Source-available vs open source: what the BSL 1.1 actually means

“Open source” has a specific meaning, and slapping it on software that isn’t is how trust gets burned. The Wardenclyffe AI Engine is source-available under the Business Source License 1.1 — a real distinction, and one worth understanding before you build on it.

The distinction, stated honestly

Open source, in the OSI sense, means the license grants everyone the right to use the software for any purpose, including running it as a competing commercial service, with no field-of-use restriction. Apache 2.0, MIT, and the GPL all qualify.

Source-available means you can read, modify, and build the source — but the license places some limit on how you may use it. The Business Source License (BSL) 1.1 is the best-known example. Calling BSL software “open source” is simply inaccurate, and we won’t do it. You get the source; you don’t get an unrestricted grant.

What the BSL 1.1 permits

The BSL is short and readable, which is part of why we chose it. The shape of it is:

• You can read all of it. The full source is published. Nothing is obfuscated or withheld.
• You can modify and self-host it, within an “Additional Use Grant” the author defines. For Wardenclyffe, that grant is generous: run it in production free as long as your store is under $1M in annual gross merchandise value.
• You can’t offer it as a competing hosted service, and above the GMV threshold you need a commercial license. That’s the restriction that keeps it out of “open source” territory — and it’s the whole reason the source can be published at all without the project being strip-mined by a larger host.
• Every release converts to Apache 2.0 on a fixed date. For Wardenclyffe that date is May 14, 2029. On that day, today’s code becomes fully open source, permanently. The BSL is a time-boxed restriction, not a forever one.

That last point is the part people miss. The BSL isn’t “proprietary with a peek.” It’s a delay: the author gets a few years of commercial protection, and then the community gets Apache. If the project vanished tomorrow, the clock would still run out and the code would still open.

Why not just use Apache from day one?

Fair question, and the honest answer is economics, not ideology. A small team publishing a genuinely useful commerce engine under Apache 2.0 invites a well-funded platform to host it, out-market the authors, and capture the value — while contributing nothing back. The BSL lets the same source be public and lets the authors fund the work that keeps it alive. If you think that trade is wrong, the GPL and Apache worlds are large and welcoming; we won’t pretend one model dominates every case.

What it means for you, concretely

• Running a normal store under $1M GMV? You have the full source, can modify it freely, pay nothing, and owe nothing. Practically, it behaves like open source for you.
• Above $1M, or embedding it in a product you sell? You need a commercial license. That’s a conversation, not a wall.
• Worried about lock-in or abandonment? The source is already in your hands, and the Apache conversion date is written into the license. Two independent safety nets.

How this pairs with self-hosting

Source-availability is what makes self-hosting meaningful rather than cosmetic. Holding the binaries is useful; being allowed to read and change the source behind them is what lets you patch a bug, audit how a payment is handled, or verify exactly how an agent’s permissions are enforced. A license you can actually read, on code you can actually run, is the point — and it’s why we’re careful to call it what it is.