What is a pricing guardrail?
A pricing guardrail is a rule that a price recommendation must satisfy before it can be proposed or applied — for example a minimum margin, a price floor, a maximum percentage drop, or a cap on changes per day. Guardrails run before any human sees the recommendation and turn a bad suggestion into a visible, explained block rather than a silent price change.
Which guardrails does a repricing system need?
Five cover almost every failure a merchant has seen. Melqart runs all five on every draft, with per-merchant overrides, and writes a blocked draft to the ledger with its reason instead of dropping it.
- Minimum margin: (price − cost) ÷ price must not fall below a percentage you set. Only enforceable when a cost basis is on file — with no cost, this gate cannot run, and the product should say so rather than pretend.
- Price floor: an absolute minimum below which no listing may go.
- Maximum drop: no single change may cut more than a set percentage from the current price.
- Velocity: a cap on executed changes per day, so a runaway loop cannot reprice the catalogue overnight.
- Implausibility: a drop large enough to suggest bad data (a box price read as a single, a currency mismatch) is blocked outright.
Why should a blocked recommendation stay visible?
Because a guardrail that silently discards is indistinguishable from a system that never noticed. If a competitor undercuts you and the recommended response would breach your margin floor, you need to know both facts: that the undercut happened and that the response was refused. Melqart keeps blocked drafts in the same ledger as approved ones, with the gate that stopped them named.
Is a guardrail the same as an approval gate?
No, and a good system has both. A guardrail is a rule the machine applies to itself; an approval gate is a person deciding. Guardrails filter out the recommendations that should never be asked; the gate decides the ones that should. In Melqart nothing reaches a store without passing both, and in the current early-access release the write step itself has not launched, so approved decisions are recorded with their evidence and applied when it does.
What is a sensible default for each guardrail?
Melqart’s defaults are a 5% minimum margin where a cost basis exists, a 15% maximum drop per change, 200 changes per day, and a block on any drop over 40% as implausible. They are conservative on purpose; a merchant with a fast-moving category loosens them deliberately, and the change is logged.
Questions people ask next
Can a guardrail be overridden?
Thresholds can be changed by an owner or admin, and the change is recorded. A single recommendation cannot be forced past a guardrail; you change the rule, not the outcome.
What happens when the cost of a product is unknown?
The margin guardrail cannot run for that product and the product says so. The other four still apply. Melqart never invents a cost to make the gate look active.