Building a SaaS engine in public: shipping the billing seam, not billing

I tagged v0.9.0 of LaraFoundry this week: billing. Except the honest headline is that I shipped the billing seam , not billing. The free core now has the whole shape of a subscription system, a payment-gateway contract, a driver manager, a real access gate over subscription columns, and it cannot take a single cent. That is on purpose, and the reason is the most interesting part of the phase. LaraFoundry is a SaaS core I'm extracting in public from a live CRM, one module at a time. The deal I made with myself early on: the core is free and stays free for everything except money. Auth, multi-tenancy, RBAC, the admin console, the activity log, i18n, files: all free. The day a business wants to charge its customers , that is the paid part. So billing could not just be "another module." It had to split cleanly down a line, with the free side carrying real, useful structure and the paid side carrying the parts that actually move money. The donor habit I would not carry Here is what the original CRM did when a company "paid" for its subscription: // TODO: real payment gateway integration // TEMPORARY: every payment is successful, for testing $paymentStatus = 'success' ; That success was hardcoded. There was no Stripe, no Paddle, no gateway at all. "Paying" wrote a row into a company_payments table and flipped the subscription date forward. For a CRM I run myself, with one real user, that was fine: I never needed the real thing, so the placeholder sat there indefinitely. The moment this becomes a reusable core, that placeholder is poison. A success that is always true is worse than no gateway, because it looks like billing works. So the rule for this phase was simple: the fake gateway does not get extracted. Whatever stands in its place has to be honest about the fact that it takes no money. What the seam actually is The free core ships a PaymentGatewayInterface : subscribe, cancel, refund, status, and verify a webhook. It describes only the mechanics of moving money. It d