How to append a user to a multi select user field in Jira Automation

[Michael Davison]

I have an automation that checks for updates on a series of fields. I would like to append the initiator of the field changes to a multi-select user picker called Transport Approvers.

I wanted to use this Transport Approvers field to capture all users who initiate the field changes.  However when I run the automation, and test with different users, I can only write over the previous user in the Transport Approvers multi-select field only allows me to write over the previous value, not append an additional one to the field. 

Is there a way this can be done? Thanks in advance.

[Michael Davison · Accepted solution]

Using the advanced option, I added this code snippet and it works perfectly:

{
    "update": {
        "MultiUserPicker": [{
                "add": {"accountId":"{{initiator.accountId}}"}
        }]
    }
}

 Where "MultiUserPicker" is the name of my field.

[Ilia Tsvetkov]

This doesn't work for me. I have a multi-user field called "Contributors".

My json is identical to yours:

{
  "update": {
    "Contributors" : [{
      "add": {"accountId":"{{initiator.accountId}}"}
    }]
  }
}

but I get this error 

Additional fields contains invalid field(s) in 'update' or 'fields' section: Contributors

Any ideas on what am I doing wrong? 

KR, Ilia

[Melanie Muschick]

If your field is a custom field, you most likely need to use its id like "customfield_12345"