---
title: "Expanding responses"
description: "Ask for a related object in the same answer with expand[], instead of making a second request."
url: https://docs.fluveo.com/start/expand/
---

> Index of every page: https://docs.fluveo.com/llms.txt. Integrating Fluveo? Read https://docs.fluveo.com/agents/integrate.md first.

> Too long? This page with code in one language only: https://docs.fluveo.com/start/expand.curl.md (cURL), https://docs.fluveo.com/start/expand.node.md (Node.js), https://docs.fluveo.com/start/expand.python.md (Python), https://docs.fluveo.com/start/expand.php.md (PHP).

# Expanding responses

Ask for a related object in the same answer with expand[], instead of making a second request.

Many fields carry just an id that points to another object. A PaymentIntent's `latest_charge` is a Charge id (`ch_...`), and its `customer` is a Customer id (`cus_...`). Send `expand[]` with the field's name, and Fluveo puts the whole object in that field.

## Expand a field

**Read a PaymentIntent with its Charge**

cURL:

```bash
curl -G https://api.fluveo.com/v1/payment_intents/pi_... \
  -H "Authorization: Bearer sk_test_..." \
  -d "expand[]=latest_charge"
```

Node.js:

```javascript
const params = new URLSearchParams({ "expand[]": "latest_charge" });
const response = await fetch(`https://api.fluveo.com/v1/payment_intents/pi_...?${params}`, {
  headers: { Authorization: "Bearer sk_test_..." },
});
const paymentIntent = await response.json();
console.log(paymentIntent.latest_charge.id, paymentIntent.latest_charge.status);
```

Python:

```python
import requests

response = requests.get(
    "https://api.fluveo.com/v1/payment_intents/pi_...",
    headers={"Authorization": "Bearer sk_test_..."},
    params={"expand[]": "latest_charge"},
)
charge = response.json()["latest_charge"]
print(charge["id"], charge["status"])
```

PHP:

```php
<?php
$ch = curl_init("https://api.fluveo.com/v1/payment_intents/pi_...?" . http_build_query(["expand" => ["latest_charge"]]));
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ["Authorization: Bearer sk_test_..."],
]);
$paymentIntent = json_decode(curl_exec($ch), true);
echo $paymentIntent["latest_charge"]["id"];
```

- On a GET, send `expand[]` in the query string. On a POST, send it in the form body: the object you get back is already expanded.
- Send `expand[]` more than once to expand several fields.
- Use dots to expand a field of an expanded object, such as `expand[]=latest_charge.balance_transaction`. A path has at most 4 parts.
- In a list, the objects sit under `data`, so start the path with `data.`: `GET /v1/payment_intents?expand[]=data.latest_charge`.
- A field that is `null` stays `null`.

## Fields you can expand

| Object | Fields | Each becomes |
| --- | --- | --- |
| PaymentIntent | `latest_charge` | Charge |
|  | `payment_method` | PaymentMethod |
|  | `customer` | Customer |
| Charge | `payment_intent` | PaymentIntent |
|  | `customer` | Customer |
|  | `balance_transaction` | BalanceTransaction |
|  | `refunds` | the list of the Charge's refunds; `refunds.data` expands each Refund |
| Refund | `charge` | Charge |
|  | `payment_intent` | PaymentIntent |
|  | `customer` | Customer |
|  | `payment_method` | PaymentMethod |
|  | `balance_transaction`, `failure_balance_transaction` | BalanceTransaction |
| PaymentMethod | `customer` | Customer |
| Customer | `tax_ids` | the list of the Customer's tax ids |
| Price | `product` | Product |
| Product | `default_price` | Price |
| Dispute | `charge` | Charge |
|  | `payment_intent` | PaymentIntent |
| Payout | `destination` | the bank account the payout goes to |
|  | `balance_transaction`, `failure_balance_transaction` | BalanceTransaction |
| BalanceTransaction | `source` | the object that made it, such as a Charge, Refund, Payout or Dispute |

A Charge also accepts `application`, `application_fee`, `failure_balance_transaction`, `on_behalf_of`, `review`, `source_transfer` and `transfer`. Fluveo never sets these fields, so they stay `null`.

A few other fields also take `expand[]` and come back as they are, such as a field Fluveo never sets, which stays `null`. A field that cannot be expanded answers `400` with `param` `expand` and a message that starts with "This property cannot be expanded". So does a path with more than 4 parts. For example, `latest_charge.payment_method` is refused because a Charge's `payment_method` is not expandable.

## Test it

1. Pay a test PaymentIntent with `pm_card_visa` (see [Testing](https://docs.fluveo.com/start/testing.md)).
2. Read it with `expand[]=latest_charge`. `latest_charge` is now an object with `"object": "charge"`.
3. Read it with `expand[]=latest_charge.payment_method`. You get `400` and `param` `expand`.

> **For AI agents:**
>
> Expand the fields in the table on this page; a field that cannot be expanded is a 400 with param expand. Paths have at most 4 dot-separated parts. In a list, prefix the path with data. (for example expand[]=data.latest_charge).

## Next

- [Metadata](https://docs.fluveo.com/start/metadata.md): Keep your own ids on Fluveo objects.
- [Pagination](https://docs.fluveo.com/start/pagination.md): Read every page of a list.