TheExtractedItem event has been fixed since I posted my code so that it now works. I get the GUID of the node with e.Item.ItemId.Id. One thing that was surprising for me is that this event happens on the sending environment (I guess all the processing happens there), so the receiving environment doesn't get the event triggered. I was expecting it to happen in the environment where it was extracted. It's a little unfortunate, but I've worked around this by calling an API on the receiving environment.

The API code I have is very specific to my project. I am updating Relations for specific content types.

But it's just an UmbracoApiController webmethod that takes a Guid as a parameter. I then get the node. Here's the code (removing the project specific stuff where I put the "do stuff with node" comment:

[HttpGet]
    public void UpdateRelations(Guid guid)
    {
        try
        {
            var umbracoHelper = new UmbracoHelper(UmbracoContext.Current);
            var node = umbracoHelper.TypedContent(guid);

            // do stuff with node
        }
        catch (Exception ex)
        {
            LogHelper.Error<MyApiController>("Error for guid " + guid.ToString(), ex);
            throw ex;
        }
    }

I have everything in a try/catch block because if there is an error, it doesn't seem to log/output a useful message.

I'm using the ExtractedItem event.

Also, forgot to mention this - not sure if it's really needed -- but I was worried about overloading the server by making a lot of API calls all at once when many nodes are transferred, so I actually queue the calls to the API using Azure Storage Queue and then have the queue call the server using Azure Functions. Not sure this is needed but I already had it in place for other things.

Here is my event handler code:

    private void ExtractionManagerEvents_ExtractedItem(object sender, ItemEventArgs e)
    {
        if (e != null && e.Item != null && e.Item.ItemId != null)
        {
            if (e.Item.GetType().Name == "Document")
            {
                LogHelper.Info<RegisterEvents>("item " + e.Item.ItemId.Id + " (" + e.Item.Name + ") was deployed. [type is " + e.Item.GetType().Name + "; provider: " + e.Item.Provider.Name + "]");
                string baseUrl = ConfigurationManager.AppSettings["ContentDeployTarget"]; // ContentDeployTarget
                IndexingQueue.QueueNode(baseUrl + "/Umbraco/Api/MyApi/UpdateRelations?guid=" + e.Item.ItemId.Id, 0);
            }
        }
    }

The QueueNode method just dumps the URL in the storage queue.

One other detail - I check the type to make sure it's a "Document" because I just want to the Document - I think the event also triggers for Property Data.

Ic. Thanks Alex