# Create Contact Filter

Create a new segmentation formula to be applied on contact lists when you send your campaigns. Segmentation can be done based on additional data saved for contacts via /contactmetadata and/or based on contact activity (or lack thereof). The properties used in Expression must already exist on your account - create them first with POST /v3/REST/contactmetadata, otherwise the request fails with Unknown identifier.

Endpoint: POST /v3/REST/contactfilter
Version: 1.0.0
Security: basicAuth

## Request fields (application/json):

  - `Description` (string)
    A description of the segment you can add for convenience, or to easier understand its functionality.

  - `Expression` (string, required)
    The rule, based on which the segment is calculated. Refer to our [Segmentation Guide](/docs/email-api/segmentation/segmentation-overview) for detailed information on the syntax.

  - `Name` (string, required)
    User-selected name for this segment.

## Response 201 fields (application/json):

  - `Count` (integer)
    Indicates the number of objects in the Data array.

  - `Data` (array)
    A JSON array containing a list of objects returned by this endpoint.

  - `Data.ID` (integer)
    Unique numeric ID for this segment.

  - `Data.Status` (string)
    Status of this segment. Indicates whether a segment was used for sending or not, or if it was deleted.

Possible values:

- used
- unused
- deleted

  - `Data.Description` (string)
    A description of the segment you can add for convenience, or to easier understand its functionality.

  - `Data.Expression` (string)
    The rule, based on which the segment is calculated. Refer to our [Segmentation Guide](/docs/email-api/segmentation/segmentation-overview) for detailed information on the syntax.

  - `Data.Name` (string)
    User-selected name for this segment.

  - `Total` (integer)
    Indicates the number of objects in the Data array.


## Response 400 fields

## Response 401 fields

## Response 403 fields

## Response 404 fields

## Response 429 fields

## Response 500 fields