License — fair-code
killBottleneck is not "open source" in the strict, OSI sense — and we say so plainly rather than borrowing the label. It is fair-code, under the Sustainable Use License (the same one n8n uses).
In plain words
| You may | You may not |
|---|---|
| Download the source, read it, run it | Resell it, or host it as a service for third parties |
| Use it internally — company, team, yourself | White-label it as your own product |
| Modify it for your own needs | |
| Self-host it for free, forever |
The one thing the license exists to prevent is somebody taking the work and selling it as a hosted service. Everything an ordinary self-hoster wants to do is allowed.
Why not Apache or MIT
Because the project is built and maintained by one person, and a permissive license would allow a well-funded party to run it as a paid service without the maintainer ever seeing any of it. The fair-code model keeps self-hosting free — which is the point — while leaving hosting as the one commercial right that is not given away.
Being honest about the label matters. Calling source-available code "open source" annoys exactly the people who care most about licensing, and they are right to be annoyed.
Need something the license does not allow?
A commercial license can be negotiated separately — for hosting it, embedding it in your own product, or white-labelling it. Get in touch.
Contributions
The project is open to read and fork, but closed to code contributions: ideas and bug reports are very welcome, pull requests with code are not accepted. If you need it to work differently, fork it for yourself — the license allows exactly that.
See CONTRIBUTING.md in the repository for the details, and SECURITY.md for how to report a vulnerability.