diff --git a/build.gradle b/build.gradle
index 14fc335..ee87cf1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,12 +10,15 @@ sourceCompatibility = 1.8
 
 repositories {
     mavenCentral()
+    google()
+    jcenter()
 }
 
 dependencies {
     compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
     compile 'io.javalin:javalin:2.6.0'
     compile 'org.slf4j:slf4j-simple:1.7.25'
+    implementation 'com.beust:klaxon:5.0.1'
     testCompile group: 'junit', name: 'junit', version: '4.12'
 }
 
diff --git a/src/main/kotlin/com/zecqtwallet/wormhole/Service.kt b/src/main/kotlin/com/zecqtwallet/wormhole/Service.kt
index fa43fa8..e1d0033 100644
--- a/src/main/kotlin/com/zecqtwallet/wormhole/Service.kt
+++ b/src/main/kotlin/com/zecqtwallet/wormhole/Service.kt
@@ -1,6 +1,18 @@
 package com.zecqtwallet.wormhole
 
+import com.beust.klaxon.JsonObject
+import com.beust.klaxon.Parser
+import com.beust.klaxon.json
 import io.javalin.Javalin
+import io.javalin.websocket.WsSession
+import java.util.concurrent.ConcurrentHashMap
+
+
+private val usermap = ConcurrentHashMap<WsSession, String>()
+
+// Allow maps to be bidirectional
+fun <K, V> Map<K, V>.getKeys(value: V) : List<K> =
+    entries.filter { it.value == value } .map { it.key }
 
 
 fun main(args : Array<String>) {
@@ -10,14 +22,62 @@ fun main(args : Array<String>) {
             ws.onConnect { session ->
                 println("Connected Session")
             }
+
             ws.onClose { session, status, message ->
                 println("Closed session")
+                usermap.remove(session)
             }
+
             ws.onMessage { session, message ->
-                println("message")
-                session.send("Reply to $message")
+                // Limit message size to 50kb of hex encoded text
+                if (message.length > 2 * 50 * 1024) {
+                    sendError(session, "Message too big")
+                }
+
+                // Parse the message as json
+                try {
+                    val j = Parser.default().parse(StringBuilder(message)) as JsonObject
+
+                    if (j.contains("register")) {
+                        doRegister(session, j["register"].toString())
+                        return@onMessage
+                    }
+
+                    if (j.contains("to")) {
+                        val s = usermap.getKeys(j["to"].toString()).filter { it != session }
+                        if (s.isEmpty()) {
+                            // Not connected
+                            sendError(session, "Peer is not connected")
+                            return@onMessage
+                        }
+
+                        s[0].send(message)
+                        return@onMessage
+                    }
+
+                } catch (e: Throwable) {
+                    session.close(1000, "Invalid json")
+                }
             }
         }
     }.start(7070)
 
 }
+
+fun doRegister(session: WsSession, id: String) {
+    if (usermap.contains(session)) {
+        // TODO: Make JSON
+        sendError(session, "Already registered a session")
+
+        usermap.remove(session)
+        session.close()
+    }
+
+    usermap[session] = id
+}
+
+fun sendError(session: WsSession, err: String) {
+    if (session.isOpen) {
+        session.send(json { obj("error" to err) }.toJsonString())
+    }
+}
\ No newline at end of file