diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
new file mode 100644
index 00000000..6b567ad4
--- /dev/null
+++ b/.github/workflows/e2e-tests.yml
@@ -0,0 +1,78 @@
+# E2E Tests for analytics-java
+# Copy this file to: analytics-java/.github/workflows/e2e-tests.yml
+#
+# This workflow:
+# 1. Checks out the SDK and sdk-e2e-tests repos
+# 2. Builds the SDK and e2e-cli
+# 3. Runs the e2e test suite
+
+name: E2E Tests
+
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+  workflow_dispatch: # Allow manual trigger
+
+jobs:
+  e2e-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout SDK
+        uses: actions/checkout@v4
+        with:
+          path: sdk
+
+      - name: Checkout sdk-e2e-tests
+        uses: actions/checkout@v4
+        with:
+          repository: segmentio/sdk-e2e-tests
+          path: sdk-e2e-tests
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '11'
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Build Java SDK and e2e-cli
+        working-directory: sdk
+        run: mvn package -pl e2e-cli -am -DskipTests
+
+      - name: Find e2e-cli jar
+        id: find-jar
+        working-directory: sdk
+        run: |
+          JAR_PATH=$(find e2e-cli/target -name "e2e-cli-*-jar-with-dependencies.jar" | head -1)
+          echo "jar_path=$JAR_PATH" >> $GITHUB_OUTPUT
+
+      - name: Install sdk-e2e-tests dependencies
+        working-directory: sdk-e2e-tests
+        run: npm ci
+
+      - name: Build sdk-e2e-tests
+        working-directory: sdk-e2e-tests
+        run: npm run build
+
+      - name: Run E2E tests
+        working-directory: sdk-e2e-tests
+        env:
+          CLI_COMMAND: java -jar ${{ github.workspace }}/sdk/${{ steps.find-jar.outputs.jar_path }}
+          E2E_TEST_SUITES: basic,retry
+          # E2E_TEST_SKIP: exponential-backoff  # skip specific test files if needed
+        run: npm test
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: e2e-test-results
+          path: sdk-e2e-tests/test-results/
+          if-no-files-found: ignore
diff --git a/e2e-cli/README.md b/e2e-cli/README.md
new file mode 100644
index 00000000..b319749e
--- /dev/null
+++ b/e2e-cli/README.md
@@ -0,0 +1,54 @@
+# analytics-java e2e-cli
+
+E2E test CLI for the [analytics-java](https://github.com/segmentio/analytics-java) SDK. Accepts a JSON input describing events and SDK configuration, sends them through the real SDK, and outputs results as JSON.
+
+Built with Kotlin (JVM) and packaged as a fat jar via Maven.
+
+## Setup
+
+```bash
+mvn package -pl e2e-cli -am
+```
+
+## Usage
+
+```bash
+java -jar e2e-cli/target/e2e-cli-*-jar-with-dependencies.jar --input '{"writeKey":"...", ...}'
+```
+
+## Input Format
+
+```jsonc
+{
+  "writeKey": "your-write-key",       // required
+  "apiHost": "https://...",           // optional — SDK default if omitted
+  "sequences": [                      // required — event sequences to send
+    {
+      "delayMs": 0,
+      "events": [
+        { "type": "track", "event": "Test", "userId": "user-1" }
+      ]
+    }
+  ],
+  "config": {                         // optional
+    "flushAt": 250,
+    "flushInterval": 10000,
+    "maxRetries": 3,
+    "timeout": 15
+  }
+}
+```
+
+Note: Java is a server-side SDK — there is no CDN settings fetch, so `cdnHost` does not apply.
+
+## Output Format
+
+```json
+{ "success": true, "sentBatches": 1 }
+```
+
+On failure:
+
+```json
+{ "success": false, "error": "description", "sentBatches": 0 }
+```
diff --git a/e2e-cli/pom.xml b/e2e-cli/pom.xml
new file mode 100644
index 00000000..b5782b8f
--- /dev/null
+++ b/e2e-cli/pom.xml
@@ -0,0 +1,91 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <artifactId>analytics-parent</artifactId>
+    <groupId>com.segment.analytics.java</groupId>
+    <version>3.5.5-SNAPSHOT</version>
+  </parent>
+
+  <groupId>com.segment.analytics.java</groupId>
+  <artifactId>e2e-cli</artifactId>
+  <version>3.5.5-SNAPSHOT</version>
+  <name>Analytics Java E2E CLI</name>
+
+  <description>E2E testing CLI for Segment Analytics for Java.</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.jetbrains.kotlin</groupId>
+      <artifactId>kotlin-stdlib</artifactId>
+      <version>${kotlin.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.segment.analytics.java</groupId>
+      <artifactId>analytics</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.jetbrains.kotlinx</groupId>
+      <artifactId>kotlinx-serialization-json</artifactId>
+      <version>1.4.1</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <sourceDirectory>src/main/kotlin</sourceDirectory>
+
+    <plugins>
+      <plugin>
+        <artifactId>kotlin-maven-plugin</artifactId>
+        <groupId>org.jetbrains.kotlin</groupId>
+        <version>${kotlin.version}</version>
+        <configuration>
+          <compilerPlugins>
+            <plugin>kotlinx-serialization</plugin>
+          </compilerPlugins>
+        </configuration>
+        <dependencies>
+          <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-maven-serialization</artifactId>
+            <version>${kotlin.version}</version>
+          </dependency>
+        </dependencies>
+        <executions>
+          <execution>
+            <id>compile</id>
+            <phase>compile</phase>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <configuration>
+          <descriptorRefs>
+            <descriptorRef>jar-with-dependencies</descriptorRef>
+          </descriptorRefs>
+          <archive>
+            <manifest>
+              <mainClass>cli.MainKt</mainClass>
+            </manifest>
