diff --git a/client/src/main/kotlin/http/SessionApi.kt b/client/src/main/kotlin/http/SessionApi.kt
new file mode 100644
index 0000000..75fa1c2
--- /dev/null
+++ b/client/src/main/kotlin/http/SessionApi.kt
@@ -0,0 +1,49 @@
+package http
+
+import http.dto.BeginSessionResponse
+import http.dto.DevCommandRequest
+import javax.swing.JOptionPane
+import kong.unirest.HttpMethod
+import util.DialogUtilNew
+import util.OnlineConstants
+import util.UpdateManager.checkForUpdates
+
+class SessionApi(private val httpClient: HttpClient) {
+    fun beginSession(name: String) {
+        val response =
+            httpClient.doCall<BeginSessionResponse>(
+                HttpMethod.POST,
+                Routes.DEV_COMMAND,
+                DevCommandRequest(name)
+            )
+
+        when (response) {
+            is FailureResponse -> handleBeginSessionFailure(response)
+            is CommunicationError ->
+                DialogUtilNew.showError(
+                    "Error communicating with server: ${response.unirestException.message}"
+                )
+            is SuccessResponse<BeginSessionResponse> -> {
+                // Errr, store the sessionId someplace, then hook back into legacy code somehow to
+                // launch the lobby etc
+                val sessionResponse = response.body
+            }
+        }
+    }
+
+    private fun handleBeginSessionFailure(response: FailureResponse<*>) {
+        when (response.errorCode) {
+            UPDATE_REQUIRED -> {
+                val response =
+                    DialogUtilNew.showQuestion(
+                        "Your client must be updated to connect. Check for updates now?"
+                    )
+
+                if (response == JOptionPane.YES_OPTION) {
+                    checkForUpdates(OnlineConstants.ENTROPY_VERSION_NUMBER)
+                }
+            }
+            else -> DialogUtilNew.showError("An error occurred: ${response.errorMessage}")
+        }
+    }
+}
diff --git a/client/src/main/kotlin/screen/online/PlayOnlineDialog.kt b/client/src/main/kotlin/screen/online/PlayOnlineDialog.kt
index 5b18ffa..d3da9b2 100644
--- a/client/src/main/kotlin/screen/online/PlayOnlineDialog.kt
+++ b/client/src/main/kotlin/screen/online/PlayOnlineDialog.kt
@@ -9,6 +9,7 @@ import javax.swing.border.EmptyBorder
 import screen.ScreenCache
 import screen.SimpleDialog
 import util.DialogUtilNew
+import util.Globals
 
 class PlayOnlineDialog : SimpleDialog() {
     private val lblName = JLabel("Name")
@@ -39,7 +40,15 @@ class PlayOnlineDialog : SimpleDialog() {
     }
 
     private fun beginSession() {
-        // TODO - write me
+        dispose()
+
+        ScreenCache.showConnectingDialog()
+
+        try {
+            Globals.sessionApi.beginSession(textFieldUsername.text)
+        } finally {
+            ScreenCache.dismissConnectingDialog()
+        }
     }
 
     override fun okPressed() {
diff --git a/client/src/main/kotlin/util/Globals.kt b/client/src/main/kotlin/util/Globals.kt
index ce95e81..7a6f6d9 100644
--- a/client/src/main/kotlin/util/Globals.kt
+++ b/client/src/main/kotlin/util/Globals.kt
@@ -3,10 +3,12 @@ package util
 import http.DevApi
 import http.HealthCheckApi
 import http.HttpClient
+import http.SessionApi
 
 object Globals {
     private val baseUrl = "http://localhost:8080"
     private val httpClient = HttpClient(baseUrl)
     val healthCheckApi = HealthCheckApi(httpClient)
     val devApi = DevApi(httpClient)
+    val sessionApi = SessionApi(httpClient)
 }
diff --git a/core/src/main/java/util/XmlConstants.java b/core/src/main/java/util/XmlConstants.java
index 5ffc9b7..8078f39 100644
--- a/core/src/main/java/util/XmlConstants.java
+++ b/core/src/main/java/util/XmlConstants.java
@@ -35,7 +35,6 @@ public interface XmlConstants
 	public static final String RESPONSE_TAG_STATISTICS_NOTIFICATION = "StatisticsNotification";
 	
 	//Server responses
-	public static final String RESPONSE_TAG_UPDATE_AVAILABLE = "UpdateAvailable";
 	public static final String RESPONSE_TAG_KICK_OFF = "KickOff";
 	public static final String RESPONSE_TAG_CHANGE_PASSWORD = "ChangePasswordResponse";
 	public static final String RESPONSE_TAG_CONNECT_SUCCESS = "ConnectSuccess";
diff --git a/server/src/main/java/util/XmlBuilderServer.java b/server/src/main/java/util/XmlBuilderServer.java
index 3bd99ff..7050833 100644
--- a/server/src/main/java/util/XmlBuilderServer.java
+++ b/server/src/main/java/util/XmlBuilderServer.java
@@ -36,17 +36,6 @@ public static Document getKickOffResponse(String username, String reason)
 		return response;
 	}
 	
-	public static Document getUpdateAvailableResponse(long fileSize, String versionNumber)
-	{
-		Document response = XmlUtil.factoryNewDocument();
-		Element rootElement = response.createElement(RESPONSE_TAG_UPDATE_AVAILABLE);
-		rootElement.setAttribute("FileSize", "" + fileSize);
-		rootElement.setAttribute("VersionNumber", versionNumber);
-		
-		response.appendChild(rootElement);
-		return response;
-	}
-	
 	public static Document getChangePasswordResponse(String username, String oldPass, String newPass)
 	{
 		String error = AccountUtil.changePassword(username, oldPass, newPass);