diff --git a/README.md b/README.md
index ae155cf..17b4333 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
-Current stable version is __0.4.1-SNAPSHOT__. The full-dpulex RPC over websock is ok, the security level is still disabled until the protocol part will be sabilized.
+Current stable version is __0.4.2-SNAPSHOT__. The full-dpulex RPC over websock is ok, the security level is still disabled until the protocol part will be sabilized.
 
 This is a connection-agnostic, kotlin multiplaftorm library providing full-duplex RPC type binary protocol, effective to work with binary data, such as encrypted data, keys, multimedia, etc. Default implementation uses websockets transport (binary frames) available on all supported platofrms (currently, JS and JVM).
 
@@ -46,7 +46,7 @@ repsitories {
 
 //...
     dependencies {
-        api("net.sergeych:parsec3:0.3.3")
+        api("net.sergeych:parsec3:0.4.2-SNAPSHOT")
     }
 ```
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 5af23b0..2d9f5b9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -10,7 +10,7 @@ plugins {
 }
 
 group = "net.sergeych"
-version = "0.4.1-SNAPSHOT"
+version = "0.4.2-SNAPSHOT"
 
 repositories {
     mavenCentral()
@@ -22,6 +22,7 @@ kotlin {
     jvmToolchain {
         languageVersion.set(JavaLanguageVersion.of("8"))
     }
+
     jvm {
         compilations.all {
             kotlinOptions.jvmTarget = "1.8"
@@ -39,6 +40,10 @@ kotlin {
         }
     }
     sourceSets {
+        all {
+            languageSettings.optIn("kotlinx.serialization.ExperimentalSerializationApi")
+            languageSettings.optIn("kotlinx.coroutines.ExperimentalCoroutinesApi")
+        }
         val commonMain by getting {
             dependencies {
                 implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.3")
@@ -83,9 +88,11 @@ kotlin {
         repositories {
             maven {
                 url = uri("https://maven.universablockchain.com/")
+                val mavenUser: String by project
+                val mavenPassword: String by project
                 credentials {
-                    username = System.getenv("maven_user")
-                    password = System.getenv("maven_password")
+                    username = mavenUser // System.getenv("maven_user")
+                    password = mavenPassword // System.getenv("maven_password")
                 }
             }
         }
diff --git a/src/commonMain/kotlin/net.sergeych.parsec3/AdapterBuilder.kt b/src/commonMain/kotlin/net.sergeych.parsec3/AdapterBuilder.kt
index dd64068..945eb27 100644
--- a/src/commonMain/kotlin/net.sergeych.parsec3/AdapterBuilder.kt
+++ b/src/commonMain/kotlin/net.sergeych.parsec3/AdapterBuilder.kt
@@ -16,7 +16,7 @@ class AdapterBuilder<S : WithAdapter, H : CommandHost<S>>(
     f: AdapterBuilder<S, H>.() -> Unit,
 ) {
 
-    internal var sessionProducer: (suspend () -> S) = { WithAdapter() as S}
+    internal var sessionProducer: (suspend () -> S) = { WithAdapter() as S }
         private set
 
 
@@ -31,6 +31,17 @@ class AdapterBuilder<S : WithAdapter, H : CommandHost<S>>(
         api.on(ca, block)
     }
 
+    val onCancelHandlers = mutableListOf<suspend () -> Unit>()
+
+
+    /**
+     * Set a onCancel handler that will be called upon adapter cancelling. Several adapters
+     * could be registered and will be called in order of registration
+     */
+    fun onCancel(f: suspend () -> Unit) {
+        onCancelHandlers += f
+    }
+
     @Suppress("unused")
     inline fun <reified T : Throwable> addError(code: String, noinline handler: (String?) -> T) {
         exceptionRegistry.register(code, handler)
@@ -41,13 +52,23 @@ class AdapterBuilder<S : WithAdapter, H : CommandHost<S>>(
         exceptionRegistry.putAll(otherRegistry)
     }
 
-    suspend fun createWith(input: Flow<ByteArray>, f: suspend (ByteArray)->Unit ): Adapter<S> {
+    suspend fun createWith(input: Flow<ByteArray>, f: suspend (ByteArray) -> Unit): Adapter<S> {
         val s = sessionProducer()
         return Adapter<S>(
-            s, api, exceptionRegistry) { f(it) }
-            .also { a->
+            s, api, exceptionRegistry
+        ) { f(it) }
+            .also { a ->
                 s._adapter = a
-                globalLaunch { input.collect { a.receiveFrame(it)} }
+                if (onCancelHandlers.isNotEmpty()) {
+                    a.onCancel = {
