I came across this question while trying to remember how I did it myself, but I think I re-found the solution. I followed the directions in this mailing list post; it is a few years old but it is still working for me in macOS Sierra.

If that post becomes unavailable, here's a copy of the key info in it. Basically, once you have your upsmon configuration set up the way you want it, you just have to create a .plist file (simply a text file with the .plist extension) and put it in the right directory, then restart. I used the verbatim text from the post for the .plist file and it is still going strong for me.

Specifically, you can create a .plist file with the following contents:

<?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>org.networkupstools.upsmon</string>
   <key>OnDemand</key>
   <false/>
   <key>ProgramArguments</key>
   <array>
           <string>/opt/local/sbin/upsmon</string>
           <string>-D</string>
   </array>
</dict>
</plist>

Then save it with a name like org.networkupstools.upsmon.plist in /Library/LaunchDaemons and it should start the service automatically on boot from that point onward.

Answer from Matt on Stack Exchange
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Reddit
reddit.com › r/mac › network ups tools (nut) client for big sur?
r/mac on Reddit: Network UPS Tools (NUT) client for Big Sur?
July 12, 2021 - And my mac workstation I have to monitor separately, from the macOs GUI, or from the powerpanel software. ... I solved it in a complicated but working way. The ups is connected to a Synology that acts like a user-friendly NUT server. A RPi that's running my Home Assistant home automation system listens to that (a native HA NUT integration) and can send shell shutdown commands to both a MacOS (Hackintosh) and Windows installs on the PC.
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GitHub
github.com › vitaliystoyanov › nut-client
GitHub - vitaliystoyanov/nut-client: Mac OS NUT desktop client based on Electron for UPS management · GitHub
Mac OS NUT desktop client based on Electron for UPS management - vitaliystoyanov/nut-client
Author   vitaliystoyanov
Top answer
1 of 2
1

So it seems I was missing the point of fink a bit.

had to do:

sudo apt-get update
fink install nut

Updating the package lists with apt-get update also fixed finkcommander.

After installing nut (5mins) Setting up the config in /sw/etc/nut/ as found on the net uncommenting a line:

MONITOR ups@<ip of synology> 1 monuser secret slave

After which sudo upsmon still gave an error of a missing library. Error:

dyld: Library not loaded /sw/lib/libssl.1.0.0.dylib

For this I installed openssl 1.0.2 using finkcommander (fink installed a version too high)

Then running sudo upsmon no error was given. Following https://community.netgear.com/t5/New-to-ReadyNAS/NUT-on-OSX-10-6-Sharing-a-UPS-with-ReadyNAS-and-Computers/td-p/661293 Showing 3 processes (one grep upsmon to be ignored):

ps aux | grep upsmon 

And finally showing me the info of the ups:

sudo upsc UPS@<ip of nas>

All that's left is auto starting upsmon on boot by adding the following : (credit https://superuser.com/questions/1228972/how-to-automatically-launch-nut-client-at-boot-on-macos/1358980#1358980). Edited to add "s" to LaunchDaemons.

sudo nano /Library/LaunchDaemons/org.networkupstools.upsmon.plist

and fill it with:

<?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>org.networkupstools.upsmon</string>
   <key>OnDemand</key>
   <false/>
   <key>ProgramArguments</key>
   <array>
           <string>/sw/sbin/upsmon</string>
           <string>-D</string>
   </array>
</dict>
</plist>
2 of 2
0

This issue is that libssl.1.0.0.dylib is a dynamic library. I ran into the same issue trying to use nut on an older MacOS. MacOS has a very complex scheme for permissions and it is easy to get them fouled up without even trying. In the case of nut, upsmon is dynamically linking to the .dylib when it really should be statically linked. You can hack the fink build file for upsmon.

sudo nano /sw/fink/dists/stable/main/finkinfo/net/nut.info

Find ConfigureParams: and where you see --enable-static, append in --disable-shared then have fink rebuild nut.

As far as I know there is no way to request fink or Mac Ports to always statically link. These decisions are not made by the developers of nut and they often make very bad decisions when it comes to bloated sub-packages.

Example:

https://trac.macports.org/ticket/41789

The developers of neon decided to pull in gtk and other libraries that completely loaded up upsmon with nonsense. What they should have done was statically linked the libs and also locked down neon @0.29.6_2 before it bloated up. For a system utility, with a very special purpose, it makes zero sense to use bloated up libs just because it is the path of least resistance.

