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A quick google didn’t reveal much about pgstream’s delivery semantics. Do these webhooks get called at most once, or at least once? I hope the latter, but in absence of information I’d guess it is the former.

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It looks to me like it's at-most-once. This code here https://github.com/xataio/pgstream/blob/bab0a8e665d37441351c... logs an error if a delivery fails but does not appear to queue it for a second attempt.

Sad! Suitable for driving “best effort” use cases like reactive UI updates or stale-while-revalidate cache refreshes, but not usable for “business logic” like updating user access lists, billing, sending emails, or maintaining a secondary index of any sort.

The current implementation of the webhook notifier will call the webhook URL at most once. There's no real reason for it beyond it being a first iteration of the webhook output plugin. I've created an issue in the repo to support retries , since this is a valuable feature (https://github.com/xataio/pgstream/issues/67).

Worth mentioning that the retry strategy is defined on a processor level. The opensearch indexer for instance does handle retries, making it "at least once" delivery.

Thanks for your feedback!

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