Network UPS Tools
Power Devices support

The primary goal of the Network UPS Tools (NUT) project is to provide support for Power Devices, such as Uninterruptible Power Supplies, Power Distribution Units, Automatic Transfer Switches, Power Supply Units and Solar Controllers. NUT provides a common protocol and set of tools to monitor and manage such devices, and to consistently name equivalent features and data points, across a vast range of vendor-specific protocols and connection media types.

NUT provides many control and monitoring features, with a uniform control and management interface. If you are just getting acquainted with NUT, that page also explains the technical design and some possible set-ups. The NUT Overview (manual page) can be another good starting point.

As of this publication, at least 190 different manufacturers, and 1371 hardware device models are known as compatible.

This software is the combined effort of many individuals and companies with free and open source code licensed under the terms of GNU Public License (GPL), see the NUT license text for specific details.

NUT GitHub Star History Chart
Tip
GitHub Stars Matter!

Potential institutional sponsors remind that having a high "GitHub Star" count helps with formal considerations for supporting FOSS projects, so please feel welcome to leave yours at https://github.com/networkupstools/nut/
Note
Two NUT websites

The main NUT site should closely follow current development, with documentation most relevant for users who build NUT from source code.

Sub-sites are available for some historic releases for users of NUT packaged with their operating system distributions. Such packages are typically based on official releases of NUT at the time of distribution, and may lag behind current development in terms of features, capabilities, bug-fixes and supported devices.

Some data, such as devices with known support at the time of release, are published to reflect both current development and historic releases; other data such as the NUT DDL or source archives are release-agnostic and only published once and for all.

News

  • Apr 21, 2025: NUT v2.8.3 released, for more details please see GitHub release page for NUT v2.8.3 and Release notes for NUT 2.8.3 - what’s new since 2.8.2.

    • ERRATA: Please check NUT PR #2955 for a possible issue about usbhid-ups ignoring instant commands without arguments, breaking default UPS shutdown scenarios

    • A few "non-critical" issues that should not get triggered in typical builds and end-user environments were also identified, detailed on GitHub

  • Apr 7, 2025: Community work has intensified on NUT v2.8.3 release candidates, testing them and making last-minute flaw discoveries on diverse real-life systems. Great thanks to everyone participating.

  • Apr 3, 2025: NUT has been accepted for another year of DigitalOcean sponsorship for FOSS compute resource hosting, for the core of multi-platform NUT CI farm

  • Mar 30, 2025: Are you wondering how NUT Quality Assurance and Build Automation happens? Perhaps you want to do similar feats in your project? Well, now I can say "I wrote a book on that!" :)

  • Mar 28, 2025: WMNut 0.71 released, addressing compatibility with C23, adding new ups.status token support, and revising some documentation and recipes

  • Feb 28, 2025: with NUT PR #2825 merged, a technologically and practically interesting revamp of NUT mesh of automake (Makefile.am) recipes was completed, allowing for a more parallelizable build routine on multi-CPU machines, utilizing more cores and completing in less "wall-clock" time that the standard SUBDIRS driven approach. It is not a radical rewrite like some other projects suggest, and so retains the general structure and certain benefits and flexibility of that standard approach, including developer build workflows with a bespoke Makefile in every significant directory. Overall, NUT CI farm build times got 25%+ shorter (which is important as some scenarios had hit the 1-hour timeout imposed by providers of free CI hosting), and we suppose this is an interesting case for other projects to draw inspiration from for their recipe refactoring.

  • Nov 6, 2024: due to update of NUT CI farm’s Jenkins core, numerous build agent configurations and OSes had to be updated to use JDK17+. NUT documentation for build prerequisites and CI setup was accordingly updated.

  • Aug 12, 2024: WMNut 0.70 released, addressing some warnings found by newer compilers and updating code style, documentation and recipes

  • Mar-Jul, 2024: much work was done about up-streaming code developed by Eaton as part of 42ITy™ project and related efforts, and expanding NUT CI farm testing (and recipe/code abilities) on MacOS with Homebrew (x86, arm), all due to be part of NUT v2.8.3 release

  • Apr 1, 2024: NUT v2.8.2 released, for more details please see GitHub release page for NUT v2.8.2 and Release notes for NUT 2.8.2 - what’s new since 2.8.1.

