diff --git a/clients/c_cpp/example.c b/clients/c_cpp/example.c
new file mode 100644
index 0000000..21b65b8
--- /dev/null
+++ b/clients/c_cpp/example.c
@@ -0,0 +1,29 @@
+ #include "pipe_io.h"
+
+
+void run2() {
+    pipe_io pipeio = pipeio_new_io("in", "out");
+    const char* line;
+    while ((line = pipeio_recv_msg(&pipeio.reader))) {
+        pipeio_send_msg(&pipeio.writer, line);
+    }
+    pipeio_close_io(&pipeio);
+}
+
+void msg_handler(const char* msg, void* ctx) {
+    pipe_writer* writer = (pipe_writer*)(ctx);
+    pipeio_send_msg(writer, msg);
+}
+
+void run1() {
+    pipe_io pipeio = pipeio_new_io("in", "out");
+    pipeio_set_msg_handler(&pipeio.reader, &msg_handler, &pipeio.writer);
+    pipeio_run(&pipeio.reader);
+    pipeio_close_io(&pipeio);
+}
+
+int main() {
+    run1();  // or run2();
+    // note that run1 and run2 do the same thing
+    // and you can use whichever API you prefer
+}
diff --git a/clients/c_cpp/example.cpp b/clients/c_cpp/example.cpp
new file mode 100644
index 0000000..c8538f1
--- /dev/null
+++ b/clients/c_cpp/example.cpp
@@ -0,0 +1,13 @@
+#include <iostream>
+#include <string>
+#include <fstream>
+#include "pipe_io.hpp"
+
+
+int main() {
+    PipeIO pipe_io("in", "out");
+    pipe_io.reader.set_message_handler(
+        [&pipe_io](std::string msg){pipe_io.writer.send_message(msg);}
+    );
+    pipe_io.reader.run();
+}
diff --git a/clients/c_cpp/pipe_io.h b/clients/c_cpp/pipe_io.h
index 09f7023..8289629 100644
--- a/clients/c_cpp/pipe_io.h
+++ b/clients/c_cpp/pipe_io.h
@@ -9,25 +9,30 @@ typedef struct pipe_reader {
     FILE* stream;
     char* line_buf;
     size_t buf_size;
+    void (*msg_handler)(const char*, void*);
+    void* handler_ctx;
 } pipe_reader;
 
-pipe_reader new_pipe_reader(const char* pipe_path) {
+static void null_handler(const char* msg, void* ctx) {}
+
+pipe_reader pipeio_new_reader(const char* pipe_path) {
     pipe_reader preader;
     preader.stream = fopen(pipe_path, "r");
     preader.line_buf = NULL;
     preader.buf_size = 0;
+    preader.msg_handler = &null_handler;
     return preader;
 }
 
-bool check_pipe_reader(const pipe_reader* preader) {
+bool pipeio_check_reader(const pipe_reader* preader) {
     if (!preader || preader->stream == NULL) {
         return false;
     }
     return true;
 }
 
-const char* recv_msg_pipe_reader(pipe_reader* preader) {
-    if (!check_pipe_reader(preader)) {
+const char* pipeio_recv_msg(pipe_reader* preader) {
+    if (!pipeio_check_reader(preader)) {
         return NULL;
     }
     ssize_t read = getline(&preader->line_buf, &preader->buf_size, preader->stream);
@@ -38,8 +43,22 @@ const char* recv_msg_pipe_reader(pipe_reader* preader) {
     return NULL;
 }
 
