API guides
Use idempotency safely
Prevent duplicate synchronous output when retrying the same generation request.
Reviewed 2026-08-05 · PDFDesignAPI Engineering
Stable request key
Send a unique idempotency key for one logical generation operation. Reuse it only when retrying exactly the same template selection and payload.
A key used with changed render inputs is rejected rather than silently producing a different document.
Concurrent and replayed requests
A concurrent request with the same key is rejected while the original is in progress. A completed matching request can replay its private result.
Idempotency history is retained while the private PDF result expires after 24 hours. Move required output to your own authorized storage.
Key design
Generate keys in the trusted application from the business operation identifier or a random value stored with that operation.
Do not include customer data or secrets in the key.