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MacPorts
ports.macports.org › port › nut
Install nut on macOS with MacPorts
If not done already, install MacPorts. To install nut, run the following command in macOS terminal (Applications->Utilities->Terminal)
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Reddit
reddit.com › r/ubiquiti › unifi ups nut macos companion app
r/Ubiquiti on Reddit: Unifi UPS NUT macOS Companion App
October 10, 2025 -

With Ubiquiti enabling a NUT server on their new UPS products I was excited to have a way to safely shutdown my hardware in the event of an outage - until I realized there are no real Mac apps that are easy to use (and free) for network UPS monitoring.

So I built NUTty - a free (forever), native Mac app that finally makes network UPS monitoring simple.

What it does:

  • Lives in your menu bar and monitors any network UPS using the NUT protocol (UniFi SmartPower, APC, CyberPower, Eaton, etc.)

  • Automatically shuts down your Mac when the battery gets critically low

  • Sends push notifications to your phone via Notify when power fails or is restored

  • Lets you create custom shutdown rules based on battery level, runtime, or UPS status

  • Supports monitoring multiple UPS devices at once

Just an Important note: If you have other UPS devices, this is specifically for network UPS devices. If your UPS plugs directly into your Mac via USB, macOS already handles it natively - you don't need this.

Built entirely in Swift/SwiftUI and free forever. Perfect for home servers, Mac minis, or any setup where you want peace of mind that your Mac won't corrupt data during a power outage.

Would love to hear feedback from anyone running network UPS setups!

https://nutty.pingie.com

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Reddit
reddit.com › r/selfhosted › ups nut macos companion app
r/selfhosted on Reddit: UPS NUT macOS Companion App
October 10, 2025 -

I was inspired with Ubiquiti enabling a NUT server on their new UPS products I was excited to have a way to safely shutdown my hardware in the event of an outage - until I realized there are no real Mac apps that are easy to use (and free) for network UPS monitoring.

So I built NUTty - a free (forever), native Mac app that finally makes network UPS monitoring simple.

What it does:

  • Lives in your menu bar and monitors any network UPS using the NUT protocol (UniFi SmartPower, APC, CyberPower, Eaton, etc.)

  • Automatically shuts down your Mac when the battery gets critically low

  • Sends push notifications to your phone via Notify when power fails or is restored

  • Lets you create custom shutdown rules based on battery level, runtime, or UPS status

  • Supports monitoring multiple UPS devices at once

Just an Important note: If you have other UPS devices, this is specifically for network UPS devices. If your UPS plugs directly into your Mac via USB, macOS already handles it natively - you don't need this.

Built entirely in Swift/SwiftUI and free forever. Perfect for home servers, Mac minis, or any setup where you want peace of mind that your Mac won't corrupt data during a power outage.

Would love to hear feedback from anyone running network UPS setups! I attempted a cross post but this was not supported in this subreddit.

https://nutty.pingie.com

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Diktio Solutions
diktiosolutions.eu › home › nut macos
NUT macOS - Diktio Solutions
February 18, 2025 - Connect your macOS system via a NUT client to the Synology NAS running NUT to shutdown your macOS system when a power failure occurs.
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Unraid
forums.unraid.net › home › community › guides › plugins and apps › [tutorial] macos nut install (physical and virtual)
[TUTORIAL] MacOS NUT install (Physical and Virtual) - Plugins and Apps - Unraid
August 9, 2020 - Purpose: Shut down MacOS gracefully prior to system shutdown to extend battery runtime Setup: Cyberpower UPS connected to a Rapsberry Pi running NUT in netserver mode (see TUTORIAL: Networked NUT for Cyberpower UPS) MacOS VM (Mojave) Requirements: Xcode Xcode command line tools Macports 1. Update...
Find elsewhere
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GitHub
github.com › networkupstools › nut › issues › 2223
{Question} Apple MacOS Sonoma & NUT-client (not working) · Issue #2223 · networkupstools/nut
December 12, 2023 - Hi, I'm trying to install nut-client on my Macmini M2 with Sonoma installed. Having a RasberryPI4 as NUT-server and already a windows machine working with Winnut client. However, after installing NUT thru macports, I'm stuck. Could anybo...
Author   networkupstools
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Reddit
reddit.com › r/synology › nut tools running on syno with mac as client?
r/synology on Reddit: NUT tools running on Syno with Mac as client?
August 25, 2021 -

I have a APC Back-UPS ES 650G2. I have these connected to it:

- RPI4 running Home Assistant (there's a NUT server addon)

- Synology DS216j (that has a builtin NUT server)

- Mac running Big Sur (has builtin UPS support but not via network)

Right now the USB cable from the UPS is connected to the Mac.

