---
schema_version: "1"
id: 06d12e73d8053773089c072fbfc77c4208924dd4d630566bc31dbd617d8d58ed
title: Object-Based Custom Lightning Types
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/lightning-type-systems/lightning-types/guides/lightning-types-object.md
canonical_url: https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-object.html
source_site: developer.salesforce.com
content_type: documentation
content_hash: 4b6ff5e8e7098a216125dafc5dd3e07c4d8e0cc267d142b5d6e8702836230b87
products:
- Lightning Types Developer Guide
- lightning-type-systems
---
# Object-Based Custom Lightning Types
With object-based custom Lightning types, you can define a custom data structure entirely within a JSON schema, without relying on an Apex class. You explicitly define every property, data type, and validation rule in the `schema.json` file. Use this approach when you need a lightweight, flexible data model for UI configuration or prompt definitions that don’t require an Apex backend.
**Supported in**:
- Prompt Builder
- Experience Builder
## Schema.json for Object-Based Custom Lightning Types
For object-based types, you define the data structure directly in the `schema.json` file by using the `lightning__objectType` value and a `properties` block.
This table lists the keywords that you can specify in a `schema.json` file.
| Keyword | Required or Optional | Type | Description |
| ---------------- | -------------------- | ------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `title` | Required | String | Name for the Lightning type |
| `description` | Optional | String | Description for the Lightning type |
| `lightning:type` | Required | String | Refers to lightning\_\_objectType type by fully qualified name |
| `properties` | Required | Object | Defines the fields for the object. Each key is a field name, and its value is an object defining that field’s `title` and `lightning:type`.
For a list of valid values, see [Lightning Types Reference](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-references.md#lightning-types). |
| `required` | Optional | Array | An array of property names that must be present in the data |
Here’s a sample code that shows the contents of the `schema.json` file for a custom Lightning type `customerFeedback`.
```json
{
"title": "customerFeedback",
"description": "Structured format for capturing customer feedback received.",
"lightning:type": "lightning__objectType",
"properties": {
"customerName": {
"title": "customerName",
"lightning:type": "lightning__textType"
},
"feedbackDate": {
"title": "feedbackDate",
"lightning:type": "lightning__dateType"
},
"satisfactionScore": {
"title": "satisfactionScore",
"lightning:type": "lightning__numberType"
}
},
"required": ["customerName"]
}
```
**note:** When you create or update an object-based custom Lightning type, an Apex class is automatically generated that matches your schema.
**See Also**
- [Create Custom Labels for Custom Lightning Types](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-core.md#create-custom-labels-for-custom-lightning-types)
## UI Configuration for Object-Based Custom Lightning Types
While `schema.json` defines the data structure, the UI configuration files in the LightningTypeBundle control the visual representation. Organize these files by channel to support specific Salesforce applications.
[**Channels**](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md#channels)
Store UI overrides in channel-specific subfolders to target different applications.
- **experienceBuilder**. Use this folder for Experience Builder sites.
[**Configuration Files**](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md#ui-configuration-files)
Configure the UI override by using this JSON file.
- **editor.json**. Points to a Lightning Web Component (LWC) that serves as a custom form for data entry.
[**Component Override**](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md#component-override)
You can customize the visual presentation by adding component overrides to your `editor.json` file.
- **Top-Level Override**. A top-level override replaces the default UI for the entire custom Lightning type. To configure this override, use the `$` symbol as the key in the `componentOverrides` section of your `editor.json`. This approach is useful for creating specialized interfaces, such as a custom card or a multi-property form handled by a single component.
- **Property-Level Override**. A property-level override replaces the default UI for specific properties of a schema within a complex type, while default editors handle the rest of the type. Instead of using `$`, specify the exact property name (such as address or phoneNumber) as the key in the `componentOverrides` section. Use property overrides when specific data requires specialized input. Default editors apply to any properties that don’t have a defined override.
[**Layout Configuration**](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md#layout-configuration)
Defines the visual arrangement and hierarchy of schema properties. By default, the UI renders properties in a vertical stack matching the schema order. Use the `layout` section in `editor.json` to create complex arrangements, such as grouping properties horizontally or organizing them into tabs.
[**Attribute Mapping**](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md#lightning-web-component-attribute-mapping)
In both configuration files, map schema properties to LWC component properties by using the `{!$attrs.PropertyName}` syntax.
**note:** For a complete list of supported channels and detailed JSON syntax, see [Lightning Type UI Configuration](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md).
**LWC Target Requirements**
To use a component as an override, include the appropriate target in the component’s `js-meta.xml` file.
- [`lightning__PropertyEditor`](https://developer.salesforce.com/docs/platform/lwc/guide/targets-lightning-property-editor.html) for overrides
**See Also**
- [Lightning Types Configuration Files](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-core.md#lightning-types-configuration-files)
- [Lightning Type UI Configuration](https://developer.salesforce.com/docs/platform/lightning-types/guide/lightning-types-ui-config.md)
## Object-Based Custom Lightning Types Modification Guidelines
You can modify custom Lightning types freely until they’re referenced in a Salesforce application. When they’re referenced, follow these guidelines to maintain the integrity of the type across Salesforce applications, such as Experience Builder and Prompt Builder.
| Keyword | Status | Guideline |
| ----------------------------- | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `title` | Permitted | You can change the title of an individual property. |
| `description` | Permitted | You can change the description of an individual property. |
| `lightning:type` | Prohibited | You can’t change the `lightning:type` value. |
| `properties` | Conditionally Permitted | **Additive changes**: You can add new optional properties.
**Destructive changes**: You can’t remove or rename an existing property. You can’t add a new required property. |
| `required` | Conditionally Permitted | You can make existing required properties optional (remove them from the required list).
You can’t add properties to the required list. |
| `maximum` | Conditionally Permitted | You can increase the value. You can’t decrease it. |
| `minimum` | Conditionally Permitted | You can decrease the value. You can’t increase it. |
| `maxLength` | Conditionally Permitted | You can increase the value. You can’t decrease it. |
| `minLength` | Conditionally Permitted | You can decrease the value. You can’t increase it. |
| `multipleOf` | Conditionally Permitted | The existing value must be divisible by the new value.
**Example**: If the existing value is 20, valid new values include 2, 4, 5, and 10. Invalid values include 15 and 40. |
| `lightning:allowedUrlSchemes` | Conditionally Permitted | You can add new schemes to the array. You can’t remove existing schemes. |