diff --git a/definitions/src/Simplex/Messaging/Broker.hs b/definitions/src/Simplex/Messaging/Broker.hs
index e525a6152b..eacc340ed6 100644
--- a/definitions/src/Simplex/Messaging/Broker.hs
+++ b/definitions/src/Simplex/Messaging/Broker.hs
@@ -13,9 +13,9 @@ import Simplex.Messaging.Protocol
 
 instance Monad m => PartyProtocol m Broker where
   api ::
-    Command from fs fs' Broker ps ps' res ->
-    Connection Broker ps ->
-    ExceptT String m (res, Connection Broker ps')
+    Command from '(Broker, s, s') a ->
+    Connection Broker s ->
+    ExceptT String m (a, Connection Broker s')
   api (CreateConn _) = apiStub
   api (Subscribe _) = apiStub
   api (Unsubscribe _) = apiStub
@@ -25,9 +25,9 @@ instance Monad m => PartyProtocol m Broker where
   api (DeleteMsg _ _) = apiStub
 
   action ::
-    Command Broker ps ps' to ts ts' res ->
-    Connection Broker ps ->
-    ExceptT String m res ->
-    ExceptT String m (Connection Broker ps')
+    Command '(Broker, s, s') to a ->
+    Connection Broker s ->
+    ExceptT String m a ->
+    ExceptT String m (Connection Broker s')
   action (PushConfirm _ _) = actionStub
   action (PushMsg _ _) = actionStub
diff --git a/definitions/src/Simplex/Messaging/Client.hs b/definitions/src/Simplex/Messaging/Client.hs
index 91f0117bec..4364cb82f2 100644
--- a/definitions/src/Simplex/Messaging/Client.hs
+++ b/definitions/src/Simplex/Messaging/Client.hs
@@ -13,17 +13,17 @@ import Simplex.Messaging.Protocol
 
 instance Monad m => PartyProtocol m Recipient where
   api ::
-    Command from fs fs' Recipient ps ps' res ->
-    Connection Recipient ps ->
-    ExceptT String m (res, Connection Recipient ps')
+    Command from '(Recipient, s, s') a ->
+    Connection Recipient s ->
+    ExceptT String m (a, Connection Recipient s')
   api (PushConfirm _ _) = apiStub
   api (PushMsg _ _) = apiStub
 
   action ::
-    Command Recipient ps ps' to ts ts' res ->
-    Connection Recipient ps ->
-    ExceptT String m res ->
-    ExceptT String m (Connection Recipient ps')
+    Command '(Recipient, s, s') to a ->
+    Connection Recipient s ->
+    ExceptT String m a ->
+    ExceptT String m (Connection Recipient s')
   action (CreateConn _) = actionStub
   action (Subscribe _) = actionStub
   action (Unsubscribe _) = actionStub
@@ -33,15 +33,15 @@ instance Monad m => PartyProtocol m Recipient where
 
 instance Monad m => PartyProtocol m Sender where
   api ::
-    Command from fs fs' Sender ps ps' res ->
-    Connection Sender ps ->
-    ExceptT String m (res, Connection Sender ps')
+    Command from '(Sender, s, s') a ->
+    Connection Sender s ->
+    ExceptT String m (a, Connection Sender s')
   api (SendInvite _) = apiStub
 
   action ::
-    Command Sender ps ps' to ts ts' res ->
-    Connection Sender ps ->
-    ExceptT String m res ->
-    ExceptT String m (Connection Sender ps')
+    Command '(Sender, s, s') to a ->
+    Connection Sender s ->
+    ExceptT String m a ->
+    ExceptT String m (Connection Sender s')
   action (ConfirmConn _ _) = actionStub
   action (SendMsg _ _) = actionStub
diff --git a/definitions/src/Simplex/Messaging/PrintScenario.hs b/definitions/src/Simplex/Messaging/PrintScenario.hs
index 4842522c54..61bbeef338 100644
--- a/definitions/src/Simplex/Messaging/PrintScenario.hs
+++ b/definitions/src/Simplex/Messaging/PrintScenario.hs
@@ -34,7 +34,7 @@ logProtocol (ProtocolCmd from to cmd) = do
   tell [(party from, commandStr cmd <> " " <> party to)]
   mockCommand cmd
 
-commandStr :: Command from fs fs' to ts ts' a -> String
+commandStr :: Command from to a -> String
 commandStr (CreateConn _) = "creates connection in"
 commandStr (Subscribe cid) = "subscribes to connection " <> show cid <> " in"
 commandStr (Unsubscribe cid) = "unsubscribes from connection " <> show cid <> " in"
@@ -46,7 +46,7 @@ commandStr (SendMsg cid _) = "sends message to connection " <> show cid <> " in"
 commandStr (PushMsg cid _) = "pushes message from connection " <> show cid <> " to"
 commandStr (DeleteMsg cid _) = "deletes message from connection " <> show cid <> " in"
 
