Does Trello's REST API enforce a hidden concurrent connection limit per API token that triggers HTTP 429 responses without exposing rate‑limit headers?
When integrating with Trello’s REST API, developers rely on the documented rate‑limit headers (X‑RateLimit‑Limit, X‑RateLimit‑Remaining) to throttle calls and avoid HTTP 429 errors. However, many endpoints omit these headers, and intermittent 429 responses have been observed even when the reported remaining quota appears sufficient. This suggests that Trello