> ## Documentation Index
> Fetch the complete documentation index at: https://docs.maalbar.dk/llms.txt
> Use this file to discover all available pages before exploring further.

# Add Materials

> Browse the materials catalog and add materials to a screening.

Materials are sourced from the Målbar catalog. Adding a material is a two-step process: first add it to the screening, then set its details.

## Browse the catalog

Call [GET /v1/materials](/api-reference/materials/get-materials) to fetch available materials. Each item has an `inputs` array. Save the `itemPublicId` and note the `fieldsType` for each input — this determines what you send in the next step.

| `fieldsType` | What to send                                                                                   |
| :----------- | :--------------------------------------------------------------------------------------------- |
| `Default`    | `itemPublicId` only                                                                            |
| `Single`     | `itemPublicId` + one `data.publicId` from `fields` as `itemSelectableMaterialPublicId`         |
| `Multiple`   | `itemPublicId` + one or more `data.publicId` from `fields` as `itemSelectableMaterialPublicId` |

## Add the material

Call [POST /v1/screenings/\{screeningId}/materials](/api-reference/materials/add-material-to-a-screening) using the screening `publicId` from the [screening step](/developer/quickstart/screening).

The response includes a screening material `publicId` — save this for the update call.

## Set material details

Call the update endpoint with the screening material `publicId` to fill in the remaining details.

**Functional unit fields:**

* `functionalUnitValue` — quantity in the chosen unit
* `functionalUnitKilogramValue` — conversion factor to kg; not needed if the unit is already `Kilogram`

**Per material/process input**, set one of:

* `locationListItemPublicId` — geographical origin (`lli_` prefix), from [GET /v1/geographical/locations](/api-reference/geographical-locations/get-geographical-locations)
* `transportLocationPublicId` — supplier location (`trl_` prefix), from your [created locations](/developer/quickstart/locations)

`recycleShare` — recycle percentage, only available if the item supports it.

For `Multiple` type inputs, also set `proportion` on each entry — values must sum to `1.0`.

## Next

[Retrieve Results →](/developer/quickstart/results)