-mockCommand :: Monad m => Command from fs fs' to ts ts' a -> m a
+mockCommand :: Monad m => Command from to a -> m a
 mockCommand (CreateConn _) =
   return
     CreateConnResponse
diff --git a/definitions/src/Simplex/Messaging/Protocol.hs b/definitions/src/Simplex/Messaging/Protocol.hs
index 3bdb6cb303..ecc677dff3 100644
--- a/definitions/src/Simplex/Messaging/Protocol.hs
+++ b/definitions/src/Simplex/Messaging/Protocol.hs
@@ -60,55 +60,48 @@ type Enabled rs bs =
     (bs == New || bs == Secured) ~ True
   )
 
-data
-  Command
-    (from :: Party)
-    (fs :: ConnState)
-    (fs' :: ConnState)
-    (to :: Party)
-    (ts :: ConnState)
-    (ts' :: ConnState)
-    (res :: Type) :: Type
-  where
+type PartyCmd = (Party, ConnState, ConnState)
+
+data Command (from :: PartyCmd) (to :: PartyCmd) (a :: Type) :: Type where
   CreateConn ::
     PublicKey ->
-    Command Recipient None New Broker None New CreateConnResponse
+    Command '(Recipient, None, New) '(Broker, None, New) CreateConnResponse
   Subscribe ::
     Enabled rs bs =>
     ConnId ->
-    Command Recipient rs rs Broker bs bs ()
+    Command '(Recipient, rs, rs) '(Broker, bs, bs) ()
   Unsubscribe ::
     Enabled rs bs =>
     ConnId ->
-    Command Recipient rs rs Broker bs bs ()
+    Command '(Recipient, rs, rs) '(Broker, bs, bs) ()
   SendInvite ::
     Invitation ->
-    Command Recipient New Pending Sender None New ()
+    Command '(Recipient, New, Pending) '(Sender, None, New) ()
   ConfirmConn ::
     SenderConnId ->
     Encrypted ->
-    Command Sender New Confirmed Broker New New ()
+    Command '(Sender, New, Confirmed) '(Broker, New, New) ()
   PushConfirm ::
     ConnId ->
     Message ->
-    Command Broker New New Recipient Pending Confirmed ()
+    Command '(Broker, New, New) '(Recipient, Pending, Confirmed) ()
   SecureConn ::
     ConnId ->
     PublicKey ->
-    Command Recipient Confirmed Secured Broker New Secured ()
+    Command '(Recipient, Confirmed, Secured) '(Broker, New, Secured) ()
   SendMsg ::
     (ss == Confirmed || ss == Secured) ~ True =>
     SenderConnId ->
     Encrypted ->
-    Command Sender ss Secured Broker Secured Secured ()
+    Command '(Sender, ss, Secured) '(Broker, Secured, Secured) ()
   PushMsg ::
     ConnId ->
     Message ->
-    Command Broker Secured Secured Recipient Secured Secured ()
+    Command '(Broker, Secured, Secured) '(Recipient, Secured, Secured) ()
   DeleteMsg ::
     ConnId ->
     MessageId ->
-    Command Recipient Secured Secured Broker Secured Secured ()
+    Command '(Recipient, Secured, Secured) '(Broker, Secured, Secured) ()
 
 -- connection type stub for all participants, TODO move from idris
 data
@@ -120,19 +113,19 @@ data
 
 class Monad m => PartyProtocol m (p :: Party) where
   api ::
-    Command from fs fs' p ps ps' res ->
-    Connection p ps ->
-    ExceptT String m (res, Connection p ps')
+    Command from '(p, s, s') a ->
+    Connection p s ->
+    ExceptT String m (a, Connection p s')
   action ::
-    Command p ps ps' to ts ts' res ->
-    Connection p ps ->
-    ExceptT String m res ->
-    ExceptT String m (Connection p ps')
+    Command '(p, s, s') to a ->
+    Connection p s ->
+    ExceptT String m a ->
+    ExceptT String m (Connection p s')
 
-apiStub :: Monad m => Connection p ps -> ExceptT String m (res, Connection p ps')
+apiStub :: Monad m => Connection p s -> ExceptT String m (a, Connection p s')
 apiStub _ = throwE "api not implemented"
 
