---
title: "Append Values to List"
method: POST
path: "/{WSID}/{version}/profiles/properties/list-append"
tags: ["User Properties"]
---

# Append Values to List

`POST /{WSID}/{version}/profiles/properties/list-append`

This API enables you to append values to list type properties of your users listed in your [User Profiles](../user-profiles-overview). If the user with distinct ID doesn't exist, it creates a new user with the provided distinct ID and updates values for all the provided properties.

**Note:** If a [property was not created earlier](../adding-new-user-property#how-to-add-a-new-user-property-from-user-profile-page), it will create a new property and the data type of the property will set to `List`. For example, if you `$append` a new property called `order_ids=245`, it will create the `order_ids` property with `List` type and value `[245]`. A list may contain only unique values, so if a value already exists, and you try to add the same value, it will be ignored.

You can append values with the following data types:
- **String:** Can be alphanumeric and contain a maximum of 255 characters. Example: `products_order=['iPhone 16 Pro', 'iPad 32 GB']`.
- **Number:** Can be an integer or a decimal. Example: `purchase_amount=[23000, 20.34]`.
- **Date:** Must be in ISO 8601 format: `YYYY-MM-DDTHH:MM:SS.sssZ`. Example: `membership_date=2020-10-01T18:30:00.000Z` or `membership_date=2020-10-01T18:30:00Z` or `membership_date=2020-10-01T18:30:00.000+05:30` or `membership_date=2020-10-01T18:30:00+02:00` or `membership_date=2020-10-01`.

You can append only one value to a property at a time. Although not recommended, a list property can contain a mix of different data types.

These user properties can be used to filter your users for creating [user cohorts](../creating-cohorts) and [campaigns](../campaign_creation#creating-a-campaign-using-cohort).

## Path parameters

- `WSID` string, required
- `version` 'live' | 'test', required

## Request body

- AppendToUserProperty
  - `$append` AppendToUserPropertyFields, required — Enter the property name as JSON key and the numeric or string value to append as JSON value
  - `distinct_id` string, required — Enter the distinct ID that you use to identify the recipient.

## Response `202`

Request has been accepted and will be processed asynchronously.

- object
  - `request_id` string, required

## Other responses

- `400` — $append object is empty
- `401` — API Key or Workspace ID is invalid. User is unauthorised.

---

[API](https://skmtc.net/fynoio/apis/fyno-rest-api.md) · [All operations](https://skmtc.net/fynoio/apis/fyno-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/fynoio/fyno-rest-api/versions/021088e9cb30/schema)