diff --git a/build.gradle.kts b/build.gradle.kts
index 68b9c44..e4380b5 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -136,6 +136,8 @@ kotlin {
         jvmTest.dependencies {
             implementation(libs.kotest.runner.junit5)
             runtimeOnly(libs.slf4j.simple)
+            implementation(libs.ktor.server.websockets)
+            implementation(libs.ktor.server.test.host)
         }
         jsMain.dependencies {
             implementation(libs.ktor.client.js)
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index fcc9549..8757743 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -35,6 +35,8 @@ ktor-client-logging = { module = "io.ktor:ktor-client-logging", version.ref = "k
 ktor-client-cio = { module = "io.ktor:ktor-client-cio", version.ref = "ktor" }
 ktor-client-js = { module = "io.ktor:ktor-client-js", version.ref = "ktor" }
 ktor-client-mock = { module = "io.ktor:ktor-client-mock", version.ref = "ktor" }
+ktor-server-websockets = { module = "io.ktor:ktor-server-websockets", version.ref = "ktor" }
+ktor-server-test-host = { module = "io.ktor:ktor-server-test-host", version.ref = "ktor" }
 
 kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version = "1.6.2" }
 
diff --git a/src/commonMain/kotlin/ktor/WebsocketLoxoneClient.kt b/src/commonMain/kotlin/ktor/WebsocketLoxoneClient.kt
index 040b428..8753512 100644
--- a/src/commonMain/kotlin/ktor/WebsocketLoxoneClient.kt
+++ b/src/commonMain/kotlin/ktor/WebsocketLoxoneClient.kt
@@ -23,17 +23,20 @@ import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.withTimeout
+import kotlin.jvm.JvmOverloads
 
-class WebsocketLoxoneClient(
-    private val endpoint: LoxoneEndpoint,
+class WebsocketLoxoneClient internal constructor(
+    private val client: HttpClient,
+    private val endpoint: LoxoneEndpoint? = null,
     private val authenticator: LoxoneTokenAuthenticator? = null
 ) : LoxoneClient {
 
-    private val logger = KotlinLogging.logger {}
+    @JvmOverloads constructor(
+        endpoint: LoxoneEndpoint,
+        authenticator: LoxoneTokenAuthenticator? = null
+    ) : this(HttpClient { install(WebSockets) }, endpoint, authenticator)
 
-    private val client = HttpClient {
-        install(WebSockets)
-    }
+    private val logger = KotlinLogging.logger {}
 
     private val webSocketSession = AtomicReference<ClientWebSocketSession?>(null)
 
@@ -74,11 +77,11 @@ class WebsocketLoxoneClient(
         webSocketSession.compareAndSet(
             null,
             client.webSocketSession(
-                host = endpoint.host,
-                port = endpoint.port,
-                path = endpoint.path + WS_PATH,
+                host = endpoint?.host,
+                port = endpoint?.port,
+                path = if (endpoint != null) endpoint.path + WS_PATH else WS_PATH,
                 block = {
-                    url.protocol = if (endpoint.useSsl) URLProtocol.WSS else URLProtocol.WS
+                    url.protocol = if (endpoint?.useSsl == true) URLProtocol.WSS else URLProtocol.WS
                 }
             )
         )
diff --git a/src/jvmTest/kotlin/ktor/WebsocketLoxoneClientTest.kt b/src/jvmTest/kotlin/ktor/WebsocketLoxoneClientTest.kt
new file mode 100644
index 0000000..45fd0e4
--- /dev/null
+++ b/src/jvmTest/kotlin/ktor/WebsocketLoxoneClientTest.kt
@@ -0,0 +1,57 @@
+package cz.smarteon.loxone.ktor
+
+import cz.smarteon.loxone.Codec
+import cz.smarteon.loxone.message.ApiInfo
+import cz.smarteon.loxone.message.MessageHeader
+import cz.smarteon.loxone.message.MessageKind.TEXT
+import cz.smarteon.loxone.message.TestingLoxValues.API_INFO_MSG_VAL
+import cz.smarteon.loxone.message.TestingMessages.okMsg
+import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.shouldBe
+import io.ktor.client.*
+import io.ktor.server.application.*
+import io.ktor.server.testing.*
+import io.ktor.server.websocket.*
+import io.ktor.websocket.*
+import kotlinx.coroutines.channels.consumeEach
+import io.ktor.client.plugins.websocket.WebSockets as ClientWebsockets
+import io.ktor.server.websocket.WebSockets as ServerWebsockets
+
+class WebsocketLoxoneClientTest : StringSpec({
+
+    "should call simple command" {
+        testWebsocket {
+            val client = WebsocketLoxoneClient(this)
+
+            client.callRaw("jdev/cfg/api") shouldBe okMsg("dev/cfg/api", API_INFO_MSG_VAL)
+
+            val response = client.call(ApiInfo.command)
+            response.code shouldBe "200"
+            response.value shouldBe API_INFO_MSG_VAL
+            response.control shouldBe "dev/cfg/api"
+        }
+    }
+
+})
+
+private suspend fun testWebsocket(test: suspend HttpClient.() -> Unit) = testApplication {
+    application { install(ServerWebsockets) }
+
+    routing {
+        webSocketRaw(path = "/ws/rfc6455") {
+            incoming.consumeEach { frame ->
+                if (frame is Frame.Text) {
+                    when (frame.readText()) {
+                        "jdev/cfg/api" -> {
+                            val text = okMsg("dev/cfg/api", API_INFO_MSG_VAL).encodeToByteArray()
+                            send(Frame.Binary(true, Codec.writeHeader(MessageHeader(TEXT, false, text.size.toLong()))))
+                            send(Frame.Text(true, text))
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    createClient { install(ClientWebsockets) }.use { it.test() }
+}