diff --git a/internal/adapters/db/db.go b/internal/adapters/db/db.go
index 7bb3372..51b59f2 100644
--- a/internal/adapters/db/db.go
+++ b/internal/adapters/db/db.go
@@ -26,6 +26,7 @@ type Piece struct {
 	PieceComplexity models.PieceComplexity
 	State           models.PieceState
 	Practices       []Practice
+	Users           []*User `gorm:"many2many:user_practices;"`
 }
 
 type Lesson struct {
@@ -35,6 +36,7 @@ type Lesson struct {
 	StartDate time.Time
 	EndDate   time.Time
 	Comment   string
+	UserID    uint
 }
 
 type Practice struct {
@@ -47,6 +49,7 @@ type Practice struct {
 	Piece     Piece
 	LessonID  uint
 	Lesson    Lesson
+	UserID    uint
 }
 
 type Warmup struct {
@@ -57,6 +60,16 @@ type Warmup struct {
 	State     models.WarmupState
 	LessonID  uint
 	Lesson    Lesson
+	UserID    uint
+}
+
+type User struct {
+	gorm.Model
+	ID        uint       `gorm:"primary_key"`
+	Name      string     `gorm:"primary_key"`
+	Pieces    []Piece    `gorm:"many2many:user_pieces;"`
+	Practices []Practice `gorm:"many2many:user_practices;"`
+	Warmups   []Warmup   `gorm:"many2many:user_warmups;"`
 }
 
 type Adapter struct {
@@ -71,7 +84,7 @@ func NewAdapter(dbUrl string) (*Adapter, error) {
 		return nil, fmt.Errorf("Db connection error: %v", openErr)
 	}
 	if err := db.AutoMigrate(
-		&Composer{}, &Piece{}, &Practice{}, &Lesson{}, &Warmup{},
+		&Composer{}, &Piece{}, &Practice{}, &Lesson{}, &Warmup{}, &User{},
 	); err != nil {
 		return nil, fmt.Errorf("Db migration error: %v", err)
 	}
@@ -304,3 +317,37 @@ func (a *Adapter) UpdatePractice(practice *models.Practice) error {
 	res := a.db.Save(practice)
 	return res.Error
 }
+
+func (a *Adapter) AddUser(user *models.User) (*models.User, error) {
+	userModel := User{
+		Name: user.Name,
+	}
+	res := a.db.Create(&userModel)
+	if res.Error == nil {
+		user.ID = int64(userModel.ID)
+	}
+	return user, res.Error
+}
+func (a *Adapter) GetUser(id int64) (*models.User, error) {
+	var u User
+	res := a.db.First(&u, id)
+	user := models.User{
+		ID:   int64(u.ID),
+		Name: u.Name,
+	}
+	return &user, res.Error
+}
+
+func (a *Adapter) GetUsers() ([]*models.User, error) {
+	var urs []User
+	var users []*models.User
+	a.db.Find(&urs)
+	for _, u := range urs {
+		user := models.User{
+			ID:   int64(u.ID),
+			Name: u.Name,
+		}
+		users = append(users, &user)
+	}
+	return users, nil
+}
diff --git a/internal/ports/db.go b/internal/ports/db.go
index 0edac47..3b80d7a 100644
--- a/internal/ports/db.go
+++ b/internal/ports/db.go
@@ -22,4 +22,8 @@ type DBPort interface {
 	AddWarmup(warmup *models.Warmup) error
 	UpdateWarmup(warmup *models.Warmup) error
 	GetActiveWarmup() (*models.Warmup, error)
+	// User
+	AddUser(user *models.User) (*models.User, error)
+	GetUser(id int64) (*models.User, error)
+	GetUsers() ([]*models.User, error)
 }
diff --git a/models/user.go b/models/user.go
new file mode 100644
index 0000000..63be04e
--- /dev/null
+++ b/models/user.go
@@ -0,0 +1,26 @@
+package models
+
+import "slices"
+
+type User struct {
+	ID        int64       `json:"id"`
+	Name      string      `json:"name"`
+	Pieces    []*Piece    `json:"pieces"`
+	Practices []*Practice `json:"practices"`
+}
+
+func NewUser(name string) *User {
+	return &User{Name: name}
+}
+
+func (u *User) AssignPiece(piece *Piece) {
+	if !slices.Contains(u.Pieces, piece) {
+		u.Pieces = append(u.Pieces, piece)
+	}
+}
+
+func (u *User) PracticePiece(practice *Practice, lesson *Lesson) {
+	if !slices.Contains(u.Practices, practice) {
+		u.Practices = append(u.Practices, practice)
+	}
+}
diff --git a/models/user_test.go b/models/user_test.go
new file mode 100644
index 0000000..3660b7b
--- /dev/null
+++ b/models/user_test.go
@@ -0,0 +1,17 @@
+package models
+
+import (
+	"slices"
+	"testing"
+)
+
+func TestAssignPiece(t *testing.T) {
+	piece := NewPiece("test piece", "test composer", PieceComplexityEasy)
+	user := NewUser("test")
+
+	user.AssignPiece(piece)
+	if !slices.Contains(user.Pieces, piece) {
+		t.Fatal("Piece wasn't added")
+	}
+
+}
diff --git a/musgit.go b/musgit.go
index 4ede0ea..f3bb7d8 100644
--- a/musgit.go
+++ b/musgit.go
@@ -13,6 +13,7 @@ type Musgit struct {
 	Practice services.PracticeService
 	Lesson   services.LessonService
 	Piece    services.PieceService
+	User     services.UserService
 }
 