-void close_pipe_reader(pipe_reader* preader) {
-    if (!check_pipe_reader(preader)) {
+void pipeio_set_msg_handler(pipe_reader* preader, void (*msg_handler)(const char*, void*), void* handler_ctx) {
+    if (msg_handler != NULL && handler_ctx != NULL) {
+        preader->msg_handler = msg_handler;
+        preader->handler_ctx = handler_ctx;
+    }
+}
+
+void pipeio_run(pipe_reader* preader) {
+    const char* line;
+    while ((line = pipeio_recv_msg(preader))) {
+        (*preader->msg_handler)(line, preader->handler_ctx);
+    }
+}
+
+void pipeio_close_reader(pipe_reader* preader) {
+    if (!pipeio_check_reader(preader)) {
         return;
     }
     fclose(preader->stream);
@@ -55,21 +74,21 @@ typedef struct pipe_writer {
     FILE* stream;
 } pipe_writer;
 
-pipe_writer new_pipe_writer(const char* pipe_path) {
+pipe_writer pipeio_new_writer(const char* pipe_path) {
     pipe_writer pwriter;
     pwriter.stream = fopen(pipe_path, "w");
     return pwriter;
 }
 
-bool check_pipe_writer(const pipe_writer* pwriter) {
+bool pipeio_check_writer(const pipe_writer* pwriter) {
     if (!pwriter || pwriter->stream == NULL) {
         return false;
     }
     return true;
 }
 
-bool send_msg_pipe_writer(pipe_writer* pwriter, const char* msg) {
-    if (!check_pipe_writer(pwriter)) {
+bool pipeio_send_msg(pipe_writer* pwriter, const char* msg) {
+    if (!pipeio_check_writer(pwriter)) {
         return false;
     }
     fprintf(pwriter->stream, "%s\n", msg);
@@ -77,8 +96,8 @@ bool send_msg_pipe_writer(pipe_writer* pwriter, const char* msg) {
     return true;
 }
 
-void close_pipe_writer(pipe_writer* pwriter) {
-    if (!check_pipe_writer(pwriter)) {
+void pipeio_close_writer(pipe_writer* pwriter) {
+    if (!pipeio_check_writer(pwriter)) {
         return;
     }
     fclose(pwriter->stream);
@@ -87,42 +106,42 @@ void close_pipe_writer(pipe_writer* pwriter) {
 
 
 typedef struct pipe_io {
-    pipe_reader preader;
-    pipe_writer pwriter;
+    pipe_reader reader;
+    pipe_writer writer;
 } pipe_io;
 
-pipe_io new_pipe_io(const char* in_pipe_path, const char* out_pipe_path) {
+pipe_io pipeio_new_io(const char* in_pipe_path, const char* out_pipe_path) {
     pipe_io pipeio;
-    pipeio.preader = new_pipe_reader(in_pipe_path);
-    pipeio.pwriter = new_pipe_writer(out_pipe_path);
+    pipeio.reader = pipeio_new_reader(in_pipe_path);
+    pipeio.writer = pipeio_new_writer(out_pipe_path);
     return pipeio;
 }
 
-bool check_pipe_io(const pipe_io* pipeio) {
+bool pipeio_check_io(const pipe_io* pipeio) {
     if (!pipeio) {
         return false;
     }
-    return (check_pipe_reader(&pipeio->preader) && check_pipe_writer(&pipeio->pwriter));
+    return (pipeio_check_reader(&pipeio->reader) && pipeio_check_writer(&pipeio->writer));
 }
 
