Read the code

The full marketplace engine – MIT-licensed, and yours to run. Built on Medusa, so any Node.js developer can clone it, ship it, and extend it.

Read the code on GitHub

Own the codeOwn the dataKeep what you build

mercur · terminal

git clone github.com/mercurjs/mercur

Cloning into 'mercur'...

cat SECURITY.md

Report privately · safe harbor · coordinated disclosure

secret-scanning ✓ Dependabot ✓ CodeQL ✓

bun run dev# your infra

api :9000 · admin /dashboard · vendor /seller

Everything a marketplace runs on

Open source · MIT

Mercur Open Source

The complete standalone marketplace engine – MIT-licensed and public. Test it, build on it, or launch a simpler marketplace yourself.

MIT-licensed and public
Complete standalone marketplace engine
See the code, architecture, and quality

Enterprise

Mercur Enterprise

Everything in open source, plus the production layer for a business that's actually operating – payments, compliance, trust, integrations, and support. Full source for licensees.

Financial control & settlement
Compliance & data residency
Trust, security & audit
Integrations to your stack
Enterprise support & SLA

MIT-licensed, and the core stays MIT.
Fork it, ship it, keep it. No relicense, no rug-pull.

Runs on the stack your team knows

Mercur is a set of Medusa v2 modules and plugins on Node.js and PostgreSQL.

API-first

A REST API across admin, vendor, and storefront scopes, with a typed client.

Event-driven

Workflows with compensation & rollback, links between modules, and subscribers for events.

Headless and modular

Mercur installs over Medusa v2 as a plugin. Your extensions live in your own repo.

Open

The code is on GitHub. Clone the repo and run it locally on Node and Postgres.

Your code

PluginsWidgetsRegistry blocks

Clients

StorefrontAdminVendor3rd-party

API · 3 scopes

/admin/vendor/store

Mercur modules

VendorCommissionPayoutBuyBox

Medusa v2

runtime · workflows · modules

Data

PostgreSQLRedis

What runs in Core

Split carts and per-vendor orders

Rule-based commissions

Vendor payouts through Stripe Connect

Offers, pricing, and per-vendor catalogs

Returns and RMA

Multi-vendor data isolation

Pluggable search (Algolia, Meilisearch)

Browse modules

Extend it without a fork

Add to the engine through a typed API across three scopes, registry blocks you copy into your own repo, a dashboard SDK, events, and custom fields – your changes live in your layer, and upgrades leave them intact.

scopes.http

# Admin, vendor and storefront scopes
GET    /admin/sellers
POST   /vendor/offers
PATCH  /vendor/offers/:id
GET    /store/offers?product_id=prod_01H8...

A generated API reference is on the way; today the typed client gives you the contracts.

Works with your coding agents

We publish AI-readable docs and run an MCP server. Your coding tools query the engine directly.

MCP serverAI-readable docsEvent-driven

Inspect the controls yourself

Secret scanning, dependency updates, and a disclosure policy live in the same public repository.

Automated scanning

Secret scanning and dependency updates on the repository.

Static analysis

Code scanning runs on every change.

A disclosure policy

A published security policy and private vulnerability reporting.

MIT, no relicense

Read it, fork it, keep it – the core stays MIT.

SECURITY.md

# Security Policy

Report privately to security@mercurjs.com.

Safe harbor for good-faith research.

Coordinated disclosure – no public report before a fix ships.

Secret scanningDependabotCodeQL

GitHub

Where to get help

Found a bug?

Open an issue

Have a question?

Start a discussion

Want to talk live?

Join the Discord

When you take it to production

Core runs the marketplace. Running one at scale, under audit, across regions adds a layer – settlement, enforced access, integrations, and support. That layer is Enterprise.

In open source	Enterprise adds
The 3P marketplace engine	A settlement ledger, statements, and exports
Auth and per-vendor isolation	SSO, enforced roles, and an audit trail
A self-hostable stack	On-prem delivery and reference architecture
Community support	SLAs and direct access

Start with the code

Clone it, run it locally, and see how it fits together.

Read the code on GitHub See live demo