 func New(dbUri string) *Musgit {
@@ -23,10 +24,12 @@ func New(dbUri string) *Musgit {
 	practiceService := services.NewPracticeService(dbAdapter)
 	lessonService := services.NewLessonService(dbAdapter)
 	pieceService := services.NewPieceService(dbAdapter)
+	userService := services.NewUserService(dbAdapter)
 	return &Musgit{
 		db:       dbAdapter,
 		Practice: *practiceService,
 		Lesson:   *lessonService,
 		Piece:    *pieceService,
+		User:     *userService,
 	}
 }
diff --git a/services/user.go b/services/user.go
new file mode 100644
index 0000000..6c8ebcb
--- /dev/null
+++ b/services/user.go
@@ -0,0 +1,69 @@
+package services
+
+import (
+	"errors"
+
+	"github.com/musgit-dev/musgit/internal/ports"
+	"github.com/musgit-dev/musgit/models"
+)
+
+var (
+	ErrUserNotFound = errors.New("User not found")
+)
+
+type UserService struct {
+	db ports.DBPort
+}
+
+func NewUserService(db ports.DBPort) *UserService {
+	return &UserService{db: db}
+}
+
+func (s *UserService) GetAll() ([]*models.User, error) {
+	users, err := s.db.GetUsers()
+	if err != nil {
+		return []*models.User{}, err
+	}
+	return users, nil
+}
+
+func (s *UserService) Get(id int64) (*models.User, error) {
+	user, err := s.db.GetUser(id)
+	if err != nil {
+		return &models.User{}, err
+	}
+	return user, nil
+}
+
+func (s *UserService) Add(name string) (*models.User, error) {
+	u := models.NewUser(name)
+	u, err := s.db.AddUser(u)
+	if err != nil {
+		return u, err
+	}
+	return u, nil
+}
+
+func (s *UserService) AssignPiece(userId int64, piece models.Piece) error {
+	user, err := s.Get(userId)
+	if err != nil {
+		return ErrUserNotFound
+	}
+	user.AssignPiece(&piece)
+	return nil
+}
+
+func (s *UserService) StartPractice(
+	userId, pieceId, lessonId int64,
+) (*models.Practice, error) {
+	var practice *models.Practice
+	user, err := s.Get(userId)
+	if err != nil {
+		return practice, ErrUserNotFound
+	}
+	piece, err := s.db.GetPiece(pieceId)
+	lesson, err := s.db.GetLesson(lessonId)
+	practice, err = piece.StartPractice()
+	user.PracticePiece(practice, &lesson)
+	return practice, err
+}
diff --git a/services/user_test.go b/services/user_test.go
new file mode 100644
index 0000000..82ea459
--- /dev/null
+++ b/services/user_test.go
@@ -0,0 +1,60 @@
+package services
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/musgit-dev/musgit/internal/adapters/db"
+	"github.com/musgit-dev/musgit/models"
+)
+
+var service *UserService
+var pieceService *PieceService
+
+func TestMain(m *testing.M) {
+	dbPort, err := db.NewAdapter(":memory:")
+	if err != nil {
+		os.Exit(1)
+	}
+	pieceService = NewPieceService(dbPort)
+
+	piece, err := pieceService.Add(
+		"test_piece",
+		"test_composer",
+		models.PieceComplexityUnknown,
+	)
+	if err != nil {
+		os.Exit(1)
+	}
+	fmt.Println("Added piece", piece.ID)
+	service = NewUserService(dbPort)
+	exitVal := m.Run()
+	os.Exit(exitVal)
+}
+
+func TestAdd(t *testing.T) {
+	user, err := service.Add("test_user")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if user.Name != "test_user" {
+		t.Fatalf("Unexpected user name, got %s, expected test user", user.Name)
+	}
+}
+
+func TestAssignPiece(t *testing.T) {
+	user, err := service.Add("test_user")
+	if err != nil {
+		t.Fatal(err)
+	}
+	piece, _ := pieceService.Get(1)
+	if piece.ID != 1 {
+		t.Fatal("Unknown piece")
+	}
+	user.AssignPiece(&piece)
+	if len(user.Pieces) != 1 {
+		t.Fatalf("Piece wasn't added")
+	}
+
+}