diff --git a/pg/connection/conversation.pony b/pg/connection/conversation.pony
index 79ae069..8581737 100644
--- a/pg/connection/conversation.pony
+++ b/pg/connection/conversation.pony
@@ -8,15 +8,15 @@ use "pg"
 
 trait Conversation
   
-  be apply(c: _Connection) 
+  be apply(c: BEConnection tag) 
   be message(m: ServerMessage val)
 
 
 actor _NullConversation is Conversation
-  let _conn: _Connection
+  let _conn: BEConnection tag
 
-  new create(c: _Connection) => _conn = c
-  be apply(c: _Connection) => None
+  new create(c: BEConnection tag) => _conn = c
+  be apply(c: BEConnection tag) => None
   be message(m: ServerMessage val) =>
     _conn.handle_message(m)
 
@@ -24,8 +24,8 @@ actor _NullConversation is Conversation
 actor _AuthConversation is Conversation
   let _pool: ConnectionManager
   let _params: Array[(String, String)] val
-  let _conn: _Connection
-  new create(p: ConnectionManager, c: _Connection, params: Array[(String, String)] val) =>
+  let _conn: BEConnection tag
+  new create(p: ConnectionManager, c: BEConnection tag, params: Array[(String, String)] val) =>
     _pool=p
     _conn=c
     _params=params
@@ -33,7 +33,7 @@ actor _AuthConversation is Conversation
   be log(msg: String) =>
     _pool.log(msg)
 
-  be apply(c: _Connection) =>
+  be apply(c: BEConnection tag) =>
     let data = recover val
     let msg = StartupMessage(_params)
     msg.done() 
@@ -149,19 +149,19 @@ actor ExecuteConversation is Conversation
 
 actor QueryConversation is Conversation
   let query: String val
-  let _conn: _Connection
+  let _conn: BEConnection tag
   let _handler: ResultCB val
   var _rows: (Rows val | Rows trn ) = recover trn Rows end
   var _tuple_desc: (TupleDescription val | None) = None
 
-  new create(c: _Connection, q: String, h: ResultCB val) =>
+  new create(c: BEConnection tag, q: String, h: ResultCB val) =>
     query = q
     _conn = c
     _handler = h
 
   be log(msg: String) => _conn.log(msg)
 
-  be apply(c: _Connection) =>
+  be apply(c: BEConnection tag) =>
     c.writev(recover val QueryMessage(query).done() end)
 
   be call_back() =>
@@ -196,7 +196,7 @@ actor TerminateConversation is Conversation
 
   be log(msg: String) => _conn.log(msg)
 
-  be apply(c: _Connection) =>
+  be apply(c: BEConnection tag) =>
     c.writev(recover val TerminateMessage.done() end)
 
   be message(m: ServerMessage val)=>
diff --git a/pg/connection/listener.pony b/pg/connection/listener.pony
index e179568..47e7f2d 100644
--- a/pg/connection/listener.pony
+++ b/pg/connection/listener.pony
@@ -16,12 +16,12 @@ class PGParseError is ParseEvent
 
 
 actor Listener
-  let _conn: _Connection
+  let _conn: BEConnection tag
   var r: Reader iso = Reader // current reader
   var _ctype: U8 = 0 // current type (keep it if the data is chuncked)
   var _clen: USize = 0 // current message len (as given by server)
 
-  new create(c: _Connection) =>
+  new create(c: BEConnection tag) =>
     _conn = c
 
   be received(data: Array[U8] iso) =>
diff --git a/pg/connection/manager.pony b/pg/connection/manager.pony
index eb457d0..900f05a 100644
--- a/pg/connection/manager.pony
+++ b/pg/connection/manager.pony
@@ -4,24 +4,28 @@ use "promises"
 use "pg"
 
 actor ConnectionManager
-  let _connections: Array[_Connection] = Array[_Connection tag]
+  let _connections: Array[BEConnection tag] = Array[BEConnection tag]
   let _params: Array[(String, String)] val
   let _host: String
   let _service: String
   let _user: String
   let _passwd_provider: PasswordProvider tag
   var _password: (String | None) = None
+  let _max_size: USize
 
   new create(host: String,
              service: String,
              user: String,
              passwd_provider: PasswordProvider tag,
-             params: Array[Param] val) =>
+             params: Array[Param] val,
+             pool_size: USize = 1
+             ) =>
     _params = params
     _host = host
     _service = service
     _passwd_provider = passwd_provider
     _user = user
+    _max_size = pool_size
 
   be log(msg: String) =>
     None
diff --git a/pg/connection/tcp.pony b/pg/connection/tcp.pony
index e64d794..5eb8861 100644
--- a/pg/connection/tcp.pony
+++ b/pg/connection/tcp.pony
@@ -22,6 +22,7 @@ interface BEConnection
   be next()
   be schedule(conv: Conversation tag)
   be terminate()
+  be received(s: ServerMessage val)
   be do_terminate()
   be cursor(query: String, notify: CursorNotify iso) => None