Unit price

POST /v1/unit-price answers "which is the better deal?" for offers sold in different sizes. Send each offer's price and quantity as written; the API normalizes the quantities, computes the exact price per unit, and ranks the offers.

Example

bash

curl "https://api.unifyunits.com/v1/unit-price" \
  -X POST \
  -H "Authorization: Bearer $UNIFYUNITS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"offers":[{"price":"4.99","quantity":"750 ml"},{"price":"6.49","quantity":"1 l"}],"decimals":2}'

The 1 l bottle costs 6.49 per litre and the 750 ml bottle 6.65, so the larger one ranks first and the smaller costs 2.52% more (premium_percent).

Rules

Quantities use the same forms as Normalize: 750 ml, 6 x 330 ml, 1 lb 4 oz, and approx 5 kg. A range such as 10-12 cm is rejected because it is not one amount.
All offers must measure the same kind of thing (all volume, all mass, and so on). Temperature and other non-additive units cannot be priced.
Prices are positive decimal strings such as 4.99 in one currency of your choice. No currency conversion happens; convert first with Currency if offers differ.
per chooses the comparison unit (default is the category base unit, such as litres for volume). locale reads quantities such as 1,5 l.
Rank 1 is cheapest and equal prices share a rank. Without decimals, unit prices keep full precision. premium_percent always has two decimal places.
Two to fifty offers per request.
Requires the Developer plan or higher. A successful request uses one conversion from your monthly quota per offer; a failed request is free.