A value asked for at the till

The customer asks: An answer for the cashier during the sale: a message, or a seal number, a reference or a warranty card number added to the sale

Verdict: Ready, with limits (3)
Door: Till key · area: Till controls and approvals › Questions and details during the sale
Recipe: A till key: one pure core, answered from your own server
Sample: S1 — warranty check (pp_wrc), connected leg
Checked: carried 2026-10-16 · not re-run

What you build

A key on the till calls your service; your answer is a message, details added to the sale, values for its lines, or any of them together.

The cashier presses the key: nothing makes the cashier press it.
Till keys answer online only: the key is dimmed on an offline till.
The key's request carries no money and no serial numbers: read them from the booked sale, after it is booked.

The cashier presses a key to record the value on the sale. It is not forced, and it needs a connection.

Tell the customer the 3 limits above, and write them into the proposal.
Follow the recipe: A till key: one pure core, answered from your own server.
Copy the sample: S1 — warranty check (pp_wrc), connected leg, and change it.
Build and test it on your sandbox (request one if you have none; what is on it).
Run the checks: your own tests, the kit's checks and the money kit's release gate (testing and release).
Release through the customer's own release gate (14. Testing and release); an app other shops install goes through the App library.

Test it with your service answering, and again with it stopped: the till must say so in words, never wait.