diff --git a/src/main/java/com/openisle/config/SecurityConfig.java b/src/main/java/com/openisle/config/SecurityConfig.java
index 98f9ad25b..2dd18b7ce 100644
--- a/src/main/java/com/openisle/config/SecurityConfig.java
+++ b/src/main/java/com/openisle/config/SecurityConfig.java
@@ -1,6 +1,7 @@
 package com.openisle.config;
 
 import com.openisle.service.JwtService;
+import com.openisle.service.UserVisitService;
 import com.openisle.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.context.annotation.Bean;
@@ -38,6 +39,7 @@ public class SecurityConfig {
     private final JwtService jwtService;
     private final UserRepository userRepository;
     private final AccessDeniedHandler customAccessDeniedHandler;
+    private final UserVisitService userVisitService;
 
     @Bean
     public PasswordEncoder passwordEncoder() {
@@ -103,7 +105,8 @@ public class SecurityConfig {
                     .requestMatchers("/api/admin/**").hasAuthority("ADMIN")
                     .anyRequest().authenticated()
             )
-            .addFilterBefore(jwtAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);
+            .addFilterBefore(jwtAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class)
+            .addFilterAfter(userVisitFilter(), UsernamePasswordAuthenticationFilter.class);
         return http.build();
     }
 
@@ -150,4 +153,18 @@ public class SecurityConfig {
             }
         };
     }
+
+    @Bean
+    public OncePerRequestFilter userVisitFilter() {
+        return new OncePerRequestFilter() {
+            @Override
+            protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
+                var auth = org.springframework.security.core.context.SecurityContextHolder.getContext().getAuthentication();
+                if (auth != null && auth.isAuthenticated() && !(auth instanceof org.springframework.security.authentication.AnonymousAuthenticationToken)) {
+                    userVisitService.recordVisit(auth.getName());
+                }
+                filterChain.doFilter(request, response);
+            }
+        };
+    }
 }
diff --git a/src/main/java/com/openisle/controller/StatController.java b/src/main/java/com/openisle/controller/StatController.java
new file mode 100644
index 000000000..0e05ca686
--- /dev/null
+++ b/src/main/java/com/openisle/controller/StatController.java
@@ -0,0 +1,26 @@
+package com.openisle.controller;
+
+import com.openisle.service.UserVisitService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDate;
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/stats")
+@RequiredArgsConstructor
+public class StatController {
+    private final UserVisitService userVisitService;
+
+    @GetMapping("/dau")
+    public Map<String, Long> dau(@RequestParam(value = "date", required = false)
+                                 @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate date) {
+        long count = userVisitService.countDau(date);
+        return Map.of("dau", count);
+    }
+}
diff --git a/src/main/java/com/openisle/repository/UserVisitRepository.java b/src/main/java/com/openisle/repository/UserVisitRepository.java
index bf5870fbc..9f05ecbeb 100644
--- a/src/main/java/com/openisle/repository/UserVisitRepository.java
+++ b/src/main/java/com/openisle/repository/UserVisitRepository.java
@@ -10,4 +10,5 @@ import java.util.Optional;
 public interface UserVisitRepository extends JpaRepository<UserVisit, Long> {
     Optional<UserVisit> findByUserAndVisitDate(User user, LocalDate visitDate);
     long countByUser(User user);
+    long countByVisitDate(LocalDate visitDate);
 }
diff --git a/src/main/java/com/openisle/service/UserVisitService.java b/src/main/java/com/openisle/service/UserVisitService.java
index 7ae912851..29c5cdefe 100644
--- a/src/main/java/com/openisle/service/UserVisitService.java
+++ b/src/main/java/com/openisle/service/UserVisitService.java
@@ -32,4 +32,9 @@ public class UserVisitService {
                 .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
         return userVisitRepository.countByUser(user);
     }
+
+    public long countDau(LocalDate date) {
+        LocalDate d = date != null ? date : LocalDate.now();
+        return userVisitRepository.countByVisitDate(d);
+    }
 }
diff --git a/src/test/java/com/openisle/controller/AdminControllerTest.java b/src/test/java/com/openisle/controller/AdminControllerTest.java
index 587f50f41..8b068e415 100644
--- a/src/test/java/com/openisle/controller/AdminControllerTest.java
+++ b/src/test/java/com/openisle/controller/AdminControllerTest.java
@@ -11,6 +11,7 @@ import com.openisle.config.CustomAccessDeniedHandler;
 import com.openisle.config.SecurityConfig;
 import com.openisle.service.JwtService;
 import com.openisle.repository.UserRepository;
+import com.openisle.service.UserVisitService;
 import com.openisle.model.Role;
 import com.openisle.model.User;
 import java.util.Optional;
@@ -31,6 +32,8 @@ class AdminControllerTest {
     private JwtService jwtService;
     @MockBean
     private UserRepository userRepository;
+    @MockBean
+    private UserVisitService userVisitService;
 
     @Test
     void adminHelloReturnsMessage() throws Exception {
diff --git a/src/test/java/com/openisle/controller/HelloControllerTest.java b/src/test/java/com/openisle/controller/HelloControllerTest.java
index 65ab22779..d8837feba 100644
--- a/src/test/java/com/openisle/controller/HelloControllerTest.java
+++ b/src/test/java/com/openisle/controller/HelloControllerTest.java
@@ -11,6 +11,7 @@ import com.openisle.config.CustomAccessDeniedHandler;
 import com.openisle.config.SecurityConfig;
 import com.openisle.service.JwtService;
 import com.openisle.repository.UserRepository;
+import com.openisle.service.UserVisitService;
 import com.openisle.model.Role;
 import com.openisle.model.User;
 import java.util.Optional;
@@ -31,6 +32,8 @@ class HelloControllerTest {
     private JwtService jwtService;
     @MockBean
     private UserRepository userRepository;
+    @MockBean
+    private UserVisitService userVisitService;
 
     @Test
     void helloReturnsMessage() throws Exception {
diff --git a/src/test/java/com/openisle/controller/StatControllerTest.java b/src/test/java/com/openisle/controller/StatControllerTest.java
new file mode 100644
index 000000000..a44df193f
--- /dev/null
+++ b/src/test/java/com/openisle/controller/StatControllerTest.java
@@ -0,0 +1,54 @@
+package com.openisle.controller;
+
+import com.openisle.config.CustomAccessDeniedHandler;
+import com.openisle.config.SecurityConfig;
+import com.openisle.service.JwtService;
+import com.openisle.repository.UserRepository;
+import com.openisle.service.UserVisitService;
+import com.openisle.model.Role;
+import com.openisle.model.User;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.Optional;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(StatController.class)
+@AutoConfigureMockMvc
+@Import({SecurityConfig.class, CustomAccessDeniedHandler.class})
+class StatControllerTest {
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private JwtService jwtService;
+    @MockBean
+    private UserRepository userRepository;
+    @MockBean
+    private UserVisitService userVisitService;
+
+    @Test
+    void dauReturnsCount() throws Exception {
+        Mockito.when(jwtService.validateAndGetSubject("token")).thenReturn("user");
+        User user = new User();
+        user.setUsername("user");
+        user.setPassword("p");
+        user.setEmail("u@example.com");
+        user.setRole(Role.USER);
+        Mockito.when(userRepository.findByUsername("user")).thenReturn(Optional.of(user));
+        Mockito.when(userVisitService.countDau(Mockito.any())).thenReturn(3L);
+
+        mockMvc.perform(get("/api/stats/dau").header("Authorization", "Bearer token"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.dau").value(3));
+    }
+}