-const char* recv_msg_pipe_io(pipe_io* pipeio) {
-    if (!check_pipe_io(pipeio)) {
-        return NULL;
-    }
-    return recv_msg_pipe_reader(&pipeio->preader);
-}
-
-bool send_msg_pipe_io(pipe_io* pipeio, const char* msg) {
-    if (!check_pipe_io(pipeio)) {
-        return false;
-    }
-    return send_msg_pipe_writer(&pipeio->pwriter, msg);
-}
-
-void close_pipe_io(pipe_io* pipeio) {
-    if (!check_pipe_io(pipeio)) {
+void pipeio_close_io(pipe_io* pipeio) {
+    if (!pipeio_check_io(pipeio)) {
         return;
     }
-    close_pipe_reader(&pipeio->preader);
-    close_pipe_writer(&pipeio->pwriter);
+    pipeio_close_reader(&pipeio->reader);
+    pipeio_close_writer(&pipeio->writer);
 }
+
+// const char* recv_msg_pipe_io(pipe_io* pipeio) {
+//     if (!check_pipe_io(pipeio)) {
+//         return NULL;
+//     }
+//     return recv_msg_pipe_reader(&pipeio->preader);
+// }
+
+// bool send_msg_pipe_io(pipe_io* pipeio, const char* msg) {
+//     if (!check_pipe_io(pipeio)) {
+//         return false;
+//     }
+//     return send_msg_pipe_writer(&pipeio->pwriter, msg);
+// }
diff --git a/clients/c_cpp/pipe_io.hpp b/clients/c_cpp/pipe_io.hpp
index 57ffd8d..da73d9a 100644
--- a/clients/c_cpp/pipe_io.hpp
+++ b/clients/c_cpp/pipe_io.hpp
@@ -3,15 +3,16 @@ extern "C" {
 }
 #include <string>
 #include <iostream>
+#include <functional>
 
 
 class PipeReader {
 public:
-    PipeReader(const char* pipe_path)
-    :preader(new_pipe_reader(pipe_path)) {}
+    PipeReader(const std::string& pipe_path)
+    :preader(pipeio_new_reader(pipe_path.c_str())) {}
 
     virtual ~PipeReader() {
-        close_pipe_reader(&this->preader);
+        pipeio_close_reader(&this->preader);
     }
 
     PipeReader(PipeReader&) = delete;
@@ -19,31 +20,34 @@ public:
     PipeReader& operator=(const PipeReader&) = delete;
     PipeReader& operator=(const PipeReader&&) = delete;
 
+    void set_message_handler(std::function<void(std::string)> message_handler) {
+        this->message_handler = message_handler;
+    }
+
     void run() {
         while (const char* linebuf = this->recv_message()) {
             std::string msg(linebuf);
-            this->handle_message(msg);
+            this->message_handler(msg);
         }
     }
 
     const char* recv_message() {
-        return recv_msg_pipe_reader(&this->preader);
+        return pipeio_recv_msg(&this->preader);
     }
 
-    virtual void handle_message(std::string msg) {}
-
 private:
     pipe_reader preader;
+    std::function<void(std::string)> message_handler = [](std::string){};
 };
 
 
 class PipeWriter {
 public:
-    PipeWriter(const char* pipe_path)
-    :pwriter(new_pipe_writer(pipe_path)) {}
+    PipeWriter(const std::string& pipe_path)
+    :pwriter(pipeio_new_writer(pipe_path.c_str())) {}
 
     virtual ~PipeWriter() {
-        close_pipe_writer(&this->pwriter);
+        pipeio_close_writer(&this->pwriter);
     }
 
     PipeWriter(PipeReader&) = delete;
@@ -52,7 +56,7 @@ public:
     PipeWriter& operator=(const PipeReader&&) = delete;
 
     void send_message(std::string msg) {
-        send_msg_pipe_writer(&this->pwriter, msg.c_str());
+        pipeio_send_msg(&this->pwriter, msg.c_str());
     }
 
 private:
@@ -60,10 +64,13 @@ private:
 };
 
 
-class PipeIO : public PipeReader, public PipeWriter {
+class PipeIO {
 public:
-    PipeIO(const char* in_pipe_path, const char* out_pipe_path)
-    :PipeReader(in_pipe_path), PipeWriter(out_pipe_path) {}
+    PipeReader reader;
+    PipeWriter writer;
+
+    PipeIO(const std::string& in_pipe_path, const std::string& out_pipe_path)
+    :reader(in_pipe_path), writer(out_pipe_path) {}
 
