Members Price

Logged-in customers on the Alpkit Shopify Plus UK store receive a per-product members price applied automatically in cart, mini-cart, cart drawer, and at checkout. All logged-in customers are members.

Three artefacts:

Folder	Deliverable
metafield-definitions/	custom.members_price (money type) product metafield definition + idempotent install script
theme-snippet/	Liquid snippet + SCSS partial + integration doc for GloandCo/alpkit
discount-function/	TypeScript Shopify Discount Function (cart.lines.discounts.generate.run target)

Design spec: docs/superpowers/specs/2026-04-28-members-price-design.md

Prerequisites

• Node 20+
• Shopify CLI 3.78+ (npm install -g @shopify/cli@latest)
• A custom-app token on alpkit-sonder.myshopify.com with write_products scope (for metafield install)
• Partner Dashboard access for the Discount Function app

Deploy order

Each step is independently rollback-able. Steps 1–4 ship the cart/checkout discount; step 5 ships the PDP display. They can be deployed apart.

1. Metafield definition

cd metafield-definitions
SHOPIFY_STORE=alpkit-sonder \
  SHOPIFY_ADMIN_TOKEN=shpat_... \
  node install.mjs

Re-running is safe — the script logs "exists" and exits 0 if already installed.

2. Tag and value on a test product

In Shopify Admin → Products → pick a test product:

• Add the tag members-price
• Set the custom.members_price field to a value below the variant price

3. Function deploy

cd discount-function
shopify app deploy

(First-time setup: shopify app config link to bind to the existing members-price-discount app, or shopify app init to create one.)

4. Create the automatic discount

In Shopify Admin → Discounts → Create discount → Function-based discount → select members-price-discount → Save. No expiry, applies to all customers (eligibility is enforced inside the Function).

5. Theme snippet PR

Follow theme-snippet/INTEGRATION.md. Five small changes in GloandCo/alpkit, opened as a PR, merged via the existing auto-deploy workflow.

Verification

Run against the live UK store after each deploy step. See design spec §6 for the full 12-item checklist.

Rollback

Artefact	How
Discount function	Toggle off the automatic discount in Admin (instant, no deploy)
Function code	shopify app versions list → shopify app release --version=<prev>
Theme snippet	Revert the PR in GloandCo/alpkit; auto-deploys
Metafield definition	Leave in place (harmless). Manual delete via Admin if required
Tag / metafield values	Bulk-clear via Matrixify export → edit → re-import

Multi-store rollout (future)

The code is store-agnostic. EU and US deploys are the same five steps with different SHOPIFY_STORE / SHOPIFY_ADMIN_TOKEN env vars and a separate Function app + Admin discount per store. No code changes required.

Open considerations

• Cart-line rendering verification. gloandco-theme's existing cart-line template likely already renders line_item.discount_allocations (it served Discount Ninja allocations until that app was removed). Verify by reading the cart drawer/page snippet and checking that Member price −£X.XX appears beneath an eligible line. If absent, add a minimal display.
• Member-rewards-tool independence. The PHP member-rewards-tool generates per-customer discount codes via Klaviyo. These are independent of the Function-based members price (different layers — code-based vs automatic line discount). No conflict.
• Localisation. Snippet labels are hardcoded English at v1. Swap to '…' | t lookups when EU/US adopts.

Tests

# Metafield install script (6 tests)
node --test metafield-definitions/install.test.mjs

# Discount function (8 tests)
cd discount-function/extensions/members-price-discount && npm test