What is an Idempotency Key?
An idempotency key is a unique value sent with an API request to ensure that even if the same request is submitted multiple times (for example, due to retries or network issues), the action only happens once.
This helps prevent duplicate operations like sending the same email multiple times or creating duplicate records. Idempotency is especially important in APIs where duplicate submissions can cause significant issues, such as payment processing or transactional email sending.
Does Postmark support idempotency keys?
At this time, Postmark does not currently support an idempotency key feature.
However, you can build similar safeguards into your integration by using:
HTTP response codes and API error codes to detect and handle duplicate or failed requests.
Webhooks to track message events and prevent duplicate processing on your side.