rest - How to add work item as child to parent?

Question

I've been able to find documentation on creating work items via the VSTS REST API, however, I haven't been able to find anything creating a work item and linking it to a Parent work item.

Searching around, I've seen some links regarding a System.LinkTypes.Hierarchy-Reverse, but no API reference on how it works, or how it might link a work item to a parent work item id. Link here

Answer 1

To add a work item with parent work item linked, you should use the REST API as:

POST https://{accountName}.visualstudio.com/{project}/_apis/wit/workitems/${type}?api-version=4.1

application/json-patch+json:

[
  {
    "op": "add",
    "path": "/fields/System.Title",
    "from": null,
    "value": "title"},
    {
    "op": "add",
    "path": "/relations/-",
    "value": {
      "rel": "System.LinkTypes.Hierarchy-Reverse",
      "url": "URL for the parent work item"
    }
    }

]

Below is the example to create a task mytask with parent work item (work item id is 184) linked:

POST https://marinaliu.visualstudio.com/Git2/_apis/wit/workitems/$Task?api-version=4.1

application/json-patch+json:

[
  {
    "op": "add",
    "path": "/fields/System.Title",
    "from": null,
    "value": "mytask"},
    {
    "op": "add",
    "path": "/relations/-",
    "value": {
      "rel": "System.LinkTypes.Hierarchy-Reverse",
      "url": "https://marinaliu.visualstudio.com/f7855e29-6f8d-429d-8c9b-41fd4d7e70a4/_apis/wit/workItems/184"
    }
    }

]