+          </archive>
+        </configuration>
+        <executions>
+          <execution>
+            <phase>package</phase>
+            <goals>
+              <goal>single</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/e2e-cli/src/main/kotlin/cli/Main.kt b/e2e-cli/src/main/kotlin/cli/Main.kt
new file mode 100644
index 00000000..6db10cbd
--- /dev/null
+++ b/e2e-cli/src/main/kotlin/cli/Main.kt
@@ -0,0 +1,159 @@
+package cli
+
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import com.segment.analytics.Analytics
+import com.segment.analytics.Callback
+import com.segment.analytics.messages.*
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.atomic.AtomicBoolean
+
+data class CLIOutput(
+    val success: Boolean,
+    val error: String? = null,
+    val sentBatches: Int = 0
+)
+
+data class CLIConfig(
+    val flushAt: Int? = null,
+    val flushInterval: Long? = null,
+    val maxRetries: Int? = null,
+    val timeout: Int? = null
+)
+
+data class EventSequence(
+    val delayMs: Long = 0,
+    val events: List<Map<String, Any>>
+)
+
+data class CLIInput(
+    val writeKey: String,
+    val apiHost: String,
+    val sequences: List<EventSequence>,
+    val config: CLIConfig? = null
+)
+
+private val gson = Gson()
+
+fun main(args: Array<String>) {
+    var output = CLIOutput(success = false, error = "Unknown error")
+
+    try {
+        // Parse --input argument
+        val inputIndex = args.indexOf("--input")
+        if (inputIndex == -1 || inputIndex + 1 >= args.size) {
+            throw IllegalArgumentException("Missing required --input argument")
+        }
+
+        val inputJson = args[inputIndex + 1]
+        val input = gson.fromJson(inputJson, CLIInput::class.java)
+
+        val flushAt = input.config?.flushAt ?: 20
+        val flushIntervalMs = input.config?.flushInterval ?: 10000L
+
+        val flushLatch = CountDownLatch(1)
+        val hasError = AtomicBoolean(false)
+        var errorMessage: String? = null
+
+        val analytics = Analytics.builder(input.writeKey)
+            .endpoint(input.apiHost)
+            .flushQueueSize(flushAt)
+            .flushInterval(maxOf(flushIntervalMs, 1000L), TimeUnit.MILLISECONDS)
+            .callback(object : Callback {
+                override fun success(message: Message?) {
+                    // Event sent successfully
+                }
+
+                override fun failure(message: Message?, throwable: Throwable?) {
+                    hasError.set(true)
+                    errorMessage = throwable?.message
+                }
+            })
+            .build()
+
+        // Process event sequences
+        for (seq in input.sequences) {
+            if (seq.delayMs > 0) {
+                Thread.sleep(seq.delayMs)
+            }
+
+            for (event in seq.events) {
+                sendEvent(analytics, event)
+            }
+        }
+
+        // Flush and shutdown
+        analytics.flush()
+        analytics.shutdown()
+
+        output = if (hasError.get()) {
+            CLIOutput(success = false, error = errorMessage, sentBatches = 0)
+        } else {
+            CLIOutput(success = true, sentBatches = 1)
+        }
+
+    } catch (e: Exception) {
+        output = CLIOutput(success = false, error = e.message ?: e.toString())
+    }
+
+    println(gson.toJson(output))
+}
+
+fun sendEvent(analytics: Analytics, event: Map<String, Any>) {
+    val type = event["type"] as? String
+        ?: throw IllegalArgumentException("Event missing 'type' field")
+
+    val userId = event["userId"] as? String ?: ""
+    val anonymousId = event["anonymousId"] as? String
+    val messageId = event["messageId"] as? String
+    @Suppress("UNCHECKED_CAST")
+    val traits = event["traits"] as? Map<String, Any> ?: emptyMap()
+    @Suppress("UNCHECKED_CAST")
+    val properties = event["properties"] as? Map<String, Any> ?: emptyMap()
+    val eventName = event["event"] as? String
+    val name = event["name"] as? String
+    val groupId = event["groupId"] as? String
+    val previousId = event["previousId"] as? String
+
+    val messageBuilder: MessageBuilder<*, *> = when (type) {
+        "identify" -> {
+            IdentifyMessage.builder().apply {
+                traits(traits)
+            }
+        }
+        "track" -> {
+            TrackMessage.builder(eventName ?: "Unknown Event").apply {
+                properties(properties)
+            }
+        }
+        "page" -> {
+            PageMessage.builder(name ?: "Unknown Page").apply {
+                properties(properties)
+            }
+        }
+        "screen" -> {
+            ScreenMessage.builder(name ?: "Unknown Screen").apply {
+                properties(properties)
+            }
+        }
+        "alias" -> {
+            AliasMessage.builder(previousId ?: "")
+        }
+        "group" -> {
+            GroupMessage.builder(groupId ?: "").apply {
+                traits(traits)
+            }
+        }
+        else -> throw IllegalArgumentException("Unknown event type: $type")
+    }
+
+    if (userId.isNotEmpty()) {
+        messageBuilder.userId(userId)
+    }
+    if (anonymousId != null) {
+        messageBuilder.anonymousId(anonymousId)
+    }
+
+    analytics.enqueue(messageBuilder)
+}
diff --git a/pom.xml b/pom.xml
index 70cfe8b4..d873d8ba 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,6 +26,7 @@
     <module>analytics-sample</module>
     <module>analytics-cli</module>
     <module>analytics-spring-boot-starter</module>
+    <module>e2e-cli</module>
   </modules>
 
   <properties>