diff --git a/internal/sync/engine.go b/internal/sync/engine.go
new file mode 100644
index 0000000..2dd1831
--- /dev/null
+++ b/internal/sync/engine.go
@@ -0,0 +1,190 @@
+package sync
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"gitm/internal/database"
+	"gitm/internal/gitea"
+	"gitm/internal/models"
+)
+
+type Engine struct {
+	maxConcurrent int
+	mu            sync.Mutex
+	activeTasks   map[int64]string
+}
+
+func NewEngine(maxConcurrent int) *Engine {
+	return &Engine{
+		maxConcurrent: maxConcurrent,
+		activeTasks:   make(map[int64]string),
+	}
+}
+
+func (e *Engine) SyncServer(serverID int64) error {
+	e.mu.Lock()
+	if _, active := e.activeTasks[serverID]; active {
+		e.mu.Unlock()
+		return fmt.Errorf("sync already in progress for server %d", serverID)
+	}
+	taskID := fmt.Sprintf("%d-%d", serverID, time.Now().Unix())
+	e.activeTasks[serverID] = taskID
+	e.mu.Unlock()
+
+	defer func() {
+		e.mu.Lock()
+		delete(e.activeTasks, serverID)
+		e.mu.Unlock()
+	}()
+
+	server, err := database.GetServer(serverID)
+	if err != nil || server == nil {
+		return fmt.Errorf("failed to get server: %w", err)
+	}
+
+	syncLog := &models.SyncLog{
+		ServerID:  serverID,
+		Status:    "in_progress",
+		Message:   "Starting sync",
+		StartedAt: time.Now(),
+	}
+	if err := database.CreateSyncLog(syncLog); err != nil {
+		return fmt.Errorf("failed to create sync log: %w", err)
+	}
+
+	client, err := gitea.NewClient(server.URL, server.Token)
+	if err != nil {
+		e.finishLog(syncLog, "failed", fmt.Sprintf("Failed to create client: %v", err))
+		return err
+	}
+
+	if _, err := client.ValidateToken(); err != nil {
+		e.finishLog(syncLog, "failed", fmt.Sprintf("Authentication failed: %v", err))
+		return err
+	}
+
+	giteaRepos, err := client.GetAllRepos()
+	if err != nil {
+		e.finishLog(syncLog, "failed", fmt.Sprintf("Failed to fetch repos: %v", err))
+		return err
+	}
+
+	reposDir, _ := database.GetSetting("repos_dir")
+	if reposDir == "" {
+		reposDir = "./data/repos"
+	}
+	serverDir := filepath.Join(reposDir, fmt.Sprintf("server_%d_%s", serverID, server.Name))
+	os.MkdirAll(serverDir, 0755)
+
+	successCount := 0
+	failedCount := 0
+	sem := make(chan struct{}, e.maxConcurrent)
+	var wg sync.WaitGroup
+	var resultsMu sync.Mutex
+
+	for _, gr := range giteaRepos {
+		wg.Add(1)
+		go func(giteaRepo gitea.GiteaRepo) {
+			defer wg.Done()
+			sem <- struct{}{}
+			defer func() { <-sem }()
+
+			localPath := filepath.Join(serverDir, giteaRepo.FullName+".git")
+			existingRepo, _ := database.GetRepoByFullName(serverID, giteaRepo.FullName)
+
+			var err error
+			if existingRepo == nil {
+				err = e.cloneMirror(giteaRepo.CloneURL, localPath)
+				if err == nil {
+					repo := &models.Repo{
+						ServerID:   serverID,
+						Name:       giteaRepo.Name,
+						FullName:   giteaRepo.FullName,
+						CloneURL:   giteaRepo.CloneURL,
+						LocalPath:  localPath,
+						SyncStatus: "success",
+					}
+					database.CreateRepo(repo)
+				}
+			} else {
+				err = e.fetchMirror(localPath)
+				if err == nil {
+					database.UpdateRepoSyncStatus(existingRepo.ID, "success")
+				}
+			}
+
+			resultsMu.Lock()
+			if err != nil {
+				failedCount++
+				failLog := &models.SyncLog{
+					ServerID:  serverID,
+					RepoID:    getRepoID(serverID, giteaRepo.FullName),
+					Status:    "failed",
+					Message:   err.Error(),
+					StartedAt: time.Now(),
