Tortoise License — engine BUSL-1.1, client Apache-2.0, skills MIT

1. In short

Each part of Tortoise carries the licence that matches how it is consumed. The engine (tortoise-graph) is licensed under the Business Source License 1.1 (BUSL-1.1). BUSL-1.1 is not an open-source license; it is a source-available license. Its source code is public, and you may copy, modify, create derivative works, redistribute, and make non-production use of it freely. Production use is free under the Additional Use Grant described below, within its limits.

The artifacts a consumer copies, vendors, or adapts are permissively licensed instead, so that using them never inherits the engine's terms:

These permissive surfaces are deliberate. Tortoise's licensing boundary sits at the network: a product that only connects to Tortoise is never bound by the engine's licence, and the artifacts it receives are permissively licensed so they can be vendored and adapted freely.

2. The license parameters

3. The Additional Use Grant ($5M)

The Additional Use Grant (AUG) permits an organization to make production use of the self-hosted version of Tortoise for its own internal purposes without a commercial license, provided that the organization's total annual revenue does not exceed US $5M (or the equivalent in other currencies) in the most recent twelve-month period.

In other words: if you run Tortoise yourself, for your own operations, and your organization's trailing-12-month revenue is at or below US $5M, production use is free. Non-production use (development, testing, evaluation) is always free, regardless of revenue.

4. What the grant never permits

The Additional Use Grant never permits offering Tortoise, or a substantially similar product, to third parties as a hosted or managed service. The grant also does not permit reselling or sublicensing the Licensed Work. These uses always require a separate commercial license, regardless of revenue.

5. The hosted service

The hosted Tortoise service (tortoise.premiselabs.co) is a separate commercial product with a free tier. It is not covered by the BUSL-1.1 grant. Use of the hosted service is governed by the Terms of Service, the Privacy Policy, and the Data Processing Agreement, not by the BUSL-1.1 license.

6. When do I need a commercial license?

You need a commercial license if either applies:

• Revenue above the threshold: your organization makes self-hosted production use of Tortoise and its total annual revenue exceeds US $5M (or the equivalent in other currencies) in the most recent twelve-month period; or
• Hosting as a service: you offer Tortoise, or a substantially similar product, to third parties as a hosted or managed service — at any revenue level.

For information about commercial licensing, email [email protected].

7. What happens after four years?

On the Change Date — four years after each version of Tortoise is published — that version is made available under the Mozilla Public License 2.0 (MPL 2.0), which is OSI-approved. The Change Date applies separately to each version, so each version converts on its own schedule.

8. The full license text

Each licensed work publishes its own authoritative text:

• Engine (Business Source License 1.1) — github.com/daniel-ospina/tortoise/blob/main/LICENSE
• Thin client (Apache-2.0) — github.com/daniel-ospina/tortoise/blob/main/client/LICENSE
• Served skills (MIT License) — app.premiselabs.co/skills/LICENSE
• Skills installer (MIT License) — the SPDX-License-Identifier: MIT header and permission notice carried inside install-tortoise-skills.sh itself, so a curl … | bash run receives it. It is served alongside skills/LICENSE, but that file covers the skills tree, not the script.

If you have questions about the license, open an issue at https://github.com/daniel-ospina/tortoise/issues.