LICENSING

Kilter Licenses

Kilter is source-available and time-locked to open source. You can read it, run it, and — on a schedule we can't quietly change — own it outright. Leaving is easy by design, because that's what keeps us honest.

Plain-language summary. This page explains how kilter is licensed; the binding terms are in the LICENSE file shipped with each release and in your written agreement. Where they differ, those documents govern.

The short version

  • Kilter is made available to clients under a Business Source License (BSL) — source-available, with one restriction: you can't turn kilter itself into a competing hosted offering.
  • Every release automatically converts to the Mozilla Public License 2.0 (MPL-2.0) two years after it ships. The restriction lifts on a fixed date we publish up front and cannot move backward.
  • Source escrow is available to clients and partners, so your access to the code survives us.

Business Source License

Clients receive kilter under the Business Source License. Under the BSL you may read the source, build it, run it in development and in production, and modify it for your own use. The single "additional use grant" restriction is the obvious one: you may not use kilter to offer a commercial hosted product that competes with Paddington's managed service. Everything a team actually wants to do — self-host, audit, patch, extend, run agentic workloads — is permitted.

Two-year MPL release

The BSL is time-boxed. Each kilter release carries a Change Date two years after its publication and a Change License of MPL-2.0. On the Change Date, that release — for everyone, not just clients — automatically re-licenses under the fully open-source MPL-2.0, and the competing-service restriction falls away. The date is set when the version ships and can only ever move earlier, never later. In practice, kilter is open source on a rolling two-year trailing edge, and the current release is source-available today.

Source escrow for clients & partners

For clients and partners who need assurance beyond the license itself, we offer source escrow. A copy of the kilter source — including the versions you run in production — is deposited with an independent escrow agent and released to you under agreed conditions, such as Paddington ceasing to operate or failing to meet defined support obligations. Escrow release is separate from, and additional to, the rights the BSL and its scheduled MPL conversion already give you.

Why we license it this way

The whole pitch of the sovereign cloud is that your infrastructure is yours to keep and easy to leave. A source-available license that converts to open source, plus escrow, is how we put that in writing. If we ever stopped earning your business, you would already hold everything you need to walk — which is exactly the enforcement mechanism that keeps our pricing and our behaviour honest.

Questions

Licensing, escrow, or partnership questions: hello@paddington.io. See also our Terms of Service.