diff --git a/definitions/src/Simplex/Messaging/Protocol.hs b/definitions/src/Simplex/Messaging/Protocol.hs
index e8b4f819bc..662ea62821 100644
--- a/definitions/src/Simplex/Messaging/Protocol.hs
+++ b/definitions/src/Simplex/Messaging/Protocol.hs
@@ -124,6 +124,8 @@ st2 = SPending :<==> SNew :<==| SConfirmed
 -- stBad = SPending :<==> SConfirmed :<==| SConfirmed
 
 
+infixl 4 :>>, :>>=
+
 data Command res (from :: Participant) (to :: Participant) state state' :: Type where
   CreateConn   :: Prf HasState 'Sender s
                => CreateConnRequest
@@ -203,8 +205,12 @@ data Command res (from :: Participant) (to :: Participant) state state' :: Type
                -> Command b from1 to2 s1 s3
 
 
+infix 6 ==>
+(==>) :: from -> to -> (from, to)
+from ==> to = (from, to)
+
 infix 5 &:
-(&:) :: Sing from
+(&:) :: (Sing from, Sing to)
      -> Command a from to s1 s2
      -> Command a from to s1 s2
 (&:) _ c = c
diff --git a/definitions/src/Simplex/Messaging/Scenarios.hs b/definitions/src/Simplex/Messaging/Scenarios.hs
new file mode 100644
index 0000000000..fea57b4c12
--- /dev/null
+++ b/definitions/src/Simplex/Messaging/Scenarios.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeOperators #-}
+
+module Simplex.Messaging.Scenarios where
+
+import Simplex.Messaging.Protocol
+import Simplex.Messaging.Types
+
+establishConnection  :: Command ()
+                          'Recipient 'Broker
+                          ('None <==> 'None <==| 'None)
+                          ('Secured <==> 'Secured <==| 'Secured)
+establishConnection =
+  SRecipient ==> SBroker     &: CreateConn "123"     :>>=  --  recipient's public key for broker
+                                \CreateConnResponse{..} ->
+  SRecipient ==> SBroker     &: Subscribe            :>>   -- TODO add subscribed state
+  SRecipient ==> SSender     &: SendInvite "invite"  :>>   -- TODO invitation object
+  SSender    ==> SBroker     &: ConfirmConn "456"    :>>   -- sender's public key for broker"
+  SBroker    ==> SRecipient  &: PushConfirm          :>>=
+                                \senderKey ->
+  SRecipient ==> SBroker     &: SecureConn senderKey :>>
+  SSender    ==> SBroker     &: SendWelcome          :>>
+  SBroker    ==> SRecipient  &: PushWelcome          :>>
+  SSender    ==> SBroker     &: SendMsg "Hello"      :>>
+  SBroker    ==> SRecipient  &: PushMsg              :>>
+  SRecipient ==> SBroker     &: DeleteMsg
diff --git a/definitions/src/Simplex/Messaging/Types.hs b/definitions/src/Simplex/Messaging/Types.hs
index 43d2e9c9f7..60fc9ab538 100644
--- a/definitions/src/Simplex/Messaging/Types.hs
+++ b/definitions/src/Simplex/Messaging/Types.hs
@@ -9,7 +9,11 @@ import GHC.Generics()
 
 newtype CreateConnRequest = CreateConnRequest
   { recipientKey :: Key
-  } deriving (Show, Generic, ToJSON, FromJSON)
+  } deriving (Eq, Show, Generic, ToJSON, FromJSON)
+
+instance IsString CreateConnRequest where
+  fromString = CreateConnRequest . pack
+
 
 data CreateConnResponse = CreateConnResponse
   { recipientId :: String
@@ -20,6 +24,10 @@ newtype SecureConnRequest = SecureConnRequest
   { senderKey :: Key
   } deriving (Show, Generic, ToJSON, FromJSON)
 
+instance IsString SecureConnRequest where
+  fromString = SecureConnRequest . pack
+
+
 data Message = Message
   { id   :: Base64EncodedString
   , ts   :: TimeStamp
@@ -35,6 +43,10 @@ newtype SendMessageRequest = SendMessageRequest
   { msg :: Base64EncodedString
   } deriving (Show, Generic, ToJSON, FromJSON)
 
+instance IsString SendMessageRequest where
+  fromString = SendMessageRequest . pack
+
+
 type Key = Base64EncodedString
 type Base64EncodedString = Text
 type TimeStamp = Text