## Extensible interface

Anything that can carry FHIR extensions: resources such as `Patient`, data types such as `CodeableConcept`, and extensions themselves. Structural, so any of those is accepted, while a type that cannot hold extensions, `Binary` being the notable example, is rejected.

**Signature:**

```typescript
export interface Extensible
```

## Properties

| Property | Modifiers | Type | Description |
| --- | --- | --- | --- |
| [extension?](/content/docs/sdk/core.extensible.extension) |  | Extension\[\] | _(Optional)_ |

- [Extensible interface](/content/docs/sdk/core.extensible#extensible-interface/index.html) 
- [Properties](/content/docs/sdk/core.extensible#properties/index.html)