Problem: I want to safely shut down the PC AND the Syno NAS. I figured the best way would be to plug the UPS USB cable to the Syno and let that act as a NUT server. BUT every solution for the Mac to act as a client is like 6 years old, ending with High Sierra at best. I have asked around at NUT tools Github, got no answer.

Question: has anyone successfully configured and is running a Mac with Big Sur to act as a NUT tools (or APCUPSD but that seems completely abandoned) client?

Thanks!

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Homebrew
formulae.brew.sh › formula › nut
nut — Homebrew Formulae
brew install nut · Network UPS Tools: Support for various power devices · https://networkupstools.org/ License: GPL-2.0-or-later · Development: Pull requests · Formula JSON API: /api/formula/nut.json · Formula code: nut.rb on GitHub · Bottle (binary package) installation support provided for: Current versions: Depends on: Depends on when building from source: Conflicts with: rhino ·
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Super User
superuser.com › questions › 1441153 › how-to-shutdown-macos-mac-osx-from-network-ups-tools-client-nut
How to shutdown macOS / mac OSX from Network UPS Tools client - NUT - Super User
May 25, 2019 - UPS1 will be connected to the Synology diskstation with the Enable UPS Support options - Then time before disk station enter safe mode which I put 5 minutes by default - then on the second UPS2 which is connected to the UPS1 to my Mac mini with the options set to if UPS1 exhausts batteries then USP2 battery will kick on then set the mac mini to shut down ect.
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App Store
apps.apple.com › us › app › ups-power-monitor › id1500180529
UPS Power Monitor App - App Store
UPS devices connected via USB must first be shared through a NUT server. Key Features: • Monitor multiple UPS devices from one app • Cloud monitoring — check your UPS status from anywhere, synced from your Mac • Parameter history charts — track battery charge, load, and other values over 24 hours, 7 days, or 30 days (requires a device running the app to continuously collect data) • Push notifications — get alerted when power switches to battery, returns to AC, or the UPS is fully charged (requires a device actively monitoring the UPS) • View detailed data such as battery charge, estimated runtime, current load, device state, voltage, and battery type* • Display all raw values provided by the UPS or NUT server for detailed diagnostics Local monitoring is available as a one-time purchase.
Rating: 0 ​
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Jimsonofficeequipments
jimsonofficeequipments.com › lqdiufy › macos-nut-client.html
Jimsonofficeequipments
acts with Windows and macOS platforms and is characterized by the support for FTP, SFTP, WebDAV, Cloud Files, Google Drive, Google Storage, and Amazon S3 protocols 5 on 2011 Mac mini NUT version: 2 Requires one mog coin or kupo nut 13 High Sierra; macOS 10 fortinet Windows NUT client This is ...
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NETGEAR Communities
community.netgear.com › netgear communities › welcome to the netgear community › enterprise solutions › readynas › new readynas users & general discussion
NUT on OSX 10.6 [Sharing a UPS with ReadyNAS and Computers] | NETGEAR Communities
November 15, 2009 - The Goal Sharing a UPS with multiple Computer and ReadyNAS devices In this setup we are letting a ReadyNAS be the NUT server and the rest of the ReadyNAS's and Mac will be client of that ReadyNAS. The UPS will have a USB connection with the Server. All of the devices will get their power from ...
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Reddit
reddit.com › r/mac › network ups tools and the mac
r/mac on Reddit: Network UPS tools and the Mac
February 2, 2018 - The community for everything related to Apple's Mac computers! ... I put together a little tutorial on YouTube to configure NUT on a Mac.
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Apple Community
discussions.apple.com › thread › 2706596
OS X Server 10.6 and a linux NUT client - Apple Community
January 19, 2011 - I would like to have one of the ... the Mac Mini to see if a controlled shutdown is necessary. With NUT, you can configure a given machine to poll the UPS (master) or poll another server (client)....