> ## Documentation Index
> Fetch the complete documentation index at: https://developers.bumxpress.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Idempotency

> Retry create requests safely with Idempotency-Key.

Write endpoints that create customers, quotes, payins, payouts, transfers, or transfer relaunches require an `Idempotency-Key` header.

```http theme={null}
Idempotency-Key: payin_2026_06_08_0001
```

## Required endpoints

| Endpoint                               | Purpose                               |
| -------------------------------------- | ------------------------------------- |
| `POST /customers`                      | Create customer                       |
| `POST /quotes/payin`                   | Create payin quote                    |
| `POST /quotes/payout`                  | Create payout quote                   |
| `POST /quotes/transfer`                | Create transfer quote                 |
| `POST /payins`                         | Create payin                          |
| `POST /payouts`                        | Create payout                         |
| `POST /transfers`                      | Create transfer                       |
| `POST /transfers/{id}/relaunch-payout` | Relaunch failed transfer disbursement |

## Rules

* Use a unique key for each distinct business intent.
* Reuse the same key only when retrying the exact same request body after a timeout or network error.
* Use a new key when creating a new payment, quote, customer, or transfer.

When a request is replayed successfully, the API marks the response metadata:

```json theme={null}
{
  "_meta": {
    "idempotency_key": "payin_2026_06_08_0001",
    "idempotency_replayed": true
  }
}
```