Hey everyone,
I’m working on an email aggregation app and running into duplicate thread issues when syncing with the Nylas API. Specifically, I’m seeing the same email appearing multiple times in my local cache after consecutive syncs.
Has anyone found a clean approach to handle this? I’m currently relying on a combination of message IDs and the update_at timestamp as a heuristic, but threads that get updated frequently still cause problems since update_at changes.
I’ve been looking at using thread-level deduplication — grouping messages by conversation thread and only inserting new messages that don’t exist in our cache. Does anyone have tips on which Nylas parameters are most reliable for this? Also, is there a recommended rate or polling interval to avoid hitting rate limits while staying reasonably up-to-date?
Would love to hear about any production patterns others have settled on.
Hi Eleanor,
Thanks for the detailed writeup, this is a common pain point when building sync layers.
Use id, not updated_at, as your dedup key:
The message id returned by Nylas is stable for the lifetime of that message. It doesn’t change when the thread gets a new reply, gets read, or gets labeled. updated_at is expected to change on both the message and the thread whenever anything in the conversation changes, so gating your insert-vs-update logic on it will always cause churn. The reliable pattern is an upsert on id, if the row exists, update it, if not, insert it. That alone removes most duplicate-row issues people hit.
Thread-level dedup:
Each message carries a thread_id. Rather than re-deriving thread grouping yourself from message data, you can also call the Threads endpoint directly (GET /v3/grants/{grant_id}/threads), which already aggregates messages into a conversation for you. One caveat, the Threads endpoint makes multiple provider calls per request, so always pass filters and a limit when calling it, especially on a schedule.
Avoid polling for this entirely if you can:
Rather than tuning a polling interval, this is exactly the case webhooks solve. Subscribe to message.created and message.updated and your local cache stays in sync in near real time, without needing updated_at heuristics at all.
Let us know if you have any question.
Best regards,
Samuel R.
Support Engineer, Nylas