Members-only check before payment
Retail Extensions · checked 2026-10-17
Members-only check before payment stops a sale of a members-only item to a customer who is not a member. It runs when the cashier presses Pay, before any money is taken. It can also ask the cashier to check ID on a large sale. This page covers what the app adds, how to write your rule, how to switch it on, and how to remove it.
What it does
When the cashier presses Pay, your shop sends the priced sale to the app's service. The service reads your rule and answers before the payment screen opens.
| The cashier sees | When |
|---|---|
| The payment screen, as always | The sale has no members-only item, or the customer is a member, and the sale is below your ID limit. |
| "This sale can't be paid", with the item and "is for members only. Add the member's customer to the sale first." | The sale has a members-only item, and the customer is not in a member customer group. Nothing is paid. |
| A Yes or No question: "This sale is ⟨amount⟩ or more. Has the customer shown ID?" | The sale total is at or above your ID limit. No goes back to the sale. |
| "This sale can't be paid", with "Member rule guard is not set up yet. Ask your administrator to choose its user and press Connect again." | The app's user has not been sent to the service yet. |
| "This sale can't be paid", with "Member rule guard cannot read your rules: your shop refused its key. Ask your administrator to press Connect again." | Your shop refused the app's key, for example after the user was disabled, got a new key or lost its role. |
| "Member rule guard did not answer. This sale can't be paid until it does. Try again, or get a manager." | The service cannot be reached, or your shop did not answer its read in time. |
A return is checked only for the items it sells, as in an exchange. What a return takes back is never checked, and the cashier is not asked about ID on a return. The app reads your rule and writes nothing to your shop.
What you set up first
- Install the app from the App library (see About Retail Extensions). The install adds the role IVENDNEXT RGD Integration, with no one in it. The check comes in switched off.
- Write your rule (below).
- Make a user for the app. Tick Is Desk User, give it the role IVENDNEXT RGD Integration alone and save. Then generate its API key: on the user, open Settings and press Generate Keys. The role needs no other rights. Give the user no User Permissions, or a rule that names a record outside them is not read.
- Search Desk for Registered Application and open IVENDNEXT RGD Rule feed. Choose the app's user as its Application User and save.
- In the App library, find the app under Installed and press Details. On the app's record, press Connect again. The record then says that it sent the API key of the app's user.
- Switch the check on (below).
Rules
Search Desk for IVENDNEXT RGD Rule and press Add. Make one record for each rule. Only a System Manager can add or change these records, unless you give another role rights on them in Role Permissions Manager.
| "Rule" | Then choose | What it means |
|---|---|---|
| Members-only item | "Item" | Only a member may buy this item. |
| Members-only item group | "Item group" | Only a member may buy an item of this group. |
| Member customer group | "Customer group" | A customer in this group is a member. |
| Ask for ID at or above | "Amount" | The cashier is asked about ID on a sale at or above this total, in the sale's currency. |
- A line counts by its own item group, and a customer by their own customer group. A group above them does not count.
- With no member customer group, nobody is a member, so a members-only item cannot be sold.
- With several ID limits, the lowest one applies. With none, the cashier is never asked. An amount of 0 asks on every sale. The amount is one number, used in whatever currency the sale is in.
- Untick "Switched on" to stop using a rule.
- The service reads your rules again within a minute of a change.
Switch the check on
- Search Desk for Retail Extension Subscription and open Member rule guard.
- Read what it is sent, and tick the consent.
- Choose the stores it answers. With none chosen, it answers every store.
- Switch it on and save.
What leaves your shop
The app's service runs at rule-guard.ivendnext.app, hosted by CitiXsys. After the install, and when you press Connect again, your site sends the service its key from the App library, its address, the check's signing key, and the API key of the app's user.
At each Pay your shop sends the priced sale: each line's item code, item group, quantity and amounts, the totals, the customer and their customer group, the coupons, the sale details the cashier captured and the payment methods offered. No card details are sent. With the app's user, the service also reads your IVENDNEXT RGD Rule records. It writes nothing to your shop.
Limits
- A rule change can take up to a minute to apply.
- A parent item group or customer group does not count. Add each group you mean.
- Offline, the till cannot ask the service. It does what the check does when the service is down: the sale is refused.
- A rule on an item with variants does not cover the variants. Add each variant, or use an item group.
- After you install the app again, give its user the role IVENDNEXT RGD Integration again, then press Connect again.
How to remove it
- In the App library, find the app under Installed and press Details.
- On the app's record, press Export and uninstall and confirm. iVendNext first exports your rule records to a file, and tells the service that the app was removed.
- iVendNext removes the check, the rule records, the feed registration and the role.
- Make a new API key for the app's user, or disable the user, so the key the service had stops working.