diff --git a/DevTools/IPCCompiler/main.cpp b/DevTools/IPCCompiler/main.cpp
index 87d140bba3..27cc6e3395 100644
--- a/DevTools/IPCCompiler/main.cpp
+++ b/DevTools/IPCCompiler/main.cpp
@@ -27,6 +27,7 @@ struct Message {
 
 struct Endpoint {
     String name;
+    int magic;
     Vector<Message> messages;
 };
 
@@ -177,6 +178,13 @@ int main(int argc, char** argv)
         consume_whitespace();
         endpoints.last().name = extract_while([](char ch) { return !isspace(ch); });
         consume_whitespace();
+        consume_specific('=');
+        consume_whitespace();
+        auto magic_string = extract_while([](char ch) { return !isspace(ch) && ch != '{'; });
+        bool ok;
+        endpoints.last().magic = magic_string.to_int(ok);
+        ASSERT(ok);
+        consume_whitespace();
         consume_specific('{');
         parse_messages();
         consume_specific('}');
@@ -244,17 +252,20 @@ int main(int argc, char** argv)
             return builder.to_string();
         };
 
-        auto do_message = [&](const String& name, const Vector<Parameter>& parameters, String response_type = {}) {
+        auto do_message = [&](const String& name, const Vector<Parameter>& parameters, const String& response_type = {}) {
             dbg() << "class " << name << " final : public IMessage {";
             dbg() << "public:";
             if (!response_type.is_null())
                 dbg() << "    typedef class " << response_type << " ResponseType;";
             dbg() << "    " << constructor_for_message(name, parameters);
             dbg() << "    virtual ~" << name << "() override {}";
+            dbg() << "    virtual i32 endpoint_magic() const override { return " << endpoint.magic << "; }";
+            dbg() << "    static i32 static_endpoint_magic() { return " << endpoint.magic << "; }";
             dbg() << "    virtual i32 id() const override { return (int)MessageID::" << name << "; }";
             dbg() << "    static i32 static_message_id() { return (int)MessageID::" << name << "; }";
             dbg() << "    virtual String name() const override { return \"" << endpoint.name << "::" << name << "\"; }";
-            dbg() << "    static OwnPtr<" << name << "> decode(BufferStream& stream)";
+            dbg() << "    static String static_name() { return \"" << endpoint.name << "::" << name << "\"; }";
+            dbg() << "    static OwnPtr<" << name << "> decode(BufferStream& stream, size_t& size_in_bytes)";
             dbg() << "    {";
 
             if (parameters.is_empty())
@@ -278,6 +289,7 @@ int main(int argc, char** argv)
                 if (i != parameters.size() - 1)
                     builder.append(", ");
             }
+            dbg() << "        size_in_bytes = stream.offset();";
             dbg() << "        return make<" << name << ">(" << builder.to_string() << ");";
             dbg() << "    }";
             dbg() << "    virtual ByteBuffer encode() const override";
@@ -285,6 +297,7 @@ int main(int argc, char** argv)
             // FIXME: Support longer messages:
             dbg() << "        auto buffer = ByteBuffer::create_uninitialized(1024);";
             dbg() << "        BufferStream stream(buffer);";
+            dbg() << "        stream << endpoint_magic();";
             dbg() << "        stream << (int)MessageID::" << name << ";";
             for (auto& parameter : parameters) {
                 dbg() << "        stream << m_" << parameter.name << ";";
@@ -317,17 +330,24 @@ int main(int argc, char** argv)
         dbg() << "public:";
         dbg() << "    " << endpoint.name << "Endpoint() {}";
         dbg() << "    virtual ~" << endpoint.name << "Endpoint() override {}";
+        dbg() << "    static int static_magic() { return " << endpoint.magic << "; }";
+        dbg() << "    virtual int magic() const override { return " << endpoint.magic << "; }";
+        dbg() << "    static String static_name() { return \"" << endpoint.name << "\"; };";
         dbg() << "    virtual String name() const override { return \"" << endpoint.name << "\"; };";
-        dbg() << "    static OwnPtr<IMessage> decode_message(const ByteBuffer& buffer)";
+        dbg() << "    static OwnPtr<IMessage> decode_message(const ByteBuffer& buffer, size_t& size_in_bytes)";
         dbg() << "    {";
         dbg() << "        BufferStream stream(const_cast<ByteBuffer&>(buffer));";
+        dbg() << "        i32 message_endpoint_magic = 0;";
+        dbg() << "        stream >> message_endpoint_magic;";
+        dbg() << "        if (message_endpoint_magic != " << endpoint.magic << ")";
+        dbg() << "            return nullptr;";
         dbg() << "        i32 message_id = 0;";
         dbg() << "        stream >> message_id;";
         dbg() << "        switch (message_id) {";
         for (auto& message : endpoint.messages) {
             auto do_decode_message = [&](const String& name) {
                 dbg() << "        case (int)" << endpoint.name << "::MessageID::" << name << ":";
-                dbg() << "            return " << endpoint.name << "::" << name << "::decode(stream);";
+                dbg() << "            return " << endpoint.name << "::" << name << "::decode(stream, size_in_bytes);";
             };
             do_decode_message(message.name);
             if (message.is_synchronous)
@@ -383,7 +403,7 @@ int main(int argc, char** argv)
 
