API Idempotency

Transfer / Transaction / Signature Idempotency

When using either one of these Wallet endpoints:

• Transfer Asset

• Broadcast Transaction

you can optionally specify an externalId in the request body. This can be helpful for you if you want to create an ID on your side before the request, and store it on the created entity (Transfer Request, Transaction Request, Signature Request), in the externalId field. It can also be helpful if you need to re-submit the same API call, in case a network error (or other) prevented you to get our server's response, even if your request has actually been processed by Dfns.

The behaviour is as follow:

• If you re-submit the same request (same url, same body, including same externalId), then we will respond with a 200 response containing the entity which was already created when you submitted it for the first time.

• Otherwise, if you re-use the same externalId to make a new request to the API (same externalId, but different body, or using a different wallet), the request will fail with a 409 ("Conflict") response, containing a body such as:

{
  "error": {
    "id": "...",
    "status": 409,
    "message": "Conflicting transfer with same externalId",
    "details": {
      "duplicate": { "id": "...", "externalId": "..." }
  }
}