Metafield Discounts

Drive discount values, prices, and caps from metafields, attributes, and line properties using linked fields.

Overview

Metafield discounts give you per-product — or even per-line — control over discount values. Instead of entering a single static number, you link the Discount value, Quantity, or Message inputs to a dynamic source that resolves when the function runs.

  • Per-product percentages — each product defines its own percent off via a metafield
  • Per-product fixed prices — flash-sale prices stored on products
  • Custom base pricing — discount percentages computed from wholesale or compare-at prices rather than the regular price
  • App-driven discounts — cart line properties or cart attributes set by bundle builder apps drive the discount
  • Computed values — an upstream Sum Values or Count Items block feeds a computed number into the discount

This page documents the mechanism — linked fields — and the Advanced settings that unlock base-price overrides.

Linked Fields

Linked fields are the underlying mechanism for all dynamic discount values. Any input with a link icon next to it can be swapped from a static value to a reference that resolves at runtime.

  • Discount value on the Apply Product Discount block
  • Discount message (uses linked string sources)
  • Quantity inside the Quantity limit section
  • Tier thresholds and values on the Tiers block
  • Numeric and string inputs on most other blocks

Supported Sources

  • Metafields — product, variant, customer, company, or shop metafields. Numeric types (number_integer, number_decimal, money) for numeric inputs; string types for message inputs
  • Cart attributes — cart.attribute.<key>, set by the storefront, checkout extensions, or apps
  • Line properties — properties._key on individual cart lines, common with bundle builders and product customizers
  • Upstream node outputs — numeric results from Count Items, Sum Values, Max, or Tiers earlier in the flow

Next to the input you want to drive dynamically

Pick a source

Browse metafields, attributes, line properties, or upstream outputs

For JSON metafields

Select the subfield key inside the JSON object

For metafields with multiple indexes

Choose which one to read (visible when more than one metafield of that type is configured on the function input)

Resolution Rules

  • Numeric links expect a positive numeric value. Non-numeric or missing values cause that line to be skipped — it gets no discount
  • Percentage values are treated as whole numbers (20 = 20%), not fractions (0.20)
  • Linked messages support the same {{percentage}} and {{amount}} placeholders as static messages
  • Linked values are resolved per cart line for product/variant sources, and once for cart, customer, or shop sources
Tip

If a discount isn’t applying to a specific product, the most common cause is that the linked metafield or property isn’t set on that product. Items without a resolved value are silently skipped.

Use Cases

Per-Product Percentage Discounts

Each product carries its own markdown.

Create metafield

Add custom.clearance_pct (number_integer) to products

Set values

20 on one product, 35 on another, leave blank on products that shouldn’t discount

Function input

Include the metafield in the function’s input configuration

Discount block

Set Discount type to Percentage

Click the link icon on Discount value and choose custom.clearance_pct

Message

Use Save {{percentage}} so each product shows its own percent

Per-Product Fixed Prices (Flash Sale)

Each product has an explicit sale price.

Create metafield

custom.flash_price (money or number_decimal)

Discount type

Fixed Price

Point at custom.flash_price

Number of items

1 (each sale is per-unit)

Message

Flash sale: {{amount}}

Individual Fixed Amount Discounts

Each product has its own dollar-off value.

Create metafield

custom.amount_off (money)

Discount type

Fixed Amount

Point at custom.amount_off

Message

Save {{amount}} on this item

Bundle Builder with Line Properties

A bundle-builder app writes _bundle_discount onto each cart line. The discount reads it directly — no metafield setup needed on products.

Confirm the property

Check the storefront / app sets properties._bundle_discount on bundle lines

Click the link icon, choose the line property, and pick _bundle_discount

Behavior

Each bundled line uses its own discount; non-bundle lines are skipped

Advanced Settings — Custom Base Pricing

The Advanced section on the Apply Product Discount block appears only when Discount type is Percentage. It lets you change the price the percentage is calculated from.

Enable Advanced Settings

Optional — Percentage only

Toggle the Advanced Settings switch on the block to reveal the fields below.

Discount base price

Required when Advanced is on

The field or metafield whose value replaces the regular product price when computing the percentage discount. Supports the same source selector as linked fields — metafields (product, variant, customer, company, shop), attributes, and JSON subfields.

Use cases:

  • Wholesale pricing — discount from the wholesale cost, not retail
  • Member base price — VIP discounts computed from a member-only price
  • Compare-at driven savings — always discount against the compare-at price
Note

Only numeric metafields and fields are selectable here. For JSON metafields, pick the numeric subfield.

Calculate target price from base field

Optional

Changes how the percentage interacts with Discount base price.

  • Off (default) — the percentage is applied to the base price, and the resulting amount becomes the discount. Example: 25% of $80 wholesale = $20 off the line’s regular price.
  • On — the percentage computes a target price from the base field, and the discount brings the item to that target. Example: 50% off a $120 compare-at price targets $60; the line is discounted to $60 regardless of its current price.

This is the cleanest way to implement “half-off compare-at” style pricing.

Combining Features

Base pricing and linked discount values stack freely. For maximum flexibility:

  • Base price from metafield A + Discount value from metafield B → per-product wholesale pricing with per-product percent off
  • Base price from metafield + static percent → uniform discount against a custom base
  • Linked discount value + default base price → per-product percentages against the regular price

Important Considerations

Warning

Products without the linked metafield or attribute receive no discount — they’re skipped entirely. This is intentional, but make sure your catalog data is complete before launching.

  • Percentage metafield values are whole numbers (20, not 0.20)
  • Money/amount metafields use the store’s currency; currency conversion is handled at checkout
  • Linked fields must be included in the function’s input configuration before they can be selected
  • JSON metafields expose subfields after you select the metafield and pick the subfield key

Troubleshooting

Discount isn’t applying to some products

  • Check that the metafield or property is actually set on those products or lines
  • Verify the metafield is included in the function’s input configuration
  • For attributes/properties, confirm the storefront or app is writing them correctly

Wrong discount amount

  • Double-check the metafield value on the product — whole number for percentages, currency amount for money fields
  • For JSON metafields, confirm the correct subfield key is selected
  • If using Advanced Settings, remember the percentage is applied to the base price, not the regular price (unless Calculate target price from base field is on, which targets an absolute price)

“Available for metafield input only” message in Advanced

The block requires a metafield input to be configured on the function before Advanced Settings can be used. Add a metafield input on the function’s input configuration, then reopen the block.