append multiple request participants through Automation without clearing the field

[Remedy Partners]

I can do this for a single user with:

{
    "update": {
        "customfield_13200": [
            {
                "add": {"name": "username"}
            }       
        ]
    }
}

and this works for multiple users if I want to clear the field first:

{
    "fields": {
        "customfield_13200" : [ { "name":"username1" }, { "name":"username2" }, { "name":"username3" }]
    }
}

but fails when trying to update (append) with multiple users:

{
    "update": {
        "customfield_13200": [
            {
                "add": [ { "name":"username1" }, { "name":"username2" }, { "name":"username3" }]
            }       
        ]
    }
}

[JasbrisMcCaw]

I use this method on JIRA DC with the Automation for JIRA add-on. The format I had to use was:

{
    "update": {
        "customfield_11808": [
            { "add": { "name":"ABC123" } },
            { "add": { "name":"DEF456" } }
        ]
    }
}

This worked for me. I know this is an old post, but hopefully this helps someone.

[Andy Heinzer]

Is there a reason you are trying to use the issue edit endpoint in REST to do this?

Jira Service Desk has some addition APIs that are intended to handle just this specific function of adding requested participants.   I would recommend trying to use those endpoints in REST instead: https://docs.atlassian.com/jira-servicedesk/REST/3.9.0/#servicedeskapi/request/{issueIdOrKey}/participant

The json format is a bit different than what you have above.  The example they list is

{
    "usernames": [
        "josh",
        "john",
        "joe"
    ]
}

[Tim Nelson]

Because they're using Automation for Jira, and it doesn't appear to be able to use that endpoint.