mon-marche-mcp

An MCP server that lets an AI assistant search the mon-marché catalog and build a grocery basket from a few instructions. It is a thin, pure-HTTP client over mon-marché's internal API (the Keplr commerce platform) and Constructor.io search — no browser automation.

It deliberately stops at the cart: there is no checkout or payment tool. You review the basket and pay yourself on the website.

Tools

Tool	Purpose	Auth
search_products	Search the catalog (name, slug, price, bio/anti-gaspi)	none
get_product	Resolve a slug to its article id + SKU	none
add_to_cart	Set the quantity of one product (by slug)	sign-in
add_many_to_cart	Build a whole basket in one call	sign-in
view_cart	Show lines and total	sign-in
remove_from_cart	Remove a line by article id	sign-in
clear_cart	Empty the cart (does not delete it)	sign-in
my_usual_products	List most frequently ordered products	sign-in
list_delivery_slots	List bookable delivery slots for the saved address	sign-in
set_delivery_slot	Attach a slot — creates the cart	sign-in

Order flow

A cart can only hold products once a delivery slot is attached. Authentication is automatic from the env credentials (it uses a bearer token and a session cookie). Follow this sequence:

1. Find products — my_usual_products (frequently ordered) and/or search_products.
2. Pick a slot — list_delivery_slots, choose a slotId.
3. Create the cart — set_delivery_slot(slotId). This creates the cart (or updates the slot on an existing one) and is required before adding products. Skipping it makes add_to_cart / add_many_to_cart fail with 404 "Le panier est introuvable".
4. Add products — add_to_cart / add_many_to_cart (by slug).
5. Confirm — view_cart.

Checkout and payment are intentionally not automated — review and pay on the website.

Setup

npm install
cp .env.example .env   # fill in MM_EMAIL / MM_PASSWORD
npm run build

The account in .env must already have a delivery zone/address configured on the website — the cart is tied to that.

Run

npm run dev      # tsx, reads .env
# or
npm run build && npm start

Register with an MCP client

{
  "mcpServers": {
    "mon-marche": {
      "command": "node",
      "args": ["/absolute/path/to/mon-marche-mcp/dist/server.js"],
      "env": {
        "MM_EMAIL": "you@example.com",
        "MM_PASSWORD": "your-password"
      }
    }
  }
}

Configuration

Var	Required	Default
MM_EMAIL	for cart ops	—
MM_PASSWORD	for cart ops	—
MM_BASE_URL	no	https://www.mon-marche.fr
MM_CONSTRUCTOR_KEY	no	public key from the site bundle

Notes & caveats

• No payment. By design. The assistant fills the cart; you check out manually.
• Unofficial API. mon-marché has no public API; this calls the same endpoints the website uses. It may change without notice — keep usage personal, single-account, and low-rate, and review your basket before paying. This may run against the site's terms of service; use at your own discretion.
• Cart shape. The authenticated cart is normalized in src/client.ts (normalizeCart). The upstream API uses cents; tools expose euros. Line quantity comes from quotation.count, unit price from itemPrice, cart total from price.quotation.preauthorization (includes shipping + prep fee).
• clear_cart only empties. There is no endpoint to fully delete a cart — DELETE /api/cart clears the contents but the cart shell and its delivery slot persist for the period. So the GET /api/cart → 404 ("no cart") state cannot be reproduced once a cart exists; set_delivery_slot then just updates the slot instead of creating a new cart.

Verified API contract

Reverse-engineered from the site's JS bundle and confirmed live. Base https://www.mon-marche.fr.

Operation	Call
Sign in	POST /api/auth/signin {email, password} → bearer token in body + Set-Cookie. Send both Authorization: Bearer <t> and Cookie on later calls.
Search	GET ac.cnstrc.com/search/{q}?key=<MM_CONSTRUCTOR_KEY>&c=ciojs-client-2.45.0&... (no auth)
Resolve product	GET /api/articleDetailBySlug/{slug} → { id, sku, name }
Usual products	GET /api/account/top-products → { items: [...] }
Saved addresses	GET /api/account/addresses → { items: [...] }
Delivery slots	POST /api/addresses/deliverySlots2 { postalCode, countryCode, location } → { deliveryZones: [{ name, deliverySlots: [{ id, from, to, orderUntil, isExpired, isFull }] }] }
Create/set delivery	PATCH /api/cart/delivery2 { timeSlot, delivery: { note, address, deliveryZone }, reasonForChange } — creates the cart
Add one	PATCH /api/cart/product { product: { id, quantity } }
Add many	PATCH /api/cart/products { products: [{ id, quantity }] }
View cart	GET /api/cart
Empty cart	DELETE /api/cart (empties only)
Payment	PUT /api/cart/createPaymentIntent — never call; out of scope

License

MIT. Note: this license covers only this project's code. It grants no rights to mon-marché's API, data, or trademarks, and does not override the site's terms of service.