Best AGPL-3.0 Licensed Open Source Repositories

The GNU Affero General Public License version 3 is a copyleft license built specifically to close what's known as the 'SaaS loophole' in the regular GPL. Under plain GPL, a company can modify open-source code, run it as a network service, and never share the changes because it never actually distributes the software to end users. AGPL-3.0 closes that gap: if you modify AGPL-licensed code and let users interact with it over a network, even without shipping any binaries, you must make the complete modified source available to those users. Aside from that network clause, it follows the same structure as GPL-3.0. You can run, study, modify, and share the code freely, including for commercial purposes. Any distributed version, and any hosted service built on it, must remain under AGPL-3.0 and come with its source code, license text, and a record of changes. You also cannot add further restrictions or wrap the code in a more permissive license when you redistribute it.

Projects reach for AGPL-3.0 when they want their code to stay open even as competitors turn it into a hosted product. It is common in self-hosted apps, databases, and collaboration tools where the maintainers worry about a cloud provider forking the project and selling it as a closed service without contributing back. It also gives commercial dual-licensing models more weight: companies can sell a separate commercial license to businesses that don't want AGPL's sharing obligations, while keeping the community edition free. The tradeoff is that AGPL scares off some companies entirely, since legal teams often ban AGPL dependencies outright to avoid the network copyleft clause spreading into their own codebase. Repos on this page under AGPL-3.0 include Immich, Grafana, and Vaultwarden, each of which uses the license to keep self-hosted deployments and any hosted forks open source.