+                        for (h in onCancelHandlers) try {
+                            h()
+                        } catch (t: Throwable) {
+                            t.printStackTrace()
+                        }
+                    }
+                }
+                globalLaunch { input.collect { a.receiveFrame(it) } }
             }
     }
 
diff --git a/src/commonMain/kotlin/net.sergeych.parsec3/KVStorage.kt b/src/commonMain/kotlin/net.sergeych.parsec3/KVStorage.kt
index aba32f4..0725dcd 100644
--- a/src/commonMain/kotlin/net.sergeych.parsec3/KVStorage.kt
+++ b/src/commonMain/kotlin/net.sergeych.parsec3/KVStorage.kt
@@ -51,7 +51,7 @@ class KVStorageDelegate<T>(
     private var cachedValue: T = defaultValue
     private var cacheReady = false
 
-    operator fun getValue(thisRef: Nothing?, property: KProperty<*>): T {
+    operator fun getValue(thisRef: Any?, property: KProperty<*>): T {
         if (cacheReady) return cachedValue
         val data = storage.get(name(property))
         if (data == null)
@@ -62,7 +62,7 @@ class KVStorageDelegate<T>(
         return cachedValue
     }
 
-    operator fun setValue(thisRef: Nothing?, property: KProperty<*>, value: T) {
+    operator fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
 //        if (!cacheReady || value != cachedValue) {
             cachedValue = value
             cacheReady = true
@@ -83,6 +83,7 @@ class MemoryKVStorage(copyFrom: KVStorage? = null) : KVStorage {
     // is used while underlying is null:
     private val data = mutableMapOf<String, ByteArray>()
 
+    @Suppress("unused")
     fun connectToStorage(other: KVStorage) {
         other.addAll(this)
         underlying = other
@@ -110,10 +111,10 @@ class MemoryKVStorage(copyFrom: KVStorage? = null) : KVStorage {
     }
 
     override val keys: Collection<String>
-        get() = underlying?.let { it.keys } ?: data.keys
+        get() = underlying?.keys ?: data.keys
 
     override fun clear() {
-        underlying?.let { it.clear() } ?: data.clear()
+        underlying?.clear() ?: data.clear()
     }
 
     init {
diff --git a/src/commonMain/kotlin/net.sergeych.parsec3/Parsec3SecureClient.kt b/src/commonMain/kotlin/net.sergeych.parsec3/Parsec3SecureClient.kt
index 9e6eb07..fe0072f 100644
--- a/src/commonMain/kotlin/net.sergeych.parsec3/Parsec3SecureClient.kt
+++ b/src/commonMain/kotlin/net.sergeych.parsec3/Parsec3SecureClient.kt
@@ -1,7 +1,7 @@
 package net.sergeych.parsec3
 
-/**
- * Parsec3 secure adapter.
- * @param transport a parsec3 transport to establish connection with, for example [Parsec3WSClient].
- */
-class Parsec3SecureClient<S : WithAdapter>(transport: Parsec3Transport<WithAdapter>)
\ No newline at end of file
+///**
+// * Parsec3 secure adapter.
+// * @param transport a parsec3 transport to establish connection with, for example [Parsec3WSClient].
+// */
+//class Parsec3SecureClient<S : WithAdapter>(transport: Parsec3Transport<WithAdapter>)
\ No newline at end of file
diff --git a/src/commonTest/kotlin/parsec3/AdapterTest.kt b/src/commonTest/kotlin/parsec3/AdapterTest.kt
index af9e820..23c6d63 100644
--- a/src/commonTest/kotlin/parsec3/AdapterTest.kt
+++ b/src/commonTest/kotlin/parsec3/AdapterTest.kt
@@ -8,6 +8,7 @@ import kotlinx.coroutines.test.runTest
 import net.sergeych.parsec3.*
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertTrue
 
 internal class AdapterTest {
 
@@ -74,6 +75,8 @@ internal class AdapterTest {
             it.register("foo_x") { IllegalArgumentException(it) }
         }
 
+        var b1Cancelled = false
+        var b2Cancelled = false
         val b1 = AdapterBuilder(ApiS1, er) {
             newSession { TestSession("42") }
             on(api.foo) {
@@ -85,6 +88,9 @@ internal class AdapterTest {
             on(ApiS1.ex2) {
                 throw IllegalArgumentException()
             }
+            onCancel {
+                b1Cancelled = true
+            }
         }
         val b2 = AdapterBuilder(ApiS2(), er) {
             on(api.bar) {
@@ -100,6 +106,7 @@ internal class AdapterTest {
                     throw t
                 }
             }
+            onCancel { b2Cancelled = true }
         }
 
         val a1 = b1.createWith(ch21.receiveAsFlow()) {
@@ -122,6 +129,9 @@ internal class AdapterTest {
         ch21.cancel()
         a1.cancel()
         a2.cancel()
+
+        assertTrue { b1Cancelled }