-actionStub :: Monad m => Connection p ps -> ExceptT String m res -> ExceptT String m (Connection p ps')
+actionStub :: Monad m => Connection p s -> ExceptT String m a -> ExceptT String m (Connection p s')
 actionStub _ _ = throwE "action not implemented"
 
 type family AllowedStates s from fs' to ts' :: Constraint where
@@ -169,7 +162,7 @@ data ProtocolEff (s :: ProtocolState) (s' :: ProtocolState) (a :: Type) :: Type
     AllowedStates s from fs' to ts' =>
     Sing from ->
     Sing to ->
-    Command from (ConnSt from s) fs' to (ConnSt to s) ts' a ->
+    Command '(from, ConnSt from s, fs') '(to, ConnSt to s, ts') a ->
     ProtocolEff s (ProtoSt s from fs' to ts') a
 
 type Protocol = XFree ProtocolEff
@@ -180,14 +173,9 @@ infix 6 ->:
   AllowedStates s from fs' to ts' =>
   Sing from ->
   Sing to ->
-  Command from (ConnSt from s) fs' to (ConnSt to s) ts' a ->
+  Command '(from, ConnSt from s, fs') '(to, ConnSt to s, ts') a ->
   Protocol s (ProtoSt s from fs' to ts') a
 (->:) f t c = xfree $ ProtocolCmd f t c
 
 start :: String -> Protocol s s ()
 start = xfree . Start
-
-infix 5 |$
-
-(|$) :: (a -> b) -> a -> b
-f |$ x = f x
diff --git a/definitions/src/Simplex/Messaging/Scenarios.hs b/definitions/src/Simplex/Messaging/Scenarios.hs
index 6cd61bb1c3..36d91f2858 100644
--- a/definitions/src/Simplex/Messaging/Scenarios.hs
+++ b/definitions/src/Simplex/Messaging/Scenarios.hs
@@ -1,15 +1,19 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RebindableSyntax #-}
 {-# OPTIONS_GHC -fno-warn-missing-fields #-}
 {-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
+{-# OPTIONS_GHC -fno-warn-unused-do-bind #-}
 
 module Simplex.Messaging.Scenarios where
 
-import Control.XMonad
+import Control.XMonad.Do
 import Data.Singletons
+import Data.String
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.Types
+import Prelude hiding ((>>), (>>=))
 
 r :: Sing Recipient
 r = SRecipient
@@ -21,19 +25,19 @@ s :: Sing Sender
 s = SSender
 
 establishConnection :: Protocol '(None, None, None) '(Secured, Secured, Secured) ()
-establishConnection =
+establishConnection = do
   start "Establish simplex messaging connection and send first message"
-    >>: r ->: b |$ CreateConn "BODbZxmtKUUF1l8pj4nVjQ"
-    >>: r ->: b |$ Subscribe "RU"
-    >>: r ->: s |$ SendInvite "invitation RU" -- invitation - TODo
-    >>: s ->: b |$ ConfirmConn "SU" "encrypted"
-    >>: b ->: r |$ PushConfirm "RU" Message {msgId = "abc", msg = "XPaVEVNunkYKqqK0dnAT5Q"}
-    >>: r ->: b |$ SecureConn "RU" "XPaVEVNunkYKqqK0dnAT5Q"
-    >>: r ->: b |$ DeleteMsg "RU" "abc"
-    >>: s ->: b |$ SendMsg "SU" "welcome" -- welcome message
-    >>: b ->: r |$ PushMsg "RU" Message {msgId = "def", msg = "welcome"}
-    >>: r ->: b |$ DeleteMsg "RU" "def"
-    >>: s ->: b |$ SendMsg "SU" "hello there"
-    >>: b ->: r |$ PushMsg "RU" Message {msgId = "ghi", msg = "hello there"}
-    >>: r ->: b |$ DeleteMsg "RU" "ghi"
-    >>: r ->: b |$ Unsubscribe "RU"
+  r ->: b $ CreateConn "BODbZxmtKUUF1l8pj4nVjQ"
+  r ->: b $ Subscribe "RU"
+  r ->: s $ SendInvite "invitation RU" -- invitation - TODo
+  s ->: b $ ConfirmConn "SU" "encrypted"
+  b ->: r $ PushConfirm "RU" Message {msgId = "abc", msg = "XPaVEVNunkYKqqK0dnAT5Q"}
+  r ->: b $ SecureConn "RU" "XPaVEVNunkYKqqK0dnAT5Q"
+  r ->: b $ DeleteMsg "RU" "abc"
+  s ->: b $ SendMsg "SU" "welcome" -- welcome message
+  b ->: r $ PushMsg "RU" Message {msgId = "def", msg = "welcome"}
+  r ->: b $ DeleteMsg "RU" "def"
+  s ->: b $ SendMsg "SU" "hello there"
+  b ->: r $ PushMsg "RU" Message {msgId = "ghi", msg = "hello there"}
+  r ->: b $ DeleteMsg "RU" "ghi"
+  r ->: b $ Unsubscribe "RU"