Two licences, one product.

Source-available under the Business Source License 1.1. You can read it, modify it and run it in production for your own organization's internal purposes, at any scale, at no cost. (The engine includes turba, its own LSM storage layer, alongside the query layer, the xyTalk parser, the server, the CLI and the MCP server.)

A commercial licence is required for any production use that makes the engine — or what it does — available to third parties, whether or not you charge for it: offering it as a hosted or managed service; using it as a component of a product, application or service that third parties reach; or supplying it to others for their own production use.

The line is internal versus third parties, not free versus paid. A free service running on xyzDB needs a licence too.

Consultants and integrators may install, deploy, operate, support or maintain it on a client's behalf, for a fee, provided the client's own use would itself be permitted.

Each version converts automatically to the Apache License 2.0 within three years of release — 2029-08-01 for version 1.0. That window can be brought forward, never pushed back.

Commercial arrangements: licensing@tuno.bar

The thin clients for Python, JavaScript/TypeScript and Rust are released under the Apache License 2.0 — a permissive, OSI-approved licence with no restriction on commercial use, including as a dependency of a hosted service.