 #ifdef DEBUG
     for (auto& endpoint : endpoints) {
-        dbg() << "Endpoint: '" << endpoint.name << "'";
+        dbg() << "Endpoint: '" << endpoint.name << "' (magic: " << endpoint.magic << ")";
         for (auto& message : endpoint.messages) {
             dbg() << "  Message: '" << message.name << "'";
             dbg() << "    Sync: " << message.is_synchronous;
diff --git a/Libraries/LibAudio/AClientConnection.cpp b/Libraries/LibAudio/AClientConnection.cpp
index 6ca9c2e2c0..ea18bd8115 100644
--- a/Libraries/LibAudio/AClientConnection.cpp
+++ b/Libraries/LibAudio/AClientConnection.cpp
@@ -3,7 +3,7 @@
 #include <SharedBuffer.h>
 
 AClientConnection::AClientConnection()
-    : ConnectionNG("/tmp/asportal")
+    : ConnectionNG(*this, "/tmp/asportal")
 {
 }
 
@@ -76,3 +76,7 @@ int AClientConnection::get_playing_buffer()
 {
     return send_sync<AudioServer::GetPlayingBuffer>()->buffer_id();
 }
+
+void AClientConnection::handle(const AudioClient::FinishedPlayingBuffer&)
+{
+}
diff --git a/Libraries/LibAudio/AClientConnection.h b/Libraries/LibAudio/AClientConnection.h
index 3d2089a57d..87ec1b4eaa 100644
--- a/Libraries/LibAudio/AClientConnection.h
+++ b/Libraries/LibAudio/AClientConnection.h
@@ -1,11 +1,13 @@
 #pragma once
 
+#include <AudioServer/AudioClientEndpoint.h>
 #include <AudioServer/AudioServerEndpoint.h>
 #include <LibCore/CoreIPCClient.h>
 
 class ABuffer;
 
-class AClientConnection : public IPC::Client::ConnectionNG<AudioServerEndpoint> {
+class AClientConnection : public IPC::Client::ConnectionNG<AudioClientEndpoint, AudioServerEndpoint>
+    , public AudioClientEndpoint {
     C_OBJECT(AClientConnection)
 public:
     AClientConnection();
@@ -26,4 +28,7 @@ public:
 
     void set_paused(bool paused);
     void clear_buffer(bool paused = false);
+
+private:
+    virtual void handle(const AudioClient::FinishedPlayingBuffer&) override;
 };
diff --git a/Libraries/LibCore/CoreIPCClient.h b/Libraries/LibCore/CoreIPCClient.h
index d21cc9ba9e..0aea1195ae 100644
--- a/Libraries/LibCore/CoreIPCClient.h
+++ b/Libraries/LibCore/CoreIPCClient.h
@@ -246,11 +246,12 @@ namespace Client {
         int m_my_client_id { -1 };
     };
 
