What the Licence Means for You¶
pg_relay_notifier is released under the MIT Licence. It's one of the shortest and most permissive open-source licences there is. This page explains it in plain English.
This is a summary, not legal advice
The full licence text is the document that actually governs your use. If your organisation has a legal or compliance process for third-party software, give them that text, not this page.
What you may do¶
Use it for anything. Personal projects, internal company systems, products you sell. There's no distinction between commercial and non-commercial use, and no user or server limit.
Read and change the source. It's a pure SQL/PL/pgSQL extension — the entire thing is a readable script. Modify it however you need.
Redistribute it. On its own or bundled inside something larger. You may charge money for whatever you build with it.
Keep your changes private. The MIT Licence isn't a "copyleft" licence: modifying pg_relay_notifier doesn't oblige you to publish your modifications or license your own software the same way.
What you must do¶
Exactly one thing: keep the copyright notice and the licence text in any copy or substantial portion of the software you distribute.
In practice, if you ship pg_relay_notifier (or a modified version) to someone else, include the LICENSE.md file. That's the entire obligation.
What you are not given¶
No warranty. The software is provided "as is". If it doesn't do what you expected, that's not a breach of anything.
No liability. The authors and copyright holders cannot be held liable for any damages arising from your use of it — including data loss or business interruption.
This is standard for open-source software, and it's why the notice in the licence is written in capital letters. It's worth reading properly.
No support entitlement. The licence grants you no right to help. That said, bugs and feature requests are genuinely welcome — see the issue tracker.
What this means in practice¶
For nearly every reader, the MIT Licence means: use it, change it, ship it, and keep the licence file with it.
If you're being asked to get third-party software approved internally, the MIT Licence is one of the most widely accepted licences in existence and is on the approved list of essentially every organisation that maintains one.
A note on pg_relay¶
pg_relay_notifier requires pg_relay, which is a separate piece of software with its own licence — also MIT, from the same publisher. Installing pg_relay_notifier means installing pg_relay too, so if you're running a licence review, cover both.
If you also install the optional pg_relay_notifier_utl_mail extension, that's covered by this same licence and the same LICENSE.md file — it's part of this repository, not a separate piece of software.