diff --git a/core/src/main/kotlin/com/r3corda/protocols/ServiceRequestMessage.kt b/core/src/main/kotlin/com/r3corda/protocols/ServiceRequestMessage.kt
index 3f878b3ce7..b8391acf90 100644
--- a/core/src/main/kotlin/com/r3corda/protocols/ServiceRequestMessage.kt
+++ b/core/src/main/kotlin/com/r3corda/protocols/ServiceRequestMessage.kt
@@ -2,6 +2,7 @@ package com.r3corda.protocols
 
 import com.r3corda.core.crypto.Party
 import com.r3corda.core.messaging.MessageRecipients
+import com.r3corda.core.messaging.SingleMessageRecipient
 import com.r3corda.core.node.services.NetworkMapCache
 
 /**
@@ -13,6 +14,17 @@ interface ServiceRequestMessage {
     fun getReplyTo(networkMapCache: NetworkMapCache): MessageRecipients
 }
 
+/**
+ * A message which specifies reply destination as a specific endpoint such as a monitoring client. This is of particular
+ * use where we want to address a specific endpoint, not necessarily a specific user (for example if the same user logs
+ * in on two machines, we want to consistently deliver messages as part of a session, to the same machine the session
+ * started on).
+ */
+interface DirectRequestMessage: ServiceRequestMessage {
+    val replyToRecipient: SingleMessageRecipient
+    override fun getReplyTo(networkMapCache: NetworkMapCache): MessageRecipients = replyToRecipient
+}
+
 interface PartyRequestMessage : ServiceRequestMessage {
 
     val replyToParty: Party