diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 4673345b..cec4f040 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -26,10 +26,10 @@ jobs:
     needs: [authorize]
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up JDK 8
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           java-version: '8'
           distribution: 'zulu'
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a00f4518..defc5257 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,10 +14,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up JDK 8
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           java-version: '8'
           distribution: 'zulu'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c92c6c0..1f539dae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,17 @@
+## [2.40.1](https://github.com/amplitude/Amplitude-Android/compare/v2.40.0...v2.40.1) (2024-04-17)
+
+
+### Bug Fixes
+
+* always run middleware flush on updateServer ([#400](https://github.com/amplitude/Amplitude-Android/issues/400)) ([fbee357](https://github.com/amplitude/Amplitude-Android/commit/fbee357d6ba9eb540101cf09393f7eebafdfd49d))
+
+# [2.40.0](https://github.com/amplitude/Amplitude-Android/compare/v2.39.9...v2.40.0) (2024-04-17)
+
+
+### Features
+
+* middleware session replay integration ([#399](https://github.com/amplitude/Amplitude-Android/issues/399)) ([28bbbe6](https://github.com/amplitude/Amplitude-Android/commit/28bbbe6ad2d0a0fe6424645e6105ecb8c2be7a4f))
+
 ## [2.39.9](https://github.com/amplitude/Amplitude-Android/compare/v2.39.8...v2.39.9) (2024-02-27)
 
 
diff --git a/gradle.properties b/gradle.properties
index 73058224..42f81b00 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
-ARTIFACT_VERSION=2.39.9
+ARTIFACT_VERSION=2.40.1
 ARTIFACT_GROUP=com.amplitude
 
 POM_PACKAGING=aar
diff --git a/src/main/java/com/amplitude/api/AmplitudeClient.java b/src/main/java/com/amplitude/api/AmplitudeClient.java
index c90b53e3..1b027eed 100644
--- a/src/main/java/com/amplitude/api/AmplitudeClient.java
+++ b/src/main/java/com/amplitude/api/AmplitudeClient.java
@@ -738,6 +738,10 @@ public void run() {
         return this;
     }
 
+    public Boolean getOptOut() {
+        return optOut;
+    }
+
     /**
      * Library name is default as `amplitude-android`.
      * Notice: You will only want to set it when following conditions are met.
@@ -2154,6 +2158,9 @@ protected void updateServer(boolean limit) {
             return;
         }
 
+        // Flush middleware
+        middlewareRunner.flush();
+
         // if returning out of this block, always be sure to set uploadingCurrently to false!!
         if (!uploadingCurrently.getAndSet(true)) {
             long totalEventCount = dbHelper.getTotalEventCount();
diff --git a/src/main/java/com/amplitude/api/MiddlewareExtended.java b/src/main/java/com/amplitude/api/MiddlewareExtended.java
new file mode 100644
index 00000000..0c929c48
--- /dev/null
+++ b/src/main/java/com/amplitude/api/MiddlewareExtended.java
@@ -0,0 +1,5 @@
+package com.amplitude.api;
+
+interface MiddlewareExtended extends Middleware {
+	void flush();
+}
\ No newline at end of file
diff --git a/src/main/java/com/amplitude/api/MiddlewareRunner.java b/src/main/java/com/amplitude/api/MiddlewareRunner.java
index ac5a44d3..73f5fb34 100644
--- a/src/main/java/com/amplitude/api/MiddlewareRunner.java
+++ b/src/main/java/com/amplitude/api/MiddlewareRunner.java
@@ -44,4 +44,12 @@ public void run(MiddlewarePayload payload, MiddlewareNext next) {
         List<Middleware> middlewareList = new ArrayList<>(this.middlewares);
         runMiddlewares(middlewareList, payload, next);
     }
+
+    void flush() {
+        for (Middleware middleware : middlewares) {
+            if (middleware instanceof MiddlewareExtended) {
+                ((MiddlewareExtended) middleware).flush();
+            }
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/test/java/com/amplitude/api/MiddlewareRunnerTest.java b/src/test/java/com/amplitude/api/MiddlewareRunnerTest.java
index d70dd2fe..485aaf95 100644
--- a/src/test/java/com/amplitude/api/MiddlewareRunnerTest.java
+++ b/src/test/java/com/amplitude/api/MiddlewareRunnerTest.java
@@ -12,6 +12,8 @@
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.util.concurrent.atomic.AtomicInteger;
+
 @RunWith(AndroidJUnit4.class)
 @Config(manifest= Config.NONE)
 public class MiddlewareRunnerTest {
@@ -79,4 +81,29 @@ public void run(MiddlewarePayload payload, MiddlewareNext next) {
         assertEquals(event.getString("user_id"), middlewareUser);
     }
 
+    @Test
+    public void testMiddlewareFlush() throws JSONException {
+        AtomicInteger runCount = new AtomicInteger(0);
+        AtomicInteger flushCount = new AtomicInteger(0);
+
+        MiddlewareExtended flushMiddleware = new MiddlewareExtended() {
+            @Override
+            public void run(MiddlewarePayload payload, MiddlewareNext next) {
+                runCount.incrementAndGet();
+            }
+
+            @Override
+            public void flush() {
+                flushCount.incrementAndGet();
+            }
+        };
+
+        middlewareRunner.add(flushMiddleware);
+
+        middlewareRunner.flush();
+
+        assertEquals(flushCount.get(), 1);
+        assertEquals(runCount.get(), 0);
+    }
+
 }