diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 145daef..63e0715 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,7 +20,9 @@ jobs:
         distribution: 'temurin'
         cache: maven
     - name: Build with Maven
-      run: mvn -B package --file pom.xml
+      run: |
+        mvn -B package --file pom.xml
+        mvn failsafe:integration-test
 
     - name: Upload coverage reports to Codecov with GitHub Action
-      uses: codecov/codecov-action@v2
\ No newline at end of file
+      uses: codecov/codecov-action@v2
diff --git a/pom.xml b/pom.xml
index 1a66d3b..59a06b7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -46,6 +46,7 @@
         <version.jackson>2.14.0</version.jackson>
         <version.commons>3.11</version.commons>
         <version.maven-artifact>3.8.5</version.maven-artifact>
+        <version.socketio>2.1.0</version.socketio>
         <groovy.version>3.0.9</groovy.version>
     </properties>
 
@@ -72,6 +73,11 @@
             <artifactId>okhttp</artifactId>
             <version>${version.okhttp}</version>
         </dependency>
+        <dependency>
+            <groupId>io.socket</groupId>
+            <artifactId>socket.io-client</artifactId>
+            <version>${version.socketio}</version>
+        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
@@ -207,6 +213,19 @@
                     </statelessTestsetReporter>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>3.0.0-M4</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
diff --git a/src/main/java/com/featureprobe/sdk/server/FPConfig.java b/src/main/java/com/featureprobe/sdk/server/FPConfig.java
index e63d3b9..5b830f9 100644
--- a/src/main/java/com/featureprobe/sdk/server/FPConfig.java
+++ b/src/main/java/com/featureprobe/sdk/server/FPConfig.java
@@ -26,6 +26,8 @@ public final class FPConfig {
 
     URL eventUrl;
 
+    URI realtimeUri;
+
     final String location;
 
     final SynchronizerFactory synchronizerFactory;
@@ -49,6 +51,7 @@ protected FPConfig(Builder builder) {
                 builder.httpConfiguration;
         this.synchronizerUrl = builder.synchronizerUrl;
         this.eventUrl = builder.eventUrl;
+        this.realtimeUri = builder.realtimeUri;
         this.startWait = builder.startWait == null ? DEFAULT_START_WAIT : builder.startWait;
     }
 
@@ -74,6 +77,8 @@ public static class Builder {
 
         private URL eventUrl;
 
+        private URI realtimeUri;
+
         private Long startWait;
 
         public Builder() {
@@ -127,6 +132,16 @@ public Builder eventUrl(URL eventUrl) {
             return this;
         }
 
+        public Builder realtimeUri(URI realtimeUri) {
+            this.realtimeUri = realtimeUri;
+            return this;
+        }
+
+        public Builder realtimeUri(String realtimeUri) {
+            this.realtimeUri = URI.create(realtimeUri);
+            return this;
+        }
+
         public Builder startWait(Long startWaitTime, TimeUnit unit) {
             this.startWait = unit.toNanos(startWaitTime);
             return this;
diff --git a/src/main/java/com/featureprobe/sdk/server/FPContext.java b/src/main/java/com/featureprobe/sdk/server/FPContext.java
index aedd3b3..1c19b00 100644
--- a/src/main/java/com/featureprobe/sdk/server/FPContext.java
+++ b/src/main/java/com/featureprobe/sdk/server/FPContext.java
@@ -5,6 +5,7 @@
 
 import java.io.InputStream;
 import java.net.MalformedURLException;
+import java.net.URI;
 import java.net.URL;
 import java.time.Duration;
 import java.util.Objects;
@@ -26,10 +27,14 @@ final class FPContext {
 
     private static final String POST_EVENTS_DATA_API = "/api/events";
 
+    private static final String REALTIME_TOGGLE_UPDATE_API = "/realtime";
+
     private  URL synchronizerUrl;
 
     private  URL eventUrl;
 
+    private URI realtimeUri;
+
     private final String serverSdkKey;
 
     private final Duration refreshInterval;
@@ -52,6 +57,11 @@ final class FPContext {
             } else {
                 this.eventUrl = config.eventUrl;
             }
+            if (Objects.isNull(config.realtimeUri)) {
+                this.realtimeUri = URI.create(config.remoteUri.toString() + REALTIME_TOGGLE_UPDATE_API);
+            } else {
+                this.realtimeUri = config.realtimeUri;
+            }
         } catch (MalformedURLException e) {
             logger.error("construction context error", e);
         }
@@ -74,6 +84,10 @@ public URL getEventUrl() {
         return eventUrl;
     }
 
+    public URI getRealtimeUri() {
+        return realtimeUri;
+    }
+
     public String getServerSdkKey() {
         return serverSdkKey;
     }
diff --git a/src/main/java/com/featureprobe/sdk/server/FeatureProbe.java b/src/main/java/com/featureprobe/sdk/server/FeatureProbe.java
index bcfeea2..803ce6c 100644
--- a/src/main/java/com/featureprobe/sdk/server/FeatureProbe.java
+++ b/src/main/java/com/featureprobe/sdk/server/FeatureProbe.java
@@ -34,6 +34,7 @@ public final class FeatureProbe {
     @VisibleForTesting
     final DataRepository dataRepository;
 
+    @VisibleForTesting
     Synchronizer synchronizer;
 
