EGR Scrap Calculator — Shopify Admin

Payout Calculation Rules

Configure separate valuation formulas for Individual retail customers and Corporate trade dealers.

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Calculation Modes:

Percentage mode: Payout = (Fine Metal Grams ÷ 31.1034768 × CAD Spot Price) × (Payout % ÷ 100) − Fixed Deduction.
Fixed CAD/g mode: Payout = Gross Weight in Grams × Fixed CAD/g Rate − Fixed Deduction. (Purity is commercially built into the fixed rate).

Accepted Purity & Karat Grades

Staff can add, modify, or remove accepted metal purities. Gold karat purity is mathematically calculated as karat ÷ 24.

Grade Label	Purity Fraction (0 to 1.0)	Percentage Equivalent	Actions

Precious Metals Spot Pricing

Configure live MetalpriceAPI feeds, manually entered CAD spot rates, or demo pricing.

Demo Pricing

Uses built-in benchmark gold, silver, platinum, and palladium spot rates for testing without API calls.

Manual CAD Spot Rates

Staff manually enter fixed CAD per troy ounce benchmark rates updated as desired.

Live MetalpriceAPI Feed

Connects to official MetalpriceAPI, automatically normalizes USD/CAD, caches quotes for 5 minutes.

Active Pricing: Demo Benchmark

Quote Timestamp: — · Cache Freshness: Live

Interactive Admin Calculator Preview

Test how current rates and formulas calculate scrap metal payouts before publishing to your live Shopify store.

Customer Segment

Metal

Purity / Karat

Weight

Unit

ESTIMATED PAYOUT

$0.00

CANADIAN DOLLARS · CAD

Applied Rate Mode Percentage

Spot Benchmark CAD/oz —

Fine Metal Content —

Gross Metal Value —

Per-Item Deduction —

Storefront Activation & Shopify App Setup

Control storefront accessibility and verify the theme app extension block.

Storefront Calculator Status

When disabled, the calculator widget on your storefront displays a friendly offline/maintenance banner and rejects quote requests. Keep disabled until payout rates are fully approved.

Disabled

Shopify App Proxy Configuration

Storefront Prefix	`apps`
Storefront Subpath	`egr-scrap` (Full URL: `https://www.xau.ca/apps/egr-scrap`)
Backend Proxy Destination	`https://calculator.xau.ca/proxy`
Required App Scope	`write_app_proxy`

Adding to Shopify Theme (Kalles)

In Shopify Admin, navigate to Online Store → Themes → Customize.
Open the Scrap Calculator page (/pages/scrap-calculator).
Click Add Block (or Add Section) and select EGR Scrap Calculator.
Configure the block headings, colors, and layout in the theme inspector, then click Save.

Scrap Calculator Management