  • Nov 15, 2023: following up with DigitalOcean sponsorship for FOSS compute resource hosting after some hiatus on the NUT CI side (too many plans, too little time)

  • Nov 9, 2023: the PyNUT module provided in NUT sources is now published as PyNUTClient by CI to https://pypi.org/project/PyNUTClient (release snapshots) and https://test.pypi.org/project/PyNUTClient/ (rolling master-branch revisions). Hopefully, pip would have easier time finding it now to help create NUT clients.

  • Oct 31, 2023: NUT 2.8.1 released, for more details please see GitHub release page for NUT v2.8.1 and Release notes for NUT 2.8.1 - what’s new since 2.8.0.

    • ERRATA: Please check NUT PR #2155 for a possible segmentation fault fix with INSTCMD processing

    • ERRATA: in nut-scanner results, apc_modbus can be suggested even if you lack a libmodbus version with USB support; try usbhid-ups instead then

  • Oct 20, 2023: a very long-awaited feature is now delivered, an APC Modbus capable NUT driver apc_modbus (due to be part of NUT v2.8.1 release)

    • NOTE: As of this publication, the upstream libmodbus project lacks the needed support for USB; a fork is available and PR to upstream is pending.

  • Oct 3, 2023: thanks to generous FOSS project support from Gandi.net, NUT DNS hosting costs are now handled by them

  • Sep 18, 2023: access to interactive NUT CI farm resources now requires a logged-in session (web scrapers overwhelmed it)

  • Sep 12, 2023: NUT documentation was restructured, in particular, from now on the current codebase provides INSTALL.nut.adoc, NEWS.adoc and UPGRADING.adoc files (with .adoc extensions) so older URLs pointing to files without these extensions may have got obsoleted. This change allows IDEs (including GitHub Web UI) to render most of the markup automagically. Also, a recipe and artifact for release-notes.pdf is now provided.

    • Important note: "Chunked HTML" documentation format generation was changed to produce HTML file names based on chapter title, not cryptic enumeration-based file names. This may help with long-term stability of URLs in blogs, etc. (chapter numbers did change over time). Existing "cryptic" filenames were aliased to new ones, but eventually will be deprecated.

  • Sep 1, 2023: WMNut 0.69 released, updated for NUT 2.8.0 API compatibility and with revised documentation, CI checks, and build recipes

  • Aug 3, 2023: revised the mark-up language and contents for NUT DDL (Devices Dumps Library) data files, so the generated pages should now expose much more structured information that was "hidden" there for years

  • May 31, 2023: published maintainer GPG key, DE0184DA7043DCF7: public key "Jim Klimov (Doing FOSS since last millennium) <jimklimov@gmail.com>" and updated metadata for past NUT v2.8.0 release

  • Feb 2, 2023: signed up for fiscal hosting with Open Source Collective at https://opencollective.com/networkupstools/ and GitHub sponsors program at https://github.com/sponsors/networkupstools

  • late 2022/early 2023: re-affirmed NUT portability goal that new releases should build and run at least wherever old ones worked, by making sure it still works on CentOS 6, Debian 7 and Solaris 8 (yes, there are users who still run them!)

  • Dec 7, 2022: confirmed DigitalOcean sponsorship for FOSS compute resource hosting

  • Sep 3, 2022: codebase of the NUT for Windows branch was merged to main codebase, not in the least to avoid bit-rot and need for re-synchronisation with merge conflicts that regularly arose as they co-existed. More community work is needed to complete some drivers' functionality and MSI package delivery, but for many use-cases it may already "just work".

