SKEIN license: questions and answers
License text on GitHub Pricing
Our approach
We think AI agents will change the way software is distributed and paid for. The familiar schemes — a fee per user per month, per seat, per new hire — fit poorly in a world where half the work is done by agents. What the new scheme will be, we don't know. Nobody knows yet.
At the same time, we need to make a living, and we need money. And we love open source: we want SKEIN to be open, so that people use it, change it, improve it and build their own things on it.
So this is what we decided:
- Only we can make money hosting SKEIN — we and those we have an agreement with. We won't charge for our hosting the classic way, so many dollars per user per month.
- For-profit organizations of 100 people or more pay us for a license — a fixed amount per year for the whole group of companies, with no per-seat fees. Prices are on the pricing page. Non-profits never pay.
- For everyone else, using SKEIN internally is free. Use it, change it, deploy it on your own servers, make money on services around it.
We won't check anything — we believe in trust.
What you can and can't do
| You can | You can't | |
|---|---|---|
| Use | install it on your servers and work in it — free if your organization has up to 99 people | for-profit organizations of 100 people or more — keep using it past the free period without a license |
| Try | test, evaluate, run a pilot and write integrations on a test environment — free for everyone | — |
| Modify | read the code, change it, fork it, build your own versions | — |
| Agents | connect as many as you like, free | — |
| Integrate | connect your own programs to SKEIN over the REST API and MCP | — |
| Host for others | let others into your SKEIN for free: students, a community, partners you work with | charge for access to your SKEIN, or for plugins, quotas, capacity or support for that instance, either yourself or through an intermediary |
| Earn on services | consulting, process design, configuration, integrations, training; installing SKEIN for a customer on infrastructure the customer controls (its own, or rented in its name) — for any fee | sell access to your instance dressed up as services |
| Name | say “Powered by SKEIN”, “for SKEIN” | call your service “SKEIN …” or pass it off as the official one |
Who pays and how much is on the pricing page. In short: free for everyone up to 99 people and for non-profits; large for-profit companies pay a fixed annual fee.
Four years after its release, each version of SKEIN moves to MPL 2.0 — an OSI-approved open source license with its own terms.
General
Is SKEIN open source?
No. The source code is open (source-available), but the license is the Business Source License 1.1 — one of the Fair Source family of licenses — not open source by the OSI definition. You can read, change, build and use it. Three limits apply. Paid hosting of SKEIN for others is not allowed. Embedding SKEIN in a product that competes with it is not allowed when that product is offered on a paid basis, including paid support. A for-profit organization of 100 people or more needs a license for production use after its free period. Testing, evaluating, a pilot and writing integrations on a test environment are free at any size. Each version becomes open source under MPL 2.0 four years after its release.
Who owns SKEIN?
SEBO - FZCO, Dubai, United Arab Emirates — the Licensor named in the license.
Where is the license itself?
In the LICENSE file at the root of the repository: license text on GitHub. The license sets out the basic rights. This FAQ explains it and may grant additional permissions, but it can't take away what the license gives. A permission published in this FAQ applies to every version released while it is published, and is not withdrawn for those versions. The change history is at the bottom of this page. The English version of the FAQ prevails; translations are for convenience.
What you can and can't do
Can I install SKEIN at my company and use it internally?
Yes — on your own servers, in an air-gapped network too, in production, together with all your affiliated companies. If the organization is for-profit, has 100 people or more together with its group, and its free period has ended — under a license, see “Pricing”.
Can I fork SKEIN?
Yes: read the code, change it, fork it, build your own versions. A fork stays under the same license — each version it is based on moves to MPL 2.0 four years after that version's release.
Can I sell SKEIN as a cloud service (SaaS)?
Not without a separate agreement with us. You can't charge for access to a SKEIN you host, or for plugins, quotas, capacity or support for that instance, either yourself or through an intermediary. For hosting providers, see below.
Can I run SKEIN for others for free — students, a community, open source projects?
Yes. Free hosting for others is allowed. A for-profit organization of 100 people or more still needs a license after its free period, on the same terms as anyone else (see “Pricing”). Giving others free access does not remove that requirement. Call the service by your own name and say “Powered by SKEIN”.
We installed SKEIN and want to let partners in for free. Who pays?
Guests don't pay. If you let partners or another organization into your SKEIN for free, only the owner of the instance pays — if it is a for-profit organization of 100 people or more. The exception: an instance that runs wholly or mainly for a for-profit organization of 100 people or more, or was set up at its request, counts as that organization's use, and that organization pays. You can't charge for access to your SKEIN, either yourself or through an intermediary.
Can I show ads on a free server?
Yes, as long as access to SKEIN itself is free. Just don't put the SKEIN name next to misleading, illegal or reputation-damaging advertising.
Can I make money consulting around SKEIN?
Yes, and we're glad you do: process design, configuration, integrations, training, consulting — for any fee. What you can't do is sell access to your own instance dressed up as services: “pay us and your SKEIN will be faster, with a bigger disk, with support” — that is paid hosting.
I'm an integrator. Can I charge for installing SKEIN for a customer?
Yes: installation, configuration, maintenance, training — if the customer has its own instance on infrastructure the customer controls and you don't supply. Giving every customer its own SKEIN is fine. Putting ten customers on your own instance and charging them for it is paid hosting. A paid installation doesn't release the customer from its own terms: if the customer is a for-profit organization of 100 people or more, it needs a license.
Can I connect my own program to SKEIN?
Yes. Talking to SKEIN over the REST API and MCP — creating tasks, reading them, connecting CI, bots, agents — is allowed. An integration in itself doesn't count as embedding; the other terms — payment by for-profit organizations of 100 people or more and the ban on paid hosting — still apply.
Can I embed SKEIN in my product?
If you want to embed SKEIN in your product, write to us.
I'm a hosting provider. Can I offer SKEIN to my customers?
Renting out servers and virtual machines on which customers install SKEIN themselves is fine. But if you install SKEIN on a server you rent out yourself, or offer it preinstalled, as a ready “one-click” image or through your own installation tools, that is your hosting of SKEIN, and you can't charge for it without an agreement with us. To offer SKEIN under its name, or to sell access to an instance on your infrastructure, write to us and we'll make an agreement.
Can I call my service “SKEIN …”?
No. “Powered by SKEIN”, “built on SKEIN”, “for SKEIN” are fine. The details are in TRADEMARKS.md in the repository.
Contributing
How do I send a change?
Through a pull request to the repository. By sending a change, you accept the contributor certificate — there is nothing to sign.
Who owns my change?
Copyright stays with its existing owners — you or, for example, your employer. The project gets a perpetual permission to use the change, including in the commercial version. The details are in CONTRIBUTOR-CERTIFICATE.md in the repository.
Why aren't changes accepted under the project's own license?
The BSL itself doesn't give us the right to grant commercial licenses to other people's code. Without that permission we couldn't include your change in the commercial version. The contributor certificate gets that permission up front and asks for no more than it needs: you give a permission, not ownership.
Security
I found a vulnerability. Where do I report it?
Don't open a public issue. Where to report and what to expect — see SECURITY.md in the repository.
Versions and the future
What happens after four years?
Four years after its release, each version moves to MPL 2.0. From then on, the BSL restrictions are lifted for it: on production use, on paid hosting and on organization size. The terms of the MPL itself remain — for example, if you distribute modified SKEIN files, you have to publish their source code. The MPL gives no rights to the SKEIN name.
Can the terms change?
For new versions — yes. A version that has already been released keeps its terms. Prices on the pricing page may change; existing customers keep their price until renewal.
Change history
- 1.0 — 23 October 2026 — first version.