Create an Array of Objects Attribute

Before data ingestion or activation can occur, you must establish a formal schema within the Attributes and Events section.

Array of Objects cannot be populated via API or utilized in segmentation logic until they are explicitly registered in the InOne panel.

To create a new Array of Objects attribute,

Navigate to the Components > Attributes and Events page and click the Create button on the Attributes tab.
Set the data type to Array of Objects.
Define a unique identifier (e.g., Subscriptions).
Adds object keys such as:

Key Name	Data Type
subscription_id	String
plan_name	String
start_date	Date
renewal_date	Date
status	String
monthly_price	Number

Object-Type Keys

If you select the Array of Objects as the data type:

An object key creation area appears under that key.
Nested fields can be defined inside the object. Each object key requires:
- Name
- Data type
- (Optional) Sample of data

Supported Data Types

When defining object keys for an Array of Objects attribute, the following data types are supported:

Data Type	Description	Subscription Example
String	Text values	plan_name: "Premium"
Number	Numeric values	monthly_price: 19.99
Date	ISO-8601 datetime	renewal_date: "2026-03-15T10:00:00Z"
Boolean	True/False values	auto_renew: true
URL	Valid web link	invoice_url: "https://example.com/invoice/1"
String Array	List of text values	tags: ["premium", "loyal"]
Number Array	List of numeric values	discount_codes: [101, 202]
Object	Nested structured object	payment: { method: "credit_card", last_four: "1234" }

Object-Type Keys

If you select Object as the data type:

A new Sub-key creation area appears under that key.
You may add multiple sub-keys, each with its own:
- Name
- Data type
- (Optional) Sample of Data

Edit an Array of Objects Attribute

After you create an Array of Objects attribute, its editability depends on how and where it is used. The following rules apply when updating an AoO attribute:

Attribute IS NOT used in any campaign or segment

Editable	Not Editable
Attribute display name System name Sample of Data Adding new keys or sub-keys PII checkbox Show on Segment checkbox	Data type Existing key names Existing key data types Existing sub-key names Existing sub-key data types

You cannot delete the existing keys and sub-keys.

Attribute IS used in at least one campaign or segment

Editable	Not Editable
Display name PII checkbox Sample of Data Adding new keys or sub-keys	System name Data type Existing key names Key data types Sub-key names Sub-key data types Show on Segment checkbox

Limitations

Each account can have a maximum of 20 Array of Objects attributes.
Each Array of Objects attribute supports up to 50 objects per profile.
Each object can contain up to 20 keys.
A maximum of 2 nesting levels is supported (keys and sub-keys).
Nested Array of Objects is not supported. Object-type keys are allowed, but another Array of Objects cannot be nested.
Object order may differ from the ingestion order.
String values cannot exceed 500 characters.
Payload size is limited to 5 MB per request (Upsert API).
The Array of Objects attributes must be registered via metadata before ingestion.
Key and sub-key names and data types cannot be renamed or deleted after creation. Structural changes require deleting and recreating the attribute.
The Array of Objects data updates can only be performed via the Upsert API.
The Array of Objects attributes cannot be included in InOne panel-based user data exports.