Medusa.js
We implement, migrate and integrate stores on Medusa v2.
What you get
Shipped code with public documentation, not a roadmap. Every point is shown on the screen where it actually happens.
Allegro on one catalogue. Offers match catalogue variants by SKU inside one sales channel. Orders drain in every twenty seconds, fulfilment status goes back out, and listing stays in the seller panel.
Invoices follow the order. A paid order becomes an inFakt invoice. B2B invoices are filed to KSeF, consumer sales stay outside it, and anything ambiguous is put in front of a person rather than guessed.
Margin on every SKU. Net purchase cost sits on the same record as the selling price, so margin and the break-even price are read rather than rebuilt. Other currencies derive from the NBP mid rate.
Bill for what was used. An append-only usage log instead of an invoice run that guesses. A delivery that gets retried costs a delay rather than a second charge.
We run our own store on it
One catalogue and one warehouse behind three channels: Allegro, our own platform's metered billing, and the storefront that prices this site's product pages.
An Allegro order arrives on a twenty-second drain. The invoice is raised in inFakt and filed to KSeF when the buyer is a business. The licence keys that order needs are bought from our supplier, stored encrypted and emailed to the buyer exactly once. Shipment status and the invoice PDF go back to Allegro. One order, four systems, no operator.
That is where the plugins came from. They were written for problems in our own books, and published because there was no good reason to keep them.
Plugins
The plugins this runs on are public. You can read them and install them before you commission anything from us.
Admin Kit
One Catalog table that sibling plugins write into: channel state, cost and margin as extra columns rather than three more screens nobody keeps in sync.
Allegro
Offers, stock and orders matched by SKU inside one sales channel, price writes bounded by a floor and a ceiling, and listing left in the seller panel.
Usage
An append-only usage event log with deterministic deduplication, billing periods and rating.
Tinybird Sink
A Tinybird sink for that log, for meters counting in billions, with deduplication moved to the read path.
FX Pricing
Daily USD and EUR prices derived from the store's PLN price at the NBP mid rate, with hand-edited prices left alone.
Is this for you
Not for everyone. We say so before we start.
When it pays off
You have several channels to keep in agreement, unusual pricing, a metered product, or an integration nobody sells as a module. That is the point where a backend you own starts to pay for itself.
When it does not
You run one catalogue on a standard process. A hosted platform will be cheaper and faster, and that is what we will tell you.
Services
If one piece is what actually hurts, that is the piece we scope. Each of these is a project on its own.
Headless commerce on Medusa
A backend that is yours, not rented
Marketplace integrations
Allegro inside the admin you already use
Pricing and margin control
Currencies and costs on the same record
Invoicing and KSeF
Documents raised where the order already is
Subscription and usage billing
Charge for what was actually used
Commerce automation
The work that surrounds an order
Questions
Worth knowing before you commission any of this.
Where are you selling today?
We will say honestly whether this stack is the right answer, and what the first piece worth building would be.
Useful to mention: which channels you sell through, roughly how big the catalogue is, and the task that eats the most hours in a week.