# Customer defined IDs in requests

fulfillmenttools allows specifying a customer-defined ID for certain entities. The ID format follows the pattern `tenant<entity>Id`. This field allows for transferring IDs from external systems to the fulfillmenttools. If this ID is unambiguous, it enables reading and writing the entity using HTTP.

Currently, this functionality applies only to stock entities.

{% hint style="info" %}
For information on retrieving entities by their `tenant<entity>Id` using a path parameter, refer to the [Uniform Resource Name (URN) pattern in path parameters](https://docs.fulfillmenttools.com/documentation/api-reference#uniform-resource-name-pattern-urn-in-path-parameters) documentation.
{% endhint %}

### Examples for stocks

#### Get stocks with a user-defined ID

```http
GET https://{projectId}.api.fulfillmenttools.com/api/stocks?tenantFacilityId=CGN-01
```

#### Search for stocks with a user-defined ID

```http
POST https://{projectId}.api.fulfillmenttools.com/api/stocks/search
```

{% code title="Request body (JSON)" %}

```json
{
    "query": {
        "tenantFacilityId": {
            "eq": "CGN-01"
        }
    }
}
```

{% endcode %}

#### Create a stock with a user-defined ID via PUT

```http
PUT https://{projectId}.api.fulfillmenttools.com/api/stocks
```

{% code title="Request body (JSON)" %}

```json
{
    "stocks": [
        {
            "facility": {
                "tenantFacilityId": "CGN-01"
            },
            "tenantArticleId": "0188104",
            "value": 100
        }
    ]
}
```

{% endcode %}

#### Create a stock with a user-defined ID via POST

```http
POST https://{projectId}.api.fulfillmenttools.com/api/stocks
```

{% code title="Request body (JSON)" %}

```json
{
    "facility": {
        "tenantFacilityId": "CGN-01"
    },
    "tenantArticleId": "0188104",
    "value": 101
}
```

{% endcode %}