Quantity pricing rules

Medusa Quantity Pricing Rules

Medusa v2 plugin for quantity range pricing (volume / tiered / wholesale). Set unit prices by quantity with fixed prices, percentage discounts, or fixed amount-off tiers.

Watch demo: https://www.youtube.com/watch?v=CjBjc7j3H6g

Features

• PostgreSQL quantity_prices table (module + migrations)
• Pricing types: fixed, percentage, fixed_discount
• Admin API (CRUD + Zod validation) and Store API (list tiers, calculate price)
• Admin UI: Settings → Extensions → Quantity Pricing, per-product widget, store summary widget
• Workflows with compensation (create / update / delete)
• Auto cleanup on product.deleted
• Optional variant, region, and customer-group scoping
• Exported helpers: resolveQuantityUnitPrice, catalog utilities, workflows

Requirements

Installation

npm install @webbycrown/medusa-quantity-pricing-rules

Register in medusa-config.ts:

1import { defineConfig } from "@medusajs/framework/utils"
2
3export default defineConfig({
4  plugins: [
5    {
6      resolve: "@webbycrown/medusa-quantity-pricing-rules",
7      options: {},
8    },
9  ],
10})

Registers the pricingEngine module automatically. Do not add a duplicate entry under modules.

Run migrations and start Medusa:

1npx medusa db:migrate
2npm run dev

Open Admin → Settings → Extensions → Quantity Pricing to create tiers.

Admin UI

Tier fields

Non-overlapping ranges per product + currency are recommended. When ranges overlap, the tier with the highest min_qty that still fits the quantity wins.

Pricing types

base is resolved in order:

1. base_unit_price on Store API / resolveQuantityUnitPrice
2. Medusa variant catalog price for currency_code
3. reference_unit_price on the rule

Store API

GET /store/quantity-pricing — requires a publishable API key.

GET /store/quantity-pricing?product_id=prod_01XXXX&currency_code=inr&quantity=25

1{
2  "quantity_prices": [],
3  "calculated_price": {
4    "unit_price": 90,
5    "quantity": 25,
6    "currency_code": "inr",
7    "rule_id": "qprice_02...",
8    "pricing_type": "fixed",
9    "line_total": 2250
10  }
11}

Without variant_id, only product-level tiers (variant_id = null) are returned.

Admin API

Authenticated admin session or token.

Create fixed tier:

1{
2  "product_id": "prod_01XXXXXXXX",
3  "min_qty": 1,
4  "max_qty": 10,
5  "pricing_type": "fixed",
6  "price": 100,
7  "currency_code": "inr"
8}

Open-ended tier (51+): set "max_qty": null.

Package exports

1import {
2  PRICING_ENGINE_MODULE,
3  resolveQuantityUnitPrice,
4  fetchCatalogPricesForProducts,
5} from "@webbycrown/medusa-quantity-pricing-rules"
6
7const unitPrice = await resolveQuantityUnitPrice(container, {
8  product_id: "prod_01...",
9  variant_id: "variant_01...",
10  quantity: 25,
11  currency_code: "inr",
12  rule_id: "qprice_02...", // optional — pin selected tier
13})
14
15const pricingEngine = container.resolve(PRICING_ENGINE_MODULE)
16const result = await pricingEngine.calculatePrice({
17  product_id: "prod_01...",
18  quantity: 25,
19  currency_code: "inr",
20})

1import {
2  createQuantityPricingRuleWorkflow,
3  updateQuantityPricingRuleWorkflow,
4  deleteQuantityPricingRuleWorkflow,
5} from "@webbycrown/medusa-quantity-pricing-rules/workflows"

The plugin does not modify cart line items automatically. Use resolveQuantityUnitPrice in your add-to-cart flow when a tier applies.

Tier matching

1. Load rules for product_id (+ optional filters).
2. Prefer variant-specific rules when variant_id is set.
3. Match min_qty ≤ quantity and (max_qty is null or quantity ≤ max_qty).
4. Highest matching min_qty wins.
5. Resolve unit price from pricing_type and base price sources.

Database

Table quantity_prices: product_id, variant_id, min_qty, max_qty, pricing_type, price, currency_code, reference_unit_price, customer_group_id, region_id.

After model changes in a fork:

1npx medusa db:generate pricingEngine
2npx medusa db:migrate

Troubleshooting

Changelog

See CHANGELOG.md.

Author

WebbyCrown — info@webbycrown.com · webbycrown.com