  • Aug 18, 2022: efforts to revive NUT for Windows development (active since spring 2022) have reached the stage of regular CI builds on AppVeyor in semi-native environment (Windows with MSYS2/MinGW x64); regular cross-builds with Linux+MinGW environment were activated earlier

  • Aug 10, 2022: "UPS management protocol", Informational RFC 9271 published by IETF at https://www.rfc-editor.org/info/rfc9271 and the IANA port number registry was updated at https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=3493 (even though this RFC is not formally an Internet Standard)

  • May 10, 2022: added free layer of CircleCI to the ecosystem of NUT builders, to cover MacOS and later maybe Windows

  • Apr 26, 2022: NUT 2.8.0 released, for more details please see GitHub release page for NUT v2.8.0 and Release notes for NUT 2.8.0 - what’s new since 2.7.4.

  • Apr 24, 2022: a "dress rehearsal" for new release issuing NUT 2.8.0-rc3, focusing on documentation and API updates to impact the ecosystem just once

  • Apr 10, 2022: preparing for new release by issuing NUT 2.8.0-rc2, fixing found bugs, adding late-coming features, and rehearsing some automation involved

  • Apr 7, 2022: nut-website repository integrated with NUT CI farm to enable regular documentation updates as NUT code development and DDL get refreshed. Users of official "historic" releases which are the basis for distribution packaging have the new sub-sites frozen in time.

  • Apr 1, 2022: preparing for new release by issuing NUT 2.8.0-rc1

  • Feb 5, 2022: main nut-website regenerated to follow iterative development of NUT features more closely

  • Feb 4, 2022: nut-website repository rearranged to allow publishing sub-sites with historic NUT releases (to help users of distributed packages configure their deployments); published v2.7.4

  • Feb 4, 2022: nut-ddl repository gets rudimentary CI to avoid not-parsable device dump filenames

  • Jan 12, 2022: completed the merge of libusb-1.0 related branches into main NUT codebase

  • Jan 10, 2022: added GitHub pull request templates for nut and nut-ddl to help people post better contributions

  • early Jan 2022: NUT CI farm migrated to a different datacenter from sponsors of Fosshost

  • May 23, 2021: complementary projects led by Roger Price now hosted in the NUT organization on GitHub: the famous Config Examples book, as well as TLS Shims and TLS UPSmon for community discussion about secured NUT client-server communications

  • March 6, 2021: great thanks to Fosshost Org for providing virtual servers that we can use for diverse build farm!

  • November 13, 2020: announced handing of maintainership reins from Arnaud Quette to Evgeny "Jim" Klimov

  • February 8, 2017: new projects 42ITy™ and Eaton Intelligent Power Controller

  • April 28, 2016: new project ntUPSd - Network UPS Tools Services for Windows

  • April 17, 2016: VMware NUT client 2.7.4 for ESXi 5.x and 6.0

  • March 9, 2016: NUT 2.7.4 released

  • May 13, 2015: Beta NUT 2.6.5-6 package for Windows released

  • April 16, 2015: NUT 2.7.3 released

  • October 26, 2014: VMware NUT client 2.7.2 for ESXi 5.x

  • April 17, 2014: NUT 2.7.2 released

  • February 18, 2014: new project nut-snmpagent

  • February 14, 2014: Formalizing the end of the relationship with Eaton

  • November 20, 2013: NUT 2.7.1 released

  • June 21, 2013: new client walNUT released

  • February 10, 2013: NUT source repository is converted to Git using reposurgeon

  • September 19, 2012: Beta NUT 2.6.5-3 package for Windows released

  • September 17, 2012: Beta NUT 2.6.5-2 package for Windows released

  • August 9, 2012: Beta NUT 2.6.5-1 package for Windows released

  • August 8, 2012: NUT 2.6.5 released

  • June 27, 2012: VMware NUT client for ESXi 5.0

  • June 5, 2012: WMNut 0.64 released, and move hosting

  • June 4, 2012: Beta NUT 2.6.4-1 package for Windows released

  • May 31, 2012: NUT 2.6.4 released, including CVE-2012-2944 fix

  • May 10, 2012: WMNut 0.63 released

  • May 9, 2012: Official publication of Riello communication protocols

  • May 2, 2012: Beta NUT 2.6.3-3 package for Windows released

  • April 26, 2012: Beta NUT 2.6.3-1 package for Windows released

  • January 4, 2012: NUT 2.6.3 released

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