 <p>You need to pass your key in the HTTP Header. You can check out this material, which talks about how to talk to Azure storage via the REST API, including updating the header value: <a href="http://msdn.microsoft.com/en-us/library/dd179428.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/dd179428.aspx</a></p> <p>If interested in some .NET code samples, use Reflector on the Microsoft.WindowsAzure.StorageClient assembly that comes with the Windows Azure SDK to see how they are doing it.</p>