I was unable to find anywhere on the internet what the accepted CodeReviewThreadType values were in the Azure DevOps Thread API.
I am trying to make our remote service add a system message like “Pull Request successfully linked with XY.” and don’t want to spam it with huge comments.

I tried abusing some of the types that I usually see in pullrequests – StatusUpdate, RefUpdate, ReviewersUpdate, IsDraftUpdate… but they seem to be translated so the "content" of the comment is ignored and the message stays empty.

Does anyone have any experience with this? I don’t need all supported types, just one that gives the desired output.

Desired output with example of content being ignored

Code sample:

await gitApi.createThread({
    comments: [
        {
            parentCommentId: 0,
            content: "System Comment Test",
            commentType: CommentType.System,
        },
    ],
    properties: {
        CodeReviewThreadType: {
            "$type": "System.String",
            "$value": "StatusUpdate"
        },
    },
}, (pr.repository!).id!, pr.pullRequestId!);