diff --git a/examples/client.rs b/examples/client.rs
index 36db0c9..4239b5c 100644
--- a/examples/client.rs
+++ b/examples/client.rs
@@ -1,32 +1,37 @@
 use serde::{Deserialize, Serialize};
-use session_rs::session::Session;
+use session_rs::{Method, session::Session, ws::Frame};
 
 #[derive(Debug, Serialize, Deserialize)]
 struct Data {}
 
-type Communication = Session<Data, Data, Data, Data, Data>;
+impl Method for Data {
+    const NAME: &'static str = "data";
+    type Request = ();
+    type Response = ();
+}
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> session_rs::Result<()> {
-    let session = Communication::connect("127.0.0.1:8080", "/").await?;
+    let session = Session::connect("127.0.0.1:8080", "/").await?;
 
-    // Spawn read loop
-    // tokio::spawn({
-    //     let session = session.clone();
-    //     async move {
-    //         loop {
-    //             match session.read().await {
-    //                 Ok(Frame::Text(text)) => {
-    //                     println!("Server says: {}", text);
-    //                 }
-    //                 Ok(_) => {}
-    //                 Err(_) => break,
-    //             }
-    //         }
-    //     }
-    // });
+    tokio::spawn({
+        let session = session.clone();
+        async move {
+            loop {
+                match session.ws.read().await {
+                    Ok(Frame::Text(text)) => {
+                        println!("Server says: {}", text);
+                    }
+                    Ok(_) => {}
+                    Err(_) => break,
+                }
+            }
+        }
+    });
 
-    session.request(&Data {}).await?;
+    session.request::<Data>(()).await?;
+
+    tokio::time::sleep(tokio::time::Duration::from_millis(1000)).await;
 
     session.close().await?;
     Ok(())
diff --git a/examples/server.rs b/examples/server.rs
index ce36cc8..d515a16 100644
--- a/examples/server.rs
+++ b/examples/server.rs
@@ -31,7 +31,7 @@ async fn main() -> session_rs::Result<()> {
                         println!("Received text: {}", text);
 
                         // Echo back
-                        if let Err(e) = session.send(&serde_json::json!({"echo": text}).to_string()).await {
+                        if let Err(e) = session.send(&text).await {
                             eprintln!("Send error: {:?}", e);
                             break;
                         }
diff --git a/src/lib.rs b/src/lib.rs
index 627be42..4761d38 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,17 @@
+use serde::{Deserialize, Serialize};
+
 pub mod server;
 pub mod session;
 pub mod ws;
 
 pub type Result<T> = std::result::Result<T, Error>;
 
+pub trait Method {
+    const NAME: &'static str;
+    type Request: Serialize + for<'de> Deserialize<'de>;
+    type Response: Serialize + for<'de> Deserialize<'de>;
+}
+
 #[derive(Debug)]
 pub enum Error {
     WebSocket(ws::Error),
diff --git a/src/session.rs b/src/session.rs
index ba0ebac..0235c95 100644
--- a/src/session.rs
+++ b/src/session.rs
@@ -1,82 +1,45 @@
-use std::{marker::PhantomData, sync::Arc};
+use std::sync::Arc;
 
 use serde::{Deserialize, Serialize};
 use tokio::sync::Mutex;
 
-use crate::ws::WebSocket;
+use crate::{Method, ws::WebSocket};
 
 #[derive(Debug, Serialize, Deserialize)]
-pub enum SessionMessageKind {
-    Request,
-    Response,
-    Notification,
+pub enum Message<M: Method> {
+    Request {
+        id: u32,
+        method: String,
+        data: M::Request,
+    },
+    Response {
+        id: u32,
+        error: bool,
+        result: M::Response,
+    },
+    Notification {
+        method: String,
+        data: M::Request,
+    },
 }
 
-#[derive(Debug, Serialize, Deserialize)]
-pub struct SessionMessage<T: Serialize> {
-    id: u32,
-    kind: SessionMessageKind,
-    data: T,
-}
-
-pub struct Session<
-    Req: Serialize + for<'a> Deserialize<'a>,
-    Res: Serialize + for<'a> Deserialize<'a>,
-    PeerReq: Serialize + for<'a> Deserialize<'a>,
-    PeerRes: Serialize + for<'a> Deserialize<'a>,
-    Notification: Serialize + for<'a> Deserialize<'a>,
-> {
-    _pd: (
-        PhantomData<Req>,
-        PhantomData<Res>,
-        PhantomData<PeerReq>,
-        PhantomData<PeerRes>,
-        PhantomData<Notification>,
-    ),
+pub struct Session {
     pub ws: WebSocket,
     id: Arc<Mutex<u32>>,
 }
 