     PipeIO(PipeReader&) = delete;
     PipeIO(PipeReader&&) = delete;
diff --git a/clients/c_cpp/test.c b/clients/c_cpp/test.c
deleted file mode 100644
index 020ec3a..0000000
--- a/clients/c_cpp/test.c
+++ /dev/null
@@ -1,11 +0,0 @@
- #include "pipe_io.h"
-
-
-int main() {
-    pipe_io pipeio = new_pipe_io("in", "out");
-    const char* line;
-    while ((line = read_line_pipe_io(&pipeio))) {
-        send_msg_pipe_io(&pipeio, line);
-    }
-    close_pipe_io(&pipeio);
-}
diff --git a/clients/c_cpp/test.cpp b/clients/c_cpp/test.cpp
deleted file mode 100644
index 4878391..0000000
--- a/clients/c_cpp/test.cpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#include <iostream>
-#include <string>
-#include <fstream>
-#include "pipe_io.hpp"
-
-
-class EchoPipeIO : public PipeIO {
-    using PipeIO::PipeIO;
-
-    virtual void handle_message(std::string msg) override {
-        this->send_message(msg);
-    }
-};
-
-
-int main() {
-    EchoPipeIO echo_pipe_io("in", "out");
-    echo_pipe_io.run();
-}
diff --git a/clients/csharp/Test.cs b/clients/csharp/Example.cs
similarity index 65%
rename from clients/csharp/Test.cs
rename to clients/csharp/Example.cs
index 2129ced..503e8e3 100644
--- a/clients/csharp/Test.cs
+++ b/clients/csharp/Example.cs
@@ -7,8 +7,8 @@ class Program
     {
         using (var t = new PipeIO("in", "out"))
         {
-            t.reader.OnMessage += (String msg) => t.writer.SendMessage(msg);
-            t.reader.Run();
+            t.Reader.OnMessage += (String msg) => t.Writer.SendMessage(msg);
+            t.Reader.Run();
         }
     }
 }
diff --git a/clients/csharp/PipeIO.cs b/clients/csharp/PipeIO.cs
index 820a647..1ba7e61 100644
--- a/clients/csharp/PipeIO.cs
+++ b/clients/csharp/PipeIO.cs
@@ -65,19 +65,19 @@ namespace Pipe.IO
 
     public class PipeIO : IDisposable
     {
-        public PipeReader reader;
-        public PipeWriter writer;
+        public PipeReader Reader;
+        public PipeWriter Writer;
 
         public PipeIO(String in_pipe_path, String out_pipe_path)
         {
-            this.reader = new PipeReader(in_pipe_path);
-            this.writer = new PipeWriter(out_pipe_path);
+            this.Reader = new PipeReader(in_pipe_path);
+            this.Writer = new PipeWriter(out_pipe_path);
         }
 
         public void Dispose()
         {
-            this.reader.Dispose();
-            this.writer.Dispose();
+            this.Reader.Dispose();
+            this.Writer.Dispose();
         }
     }
 }
diff --git a/clients/go/test.go b/clients/go/example.go
similarity index 73%
rename from clients/go/test.go
rename to clients/go/example.go
index 8ea1eb5..8558d67 100644
--- a/clients/go/test.go
+++ b/clients/go/example.go
@@ -13,8 +13,8 @@ func main() {
 	}
 	defer pipeio.Close()
 
-	pipeio.HandleMessage(func(msg []byte) {
+	pipeio.Reader.SetMessageHandler(func(msg []byte) {
 		pipeio.Writer.SendMessage(msg)
 	})
-	pipeio.Run()
+	pipeio.Reader.Run()
 }
diff --git a/clients/go/pipeio/pipeio.go b/clients/go/pipeio/pipeio.go
index 83f2403..c93e49e 100644
--- a/clients/go/pipeio/pipeio.go
+++ b/clients/go/pipeio/pipeio.go
@@ -9,8 +9,11 @@ import (
 type pipeReader struct {
 	pipe *os.File
 	scanner *bufio.Scanner
+	messageHandler messageHandlerFunc
 }
 