-    template<typename Endpoint>
+    template<typename LocalEndpoint, typename PeerEndpoint>
     class ConnectionNG : public CObject {
     public:
-        ConnectionNG(const StringView& address)
-            : m_connection(CLocalSocket::construct(this))
+        ConnectionNG(LocalEndpoint& local_endpoint, const StringView& address)
+            : m_local_endpoint(local_endpoint)
+            , m_connection(CLocalSocket::construct(this))
             , m_notifier(CNotifier::construct(m_connection->fd(), CNotifier::Read, this))
         {
             // We want to rate-limit our clients
@@ -312,8 +313,7 @@ namespace Client {
                 }
                 ASSERT(rc > 0);
                 ASSERT(FD_ISSET(m_connection->fd(), &rfds));
-                bool success = drain_messages_from_server();
-                if (!success)
+                if (!drain_messages_from_server())
                     return nullptr;
                 for (ssize_t i = 0; i < m_unprocessed_messages.size(); ++i) {
                     if (m_unprocessed_messages[i]->id() == MessageType::static_message_id()) {
@@ -358,30 +358,42 @@ namespace Client {
     private:
         bool drain_messages_from_server()
         {
+            Vector<u8> bytes;
             for (;;) {
                 u8 buffer[4096];
                 ssize_t nread = recv(m_connection->fd(), buffer, sizeof(buffer), MSG_DONTWAIT);
                 if (nread < 0) {
-                    if (errno == EAGAIN) {
-                        return true;
-                    }
+                    if (errno == EAGAIN)
+                        break;
                     perror("read");
                     exit(1);
                     return false;
                 }
                 if (nread == 0) {
                     dbg() << "EOF on IPC fd";
+                    // FIXME: Dying is definitely not always appropriate!
                     exit(1);
                     return false;
                 }
-
-                auto message = Endpoint::decode_message(ByteBuffer::wrap(buffer, sizeof(buffer)));
-                ASSERT(message);
-
-                m_unprocessed_messages.append(move(message));
+                bytes.append(buffer, nread);
             }
+
+            size_t decoded_bytes = 0;
+            for (size_t index = 0; index < (size_t)bytes.size(); index += decoded_bytes) {
+                auto remaining_bytes = ByteBuffer::wrap(bytes.data() + index, bytes.size() - index);
+                if (auto message = LocalEndpoint::decode_message(remaining_bytes, decoded_bytes)) {
+                    m_local_endpoint.handle(*message);
+                } else if (auto message = PeerEndpoint::decode_message(remaining_bytes, decoded_bytes)) {
+                    m_unprocessed_messages.append(move(message));
+                } else {
+                    ASSERT_NOT_REACHED();
+                }
+                ASSERT(decoded_bytes);
+            }
+            return true;
         }
 
+        LocalEndpoint& m_local_endpoint;
         RefPtr<CLocalSocket> m_connection;
         RefPtr<CNotifier> m_notifier;
         Vector<OwnPtr<IMessage>> m_unprocessed_messages;
diff --git a/Libraries/LibCore/CoreIPCServer.h b/Libraries/LibCore/CoreIPCServer.h
index e4b7a0ae5b..af65613fe4 100644
--- a/Libraries/LibCore/CoreIPCServer.h
+++ b/Libraries/LibCore/CoreIPCServer.h
@@ -256,7 +256,7 @@ namespace Server {
             , m_client_id(client_id)
         {
             add_child(socket);
-            m_socket->on_ready_to_read = [this] { drain_client(); };
+            m_socket->on_ready_to_read = [this] { drain_messages_from_client(); };
         }
 
         virtual ~ConnectionNG() override
@@ -287,15 +287,16 @@ namespace Server {
             ASSERT(nwritten == buffer.size());
         }
 