-impl<
-    Req: Serialize + for<'a> Deserialize<'a>,
-    Res: Serialize + for<'a> Deserialize<'a>,
-    PeerReq: Serialize + for<'a> Deserialize<'a>,
-    PeerRes: Serialize + for<'a> Deserialize<'a>,
-    Notification: Serialize + for<'a> Deserialize<'a>,
-> Session<Req, Res, PeerReq, PeerRes, Notification>
-{
+impl Session {
     pub fn clone(&self) -> Self {
         Self {
-            _pd: (
-                PhantomData,
-                PhantomData,
-                PhantomData,
-                PhantomData,
-                PhantomData,
-            ),
             ws: self.ws.clone(),
             id: self.id.clone(),
         }
     }
 }
 
-impl<
-    Req: Serialize + for<'a> Deserialize<'a>,
-    Res: Serialize + for<'a> Deserialize<'a>,
-    PeerReq: Serialize + for<'a> Deserialize<'a>,
-    PeerRes: Serialize + for<'a> Deserialize<'a>,
-    Notification: Serialize + for<'a> Deserialize<'a>,
-> Session<Req, Res, PeerReq, PeerRes, Notification>
-{
+impl Session {
     pub fn from_ws(ws: WebSocket) -> Self {
         Self {
-            _pd: (
-                PhantomData,
-                PhantomData,
-                PhantomData,
-                PhantomData,
-                PhantomData,
-            ),
             ws,
             id: Arc::new(Mutex::new(0)),
         }
@@ -87,55 +50,49 @@ impl<
     }
 }
 
-impl<
-    Req: Serialize + for<'a> Deserialize<'a>,
-    Res: Serialize + for<'a> Deserialize<'a>,
-    PeerReq: Serialize + for<'a> Deserialize<'a>,
-    PeerRes: Serialize + for<'a> Deserialize<'a>,
-    Notification: Serialize + for<'a> Deserialize<'a>,
-> Session<Req, Res, PeerReq, PeerRes, Notification>
-{
-    pub async fn send_id<T: Serialize>(
-        &self,
-        id: u32,
-        kind: SessionMessageKind,
-        data: &T,
-    ) -> crate::Result<()> {
+impl Session {
+    pub async fn send<M: Method>(&self, data: &Message<M>) -> crate::Result<()> {
         self.ws
-            .send_text_payload(&serde_json::to_vec(&SessionMessage { id, kind, data })?)
+            .send_text_payload(&serde_json::to_vec(&data)?)
             .await?;
-
         Ok(())
     }
 
-    pub async fn send<T: Serialize>(
-        &self,
-        kind: SessionMessageKind,
-        data: &T,
-    ) -> crate::Result<()> {
-        self.send_id(
-            {
-                let mut i = self.id.lock().await;
-                *i += 1;
-                *i
-            },
-            kind,
-            data,
-        )
+    pub async fn use_id(&self) -> u32 {
+        let mut id = self.id.lock().await;
+        *id += 1;
+        *id
+    }
+
+    pub async fn request<M: Method>(&self, req: M::Request) -> crate::Result<()> {
+        self.send::<M>(&Message::Request {
+            id: self.use_id().await,
+            method: M::NAME.to_string(),
+            data: req,
+        })
         .await
     }
 
-    pub async fn request(&self, data: &Req) -> crate::Result<()> {
-        self.send(SessionMessageKind::Request, data).await
+    pub async fn respond<M: Method>(
+        &self,
+        to: u32,
+        error: bool,
+        res: M::Response,
+    ) -> crate::Result<()> {
+        self.send::<M>(&Message::Response {
+            id: to,
+            error,
+            result: res,
+        })
+        .await
     }
 
-    pub async fn respond(&self, to_req: &SessionMessage<PeerReq>, data: &Res) -> crate::Result<()> {
-        self.send_id(to_req.id, SessionMessageKind::Response, data)
-            .await
-    }
-
-    pub async fn notify(&self, data: &Res) -> crate::Result<()> {
-        self.send(SessionMessageKind::Notification, data).await
+    pub async fn notify<M: Method>(&self, data: M::Request) -> crate::Result<()> {
+        self.send::<M>(&Message::Notification {
+            method: M::NAME.to_string(),
+            data,
+        })
+        .await
     }
 
     pub async fn close(&self) -> crate::Result<()> {