diff --git a/chfs-ng/cmd/chfs/main.go b/chfs-ng/cmd/chfs/main.go
index cd1a832..991f77d 100644
--- a/chfs-ng/cmd/chfs/main.go
+++ b/chfs-ng/cmd/chfs/main.go
@@ -11,6 +11,7 @@ import (
 	"chfs-ng/internal/api"
 	"chfs-ng/internal/auth"
 	"chfs-ng/internal/config"
+	"chfs-ng/internal/opslog"
 	"chfs-ng/internal/storage"
 )
 
@@ -67,7 +68,7 @@ func main() {
 	if len(cfg.Path) == 1 {
 		store = storage.Local{Root: root}
 	}
-	srv := &api.Server{Store: store, Auth: mgr, Sessions: map[string]*auth.Account{}, WebDAVRoot: root, Allow: cfg.Allow, MultiRoot: len(cfg.Path) > 1, RemoveMode: cfg.FileRemove}
+	srv := &api.Server{Store: store, Auth: mgr, Sessions: map[string]*auth.Account{}, WebDAVRoot: root, Allow: cfg.Allow, MultiRoot: len(cfg.Path) > 1, RemoveMode: cfg.FileRemove, Log: opslog.New(cfg.Log)}
 	addr := ":" + itoa(cfg.Port)
 	log.Printf("chfs-ng listening on %s root=%s removeMode=%d", addr, filepath.Clean(root), cfg.FileRemove)
 	if cfg.SSLCert != "" && cfg.SSLKey != "" {
diff --git a/chfs-ng/internal/api/server.go b/chfs-ng/internal/api/server.go
index 548051d..1a54d14 100644
--- a/chfs-ng/internal/api/server.go
+++ b/chfs-ng/internal/api/server.go
@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"chfs-ng/internal/auth"
+	"chfs-ng/internal/opslog"
 	"chfs-ng/internal/storage"
 	"github.com/emersion/go-webdav"
 )
@@ -27,6 +28,7 @@ type Server struct {
 	Allow      string
 	MultiRoot  bool
 	RemoveMode int
+	Log        *opslog.Logger
 }
 type fileInfo struct {
 	Name      string `json:"name"`
@@ -68,6 +70,26 @@ func account(r *http.Request, s *Server) *auth.Account {
 	}
 	return s.Auth.Guest
 }
+
+func (s *Server) logOp(r *http.Request, action string) {
+	if s.Log == nil {
+		return
+	}
+	a := account(r, s)
+	user := ""
+	if a != nil {
+		user = a.Username
+	}
+	_ = s.Log.Write(clientIPString(r), user, action)
+}
+
+func clientIPString(r *http.Request) string {
+	ip := clientIP(r)
+	if ip == nil {
+		return "-"
+	}
+	return ip.String()
+}
 func writeJSON(w http.ResponseWriter, v any) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	json.NewEncoder(w).Encode(v)
@@ -140,6 +162,7 @@ func (s *Server) newdir(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, e.Error(), 500)
 		return
 	}
+	s.logOp(r, fmt.Sprintf("created directory:'%s'", p))
 	writeJSON(w, map[string]any{"ok": true})
 }
 func (s *Server) rename(w http.ResponseWriter, r *http.Request) {
@@ -154,6 +177,7 @@ func (s *Server) rename(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, e.Error(), 500)
 		return
 	}
+	s.logOp(r, fmt.Sprintf("renamed '%s' to '%s'", old, neu))
 	writeJSON(w, map[string]any{"ok": true})
 }
 func (s *Server) remove(w http.ResponseWriter, r *http.Request) {
@@ -173,6 +197,7 @@ func (s *Server) remove(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, e.Error(), 500)
 			return
 		}
+		s.logOp(r, fmt.Sprintf("removed '%s'", strings.Trim(p, "/")))
 	}
 	writeJSON(w, map[string]any{"ok": true})
 }
@@ -256,6 +281,7 @@ func (s *Server) newtext(w http.ResponseWriter, r *http.Request) {
 	}
 	defer f.Close()
 	io.WriteString(f, r.FormValue("text"))
+	s.logOp(r, fmt.Sprintf("create a text file:'%s'", p))
 	writeJSON(w, map[string]any{"ok": true})
 }
 func (s *Server) updatetext(w http.ResponseWriter, r *http.Request) {
@@ -277,6 +303,7 @@ func (s *Server) updatetext(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, e.Error(), 500)
 		return
 	}
+	s.logOp(r, fmt.Sprintf("update text file:'%s'", p))
 	writeJSON(w, map[string]any{"ok": true})
 }
 func (s *Server) upload(w http.ResponseWriter, r *http.Request) {
@@ -305,6 +332,9 @@ func (s *Server) upload(w http.ResponseWriter, r *http.Request) {
 			saved = append(saved, h.Filename)
 		}
 	}
+	for _, name := range saved {
+		s.logOp(r, fmt.Sprintf("upload '%s'", path.Join(dir, name)))
+	}
 	w.WriteHeader(http.StatusCreated)
 	writeJSON(w, map[string]any{"ok": true, "files": saved})
 }
@@ -515,6 +545,7 @@ func (s *Server) downloadDir(w http.ResponseWriter, r *http.Request) {
 		}
 		return nil
 	}
+	s.logOp(r, fmt.Sprintf("download directory '%s'", p))
 	if err := walk(p, ""); err != nil {
 		return
 	}
diff --git a/chfs-ng/internal/opslog/opslog.go b/chfs-ng/internal/opslog/opslog.go
new file mode 100644
index 0000000..a0842a1
--- /dev/null
+++ b/chfs-ng/internal/opslog/opslog.go
@@ -0,0 +1,39 @@
+package opslog
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+type Logger struct {
+	dir string
+	mu  sync.Mutex
+}
+
+func New(dir string) *Logger {
+	if dir == "" {
+		return nil
+	}
+	return &Logger{dir: dir}
+}
+
+func (l *Logger) Write(ip, user, action string) error {
+	if l == nil || l.dir == "" {
+		return nil
+	}
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if err := os.MkdirAll(l.dir, 0755); err != nil {
+		return err
+	}
+	f, err := os.OpenFile(filepath.Join(l.dir, "ops.log"), os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = fmt.Fprintf(f, "%s - %s - user(%s) %s\\n", time.Now().Format("2006-01-02 15:04:05"), ip, user, action)
+	return err
+}