The GNU Affero General Public License (AGPL) is a copyleft open-source license that extends the GPL's source-sharing rules to software users interact with over a network.
What AGPL-3.0 requires
The Free Software Foundation published AGPL-3.0 in 2007. It is the GPL-3.0 plus one extra clause, section 13, often called the network clause.
Under the plain GPL, obligations start when you distribute the software. Running a modified GPL program as a web service is not distribution, so you could keep your changes private. The AGPL closes that gap:
- If you modify AGPL software, and
- users interact with it remotely over a network,
- you must offer those users the corresponding source of your modified version, under the AGPL.
What it does not require:
- Nothing, if you run the software unmodified.
- Nothing about your separate programs that only talk to it over an API.
- No fee, no registration.
An example
A company self-hosts an AGPL scheduler for its own marketing team, unchanged. No obligation applies. Another company adds a feature and sells access to its modified version as a hosted service. It must make its modified source available to those customers.
This is a summary, not legal advice. Check with counsel for your case.
Why it matters for AI-agent publishing
The AGPL keeps improvements to a hosted tool open, so a vendor cannot take the code, change it, and offer a closed service.
SocialHandoff is licensed under AGPL-3.0. Using it, self-hosting it, or connecting agents to its API does not require you to open your own code. See the open source page and open source for license families.