Example of adding a comment to a pull request in Azure Devops using the REST API

PostCommentToAzureDevopsPullRequest.ps1

# status 4 = closed
$Body = @"
{
  "comments": [
    {
      "parentCommentId": 0,
      "content": "Just ye olde comment added and marked as closed..",
      "commentType": 1
    }
  ],
  "status": 4
}
"@

# This token came from an Azure Devops pipeline, use whatever auth you need elsewhere.
$Headers = @{Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN" }

try {
  # Similary to above, these were taken from a pipeline, denoting repo details. fill in as needed.
  $url = "$($env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI)$env:SYSTEM_TEAMPROJECTID/_apis/git/repositories/$($env:BUILD_REPOSITORY_NAME)/pullRequests/$($env:BUILD_PULLREQUEST_ID)/threads?api-version=6.0"

  $response = Invoke-RestMethod -Uri $url -Method POST -Headers $Headers -Body $Body -ContentType application/json

  if ($Null -ne $response) {
    Write-Host "Added deploy complete comment on the pull request."
  }
}
catch {
 $_
}

Thanks for sharing it. The original doc can be useful here: https://docs.microsoft.com/en-us/rest/api/azure/devops/git/pull-request-threads?view=azure-devops-rest-6.0

Yup, Thanks for filling it in :]