title: YouTube API: Get upload playlistID for YouTube Channel
body: <p>I'm trying to figure out the best way to get a channel's upload playlistID given the channel's channelID. E.g. for the channel with channelID</p>
  
  <blockquote>
    <p>UC9CuvdOVfMPvKCiwdGKL3cQ</p>
  </blockquote>
  
  <p>The corresponding upload playlistID is</p>
  
  <blockquote>
    <p>UU9CuvdOVfMPvKCiwdGKL3cQ</p>
  </blockquote>
  
  <p>Notice the second character has changed from a "C" to a "U"</p>
  
  <p>I can do this transformation via string manipulation, but I'm curious if there's a better, less hacky way to find the upload playlist ID through the official youtube api.</p>
  
  <p>Here's some Kotlin code that shows my issue:</p>
  
  <p>I can find the ChannelID for the "Game Grumps" channel through the following youtube api v3 search: </p>
  
  <pre><code>            val req = youtube.search().list("snippet");
              req.key = {API_KEY}
              req.q = "Game Grumps"
              req.type = "channel"
              val response = req.execute();
  </code></pre>
  
  <p>The resulting Channel id (response.items[0].snippet.channelId) is UC9CuvdOVfMPvKCiwdGKL3cQ</p>
  
  <p>But when I run the following to try to get the videos uploaded by the channel, I have to use the transformed ChannelID (starting with UU instead of UC)</p>
  
  <pre><code>            val req = youtube.PlaylistItems().list("snippet")
              req.playlistId = "UU9CuvdOVfMPvKCiwdGKL3cQ"
              req.key = {API_KEY}
              val response = req .execute()
  </code></pre>
  
  <p>If I use the untransformed "UC" channelID, I get the following error: The playlist identified with the requests <code>playlistId</code> parameter cannot be found.</p>
  
  <p>Instead of just replacing the second character with a "U", what's the more robust way (e.g. using the youtube API) of translating a ChannelID to a PlaylistID (for the uploads from that channel)?</p>