Idempotency and handling duplicate webhook events

Why your webhook handler must be idempotent

Due to network conditions, Leafy Energy may occasionally deliver the same event more than once. Your handler must therefore be idempotent: processing an event twice must not trigger the action twice.

Using the event ID

• Each event has a unique id.
• Store processed event IDs in a datastore (for example Redis or a database).
• Ignore events whose ID has already been processed.

Example strategy

1. Receive webhook.
2. Check whether event.id exists in a “processed-events” table.
3. If not, handle the event and mark it as processed.

In demo sessions you can deliberately send duplicates to demonstrate how to build robust integrations.