+				}
+				database.CreateSyncLog(failLog)
+			} else {
+				successCount++
+			}
+			resultsMu.Unlock()
+		}(gr)
+	}
+
+	wg.Wait()
+	database.UpdateServerLastSync(serverID)
+
+	message := fmt.Sprintf("Sync completed: %d succeeded, %d failed", successCount, failedCount)
+	e.finishLog(syncLog, "success", message)
+	return nil
+}
+
+func (e *Engine) cloneMirror(url, path string) error {
+	if _, err := os.Stat(path); err == nil {
+		return nil
+	}
+	os.MkdirAll(filepath.Dir(path), 0755)
+	cmd := exec.Command("git", "clone", "--mirror", url, path)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("clone failed: %w - %s", err, string(output))
+	}
+	return nil
+}
+
+func (e *Engine) fetchMirror(path string) error {
+	cmd := exec.Command("git", "--git-dir", path, "fetch", "--all", "--prune")
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("fetch failed: %w - %s", err, string(output))
+	}
+	return nil
+}
+
+func (e *Engine) finishLog(log *models.SyncLog, status, message string) {
+	now := time.Now()
+	log.Status = status
+	log.Message = message
+	log.FinishedAt = &now
+	database.UpdateSyncLog(log.ID, status, message, log.FinishedAt)
+}
+
+func (e *Engine) IsSyncing(serverID int64) bool {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	_, active := e.activeTasks[serverID]
+	return active
+}
+
+func getRepoID(serverID int64, fullName string) *int64 {
+	repo, _ := database.GetRepoByFullName(serverID, fullName)
+	if repo != nil {
+		return &repo.ID
+	}
+	return nil
+}
diff --git a/internal/sync/scheduler.go b/internal/sync/scheduler.go
new file mode 100644
index 0000000..0492b44
--- /dev/null
+++ b/internal/sync/scheduler.go
@@ -0,0 +1,74 @@
+package sync
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/robfig/cron/v3"
+	"gitm/internal/database"
+	"gitm/internal/models"
+)
+
+type Scheduler struct {
+	cron       *cron.Cron
+	engine     *Engine
+	serverJobs map[int64]cron.EntryID
+}
+
+func NewScheduler(engine *Engine) *Scheduler {
+	return &Scheduler{
+		cron:       cron.New(),
+		engine:     engine,
+		serverJobs: make(map[int64]cron.EntryID),
+	}
+}
+
+func (s *Scheduler) Start() {
+	s.cron.Start()
+	log.Println("Scheduler started")
+}
+
+func (s *Scheduler) Stop() {
+	s.cron.Stop()
+	log.Println("Scheduler stopped")
+}
+
+func (s *Scheduler) UpdateServer(server *models.GiteaServer) {
+	if entryID, exists := s.serverJobs[server.ID]; exists {
+		s.cron.Remove(entryID)
+		delete(s.serverJobs, server.ID)
+	}
+	if server.SyncInterval <= 0 || server.Status != "active" {
+		return
+	}
+	schedule := fmt.Sprintf("*/%d * * * *", server.SyncInterval)
+	entryID, err := s.cron.AddFunc(schedule, func() {
+		log.Printf("Scheduled sync for server %d (%s)", server.ID, server.Name)
+		if err := s.engine.SyncServer(server.ID); err != nil {
+			log.Printf("Scheduled sync failed for server %d: %v", server.ID, err)
+		}
+	})
+	if err != nil {
+		log.Printf("Failed to schedule for server %d: %v", server.ID, err)
+		return
+	}
+	s.serverJobs[server.ID] = entryID
+}
+
+func (s *Scheduler) RemoveServer(serverID int64) {
+	if entryID, exists := s.serverJobs[serverID]; exists {
+		s.cron.Remove(entryID)
+		delete(s.serverJobs, serverID)
+	}
+}
+
+func (s *Scheduler) ReloadAll() error {
+	servers, err := database.GetServers()
+	if err != nil {
+		return err
+	}
+	for _, server := range servers {
+		s.UpdateServer(&server)
+	}
+	return nil
+}