Precondition failed

What it means

If-Match did not match the resource's current edit_seq; the body carries the current one.

What to do

GET the resource, reapply your change to what it holds now, and send its current ETag (or the edit_seq in this body) as If-Match.

Example

Sent as application/problem+json with status 412. detail varies with the request; branch on type.

{
  "type": "https://impartire.com/problems/precondition-failed",
  "title": "Precondition failed",
  "status": 412,
  "detail": "If-Match does not match the asset's current edit_seq (7). GET it, reapply your change, and retry.",
  "instance": "/api/v1/assets/6f1c2a4e-0b7d-4f7e-9a51-2d3c4b5a6e7f",
  "request_id": "01JB8Z5W6Q4N3X2V1T0S9R8P7M",
  "edit_seq": 7
}