There are two hard ways to do this
- Replatform onto a SaaS marketplace — Rebuild what already works, rent the engine, and give up a share of every sale.
- Bolt it on with plugins and custom code — Payouts, split payments, settlement, BuyBox, returns, and disputes – each one becomes yours to maintain.
What adding Mercur gets you
- Zero GMV fees — The license is your only platform cost.
- Own the source — Open source, full source for licensees.
- Your infrastructure — Any cloud, on-premise, or air-gapped.
- 80% already inside — You customize the last 20%.
How a third-party sale actually runs
- Onboard a vendor — Registration, verification and account lifecycle.
- List the catalog — Per-vendor offers against your master products.
- Win the sale — The BuyBox picks one winning offer up front.
- Take a mixed cart — First-party stock and third-party offers in one basket.
- Split the order — One customer payment becomes per-vendor orders.
- Fulfill and track — Shipping costed per vendor, with enriched tracking.
- Settle and pay out — Commission, ledger and vendor payouts.
- Handle returns and disputes — Per-line RMAs, claims and cases.
SaaS marketplace vs Mercur
| Category | SaaS marketplace | Mercur |
|---|---|---|
| Core technology | Closed, vendor-only | Open source (MIT), public |
| Enterprise code | Black box | Full source for licensees |
| Integrations | Separate products | Built into one platform |
| Customization | Tickets and workarounds | Your own layer, official extension points |
| Deployment | Vendor cloud only | Any cloud or on-premise |
| Cost model | A percentage of your GMV | Zero GMV fees |
| Exit | Lock-in | You keep what you paid for |
Shopify, Magento, or your own stack
Mercur adds the marketplace layer beside the storefront you already run. Ready paths exist for Shopify and Magento, and the API-first design means a custom stack integrates at exactly the seams you choose.
How we run the engagement
- Discovery — Map data and integrations.
- Architecture — Agree the target on Mercur.
- MVP — Ship the first working slice.
- Rollout — Go live with third-party vendors.