How to create a work item with custom field values populated ​​using Rest API?

Question

I have a custom field on work items (Task) called "VOLAN".

By following this document : https://learn.microsoft.com/en-us/rest/api/azure/devops/wit/work-items/create?view=azure-devops-rest-7.1&tabs=HTTP try sending the following content to the API endpoint and getting 200 responses. But the value is not populated when checking it from ADO UI.

[
  {
    "op": "add",
    "path": "/fields/System.Title",
    "from": null,
    "value": "Sample task",
    fields: [
        {"System.VOLAN" : TestValue}  
    ]   
 } 
]

Can't figure it out, any help would be greatly appreciated.

Answer 1

Hi @Volantis Jan
The issue with your request is that the fields property does not belong inside the patch request body. In Azure DevOps REST API, each field must be added individually with its proper reference name.

[
  {
    "op": "add",
    "path": "/fields/System.Title",
    "value": "Sample Task"
  },
  {
    "op": "add",
    "path": "/fields/Custom.VOLAN",
    "value": "<YourValue>"
  }
]

By using above Request Body I was successfully set the Custom Field Value as shown below:

Hope this helps.

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