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

# Idempotency

Idempotency keys help prevent duplicate transactions by ensuring that identical requests are processed only once. When you include an idempotency key in your request headers:

* If you make a request with the same idempotency key and identical request body as a previous request, you'll receive the same response as the original request, but the request will be processed only once.
* If you make a request with the same idempotency key but a different request body, you'll receive a `409 Conflict` error.

This is particularly useful for retry scenarios where you want to ensure that a transaction isn't processed multiple times due to network issues or other temporary failures.

Requests that move money have idempotency keys as optional request headers. Here's how they work:

```json RequestHeaders theme={null}
{
    ...
    "Idempotency-Key": "8c9accbb-b9e9-49af-91f4-ef2ba3a9cf04"
}
```

Best practices for idempotency keys:

* Use a unique value for each unique transaction
* Generate keys that are long enough to avoid collisions
* Consider using UUIDs or other unique identifiers