+type messageHandlerFunc func([]byte)
+
 func NewPipeReader(pipePath string) (*pipeReader, error) {
 	pipe, err := os.Open(pipePath)
 	scanner := bufio.NewScanner(pipe)
@@ -21,9 +24,28 @@ func NewPipeReader(pipePath string) (*pipeReader, error) {
 	return &pipeReader{
 		pipe: pipe,
 		scanner: scanner,
+		messageHandler: func([]byte){},
 	}, nil
 }
 
+func (preader *pipeReader) Close() {
+	preader.pipe.Close()
+}
+
+func (preader *pipeReader) SetMessageHandler(fun messageHandlerFunc) {
+	preader.messageHandler = fun
+}
+
+func (preader *pipeReader) Run() {
+	for {
+		msg := preader.RecvMessage()
+		if msg == nil {
+			break
+		}
+		preader.messageHandler(msg)
+	}
+}
+
 func (preader *pipeReader) RecvMessage() []byte {
 	if preader.scanner.Scan() {
 		return preader.scanner.Bytes()
@@ -31,10 +53,6 @@ func (preader *pipeReader) RecvMessage() []byte {
 	return nil
 }
 
-func (preader *pipeReader) Close() {
-	preader.pipe.Close()
-}
-
 
 type pipeWriter struct {
 	pipe *os.File
@@ -60,11 +78,8 @@ func (pwriter *pipeWriter) SendMessage(msg []byte) {
 type pipeIO struct {
 	Reader pipeReader
 	Writer pipeWriter
-	handleMessage handleMessageFunc
 }
 
-type handleMessageFunc func([]byte)
-
 func NewPipeIO(inPipePath, outPipePath string) (*pipeIO, error) {
 	reader, err := NewPipeReader(inPipePath)
 	if err != nil {
@@ -77,7 +92,6 @@ func NewPipeIO(inPipePath, outPipePath string) (*pipeIO, error) {
 	return &pipeIO{
 		Reader: *reader,
 		Writer: *writer,
-		handleMessage: func([]byte){},
 	}, nil
 }
 
@@ -85,17 +99,3 @@ func (pipeio *pipeIO) Close() {
 	pipeio.Reader.Close()
 	pipeio.Writer.Close()
 }
-
-func (pipeio *pipeIO) Run() {
-	for {
-		msg := pipeio.Reader.RecvMessage()
-		if msg == nil {
-			break
-		}
-		pipeio.handleMessage(msg)
-	}
-}
-
-func (pipeio *pipeIO) HandleMessage(fun handleMessageFunc) {
-	pipeio.handleMessage = fun
-}
diff --git a/clients/java/Example.java b/clients/java/Example.java
new file mode 100644
index 0000000..359e615
--- /dev/null
+++ b/clients/java/Example.java
@@ -0,0 +1,13 @@
+public class Example {
+    public static void main(String[] args) {
+        try (PipeIO pipeio = new PipeIO("in", "out")) {
+            pipeio.reader.setMessageHandler(new MessageHandler(){
+                @Override
+                public void call(String msg) {
+                    pipeio.writer.sendMessage(msg);
+                }
+            });
+            pipeio.reader.run();
+        }
+    }
+}
diff --git a/clients/java/MessageHandler.java b/clients/java/MessageHandler.java
new file mode 100644
index 0000000..7af755e
--- /dev/null
+++ b/clients/java/MessageHandler.java
@@ -0,0 +1,3 @@
+public interface MessageHandler {
+    public void call(String msg);
+}
diff --git a/clients/java/PipeIO.java b/clients/java/PipeIO.java
index b9e8702..f7b5920 100644
--- a/clients/java/PipeIO.java
+++ b/clients/java/PipeIO.java
@@ -2,25 +2,16 @@ import java.io.IOException;
 
 
 public class PipeIO implements AutoCloseable {
-    protected PipeReader reader;
-    protected PipeWriter writer;
+    public PipeReader reader;
+    public PipeWriter writer;
 
