Callbacks | Knowledge Center

CM.com supports webhook callbacks on Voice API calls. For each Voice API request, a callback-url property can be passed. The callback request will include whether or not the call was successful and other information such as call duration, whether voicemail was detected and the unique identifier of the call (call id).

Detailed information on the contents of the webhook callbacks can be found on the developer documentation.

FAQ

Does CM.com support authentication on the webhook callbacks?

No, CM.com does not support authentication. CM.com only pushes data and all contents are encrypted using TLS. Only TLS 1.2 and 1.3 are supported.

Can CM.com supply the source IP(s) from where the callbacks originate for firewall whitelisting?

No, CM.com does not support whitelisting of its IP addresses. Source IPs can and will change without notice. The webhook url should be accessible without any restrictions.

What happens when the webhook is unavailable?

Callbacks are retried with an increasing delay of 5m, 10m, 20m, 1h, 2h, 4h, 8h, 16h and finally 24h, until the callback succeeds. If the callback is still not successful, the callback is deleted. After a timeout of 15 seconds, a request is cancelled and will be retried. If a request results in a HTTP status code >500, the callback will be retried.