---
title: "Custom Attributes"
method: POST
path: "/attributes/custom"
tags: ["Custom Attributes"]
---

# Custom Attributes

`POST /attributes/custom`

Make a call to this endpoint for any attribute-based data. There are no limits to the amount of custom attributes that can be created. Note that you can create net-new properties with this API, however, it cannot be used to create new values for an existing UI-created property name. If a property name is created through the Attentive platform, all possible property values must also be defined in the platform. For example, if a property has possible values of "Adult, Teen, Children's", those are the only values that will be accepted through the API. This does not apply for properties with the type "Custom input", for example: Full Name. Also, please note that the API does not support arrays. For example, attempting to pass an array such as '["chicago", "new york"]' for an attribute like 'favorite_city' will result in a 400 error.

**Note : The maximum length for an attribute name is 200 characters.**

## Request body

- CustomAttributesRequest
  - `properties` object, required — Any metadata associated with the attribute. Object keys are expected to be strings. Object values can be any type. The key will be assigned a type corresponding to the type seen of the first value. For example, if 'Age' is passed with the first value of '24', 'Age' will be typed as a 'Number'. There is no need to pass strings in double quotes. Both object keys and object values are case sensitive. "Favorite color" and "Favorite Color" would be considered different custom attributes.
  - `user` EventUser, required — User associated with the action. Note that this is a visitor to the site and does not need to be actively subscribed to Attentive. Phone, email, or an external identifier (clientUserId or another custom identifier) are required
    - `phone` string — Phone number of the user associated with the action. [E.164 format](https://en.wikipedia.org/wiki/E.164) is required. This field is required if either email or an externalIdentifier is not provided.
    - `email` string — Email of the user associated with the action. This field is required if either phone or an externalIdentifier is not provided.
    - `externalIdentifiers` ExternalIdentifiers — clientUserId or another custom identifier. This field is required if either phone or email is not provided. If using an external identifier instead of phone or email, the external identifier must first be associated with a phone or email using the Identity API.
      - `clientUserId` string — (optional) Your primary ID for a user
      - `customIdentifiers` object[] — (optional) Namespaced custom identifiers and their values.
        - `name` string
        - `value` string

## Response `200`

Ok

## Other responses

- `400` — Invalid parameter in request query or body
- `401` — Unauthorized
- `403` — Access Denied
- `404` — The specified resource was not found
- `429` — The user has sent too many requests in a given amount of time
- `500` — Internal Server Error

---

[API](https://skmtc.net/attentive/apis/attentive-api-v2.md) · [All operations](https://skmtc.net/attentive/apis/attentive-api-v2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/attentive/attentive-api-v2/revisions/be387e501197/schema)