Copyleft, by default

Why AGPL for some and GPL for others

AGPL where the software is something you would run as a service for other people, GPL where it is a tool you run on your own machine. The distinction is the one the licenses themselves draw: AGPL closes the gap where a network service can be built on copyleft code without ever handing the improvements back, and mail and observability are exactly that shape. A migration script is not, so it does not need the extra clause.

Open core, without a license carve-out

Cairn OBS is described as open core, and that is worth being precise about rather than quietly dropping. It means there is an enterprise/ directory in the tree and an intention to sell support and hosting around it. It does not mean the license changes when you open that directory: it is AGPLv3, like every other path in the repository. Multi-tenant RBAC, the directory integration, the alerting evaluator, the Terraform provider and the AI-assisted query authoring are all in the same tree under the same terms. There is no build with more features in it than the one you can compile.

What this costs

The trade is deliberate. Copyleft makes some commercial arrangements awkward, and a company that wants to embed one of these in a closed product will need a different conversation rather than a different download. That is the intended outcome. The reason to accept it is the one on how we work: the code under an incident should be code you can read, and a license is what makes that true next year as well as today.

If you are trying to work out whether your intended use is compatible, the license text in each repository governs and this page does not — it describes what is there, it does not grant anything. Ask at licensing@coffeylabs.org if it is genuinely unclear.