Using Custom Software to create a LaunchDaemon or LaunchAgent – Addigy

LaunchDaemons and LaunchAgents allow you to run scripts automatically at system startup or user login on managed Macs. This article walks through how to create the required files and deploy them using Addigy's Smart Software.

Overview

macOS uses a system called launchd to run background processes and scripts automatically. By creating a property list (.plist) and pairing it with a script, you can trigger automated actions on your devices — such as setting configurations, running maintenance tasks, or enforcing settings at login.

The key difference between the two types:

LaunchDaemon — Runs as root. Use this for system-level tasks that don't require a logged-in user.
LaunchAgent — Runs as the logged-in user. Use this for tasks that should execute in the context of a specific user session.

Which type you create is determined by where the .plist file is placed on the device:

/Library/LaunchDaemons → runs as root (LaunchDaemon)
/Library/LaunchAgents → runs as the logged-in user (LaunchAgent)

Step 1: Create Your Script

Write the shell script you want to run at launch or login. The script content is entirely up to you — it can run any command or series of commands appropriate for your use case.

Important: Test your script manually on a Mac before packaging it for deployment. A script that fails silently can be difficult to troubleshoot after deployment.

Step 2: Create the .plist File

The .plist file tells macOS how and when to run your script. Copy the template below and save it as a .plist file, updating the values to match your script's name and path.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>Label</key>
    <string>com.example.app</string>
    <key>Program</key>
    <string>/Library/Addigy/Name_of_Script.sh</string>
    <key>RunAtLoad</key>
    <true/>
  </dict>
</plist>

Key values to update:

Label — A unique identifier for this job (e.g., com.yourcompany.scriptname)
Program — The full path to your script as it will exist on the device

Step 3: Create the Smart Software Installation Script

Addigy's Smart Software supports a custom installation script that runs during deployment. This script handles three things: setting the correct file permissions, placing your files in the right directories, and loading the .plist with launchctl.

Create a new Smart Software item and upload your .plist file and .sh script as Installation Files.

Copy the script below to use as the Installation Command and replace:

Your Smart Software Item (1.0) with the name and version of your Smart Software item
Name_of_Script.sh with the name of your .sh script
Name_of_Property_List.plist with the name of your .plist file

Update the target directory to /Library/LaunchDaemons or /Library/LaunchAgents depending on which type you're creating.

# Set execute permission on the script
chmod +x "/Library/Addigy/ansible/packages/Your Smart Software Item (1.0)/Name_of_Script.sh"

# Copy files to their target directories
cp "/Library/Addigy/ansible/packages/Your Smart Software Item (1.0)/Name_of_Script.sh" /Library/Addigy/
cp "/Library/Addigy/ansible/packages/Your Smart Software Item (1.0)/Name_of_Property_List.plist" /Library/LaunchAgents/

# Load the plist to activate the LaunchAgent/LaunchDaemon
sudo launchctl load -w /Library/LaunchAgents/Name_of_Property_List.plist

Finally, save the Smart Software item and add it to a policy for deployment.

Best practice: Before rolling out to your full device fleet, assign the Smart Software item to a policy containing only test Macs. Verify the script runs as expected before broader deployment.