What Is Object Expansion?
Some objects returned by the API contain references to other objects (e.g., an invoice references an organization, items, or payments). By default, these fields may appear only as IDs. Using theexpand parameter, you can request that specific fields be fully populated with their related object data in a single API call.
Current Support
At the moment, object expansion is supported only for invoice retrieval, and is done via aPOST request:
Example endpoint and payload
Get Invoice Endpoint
Check the get invoice details endpoint and try out the request yourself
POST /invoices/:id
- organization – Full details of the organization that owns the invoice
- items – List of items associated with the invoice
- calculations – Details about taxes, discounts, and fees
- items.product – Full product details for each line item
- items.billing_schema – Billing rules associated with each item
- items.payment_intent – Payment intent (if one was created for the invoice)
Best Practices
- Only expand what you need — requesting too many nested objects can increase response size and latency.
- Use dot notation (items.product) to expand nested fields on lists or sub-objects.
- If no expand parameter is passed, related objects will default to their reference form (e.g., just an ID).

