# Contextual Schema Extensions

Contextual Object Type schemas start with standard JSON Schema, but they also support a small set of platform-specific extensions that drive record identity, UI behavior, generated values, and relation-aware features.

These extension fields are understood by Contextual tooling and are removed or interpreted before the underlying JSON Schema validation runs.

## Common top-level extensions

* `primaryKey` - identifies the permanent record key for the Object Type
* `relations` - describes record relationships used by related-record and relation-aware UI features

## Common property-level extensions

* `secret: true` - stores the property value as an encrypted secret instead of a plain record value
* `generate` - automatically populates the property when a record is created
* `renderer` - selects a specialized UI renderer for the property in Contextual's admin experience

## Renderer examples

The admin console supports renderer-driven experiences beyond what vanilla JSON Schema provides. Examples visible in the current product code include:

* `code-editor`
* `relation`
* `flow-relation`

These values are used by Contextual UI renderers and should be treated as platform features rather than generic JSON Schema keywords.

## Related pages

* [ID and PrimaryKey Permanence](/documentation-and-resources/components-and-data/object-types/object-type-details/data-schema/id-and-primarykey-permanence.md)
* [Automatic Record Metadata](/documentation-and-resources/components-and-data/object-types/object-type-details/data-schema/automatic-metadata.md)
* [Secrets](/documentation-and-resources/components-and-data/object-types/object-type-details/data-schema/secret.md)
* [Generated Values](/documentation-and-resources/components-and-data/object-types/object-type-details/data-schema/generated-properties.md)
* [UI Schemas](/documentation-and-resources/components-and-data/object-types/object-type-details/ui-schemas.md)


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