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Packet pricing

Each packet (physical stock location) carries two computed price fields:

Field Description
itemValue Price per unit (computed)
totalValue itemValue × count

Both are recalculated automatically whenever a StockOperation is saved.

Calculation order (Packet.calculate())

The algorithm runs in three steps:

1. FIFO from priced inflow operations

Operations of type add, trans_in, and buy with unit_price > 0 form price layers ordered chronologically. Outflow operations (remove, trans_out, service, sell) consume the oldest layers first (FIFO).

The remaining layers after consuming all outflows give a FIFO value and a FIFO count.

2. Average price for unaccounted units

If packet.count > FIFO count (i.e. some units have no matching priced inflow), the gap is filled using the average purchase price across all priced inflow operations:

unaccounted = packet.count − FIFO count
average_price = Σ(quantity × unit_price) / Σ(quantity)   [over priced inflows]
total_value = FIFO value + unaccounted × average_price

3. Internal price fallback

If there are no priced inflow operations at all (step 2 denominator is zero), the gap is filled using component.internal_price:

total_value = FIFO value + unaccounted × component.internal_price

If internal_price is also not set, the unaccounted units are valued at 0 and itemValue will be 0.

Price source badge

The packet detail page shows a badge indicating which pricing method was used:

Badge Meaning
Purchase (FIFO) itemValue comes from priced buy/add operations
Internal price itemValue comes from component.internal_price fallback
⚠ Internal price (not applied) internal_price is set but itemValue is still 0 (packet may be empty or needs recalculation)
No price Neither purchase price nor internal_price is available

Inventory operations

When an inventory (operation_type = 'inventory') is recorded, the current itemValue of the packet is snapshotted into the operation's metadata:

{
  "counted_quantity": 10,
  "recorded_quantity": 8,
  "counted_price": 45.50
}

counted_price captures the price at the moment of counting — it will not change even if subsequent purchases alter the packet's itemValue.

Inventory PDF report

The stocktaking PDF report (GET /api/warehouse/stocktaking/<id>/report/) uses counted_price from metadata to value each inventoried packet:

value = counted_quantity × counted_price

For inventory operations recorded before counted_price was introduced, the report falls back to the packet's current itemValue. This fallback will be removed once all legacy operations have been superseded.

Non-inventoried packets are valued using their current itemValue.

component.internal_price

internal_price is a manually maintained field on the component. It represents the agreed internal cost per unit and is used as a fallback when no purchase price history exists.

It can be set via the component edit form or via the MCP tool update_component.