title: VS402881: No artifact version is specified corresponding to artifact source 'MyBuild.' Release Management vNext REST API
body: <p>I'm using TFS 2015.2 RTM and I just found out that the Release Management vNext REST API is in 2.2-preview.1 on-premises. I want to create a release, but I don't know the exact JSON to put in the body of the POST request since the <a href="https://www.visualstudio.com/integrate/api/rm/releases#Createarelease" rel="noreferrer">documentation</a> only works for VSTS. </p>
  
  <p>When I send the request, I get the error message: </p>
  
  <pre><code>VS402881: No artifact version is specified corresponding to artifact source 'MyBuild.' Specify a valid value and try again. 
  </code></pre>
  
  <p>Here's the JSON: </p>
  
  <pre><code>$body = @"
       {
            definitionId": 1,
      "description": "test",
      "artifacts": [ 
        {
           "alias": "Tailspin Toys", 
           "version": {
                 "id": 147,
           },
           "instanceReference": {
              "id": 5
          }
         }
       ]
  } 
  "@
  </code></pre>
  
  <p>And here's the Invoke-RestMethod command: </p>
  
  <pre><code>$releaseResponse = Invoke-RestMethod -Method Post -Credential $credential -ContentType application/json -Uri $postUri -Body $body
  </code></pre>
  
  <p>What JSON items am I missing? How do I find what to put in the JSON body if the docs don't have what is missing? </p>