# Northlight Apps — LinkLock: Stop Code Leaks

> LinkLock is a Shopify app by Northlight Apps that makes creator, influencer and affiliate discount codes work only for shoppers who arrive through the creator's link. A leaked code typed in without the link gives no discount, and the shopper sees a short explanation. This site also hosts Northlight's free discount checker and guides.

## The problem it solves
A normal Shopify discount code works for anyone who types it. Creator and affiliate codes end up on coupon sites, in browser coupon extensions and in group chats, so stores pay the discount (and sometimes affiliate commission) on sales they would have made anyway. Shopify has no built-in setting for "this code only works through this link".

## What it does
- Locks a code to its owner's link. Shoppers who come through the link get the discount automatically; shoppers who type the copied code without the link get no discount and see "This code only works through the creator's link."
- Works with codes the store already has, including codes made by an affiliate app or by hand (one click: "Lock to a link"). The code on each order stays the same.
- Free code health check: finds guessable, unlimited and never-ending codes.
- Links can expire on a chosen date; a new link key disables all old links at once.
- Optional "Buy it now" support so real customers keep their discount (off by default).
- Before uninstalling, LinkLock can convert its discounts back to normal Shopify discounts so codes keep working.
- No customer data stored.

## Limits
- It does not block browser extensions or scan coupon sites; it makes leaked codes worthless without the link.
- If the creator's link itself is shared, the discount is shared too (use expiry dates or a new key).
- POS and draft orders don't carry the link, so locked codes don't apply there.
- Requires the Online Store channel and the LinkLock theme app embed.

## Plans
- Free: code health check, 1 locked code (new or existing), refusal message, Buy it now support.
- Starter: US$12/month or US$120/year, 14-day free trial; unlimited locked codes and link expiry dates. Free on development stores.
- Status (30 Oct 2026): submitted to the Shopify App Store, in review.

## Test results (proof)
- Automated tests on a real Shopify store and checkout, twice a day, latest result per test (failures are shown too): https://linklock-cj7.pages.dev/proof/
- Machine-readable: https://linklock-cj7.pages.dev/proof/status.json

## Free tools and guides (no install, no sign-up)
- Discount checker — which products hide an automatic discount: https://linklock-cj7.pages.dev/tools/discount-check/
- Guide: how to stop discount code leaks on Shopify: https://linklock-cj7.pages.dev/guides/discount-code-leaks/
- Guide: automatic discount not showing on the product page: https://linklock-cj7.pages.dev/guides/automatic-discount-not-showing/

## Other Northlight apps
- Pricelight: Discount Display — shows the real checkout price of automatic discounts on product pages: https://pricelight.pages.dev/llms.txt

## Links
- Support and FAQ: https://linklock-cj7.pages.dev/support
- Privacy policy: https://linklock-cj7.pages.dev/privacy
- Terms: https://linklock-cj7.pages.dev/terms
- Contact: northlight.apps@gmail.com