Accessing Entry Event Data - Journey Builder Custom Activity

Question

Background

I am developing a simple custom activity for JB. There are lots of gotchas apparently. I have read the following sources from cover to cover and still cannot make it all together:

How Data Binding Works

Accessing Data Extension field values

Accessing subscriber profile attribute values

I need to access the values of the fields from Data Extension as inArguments. This Data Extension is linked to the Journey Entry Event. Hence I should be accessing entry event attributes basically.

I created a journey, added an Entry Source of type "Contact Data Entry Event". Data Extension I am trying to pull data from is linked to this Entry Event.

Entry Source Name: TEST_CUSTOM_EVENT_AUTOMATION_STUDIO

Data Extension External Key: TEST_CUSTOM_EVENT_DE

Data Extension field name: FirstName

config.json:

     "arguments": {
         "execute": {
            "inArguments": [
                 { "Contact.Key":"{{Contact.Key}}" },
                 { "FirstName":"

{{Event.TEST_CUSTOM_EVENT_AUTOMATION_STUDIO.FirstName}}"
 },
                 { "FirstName":"Test" }
             ],
             "outArguments": [
             ],
             "url": "https://zapier-jb-test.herokuapp.com/jb/activities/send-to-zapier/execute/",
             "verb": "POST",
             "body": "",
             "header": "",
             "format": "json",
             "useJwt": false,
             "timeout": 10000
         }
     },

Received inArguments in Execute API :

{  inArguments: [ 
    { 'Contact.Key': 'customevent1' },
    { FirstName: '' },
    { FirstName: 'Test' },
], ...}

Question

How can I access these data?

Answer 1

I found where the bug was. I should have used the "real" EVENT DEFINITION KEY instead of its NAME. When you are in a journey you won't see this value. For this you need to go to Entry Sources and find your Event there.

So now it works!

config.json:

     "arguments": {
         "execute": {
            "inArguments": [
                 { "Contact.Key":"{{Contact.Key}}" },
                 { "FirstName":"{{Event.ContactEvent-72af1529-1d7d-821e-2a08-34fb5068561d.FirstName}}" }
             ],
             "outArguments": [
             ],
             "url": "https://zapier-jb-test.herokuapp.com/jb/activities/send-to-zapier/execute/",
             "verb": "POST",
             "body": "",
             "header": "",
             "format": "json",
             "useJwt": false,
             "timeout": 10000
         }
     },

And the API Output:

{  inArguments: [ 
    { 'Contact.Key': 'customevent1' },
    { FirstName: 'Foo1' }
], ...}