Mercur

What is Mercur?

Mercur is an open source, headless platform for building multi-vendor marketplaces. It extends Medusa — inheriting its battle-tested commerce core for catalog, orders, payments, shipping, and tax — and layers on the marketplace pieces Medusa doesn’t ship: multiple vendors, competing offers, commissions, and split payouts.

What is Mercur best for?

Teams building a B2C, B2B, or hybrid marketplace who want to own the code and skip SaaS license fees or a cut of GMV. It suits developers comfortable with a TypeScript/Node stack who need to customize marketplace logic deeply rather than fit inside a hosted product’s limits.

What can Mercur do?

• Onboard and manage vendors with configurable KYC verification
• Show competing vendor offers on a single product card (buy-box style)
• Split orders across vendors and settle payments to each one
• Automate vendor payouts through Stripe Connect
• Track commissions per vendor or category
• Provide a vendor panel, an admin console, and a customizable storefront
• Run on an API-first, event-driven architecture (TypeScript, PostgreSQL, Redis)

Where does Mercur fall short?

• It’s young compared to enterprise incumbents like Mirakl — the ecosystem, integrations, and third-party support are far thinner, so you build and maintain more yourself.
• Some capabilities are gated behind the paid Enterprise edition (deduplication, a Buy Box engine, advanced vendor KYC), so the MIT core doesn’t cover every feature marketing highlights.
• Because it’s built on Medusa, you inherit Medusa’s constraints and upgrade cadence too — deep customizations can collide with framework updates.

Is Mercur free?

Yes — the Mercur core is MIT-licensed and free to self-host, with no GMV fees or per-transaction cuts. Mercur Enterprise is a paid, licensed edition that adds modules like deduplication, a Buy Box engine, and advanced KYC; it still deploys on your own infrastructure. The company frames the license as your only platform cost.

What does Mercur replace?

Mercur is a self-hosted alternative to hosted marketplace platforms like Mirakl, Sharetribe, and Marketplacer. It does the same multi-vendor job — vendor onboarding, commissions, order splitting, payouts — but you run it on your own stack and pay no percentage of sales.

FAQ

Is Mercur open source? Yes. The core is MIT-licensed and the source is public. A separate paid Enterprise edition adds extra modules, but the standalone marketplace engine is fully open source and free to self-host.

Can I self-host Mercur for free? Yes. The MIT core runs on your own infrastructure at no license cost — you only pay for hosting. The Enterprise edition is optional and paid.

Is Mercur a good Mirakl alternative? For teams that want full code ownership and no GMV fees, yes. Mirakl is a more mature enterprise product with a larger ecosystem, so Mercur trades that maturity for control, customization, and no per-sale cut.

What do I need to run Mercur? A Node.js environment plus PostgreSQL and Redis, and a Stripe Connect account for vendor payouts. It deploys with standard containers on any cloud, on-premise, or air-gapped infrastructure.