-        void drain_client()
+        void drain_messages_from_client()
         {
-            unsigned messages_received = 0;
+            Vector<u8> bytes;
             for (;;) {
                 u8 buffer[4096];
                 ssize_t nread = recv(m_socket->fd(), buffer, sizeof(buffer), MSG_DONTWAIT);
                 if (nread == 0 || (nread == -1 && errno == EAGAIN)) {
-                    if (!messages_received) {
+                    if (bytes.is_empty()) {
                         CEventLoop::current().post_event(*this, make<DisconnectedEvent>(client_id()));
+                        return;
                     }
                     break;
                 }
@@ -303,17 +304,21 @@ namespace Server {
                     perror("recv");
                     ASSERT_NOT_REACHED();
                 }
-                auto message = m_endpoint.decode_message(ByteBuffer::wrap(buffer, nread));
+                bytes.append(buffer, nread);
+            }
+
+            size_t decoded_bytes = 0;
+            for (size_t index = 0; index < (size_t)bytes.size(); index += decoded_bytes) {
+                auto remaining_bytes = ByteBuffer::wrap(bytes.data() + index, bytes.size() - index);
+                auto message = Endpoint::decode_message(remaining_bytes, decoded_bytes);
                 if (!message) {
-                    dbg() << "drain_client: Endpoint didn't recognize message";
+                    dbg() << "drain_messages_from_client: Endpoint didn't recognize message";
                     did_misbehave();
                     return;
                 }
-                ++messages_received;
-
-                auto response = m_endpoint.handle(*message);
-                if (response)
+                if (auto response = m_endpoint.handle(*message))
                     post_message(*response);
+                ASSERT(decoded_bytes);
             }
         }
 
diff --git a/Libraries/LibIPC/IEndpoint.h b/Libraries/LibIPC/IEndpoint.h
index e0098f773d..1468f68c32 100644
--- a/Libraries/LibIPC/IEndpoint.h
+++ b/Libraries/LibIPC/IEndpoint.h
@@ -13,6 +13,7 @@ class IEndpoint {
 public:
     virtual ~IEndpoint();
 
+    virtual int magic() const = 0;
     virtual String name() const = 0;
     virtual OwnPtr<IMessage> handle(const IMessage&) = 0;
 
diff --git a/Libraries/LibIPC/IMessage.h b/Libraries/LibIPC/IMessage.h
index 6a0a81b1e1..813b4f528e 100644
--- a/Libraries/LibIPC/IMessage.h
+++ b/Libraries/LibIPC/IMessage.h
@@ -7,6 +7,7 @@ class IMessage {
 public:
     virtual ~IMessage();
 
+    virtual int endpoint_magic() const = 0;
     virtual int id() const = 0;
     virtual String name() const = 0;
     virtual ByteBuffer encode() const = 0;
diff --git a/Servers/AudioServer/ASClientConnection.cpp b/Servers/AudioServer/ASClientConnection.cpp
index 47595c458d..e6704db19c 100644
--- a/Servers/AudioServer/ASClientConnection.cpp
+++ b/Servers/AudioServer/ASClientConnection.cpp
@@ -1,10 +1,9 @@
 #include "ASClientConnection.h"
 #include "ASMixer.h"
-
+#include "AudioClientEndpoint.h"
 #include <LibAudio/ABuffer.h>
 #include <LibCore/CEventLoop.h>
 #include <SharedBuffer.h>
-
 #include <errno.h>
 #include <stdio.h>
 #include <sys/socket.h>
@@ -30,10 +29,9 @@ void ASClientConnection::die()
     s_connections.remove(client_id());
 }
 
-void ASClientConnection::did_finish_playing_buffer(Badge<ASMixer>, int buffer_id)
+void ASClientConnection::did_finish_playing_buffer(Badge<ASBufferQueue>, int buffer_id)
 {
-    (void)buffer_id;
-    //post_message(AudioClient::FinishedPlayingBuffer(buffer_id));
+    post_message(AudioClient::FinishedPlayingBuffer(buffer_id));
 }
 
