diff --git a/.gitignore b/.gitignore
index cf36aff..76e5862 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@
 
 # Package Files #
 *.jar
+!gradle/wrapper/gradle-wrapper.jar
 *.war
 *.nar
 *.ear
@@ -30,3 +31,4 @@ out/
 
 # Ignore Gradle build output directory
 build
+.idea
diff --git a/build.gradle.kts b/build.gradle.kts
index deec48f..695115a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -14,5 +14,5 @@ repositories {
 
 plugins {
     // Apply the org.jetbrains.kotlin.jvm Plugin to add support for Kotlin.
-    kotlin("jvm") version "1.8.0"
+    kotlin("jvm") version "1.8.10"
 }
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..ccebba7
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index ae04661..bdc9a83 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.2-bin.zip
+networkTimeout=10000
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 744e882..79a61d4 100755
--- a/gradlew
+++ b/gradlew
@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015-2021 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,67 +17,101 @@
 #
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # Attempt to set APP_HOME
+
 # Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
 
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MSYS* | MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
@@ -87,9 +121,9 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
         # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -98,7 +132,7 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
     fi
 else
-    JAVACMD="java"
+    JAVACMD=java
     which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
@@ -106,80 +140,105 @@ location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
 fi
 
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
 # For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
     # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
         fi
-        i=`expr $i + 1`
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
     done
-    case $i in
-        0) set -- ;;
-        1) set -- "$args0" ;;
-        2) set -- "$args0" "$args1" ;;
-        3) set -- "$args0" "$args1" "$args2" ;;
-        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
-    esac
 fi
 
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=`save "$@"`
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
 
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index 107acd3..93e3f59 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -14,7 +14,7 @@
 @rem limitations under the License.
 @rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +25,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,7 +41,7 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -75,13 +76,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal
diff --git a/sample/build.gradle.kts b/sample/build.gradle.kts
index 1e04408..e8382a1 100644
--- a/sample/build.gradle.kts
+++ b/sample/build.gradle.kts
@@ -3,7 +3,7 @@
  * @author Fred George  fredgeorge@acm.org
  * Licensed under the MIT License; see LICENSE file in root.
  */
- 
+
 plugins {
     // Apply the org.jetbrains.kotlin.jvm Plugin to add support for Kotlin.
     kotlin("jvm")
@@ -26,8 +26,8 @@ dependencies {
     implementation(project(":river"))
 
     // Align versions of all Kotlin components
-    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.8.0"))
+    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.8.10"))
 
