongodb) RemoveUser(username string) error {
 // GetSession check if a session is available and still valid
 // veryfing time of last seen contact against pre-defined
 // timeout value.
-func (d *Mongodb) GetSession(token []byte) (*Session, error) {
+func (d *Mongodb) GetSession(token []byte) (*ty.Session, error) {
 	// build query
 	selector := bson.M{
 		"token": bson.M{"$eq": token},
 	}
 	// perform db query
-	var session Session
+	var session ty.Session
 	err := d.session.DB(d.database).C(d.sessionsCollection).Find(selector).One(&session)
 	if err != nil {
 		return nil, err
@@ -198,7 +202,7 @@ func (d *Mongodb) GetSession(token []byte) (*Session, error) {
 }
 
 // SetSession add a session data to the database.
-func (d *Mongodb) SetSession(session *Session) error {
+func (d *Mongodb) SetSession(session *ty.Session) error {
 	selector := bson.M{
 		"token": session.Token,
 	}
diff --git a/lib/auth/database_test.go b/lib/database/mock/database_mock.go
similarity index 97%
rename from lib/auth/database_test.go
rename to lib/database/mock/database_mock.go
index 87c642f..353dc98 100644
--- a/lib/auth/database_test.go
+++ b/lib/database/mock/database_mock.go
@@ -9,7 +9,7 @@
 // optimisation logic.
 //
 
-package auth
+package authmock
 
 // Golang std libs
 import (
@@ -27,7 +27,7 @@ type mockdb struct {
 	sessionStorage map[string]*Session
 }
 
-func newMockDb(args *DbArgs) *mockdb {
+func NewMockDb(args *DbArgs) *mockdb {
 	return &mockdb{
 		addresses:      composeDbAddress(args),
 		user:           args.User,
diff --git a/storageservice/commands.go b/storageservice/commands.go
index 6a4453d..ef6b827 100644
--- a/storageservice/commands.go
+++ b/storageservice/commands.go
@@ -17,14 +17,14 @@ import (
 
 // Internal libs
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	ty "github.com/nexocrew/3nigm4/lib/auth/types"
 	ct "github.com/nexocrew/3nigm4/lib/commons"
 )
 
 // createStorageResource upload a data chunk to the S3 backend service
 // after authorising the user. It operates in async mode to perform the
 // actual upload using a working queue to integrate S3 backend.
-func createStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *auth.UserInfoResponseArg) {
+func createStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *ty.UserInfoResponseArg) {
 	if args.Arguments.Data == nil ||
 		len(args.Arguments.Data) == 0 {
 		riseError(http.StatusBadRequest,
@@ -110,7 +110,7 @@ func createStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobP
 // checkAclPermission verify all possible acl scenarios and check if the
 // requiring user has required permissions to access the file. If user can
 // download it it'll return true otherwise false.
-func checkAclPermission(userInfo *auth.UserInfoResponseArg, fileLog *FileLog) bool {
+func checkAclPermission(userInfo *ty.UserInfoResponseArg, fileLog *FileLog) bool {
 	// check access credentials
 	switch fileLog.Acl.Permission {
 	case Private:
@@ -138,7 +138,7 @@ func checkAclPermission(userInfo *auth.UserInfoResponseArg, fileLog *FileLog) bo
 // it is exposed via a REST GET method and returns a txId usable with the verify
 // API call toretrieve the actual downloaded data (from S3 storage). The user
 // must be correctly authenticated to be able to access the requested resource.
-func retrieveStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *auth.UserInfoResponseArg) {
+func retrieveStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *ty.UserInfoResponseArg) {
 	// retain db
 	dbSession := db.Copy()
 	defer dbSession.Close()
@@ -200,7 +200,7 @@ func retrieveStorageResource(w http.ResponseWriter, r *http.Request, args *ct.Jo
 
 // deleteStorageResource remove a file from the S3 storage: only the original file
 // owner (who uploaded it) can remove a file from there.
-func deleteStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *auth.UserInfoResponseArg) {
+func deleteStorageResource(w http.ResponseWriter, r *http.Request, args *ct.JobPostRequest, userInfo *ty.UserInfoResponseArg) {
 	// retain db
 	dbSession := db.Copy()
 	defer dbSession.Close()
diff --git a/storageservice/handlers.go b/storageservice/handlers.go
index 1ae2e24..231e9dd 100644
--- a/storageservice/handlers.go
+++ b/storageservice/handlers.go
@@ -18,7 +18,7 @@ import (
 
 // Internal libs
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	ty "github.com/nexocrew/3nigm4/lib/auth/types"
 	ct "github.com/nexocrew/3nigm4/lib/commons"
 )
 
@@ -47,7 +47,7 @@ func riseError(status int, msg string, w http.ResponseWriter, ipa string) {
 // authoriseGettingUserInfos authorises the provided token
 // and return user associated data. If returns a nil value
 // it means something went wrong.
-func authoriseGettingUserInfos(authToken string) (*auth.UserInfoResponseArg, error) {
+func authoriseGettingUserInfos(authToken string) (*ty.UserInfoResponseArg, error) {
 	if authToken == "" {
 		return nil, fmt.Errorf("authorisation token is nil")
 	}
diff --git a/storageservice/serve_cmd.go b/storageservice/serve_cmd.go
index 689bbed..4442b3f 100644
--- a/storageservice/serve_cmd.go
+++ b/storageservice/serve_cmd.go
@@ -15,7 +15,7 @@ import (
 
 // Internal dependencies
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	auth "github.com/nexocrew/3nigm4/lib/auth/client"
 	s3c "github.com/nexocrew/3nigm4/lib/s3"
 )
 
diff --git a/storageservice/serve_test.go b/storageservice/serve_test.go
index ece85b7..ad2f14d 100644
--- a/storageservice/serve_test.go
+++ b/storageservice/serve_test.go
@@ -21,7 +21,8 @@ import (
 
 // Internal dependencies.
 import (
-	"github.com/nexocrew/3nigm4/lib/auth"
+	"github.com/nexocrew/3nigm4/lib/auth/client"
+	"github.com/nexocrew/3nigm4/lib/auth/mock"
 	ct "github.com/nexocrew/3nigm4/lib/commons"
 	"github.com/nexocrew/3nigm4/lib/itm"
 	"github.com/nexocrew/3nigm4/lib/logger"