 OwnPtr<AudioServer::GreetResponse> ASClientConnection::handle(const AudioServer::Greet& message)
diff --git a/Servers/AudioServer/ASClientConnection.h b/Servers/AudioServer/ASClientConnection.h
index b23886dcba..4147a231d0 100644
--- a/Servers/AudioServer/ASClientConnection.h
+++ b/Servers/AudioServer/ASClientConnection.h
@@ -13,7 +13,7 @@ class ASClientConnection final : public IPC::Server::ConnectionNG<AudioServerEnd
 public:
     explicit ASClientConnection(CLocalSocket&, int client_id, ASMixer& mixer);
     ~ASClientConnection() override;
-    void did_finish_playing_buffer(Badge<ASMixer>, int buffer_id);
+    void did_finish_playing_buffer(Badge<ASBufferQueue>, int buffer_id);
 
     virtual void die() override;
 
diff --git a/Servers/AudioServer/ASMixer.h b/Servers/AudioServer/ASMixer.h
index 960dce9996..5de1b624fc 100644
--- a/Servers/AudioServer/ASMixer.h
+++ b/Servers/AudioServer/ASMixer.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "ASClientConnection.h"
 #include <AK/ByteBuffer.h>
 #include <AK/NonnullRefPtrVector.h>
 #include <AK/Queue.h>
@@ -36,6 +37,7 @@ public:
         ++m_played_samples;
 
         if (m_position >= m_current->sample_count()) {
+            m_client->did_finish_playing_buffer({}, m_current->shared_buffer_id());
             m_current = nullptr;
             m_position = 0;
         }
@@ -61,8 +63,10 @@ public:
 
     int get_remaining_samples() const { return m_remaining_samples; }
     int get_played_samples() const { return m_played_samples; }
-    int get_playing_buffer() const {
-        if(m_current) return m_current->shared_buffer_id();
+    int get_playing_buffer() const
+    {
+        if (m_current)
+            return m_current->shared_buffer_id();
         return -1;
     }
 
diff --git a/Servers/AudioServer/AudioClient.ipc b/Servers/AudioServer/AudioClient.ipc
index 52a87281b0..ed9ba77b3a 100644
--- a/Servers/AudioServer/AudioClient.ipc
+++ b/Servers/AudioServer/AudioClient.ipc
@@ -1,4 +1,4 @@
-endpoint AudioClient
+endpoint AudioClient = 82
 {
     FinishedPlayingBuffer(i32 buffer_id) =|
 }
diff --git a/Servers/AudioServer/AudioServer.ipc b/Servers/AudioServer/AudioServer.ipc
index 1bdc7c8091..b48cbc6c06 100644
--- a/Servers/AudioServer/AudioServer.ipc
+++ b/Servers/AudioServer/AudioServer.ipc
@@ -1,4 +1,4 @@
-endpoint AudioServer
+endpoint AudioServer = 85
 {
     // Basic protocol
     Greet(i32 client_pid) => (i32 server_pid, i32 client_id)
diff --git a/Servers/AudioServer/Makefile b/Servers/AudioServer/Makefile
index 9cf71eeb0f..ebdf331a8b 100644
--- a/Servers/AudioServer/Makefile
+++ b/Servers/AudioServer/Makefile
@@ -13,11 +13,14 @@ DEFINES += -DUSERLAND
 
 all: $(APP)
 
-*.cpp: AudioServerEndpoint.h
+*.cpp: AudioServerEndpoint.h AudioClientEndpoint.h
 
 AudioServerEndpoint.h: AudioServer.ipc
 	@echo "IPC $<"; $(IPCCOMPILER) $< > $@
 
+AudioClientEndpoint.h: AudioClient.ipc
+	@echo "IPC $<"; $(IPCCOMPILER) $< > $@
+
 $(APP): $(OBJS)
 	$(LD) -o $(APP) $(LDFLAGS) $(OBJS) -lc -lcore -lipc -lthread -lpthread
 
@@ -27,5 +30,5 @@ $(APP): $(OBJS)
 -include $(OBJS:%.o=%.d)
 
 clean:
-	@echo "CLEAN"; rm -f $(APP) $(OBJS) *.d AudioServerEndpoint.h
+	@echo "CLEAN"; rm -f $(APP) $(OBJS) *.d AudioServerEndpoint.h AudioClientEndpoint.h