# Expand

Many objects refer to others by ID. Add `expand[]` to get the related object inline, in one request instead of two.

```http
GET /v1/events/evt_01JB...?expand[]=organization&expand[]=ticket_types
```

Without `expand[]`, `organization` is an ID string. With it, `organization` is the full object.

- Expansion works up to 2 levels deep, for example `expand[]=ticket_types.event`.
- You can expand on single objects and on lists.
- Ask only for what you use. Expanded responses are larger and slower.
- An unknown path returns `400` `invalid_request_error` with the path in `param`.