diff --git a/cmd/evening_detective_server/main.go b/cmd/evening_detective_server/main.go
index 0d11b54..401a42a 100644
--- a/cmd/evening_detective_server/main.go
+++ b/cmd/evening_detective_server/main.go
@@ -3,13 +3,15 @@ package main
 import (
 	"context"
 	_ "embed"
+	"evening_detective_server/internal/app"
+	"evening_detective_server/internal/repos/users_repo"
+	"evening_detective_server/internal/services/users_service"
+	proto "evening_detective_server/proto"
 	"log"
 	"net"
 	"net/http"
 	"os"
-	"evening_detective_server/internal/app"
-	proto "evening_detective_server/proto"
-	
+
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/jackc/pgx/v5/pgxpool"
 	"github.com/joho/godotenv"
@@ -38,6 +40,9 @@ func main() {
 		log.Fatalf("QueryRow failed: %v\n", err)
 	}
 
+	usersRepo := users_repo.NewUserRepo(dbpool)
+	usersService := users_service.NewUsersService(usersRepo)
+
 	// Create a listener on TCP port
 	lis, err := net.Listen("tcp", ":8080")
 	if err != nil {
@@ -47,7 +52,12 @@ func main() {
 	// Create a gRPC server object
 	s := grpc.NewServer()
 	// Attach the Greeter service to the server
-	proto.RegisterEveningDetectiveServerServer(s, app.NewServer())
+	proto.RegisterEveningDetectiveServerServer(
+		s,
+		app.NewServer(
+			usersService,
+		),
+	)
 	// Serve gRPC server
 	log.Println("Serving gRPC on 0.0.0.0:8080")
 	go func() {
diff --git a/internal/app/server.go b/internal/app/server.go
index 68efc62..e99198c 100644
--- a/internal/app/server.go
+++ b/internal/app/server.go
@@ -2,15 +2,22 @@ package app
 
 import (
 	"context"
+	"evening_detective_server/internal/services/users_service"
 	proto "evening_detective_server/proto"
 )
 
 type server struct {
 	proto.UnsafeEveningDetectiveServerServer
+
+	usersService *users_service.UsersService
 }
 
-func NewServer() proto.EveningDetectiveServerServer {
-	return &server{}
+func NewServer(
+	usersService *users_service.UsersService,
+) proto.EveningDetectiveServerServer {
+	return &server{
+		usersService: usersService,
+	}
 }
 
 func (s *server) Ping(_ context.Context, _ *proto.PingReq) (*proto.PingRsp, error) {
@@ -21,6 +28,12 @@ func (s *server) Echo(_ context.Context, req *proto.EchoReq) (*proto.EchoRsp, er
 	return &proto.EchoRsp{Text: req.Text}, nil
 }
 
-func (s *server) Signup(context.Context, *proto.SignupReq) (*proto.SignupRsp, error) {
-	panic("unimplemented")
+func (s *server) Signup(ctx context.Context, signupReq *proto.SignupReq) (*proto.SignupRsp, error) {
+	err := s.usersService.AddUser(ctx, signupReq.Username, signupReq.Email)
+	if err != nil {
+		return &proto.SignupRsp{
+			Error: err.Error(),
+		}, nil
+	}
+	return &proto.SignupRsp{}, nil
 }
diff --git a/internal/repos/users_repo/repo.go b/internal/repos/users_repo/repo.go
new file mode 100644
index 0000000..8711896
--- /dev/null
+++ b/internal/repos/users_repo/repo.go
@@ -0,0 +1,50 @@
+package users_repo
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type UsersRepo struct {
+	pool *pgxpool.Pool
+}
+
+func NewUserRepo(pool *pgxpool.Pool) *UsersRepo {
+	return &UsersRepo{
+		pool: pool,
+	}
+}
+
+func (s *UsersRepo) AddUser(
+	ctx context.Context,
+	username string,
+	email string,
+	passwoedHash string,
+	role string,
+) error {
+	tag, err := s.pool.Exec(
+		ctx,
+		`INSERT INTO users (username, email, password_hash, role)
+		SELECT $1, $2, $3, $4
+		WHERE NOT EXISTS (
+			SELECT 1 FROM users 
+			WHERE username = $5 OR email = $6
+		)`,
+		username,
+		email,
+		passwoedHash,
+		role,
+
+		username,
+		email,
+	)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return errors.New("username или email уже используется")
+	}
+	return nil
+}
diff --git a/internal/services/users_service/service.go b/internal/services/users_service/service.go
new file mode 100644
index 0000000..d6fb76b
--- /dev/null
+++ b/internal/services/users_service/service.go
@@ -0,0 +1,31 @@
+package users_service
+
+import (
+	"context"
+	"evening_detective_server/internal/repos/users_repo"
+)
+
+type UsersService struct {
+	usersRepo *users_repo.UsersRepo
+}
+
+func NewUsersService(usersRepo *users_repo.UsersRepo) *UsersService {
+	return &UsersService{
+		usersRepo: usersRepo,
+	}
+}
+
+func (s *UsersService) AddUser(
+	ctx context.Context,
+	username string,
+	email string,
+) error {
+	err := s.usersRepo.AddUser(
+		ctx,
+		username,
+		email,
+		"hello", // TODO: generate password and send email
+		"user",
+	)
+	return err
+}
diff --git a/migrations/20260628175120_create_users_table.sql b/migrations/20260628175120_create_users_table.sql
index ae29455..485f0dd 100644
--- a/migrations/20260628175120_create_users_table.sql
+++ b/migrations/20260628175120_create_users_table.sql
@@ -4,7 +4,7 @@ CREATE TABLE IF NOT EXISTS users (
     username VARCHAR(50) NOT NULL UNIQUE,
     email VARCHAR(100) NOT NULL UNIQUE,
     password_hash VARCHAR(255) NOT NULL,
-    role VARCHAR(20) DEFAULT 'user' CHECK (role IN ('admin', 'author', 'organizer', 'user')),
+    role VARCHAR(20) CHECK (role IN ('admin', 'author', 'organizer', 'user')),
     is_active BOOLEAN DEFAULT TRUE,
     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
 );