> For the complete documentation index, see [llms.txt](https://docs.truecaller.com/truecaller-for-business/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.truecaller.com/truecaller-for-business/features/call-me-back/why-am-i-receiving-duplicate-webhook-events.md).

# Why am I receiving duplicate webhook events?

The outgoing webhook feature is built with at-least once delivery semantics, which guarantees no data is lost but may result in the same event being delivered more than once.This is expected behaviour.\
In distributed systems, machines can go down or restart before an acknowledgement of delivery is received, so the system resends events to ensure they reach their destination. \
To further guarantee delivery, automatic retries are triggered using an exponential backoff strategy — up to 7 attempts over a 48-hour period.\
To handle this, every event includes a unique `event_id`. Before writing to your database, check whether the `event_id` has already been processed and discard any duplicates. \
This pattern — known as idempotent processing — is the recommended approach for integrating with any at-least once delivery system.


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