customFields is no longer accepted

What changed

Usually ignored rather than rejected, so the call succeeds and does something subtly different.

Affects customFields on FDXNotificationPayload reachable from 1 operation. Grep for it: nothing else will tell you.

Who is affected

Code that sends Plaid's FDXNotificationPayload objects, used by 1 Plaid operation.

Before and after

Code that breaks

await client.post("/…", {
  // customFields is now ignored, not rejected
  customFields: value,
});

Based on Plaid’s published API specification. How severity is decided.