How do I set a custom "User" field using the API

[Denise Wermager]

I have been trying to set the value of a custom field that contains a single user name via the API and I keep receiving the following error:

"errorMessages": [
"Can not instantiate value of type [simple type, class com.atlassian.jira.rest.api.issue.FieldOperation] from JSON String; no single-String constructor/factory method (through reference chain: com.atlassian.jira.rest.v2.issue.IssueUpdateBean[\"update\"])"

The command I am using is as follows except username has the name of an actual user:

{"update":{"fields":["customfield_10108": {name:"username"}]}}

I have also tried {"update":{"fields":["customfield_10108": {"name":"username"}]}} 

Any help is greatly appreciated.

BTW: Using JIRA Server 8.5.3

[Bill Sheboy · Accepted solution]

Hi @Denise Wermager 

In your first JSON example, it seems you have some extra curly brackets; are using update and fields; and are missing quotation marks around the field "name".  Perhaps try this, as with a single value you only need fields:

{
    "fields": {
        "customfield_10108": { "name": "username" }
    }
}

Here is a documentation references that may help also:

https://confluence.atlassian.com/automation/advanced-field-editing-993924663.html

Best regards,

Bill

[Denise Wermager]

Thank you!