     @VisibleForTesting
diff --git a/src/main/java/com/featureprobe/sdk/server/PollingSynchronizer.java b/src/main/java/com/featureprobe/sdk/server/PollingSynchronizer.java
index e0d13d6..350f90d 100644
--- a/src/main/java/com/featureprobe/sdk/server/PollingSynchronizer.java
+++ b/src/main/java/com/featureprobe/sdk/server/PollingSynchronizer.java
@@ -4,7 +4,11 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.featureprobe.sdk.server.exceptions.HttpErrorException;
 import com.featureprobe.sdk.server.model.Repository;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import io.socket.client.IO;
+import io.socket.client.Socket;
+import io.socket.engineio.client.transports.WebSocket;
 import okhttp3.Headers;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
@@ -14,6 +18,8 @@
 import java.io.IOException;
 import java.net.URL;
 import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
@@ -24,12 +30,15 @@
 final class PollingSynchronizer implements Synchronizer {
 
     private static final Logger logger = Loggers.SYNCHRONIZER;
-    private static final String GET_SDK_KEY_HEADER = "Authorization";
-    final ObjectMapper mapper = new ObjectMapper();
-    DataRepository dataRepository;
+    private final ObjectMapper mapper = new ObjectMapper();
+    private final DataRepository dataRepository;
     private final Duration refreshInterval;
     private final URL apiUrl;
     private volatile ScheduledFuture<?> worker;
+
+    @VisibleForTesting
+    Socket socket;
+
     private final OkHttpClient httpClient;
     private final Headers headers;
 
@@ -47,14 +56,15 @@ final class PollingSynchronizer implements Synchronizer {
         this.apiUrl = context.getSynchronizerUrl();
         this.dataRepository = dataRepository;
         this.initFuture = new CompletableFuture<>();
-        OkHttpClient.Builder builder = new OkHttpClient.Builder()
+        this.headers = context.getHeaders();
+        this.httpClient = new OkHttpClient.Builder()
                 .connectionPool(context.getHttpConfiguration().connectionPool)
                 .connectTimeout(context.getHttpConfiguration().connectTimeout)
                 .readTimeout(context.getHttpConfiguration().readTimeout)
                 .writeTimeout(context.getHttpConfiguration().writeTimeout)
-                .retryOnConnectionFailure(false);
-        headers = context.getHeaders();
-        httpClient = builder.build();
+                .retryOnConnectionFailure(false)
+                .build();
+        this.socket = connectSocket(context);
     }
 
     @Override
@@ -77,6 +87,10 @@ public void close() throws IOException {
                 worker.cancel(true);
                 worker = null;
             }
+            if (socket != null) {
+                socket.close();
+                socket = null;
+            }
         }
     }
 
@@ -89,8 +103,8 @@ private void poll() {
         try (Response response = httpClient.newCall(request).execute()) {
             String body = response.body().string();
             if (!response.isSuccessful()) {
-                throw new HttpErrorException(String.format("Http request error: code: {}, body: {}:" + response.code(),
-                        response.body()));
+                throw new HttpErrorException(String.format("Http request error: code: %d, body: %s",
+                        response.code(), response.body().toString()));
             }
             logger.debug("Http response: {}", response);
             logger.debug("Http response body: {}", body);
@@ -102,4 +116,30 @@ private void poll() {
             logger.error("Unexpected error from polling processor", e);
         }
     }
+
+    private Socket connectSocket(FPContext context) {
+        IO.Options sioOptions = IO.Options.builder()
+                .setTransports(new String[]{WebSocket.NAME})
+                .setPath(context.getRealtimeUri().getPath())
+                .build();
+        Socket sio = IO.socket(context.getRealtimeUri(), sioOptions);
+
+        sio.on("connect", objects -> {
+            logger.info("connect socketio success");
+            Map<String, String> credentials = new HashMap<>(1);
+            credentials.put("key", context.getServerSdkKey());
+            sio.emit("register", credentials);
+        });
+
+        sio.on("update", objects -> {
+            logger.info("socketio recv update event");
+            poll();
+        });
+
+        sio.on("disconnect", objects -> logger.info("socketio disconnected"));
+
+        sio.on("connect_error", objects -> logger.error("socketio error: {}", objects));
+
+        return sio.connect();
+    }
 }
diff --git a/src/test/groovy/com/featureprobe/sdk/server/PollingSynchronizerIT.groovy b/src/test/groovy/com/featureprobe/sdk/server/PollingSynchronizerIT.groovy
new file mode 100644
index 0000000..cf1a389
--- /dev/null
+++ b/src/test/groovy/com/featureprobe/sdk/server/PollingSynchronizerIT.groovy
@@ -0,0 +1,39 @@
+package com.featureprobe.sdk.server
+
+import ch.qos.logback.classic.Level
+import ch.qos.logback.classic.Logger
+import org.slf4j.LoggerFactory
+import spock.lang.Specification
+
+class PollingSynchronizerIT extends Specification {
+
+    def "Socketio realtime toggle update"() {
+
+        (LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME) as Logger).setLevel(Level.DEBUG)
+
+        given:
+        def config = FPConfig.builder()
+                .pollingMode()
+                .remoteUri("https://featureprobe.io/server")
+                .realtimeUri("https://featureprobe.io/server/realtime")
+                .useMemoryRepository()
+                .build()
+        def featureProbe = new FeatureProbe("server-61db54ecea79824cae3ac38d73f1961d698d0477", config)
+        def repository = featureProbe.dataRepository
+        def socket = (featureProbe.synchronizer as PollingSynchronizer).socket
+        def updateCnt = 0
+        socket.on("update", objects -> updateCnt++)
+
+        sleep(5000)
+
+        featureProbe.close()
+
+        sleep(5000)
+
+        expect:
+        repository.initialized()
+        !socket.connected()
+        updateCnt > 0
+    }
+}
+