> For the complete documentation index, see [llms.txt](https://docs.flowretail.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flowretail.com/docs/developers/field-naming-and-data-structure.md).

# Field naming & data structure

How fields are named, how references work, and how to clear a value.

These are the conventions the API is built on. They are published because knowing them lets you predict a field name instead of looking it up.

## Naming rules

**Identifiers end in `Uid`.** Any field referencing a technical unique identifier is named for the entity plus `Uid` — `productUid`, `orderUid`, `warehouseUid`. They are strings, not integers.

**Quantities start with `quantity`.** Any stock or count field leads with it — `quantityOrdered`, `quantityInStock`, `quantityReserved`.

**References reuse the target's name.** When one entity points at another, the field keeps the name it has on the original entity. An order line referencing a product calls it `productUid`, never `itemUid` or `articleUid`. If you know the entity, you know the field.

## Required and optional references

| Type          | Meaning                                                |
| ------------- | ------------------------------------------------------ |
| `Uid`         | Required reference. Always present.                    |
| `OptionalUid` | Optional reference. May be absent, and may be cleared. |

## Clearing a field

This one is not guessable, and getting it wrong silently leaves the old value in place.

| Field type    | Clear it by sending |
| ------------- | ------------------- |
| Text          | `""` (empty string) |
| `OptionalUid` | `""` (empty string) |
| Date          | `null`              |

Sending `null` to a text field is **not** the same as sending `""`, and will not clear it.

## List and search responses

Every list and search endpoint returns the same two keys:

```json
{
  "items": [ ... ],
  "paging": {
    "totalCount": 27,
    "pageNumber": 1,
    "pageSize": 24
  }
}
```

* `items` — the results.
* `paging` — where you are: `totalCount`, `pageNumber`, `pageSize`.

There is no cursor and no `next` link. You are on the last page when `items.length < pageSize`.

## Forward compatibility

Fields are added over time without a version bump. Parse the fields you use and ignore the rest — a client that rejects unknown fields will break on a release that was meant to be additive.


---

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