---
title: neededbuildresources
summary: An MD station property giving ware shortages for one particular build task.
section: reference
kind: api
status: reference
tags: ["X4","modding","needed","build","resources"]
sources: ["https://wiki.egosoft.com/X4%20Foundations%20Wiki/Modding%20Support/"]
---
## Return value

| Type | Meaning |
| --- | --- |
| [MD table](wiki:type-md-values) | The .table form yields an MD table keyed by wares with shortage quantities. It is not a Lua table. |

[Types and methods](wiki:types)

## Observed expression


Layer: Mission Director. This is a station property for a build task, not a Lua function. `$Station` must exist and `$Build` must be its valid task. The handler must resolve these variables; the fragment does not create them.




```xml
<set_value name="$Needed"
           exact="$Station.neededbuildresources.{$Build}.table" />
<set_value name="$Wares" exact="$Needed.keys.list" />
```



**What happens:** $Needed holds this task's shortage table and $Wares its key list. Exact wares and quantities depend on the station/task; there is no fixed printed output.

## Iterate the result


The table describes shortages for that order. Station stock, the ware recipe and build-task missing resources are different facts. The example reads each ware ID and the corresponding required amount.




```xml
<do_for_each name="$Ware" in="$Wares">
  <set_value name="$WareID" exact="$Ware.id" />
  <set_value name="$Amount" exact="$Needed.{$Ware}" />
</do_for_each>
```



**What happens:** Each $Ware key supplies its ID and shortage quantity $Amount. This example reads data; it does not deliver wares.

## Limits


Check task lifecycle and station association first. Do not reuse a handle after completion or cancellation. Handle a valid empty set separately from a missing order. Reading this property should neither create ships nor supply resources; UI display has its own verification.