LaunchD spawning two instances of LaunchAgent

Question

I have this application that is divided in 3 parts.

• A server that handles all the networking code
• A agent that handles all System related code
• A manager (NSApplication) to interact with the other two processes.

Goals

• All three process should be kept alive if they crash
• All three processes must not restart if the user quits them though the NSApplication
• They need to run during the login window.

My current set up using LaunchD is as follows.

My Server process plist (relevant part) saved in System/LaunchDaemons

key>MachServices</key>
<dict>
    <key>com.myCompany.Agent.xpc</key>
    <true/>
    <key>com.myCompany.Manager.xpc</key>
    <true/>
</dict>
<key>ProgramArguments</key>
<array>
    <string>PathToExecutable</string>
    <string>-service</string>
</array>
<key>RunAtLoad</key>
<false/>

My agent plist (saved in System/LaunchAgent)

<key>QueueDirectories</key>
<array>
    <string>PathToDirectory</string>
</array>
<key>RunAtLoad</key>
<false/>
<key>ProgramArguments</key>
<array>
    <string>PathToExecutable</string>
    <string>service</string>
</array>

my Manager app plist (saved in System/LaunchAgent)

<key>LimitLoadToSessionType</key>
        <string>Aqua</string>
    <key>RunAtLoad</key>
        <false/>
    <key>ProgramArguments</key>
        <array>
            <string>PathToExecutable</string>
        </array>
    <key>MachServices</key>
        <dict>
            <key>com.myCompany.Agent.manager.xpc</key>
            <true/>
        </dict>

Currently I have another app that saves a file to the path of the QueueDirectories which triggers the launch of my Agent which then triggers the Server and Manager by starting a XPC Connection. QueueDirectories keeps the Agent alive (and hence all other processes) til file is removed and processes are quited through the manager.

XPC Connections

• Server listens for a connection from agent and manager
• Manager listens for a connection from agent and starts a connection with server
• Agent starts a connection with Manager and Server

Agent and Manager are owned by the user and server by root

The problems

When I start Agent by saving a file in the QueueDirectories path and connect to the Server over xpc I end up with two Agents, one owned by the user (the one I expect) and one owned by root.

But if I manually start the Agent I do not have that problem.

As I mentioned before, the server listens for a connection from the Agent.

How do I stop getting two instances? or what is a better way to approach this?