+        assertTrue { b2Cancelled }
     }
 
 }
\ No newline at end of file
diff --git a/src/commonTest/kotlin/parsec3/MemoryKVStorageTest.kt b/src/commonTest/kotlin/parsec3/MemoryKVStorageTest.kt
index 49c90f6..484e6ad 100644
--- a/src/commonTest/kotlin/parsec3/MemoryKVStorageTest.kt
+++ b/src/commonTest/kotlin/parsec3/MemoryKVStorageTest.kt
@@ -1,12 +1,18 @@
 package parsec3
 
 import net.sergeych.mptools.toDump
+import net.sergeych.parsec3.KVStorage
 import net.sergeych.parsec3.MemoryKVStorage
 import net.sergeych.parsec3.stored
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertNull
 
+class TextSt(kvs: KVStorage) {
+    var x: String? by kvs.stored(null)
+}
+
+@Suppress("UNUSED_VARIABLE")
 internal class MemoryKVStorageTest {
 
     @Test
@@ -18,12 +24,20 @@ internal class MemoryKVStorageTest {
         s["foo"] = byteArrayOf(1,2,3)
 
         var bar: String? by s.stored(null)
+        val bal: String? by s.stored(null)
         assertNull(bar)
         bar = "foo"
         println(s.get("bar")?.toDump())
         assertEquals("foo", bar)
-        var foo: String by s.stored("", "bar")
+        val foo: String by s.stored("", "bar")
         assertEquals("foo", foo)
+
+        val t1 = TextSt(s)
+        assertNull(t1.x)
+        t1.x  = "bar"
+        assertEquals("bar",t1.x)
+        val t2 = TextSt(s)
+        assertEquals("bar",t2.x)
 //
 //        var i: Int? by s(defaultValue = 17)
 //        i = 19
diff --git a/src/jvmMain/kotlin/net/sergeych/parsec3/WsServer.kt b/src/jvmMain/kotlin/net/sergeych/parsec3/WsServer.kt
index a605b39..b228ae7 100644
--- a/src/jvmMain/kotlin/net/sergeych/parsec3/WsServer.kt
+++ b/src/jvmMain/kotlin/net/sergeych/parsec3/WsServer.kt
@@ -6,10 +6,7 @@ import io.ktor.server.websocket.*
 import io.ktor.websocket.*
 import net.sergeych.mp_logger.LogTag
 import net.sergeych.mp_logger.warning
-import net.sergeych.unikrypto.DiffieHellman
 import java.time.Duration
-import java.util.concurrent.atomic.AtomicInteger
-import java.util.concurrent.atomic.AtomicLong
 
 /**
  * Creates a ktor server initialization module capable to perform p3 transport layer (not secure).
@@ -52,25 +49,23 @@ fun <S: WithAdapter, H : CommandHost<S>>Application.parsec3TransportServer(
             }
             adapter.close()
         }
-        var totalConnections = AtomicLong(0)
-        var activeConnections = AtomicInteger(0)
 
     }
 }
 
-fun <S: WithAdapter, H : CommandHost<S>>Application.parsec3SecureServer(
-    api: H,
-    exceptionsRegistry: ExceptionsRegistry = ExceptionsRegistry(),
-    path: String = "/api/p3",
-    f: AdapterBuilder<S, H>.() -> Unit,
-) {
-    val log = LogTag("P3WSS")
-//    parsec3TransportServer(api, ex)
-//    install(WebSockets) {
-//        pingPeriod = Duration.ofSeconds(45)
-//        timeout = Duration.ofSeconds(15)
-//        maxFrameSize = Long.MAX_VALUE
-//        masking = false
-//    }
-    val dh = DiffieHellman()
-}
+//fun <S: WithAdapter, H : CommandHost<S>>Application.parsec3SecureServer(
+//    api: H,
+//    exceptionsRegistry: ExceptionsRegistry = ExceptionsRegistry(),
+//    path: String = "/api/p3",
+//    f: AdapterBuilder<S, H>.() -> Unit,
+//) {
+//    val log = LogTag("P3WSS")
+////    parsec3TransportServer(api, ex)
+////    install(WebSockets) {
+////        pingPeriod = Duration.ofSeconds(45)
+////        timeout = Duration.ofSeconds(15)
+////        maxFrameSize = Long.MAX_VALUE
+////        masking = false
+////    }
+//    val dh = DiffieHellman()
+//}
diff --git a/src/jvmTest/kotlin/net/sergeych/parsec3/WsServerKtTest.kt b/src/jvmTest/kotlin/net/sergeych/parsec3/WsServerKtTest.kt
index e19ef82..b8c845f 100644
--- a/src/jvmTest/kotlin/net/sergeych/parsec3/WsServerKtTest.kt
+++ b/src/jvmTest/kotlin/net/sergeych/parsec3/WsServerKtTest.kt
@@ -31,7 +31,7 @@ internal class WsServerKtTest {
     @Test
     fun testWsServer() {
 
-        embeddedServer(Netty, port = 8081) {
+        embeddedServer(Netty, port = 8089) {
             parsec3TransportServer(
                 TestApiServer,
             ) {
@@ -42,7 +42,7 @@ internal class WsServerKtTest {
             }
         }.start(wait = false)
 
-        val client = Parsec3WSClient("ws://localhost:8081/api/p3", TestApiClient) {
+        val client = Parsec3WSClient("ws://localhost:8089/api/p3", TestApiClient) {
             on(api.bar) {
                 "bar:$it"
             }