About CRA Sentinel

A forecourt turns over a great deal of money in small pieces, through several hands, across shifts that overlap. Counting what is in the till at the end of the night is straightforward. Knowing what should have been in it is not.

The hard part is holding four things together at once: what the meters say was sold, what that fuel was worth at the price it went out at, what actually came in across cash, cards and transfers, and what went back out as expenses — and then being able to say later who entered each of those figures, and what changed afterwards.

Those questions are usually answered across a paper book, a spreadsheet, a WhatsApp thread and somebody’s memory. That works until a shift is short and nobody can reconstruct which reading was wrong, or until an opening reading quietly stops matching the closing one before it and no one flips back to notice.

CRA Sentinel makes that daily work one place — the readings, the money, the expenses, the difference, and the record of who entered what.

Say what it cannot check. A nozzle added without its current meter reading has no baseline, and the first shift on it is marked as such rather than compared against zero and reported as a 25,000-litre discrepancy.

Attribute every decision to a person. Machine API keys are refused for finalizing a shift, approving a discrepancy or reopening a locked record. A record saying a manager signed something off should not be producible by a script.

Never quietly rewrite history. Financial edits are kept as revisions with both values, and audit entries are append-only and hash-chained, so an alteration is detectable rather than invisible.

Use exact arithmetic. Money is decimal, never binary floating point, from the database column to the JSON on the wire. A shortage is the difference between two large numbers, and that is precisely where a float loses the cents it is made of.

Do not overclaim. The product does not stop theft, does not read your pumps, and does not decide what a difference means. Selling record integrity while overstating what the software does would be a strange way to start.