-    public PipeIO(String in_pipe_path, String out_pipe_path) throws IOException {
+    public PipeIO(String in_pipe_path, String out_pipe_path) {
         this.reader = new PipeReader(in_pipe_path);
         this.writer = new PipeWriter(out_pipe_path);
     }
 
-    public void close() throws IOException {
+    public void close() {
         this.reader.close();
         this.writer.close();
     }
-
-    public void run() throws IOException {
-        String msg;
-        while ((msg = this.reader.recvMessage()) != null) {
-            this.handleMessage(msg);
-        }
-    }
-
-    public void handleMessage(String msg) throws IOException {}
 }
diff --git a/clients/java/PipeReader.java b/clients/java/PipeReader.java
index b83f11b..e59d918 100644
--- a/clients/java/PipeReader.java
+++ b/clients/java/PipeReader.java
@@ -1,21 +1,50 @@
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.lang.AutoCloseable;
 
 
 public class PipeReader implements AutoCloseable {
     private BufferedReader pipe;
+    private MessageHandler messageHandler;
 
-    public PipeReader(String pipe_path) throws IOException {
-        this.pipe = new BufferedReader(new FileReader(pipe_path));
+    public PipeReader(String pipe_path) {
+        try {
+            this.pipe = new BufferedReader(new FileReader(pipe_path));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+        this.messageHandler = new MessageHandler(){
+            @Override
+            public void call(String msg) {}
+        };
     }
 
-    public void close() throws IOException {
-        this.pipe.close();
+    public void close() {
+        try {
+            this.pipe.close();
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 
-    public String recvMessage() throws IOException {
-        return this.pipe.readLine();
+    public void setMessageHandler(MessageHandler handler) {
+        this.messageHandler = handler;
+    }
+
+    public void run() {
+        String msg;
+        while ((msg = this.recvMessage()) != null) {
+            this.messageHandler.call(msg);
+        }
+    }
+
+    public String recvMessage() {
+        try {
+            return this.pipe.readLine();
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 }
diff --git a/clients/java/PipeWriter.java b/clients/java/PipeWriter.java
index 1329a38..a232ebe 100644
--- a/clients/java/PipeWriter.java
+++ b/clients/java/PipeWriter.java
@@ -1,22 +1,35 @@
 import java.io.BufferedWriter;
 import java.io.FileWriter;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.lang.AutoCloseable;
 
 
 public class PipeWriter implements AutoCloseable {
     private BufferedWriter pipe;
 
-    public PipeWriter(String pipe_path) throws IOException {
-        this.pipe = new BufferedWriter(new FileWriter(pipe_path));
+    public PipeWriter(String pipe_path) {
+        try {
+            this.pipe = new BufferedWriter(new FileWriter(pipe_path));
+        } catch(IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 
-    public void close() throws IOException {
-        this.pipe.close();
+    public void close() {
+        try {
+            this.pipe.close();
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 
-    public void sendMessage(String msg) throws IOException {
-        this.pipe.write(msg + "\n");
-        this.pipe.flush();
+    public void sendMessage(String msg) {
+        try {
+            this.pipe.write(msg + "\n");
+            this.pipe.flush();
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 }
diff --git a/clients/java/Test.java b/clients/java/Test.java
deleted file mode 100644
index 9f936de..0000000
--- a/clients/java/Test.java
+++ /dev/null
@@ -1,22 +0,0 @@
-import java.io.IOException;
-
-
-public class Test extends PipeIO {
-    public Test(String in_pipe_path, String out_pipe_path) throws IOException {
-        super(in_pipe_path, out_pipe_path);
-    }
-
-    @Override
-    public void handleMessage(String msg) throws IOException {
-        this.writer.sendMessage(msg);
-    }
-
-    public static void main(String[] args) {
-        try(Test test = new Test("in", "out")) {
-            test.run();
-        }
-        catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-}