Callbacks & idempotency

Pass a public HTTPS callBackUrl when creating a task. VezAPI confirms the task status and billing before forwarding a customer response. Callback URLs must not target private networks or require redirects.

Verify a callback

Your account’s verification key is available under Dashboard → Settings. Use HMAC-SHA256 over timestamp.eventId.rawBody. Compare against X-VezAPI-Signature, check the X-VezAPI-Timestamp within five minutes, and deduplicate X-VezAPI-Event-Id.

Retry without duplicate generation

Use a unique Idempotency-Key for each submission. Repeating the same key and payload retrieves the original submission state. A different payload with that key returns a conflict. Callback retries and queue redelivery never create another generation.