title: eBay Trading SOAP API — invalid AppId?
body: <p>I'm trying to get my first call through to the eBay Sandbox using the SOAP API</p>
  
  <p>I keep getting an <strong>Invalid AppId</strong> response.  I quadruple checked that I do in fact have the proper AppIp for the Sandbox environment.  eBay documentation is fairly unhelpful.</p>
  
  <p>I'm using SUDS and Python 2.7 to make the calls.</p>
  
  <p><strong>Request</strong></p>
  
  <pre><code>DEBUG:suds.client:sending to (https://api.sandbox.ebay.com/wsapi?callname=GetCategories&amp;appid=MyAppId&amp;siteid=2&amp;version=785&amp;routing=default)
  message:
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;SOAP-ENV:Envelope xmlns:ns0="urn:ebay:apis:eBLBaseComponents" xmlns:ns1="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.o
  rg/2001/XMLSchema-instance" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"&gt;
     &lt;SOAP-ENV:Header&gt;
        &lt;ns0:RequesterCredentials ns1:mustUnderstand="0"&gt;
           &lt;eBayAuthToken&gt;MySandboxUserAuthToken&lt;/eBayAuthToken&gt;
        &lt;/ns0:RequesterCredentials&gt;
     &lt;/SOAP-ENV:Header&gt;
     &lt;ns1:Body&gt;
        &lt;ns0:GetCategoriesRequest&gt;
           &lt;ns0:DetailLevel xsi:type="ns0:GetCategoriesRequestType"&gt;
              &lt;ns0:DetailLevel&gt;ReturnAll&lt;/ns0:DetailLevel&gt;
              &lt;ns0:Version&gt;785&lt;/ns0:Version&gt;
              &lt;ns0:ErrorHandling/&gt;
              &lt;ns0:WarningLevel&gt;High&lt;/ns0:WarningLevel&gt;
              &lt;ns0:LevelLimit&gt;1&lt;/ns0:LevelLimit&gt;
           &lt;/ns0:DetailLevel&gt;
        &lt;/ns0:GetCategoriesRequest&gt;
     &lt;/ns1:Body&gt;
  &lt;/SOAP-ENV:Envelope&gt;
  </code></pre>
  
  <p><strong>Response</strong></p>
  
  <pre><code>...
  &lt;FaultDetail&gt;
     &lt;ErrorCode&gt;127&lt;/ErrorCode&gt;
     &lt;Severity&gt;Error&lt;/Severity&gt;
     &lt;DetailedMessage&gt;API application &amp;quot;{0}&amp;quot; invalid.&lt;/DetailedMessage&gt;
  &lt;/FaultDetail&gt;
  ...
  </code></pre>