     // Use the Kotlin JDK 8 standard library.
-    implementation("org.jetbrains.kotlin:kotlin-stdlib:1.8.0")
+    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.8.10")
 }
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/offer/RuneOffer.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/offer/RuneOffer.kt
new file mode 100644
index 0000000..1ded4a5
--- /dev/null
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/offer/RuneOffer.kt
@@ -0,0 +1,37 @@
+package com.nrkei.training.microservices.offer
+
+import com.nrkei.training.microservices.filter.Validation
+import com.nrkei.training.microservices.filter.rules
+import com.nrkei.training.microservices.packet.Packet
+import com.nrkei.training.microservices.rapid.RapidsConnection
+import com.nrkei.training.microservices.rapid.rabbitmq.RabbitMqRapids
+import com.nrkei.training.microservices.river.River
+import com.nrkei.training.microservices.river.Status
+
+class RuneOffer : River.PacketListener {
+    companion object {
+        private const val COMMUNITY = "community"
+        private const val OFFER_ENGINE_FAMILY = "offer_engine_family"
+        private const val NEED = "need"
+        private const val CAR_RENTAL_OFFER = "car_rental_offer"
+
+        @JvmStatic
+        fun main(args: Array<String>) {
+            require(args.size == 2) { "Missing IP and Port arguments! The IP address of the Rapids (as a string), and the Port number of the Rapids (also as a string)." }
+            RabbitMqRapids(ipAddress = args[0], port = args[1]).register(RuneOffer())
+        }
+    }
+    override val rules: List<Validation>
+        get() = rules {
+            require key NEED value CAR_RENTAL_OFFER     // Reject packet unless it has key:value pair a_key:a_value
+        }
+
+    override fun packet(connection: RapidsConnection, packet: Packet, infoWarnings: Status) {
+        connection.publish(
+                Packet(COMMUNITY to OFFER_ENGINE_FAMILY,
+                        "solution" to "Got a better car offer for you, " + packet["programmer"],
+                        "car" to "Tesla Model Y")
+        )
+        println("Offered car to " + packet["programmer"])
+    }
+}
\ No newline at end of file
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodOffer.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodOffer.kt
new file mode 100644
index 0000000..6f11da9
--- /dev/null
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodOffer.kt
@@ -0,0 +1,40 @@
+package com.nrkei.training.microservices.rental
+
+import com.nrkei.training.microservices.filter.Validation
+import com.nrkei.training.microservices.filter.rules
+import com.nrkei.training.microservices.packet.Packet
+import com.nrkei.training.microservices.rapid.RapidsConnection
+import com.nrkei.training.microservices.rapid.rabbitmq.RabbitMqRapids
+import com.nrkei.training.microservices.river.River
+import com.nrkei.training.microservices.river.Status
+import kotlin.random.Random
+
+class GodOffer  : River.PacketListener {
+    companion object {
+            @JvmStatic
+        fun main(args: Array<String>) {
+            require(args.size == 2) { "Missing IP and Port arguments! The IP address of the Rapids (as a string), and the Port number of the Rapids (also as a string)." }
+            RabbitMqRapids(ipAddress = args[0], port = args[1]).register(GodOffer())
+        }
+    }
+
+    override val rules: List<Validation>
+        get() = rules {
+            require key Messages.Key.NEED value Messages.Value.CAR_RENTAL_OFFER
+            forbid key Messages.Key.PROBABILITY
+            forbid key Messages.Key.BEST_OFFER
+        }
+
+    override fun packet(connection: RapidsConnection, packet: Packet, infoWarnings: Status) {
+        val answer = packet.clone()
+        answer[Messages.Key.MESSAGE ] = "Got a car for you, " + packet["user"]
+        answer[Messages.Key.CAR] = "Delorean"
+        answer[Messages.Key.DAILY_RATE] = Random.nextInt(100,2000)
+        answer[Messages.Key.PROBABILITY]= Random.nextInt(0,100)
+
+        connection.publish(answer)
+        println("Offered car to " + packet["user"])
+
+    }
+
+}
\ No newline at end of file
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodSolutionPicker.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodSolutionPicker.kt
new file mode 100644
index 0000000..5cd3006
--- /dev/null
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/GodSolutionPicker.kt
@@ -0,0 +1,54 @@
+package com.nrkei.training.microservices.rental
+
+import com.nrkei.training.microservices.filter.Validation
+import com.nrkei.training.microservices.filter.rules
+import com.nrkei.training.microservices.packet.Packet
+import com.nrkei.training.microservices.rapid.RapidsConnection
+import com.nrkei.training.microservices.rapid.rabbitmq.RabbitMqRapids
+import com.nrkei.training.microservices.river.River
+import com.nrkei.training.microservices.river.Status
+
+class GodSolutionPicker : River.PacketListener {
+    companion object {
+        @JvmStatic
+        fun main(args: Array<String>) {
+            require(args.size == 2) { "Missing IP and Port arguments! The IP address of the Rapids (as a string), and the Port number of the Rapids (also as a string)." }
+            RabbitMqRapids(ipAddress = args[0], port = args[1]).register(GodSolutionPicker())
+        }
+    }
+
+    override val rules: List<Validation>
+        get() = rules {
+            require key Messages.Key.PROBABILITY
+            require key Messages.Key.DAILY_RATE
+            require key Messages.Key.USER
+            require key Messages.Key.CAR
+            forbid key Messages.Key.BEST_OFFER
+        }
+
+    val bestOffersPerUser = mutableMapOf<String, Packet>()
+
+    override fun packet(connection: RapidsConnection, packet: Packet, infoWarnings: Status) {
+        val user = "${packet[Messages.Key.USER]}"
+        val car  = packet[Messages.Key.CAR]
+        val probability  = packet[Messages.Key.PROBABILITY].toString().toInt()
+        val rate  = packet[Messages.Key.DAILY_RATE].toString().toInt()
+
+        val previous = bestOffersPerUser.get(user)
+        var best = previous ?: packet
+        if ( previous != null ) {
+            if ( calc(packet[Messages.Key.PROBABILITY].toString().toInt(), packet[Messages.Key.DAILY_RATE].toString().toInt()) < calc( probability, rate)) {
+                best = packet
+            }
+        }
+        bestOffersPerUser.put(user, best)
+
+        println("=== Best solution => "+best)
+        best[Messages.Key.BEST_OFFER] = "true"
+        connection.publish( best )
+    }
+
+    private fun calc(probability : Int, rate : Int ): Int {
+        return probability * rate
+    }
+}
\ No newline at end of file
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/KjetilSolution.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/KjetilSolution.kt
new file mode 100644
index 0000000..263c550
--- /dev/null
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/KjetilSolution.kt
@@ -0,0 +1,54 @@
+package com.nrkei.training.microservices.rental
+
+import com.nrkei.training.microservices.filter.rules
+import com.nrkei.training.microservices.packet.Packet
+import com.nrkei.training.microservices.rapid.RapidsConnection
+import com.nrkei.training.microservices.rapid.rabbitmq.RabbitMqRapids
+import com.nrkei.training.microservices.river.River
+import com.nrkei.training.microservices.river.Status
+
+class KjetilSolution {
+    companion object {
+
+        @JvmStatic
+        fun main(args: Array<String>) {
+            require(args.size == 2) { "Missing IP and Port arguments! The IP address of the Rapids (as a string), and the Port number of the Rapids (also as a string)." }
+            RabbitMqRapids(ipAddress = args[0], port = args[1]).also { rapids ->
+                listen(rapids)
+            }
+        }
+
+        private fun listen(rapidsConnection: RapidsConnection) {
+            try {
+                rapidsConnection.register(object : River.PacketListener {
+                    override val rules = rules {
+                        require key Messages.Key.COMMUNITY value Messages.Value.OFFER_ENGINE_FAMILY
+                        require key Messages.Key.NEED value Messages.Value.CAR_RENTAL_OFFER
+                    }
+
+                    override fun packet(connection: RapidsConnection, packet: Packet, infoWarnings: Status) {
+                        Packet(
+                            Messages.Key.COMMUNITY to Messages.Value.OFFER_ENGINE_FAMILY,
+                            Messages.Key.CAR_RENTAL_OFFER_MESSAGE to "Got a car for you " + packet["programmer"],
+                            Messages.Key.CAR_RENTAL_OFFER to "SUX 5000",
+                            Messages.Key.DAILY_RATE to "1000",
+                            Messages.Key.LOCATION to "Arbins"
+                        )
+                        rapidsConnection.publish(
+                            Packet(
+                                Messages.Key.COMMUNITY to Messages.Value.OFFER_ENGINE_FAMILY,
+                                Messages.Key.CAR_RENTAL_OFFER_MESSAGE to "Got a car for you " + packet["programmer"],
+                                Messages.Key.CAR_RENTAL_OFFER to "SUX 5000",
+                                Messages.Key.DAILY_RATE to "1000",
+                                Messages.Key.LOCATION to "Arbins"
+                            )
+                        )
+                        println("Offered a car to ${packet["programmer"]}: $packet")
+                    }
+                })
+            } catch (e: Exception) {
+                throw RuntimeException("Could not publish message:", e)
+            }
+        }
+    }
+}
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Messages.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Messages.kt
new file mode 100644
index 0000000..a8ad847
--- /dev/null
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Messages.kt
@@ -0,0 +1,24 @@
+package com.nrkei.training.microservices.rental
+
+object Messages {
+
+    object Key {
+
+        const val BEST_OFFER = "best"
+        const val COMMUNITY = "community"
+        const val NEED = "need"
+        const val USER = "user"
+        const val MESSAGE = "message"
+        const val CAR = "car"
+        const val CAR_RENTAL_OFFER = "car_rental_offer";
+        const val CAR_RENTAL_OFFER_MESSAGE = "car_rental_offer_message";
+        const val DAILY_RATE = "daily_rate"
+        const val PROBABILITY = "probability"
+        const val LOCATION = "location"
+    }
+
+    object Value {
+        const val OFFER_ENGINE_FAMILY = "offer_engine_family"
+        const val CAR_RENTAL_OFFER = "car_rental_offer"
+    }
+}
diff --git a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Need.kt b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Need.kt
index aea5602..68091a4 100644
--- a/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Need.kt
+++ b/sample/src/main/kotlin/com/nrkei/training/microservices/rental/Need.kt
@@ -14,11 +14,6 @@ import com.nrkei.training.microservices.rapid.rabbitmq.RabbitMqRapids
 class Need {
 
