The GNU Affero General Public License version 3 (AGPL-3.0) is an open-source license. It defines what users may do with the software and what obligations follow from that. For an ERP system like Nuclos, which is licensed under the AGPL, it sets the legal frame for operating, modifying and redistributing it.

What the AGPL grants

The AGPL grants three core rights:

• Free use. The software can be deployed internally without limit, with no license fee per user or seat.
• Right to modify. The source code can be adapted, extended and integrated into a company’s own processes.
• Right to inspect. The full source code is open. Modifications can be reviewed, audited, and, if needed, continued by a different team.

The network clause: the difference from GPL

The AGPL differs from the plain GNU GPL through one added obligation: the network-use clause. Under the GPL, the duty to disclose source code applies only when the software itself is distributed as a program. If it is only offered as a service over a network, for example as a hosted web application, the GPL does not trigger a disclosure duty.

The AGPL closes exactly this gap. Anyone who makes a modified version of AGPL-licensed software available to others as a network service, for example as a SaaS offering, must provide those users with the complete, modified source code. Purely internal operation with no third-party network access does not trigger this duty.

Why this structurally rules out lock-in

For an ERP, this means a vendor cannot run a closed, proprietary version of the software as a network service without disclosing that version’s source code. Since Nuclos itself is licensed under the AGPL-3.0, this applies to Nuclos as a vendor as well. Customers retain a claim to source code and data regardless of whether an instance is self-hosted or operated externally. For management, the practical takeaway is: no hidden lock-in through closed-door further development that only the vendor can see.

The AGPL is a structural argument for independence, not a substitute for checking contracts, export paths and the operating model in each specific case. The broader question of why open source matters for ERP is covered in more depth in Open source ERP.

This article is a general, technical overview of the license terms and not legal advice. For a legal assessment of a specific situation, for example your own redistribution or combination with other software, consult a lawyer. Nuclos does not guarantee the legal accuracy of this overview for any individual case.