Outbound webhooks are not available yet. To react to events, poll the read endpoints at a regular interval, within the 100 requests per minute limit.
What exists today
The external API does not send webhooks to your system yet. The only webhooks in operation are the ones Avos receives from payment providers, and they are not customer-configurable. If you need real-time notification, write to support through the contact form so we can discuss the use case.
Tracking by polling
To know when a period was approved or paid, poll GET /payroll/periods at a regular interval and compare the status with what you stored last time; the same logic applies to new or changed employees (GET /employees) and to time entries (GET /time-entries, filtered by date).
With the 100 requests per minute per key limit, one poll per minute per resource is far below the ceiling and gives a maximum delay of one minute, enough for most payroll integrations.
Idempotency on your side
Store the id and status of every period and employee you have processed, and handle only what changed. Avos does not resend anything or guarantee ordering between polls, so deduplication belongs in the system consuming the API.