Most software licences are either fully open — take it and go — or fully proprietary — pay first, use second. VBWD uses a third option that is less common and, once you see the mechanics, quite deliberate: the Business Source License 1.1, with a free-use threshold denominated not in dollars but in Bitcoin. You can use VBWD commercially, for free, until your VBWD-attributable sales pass the value of 6.7 BTC in a year. This post explains exactly how that works, why the threshold is priced in Bitcoin, and how to reason about which side of the line you are on.

What the Business Source License 1.1 is

BSL 1.1 is a source-available licence. That means the source code is public — you can read it, modify it, self-host it, and learn from it — but it is not open source in the OSI sense, because it places a limit on production use. The licensor grants an "Additional Use Grant" that defines the free zone, and beyond that grant you need a commercial licence. Critically, BSL is time-limited: every BSL licence names a Change Date and a Change License, and on that date the code automatically converts to the more permissive licence. For VBWD the Change License is Apache-2.0.

So BSL sits between the two poles on purpose. It gives you the transparency and freedom of open source for the vast majority of users, reserves paid licensing for the largest commercial users, and guarantees the whole thing becomes fully open source on a fixed future date. It is a way to fund sustained development without closing the source.

The Additional Use Grant, in plain terms

Here is the grant that matters for VBWD, stated as plainly as possible. You may use VBWD — including for commercial purposes, including to run a real SaaS you charge money for — for free, as long as your annual VBWD-attributable sales stay below the value of 6.7 BTC. Cross that threshold and you need to buy a commercial licence. Non-production use — development, testing, personal projects, evaluation, education — is unlimited and always free, regardless of the threshold.

Two phrases in that sentence do real work. "VBWD-attributable sales" means the revenue your VBWD-based product generates, not your company's total revenue — the grant is scoped to the value the software helps you realise, not to your unrelated business lines. And "the value of 6.7 BTC" means the threshold is a Bitcoin quantity that gets converted to your currency for comparison, using the year's average exchange rate. We will come back to exactly how that conversion works, because it is the interesting part.

Why the threshold is priced in Bitcoin

The obvious question is why not just write "€500,000" or "$500,000" and be done. There are a few reasons, and they are practical rather than ideological.

A fiat threshold silently tightens over time. Inflation means a fixed dollar or euro number represents less real economic activity every year. A "$500k" free tier written today is a materially smaller allowance in a decade — the licence gets stricter without anyone changing a word. Pricing the threshold in a fixed quantity of a scarce asset resists that drift: 6.7 BTC is 6.7 BTC regardless of what fiat does.

It matches a long-horizon licence to a long-horizon unit. BSL is explicitly a multi-year instrument with a Change Date years out. Denominating its threshold in a fixed fiat figure couples a long-lived legal document to a unit that erodes; denominating it in Bitcoin couples it to a fixed-supply unit, which is a more honest match for the timescale.

It is unambiguous and globally uniform. A single BTC quantity means the same thing to a developer in any country, without maintaining per-currency thresholds or arguing about which currency's inflation applies. The conversion to local currency is a well-defined arithmetic step, not a negotiation.

None of this requires you to hold, use, or care about Bitcoin. It is a unit of account for the threshold, nothing more. Your sales are measured in whatever currency you actually earn.

How the conversion actually works

Because the threshold is a Bitcoin quantity and your sales are in fiat, there has to be a defined way to compare them. The licence specifies it: the threshold is valued at the arithmetic average of the daily BTC/USD price over the reporting year, and your VBWD-attributable sales are converted to USD at fair market rates for the same period. In other words, you do not use the spot price on any single day — which would make the threshold swing wildly with Bitcoin's volatility — you use the year's average, which smooths it into a stable figure for that year.

Concretely: take each day's BTC/USD close over the reporting year, average them, and multiply by 6.7. That product is your threshold in USD for the year. Compare it to your VBWD-attributable sales, also expressed in USD. If your sales are below it, you are inside the free grant. The use of a full-year average is what defends against volatility: a spike or crash on any given day cannot by itself push you over or under, because the line is set by the year as a whole.

Which side of the line are you on?

For the overwhelming majority of people evaluating VBWD, the answer is "comfortably inside the free grant," and it is worth being concrete about who that includes.

The threshold is designed so that the people who benefit most from paying nothing — builders, learners, small operators — pay nothing, and the people for whom the software is generating substantial revenue contribute back. That is the entire logic of the model.

The Change Date: it becomes Apache-2.0

The final piece is the one that distinguishes BSL from ordinary proprietary licensing. BSL is not "source-available forever." Every version carries a Change Date — roughly four years from its first public release — after which that version is governed by the Change License, which for VBWD is Apache-2.0. On that date, the code you are looking at becomes fully open source, permissively licensed, with no threshold at all.

This matters for anyone worried about building on source-available software. The worst case — "what if the licence terms turn against me?" — is bounded by the Change Date: the version you adopted converts to Apache-2.0 on a known schedule. You are not betting your business on a licensor's future goodwill; you are relying on a term already written into the licence.

An honest note on enforcement

Because the code is source-available, the threshold is a legal boundary, not a technical lock. Nothing in the source stops you from exceeding the grant; the licence obliges you not to, and the obligation is enforceable the way software licences are — legally. This is a deliberate honesty about what source-available means. The model works because it aligns incentives: the people over the threshold are, by definition, running a substantial business that has every reason to be properly licensed, and a small licence fee against large revenue is not a burden worth risking a licence violation over.

The takeaway

VBWD's licence is BSL 1.1 with a Bitcoin-denominated free-use grant: free for commercial and non-commercial use until your VBWD-attributable annual sales exceed the value of 6.7 BTC (measured at the year's average BTC/USD), with a commercial licence required above that, and automatic conversion to Apache-2.0 on the Change Date. The Bitcoin denomination is a unit-of-account choice that keeps the threshold from eroding over the licence's long life; it asks nothing of you but the ability to do one multiplication. For builders, learners, agencies, and early-stage SaaS, the practical meaning is simple: use it, ship with it, charge for it, and pay nothing until it is making you real money.

The authoritative terms are in the LICENSE file that ships with the source — read it directly; this post explains the mechanics, but the file is the contract.

generate an image