     companion object {
-        private const val COMMUNITY = "community"
-        private const val OFFER_ENGINE_FAMILY = "offer_engine_family"
-        private const val NEED = "need"
-        private const val CAR_RENTAL_OFFER = "car_rental_offer"
-
         @JvmStatic
         fun main(args: Array<String>) {
             require(args.size == 2) { "Missing IP and Port arguments! The IP address of the Rapids (as a string), and the Port number of the Rapids (also as a string)." }
@@ -30,8 +25,9 @@ class Need {
         private fun publish(rapidsConnection: RapidsConnection) {
             try {
                 Packet(
-                    COMMUNITY to OFFER_ENGINE_FAMILY,
-                    NEED to CAR_RENTAL_OFFER
+                    Messages.Key.COMMUNITY to Messages.Value.OFFER_ENGINE_FAMILY,
+                    Messages.Key.NEED to Messages.Value.CAR_RENTAL_OFFER,
+                    Messages.Key.USER to System.getProperty("user.name", "God")
                 ).also { needPacket ->
                     while (true) {
                         println(String.format(" [<] %s", needPacket))
diff --git a/sample_java/src/main/java/com.nrkei.training.microservices/system/JMonitor.java b/sample_java/src/main/java/com.nrkei.training.microservices/system/JMonitor.java
index b162d9c..3ac1b6f 100644
--- a/sample_java/src/main/java/com.nrkei.training.microservices/system/JMonitor.java
+++ b/sample_java/src/main/java/com.nrkei.training.microservices/system/JMonitor.java
@@ -20,7 +20,7 @@ public class JMonitor implements SystemListener {
     @NotNull
     @Override
     public String getName() {
-        return "${this.javaClass.simpleName} [${this.hashCode()}]";
+        return "%s[%d]".formatted(getClass().getSimpleName(), hashCode());
     }