Technically, nearly all Webhooks are based on some event happening in the third party's system and triggering the callback, but some APIs are built with a specific structure that uses a single URL for the callback. There may be multiple triggers or events that can happen on in that system that you would want o know about. Details on how to physically set up and subscribe to these events would be outlined in the Connector specific instructions, but they will need to be set up in Nexus first so you are able to provide the details necessary to them. Some systems will just send all events as they happen, while others will allow you to choose which ones are sent via their UI or through the API.
To get started, select the 'Manage Webhooks' tab in the IOLITE Nexus App and choose the appropriate Connector from the list.
Choose the Function that you would like to configure. Most connectors will only offer one, but depending on the complexity there maybe multiple options.
The first time you will be asked to create a Webhook Group. Provide a name for the group. Depending on the architecture and security settings that have been set up, you may have and External Id and sometimes a Signature Secret that has been provided by the API. If so, will need to enter that so that Nexus can verify that the payload is being sent by the trusted source. More information on that will be in the Connector Specific instructions. Next you will want to choose which Registered Events you want to accept. As a general rule for the Webhook Group, it is ok to select everything and narrow down what the choices at the individual Webhook level.
There will be a specific Callback URL generated that is unique to your Salesforce Org, Connector and API Function. This is the URL that you will give to the API so they know where to send the payload. The URL can get long, so make sure when doing a Copy/Paste, that you have the entire link address selected. Once you click Save, then the Webhook Group details will be available. You can View or Edit this at any time by using the dropdown arrow on the row. In addition to the Group, there will also be a blank Webhook Template created. Use this by selecting the 'Clone' option to create individual Webhooks for each event or events you would like to receive.
In the Webhook window, change the Label to something logical (i.e. named after the event), mark as Active as needed and select the event. Since there are often different response payload formats for each event, it is possible that you would have one Webhook record for each event. This will depend on the connector and how you want to map the information being sent. If the mapping is the same for more than one event, then you can combine events into a single callout. More specific details on mapping will be found in the Connector specific instructions.
Once saved, the newly create webhook will be added to the list and can be Viewed, Edited or Cloned as desired. Continue this for any Event(s) you wish to receive.
Now that you have the Webhooks created and activated, you will need to go back to the Nexus Admin tab to do the mapping to the Salesforce objects and fields. The Webhook will now be found as a Connector Function on the Connector you chose in the first step. From there you can map and activate as needed as you would with any other connector. The difference you will notice is that there is no Outbound Data Event, only Inbound. This is because it is an asynchronous unsolicited callback that is handled with the Nexus Listener.