<form method="POST" action="http://www.thingiverse.com/api/upload">
	<input type="hidden" name="url" value="{{base64_encoded_url}}">
	<input type="hidden" name="service" value="My Service Name">
	<input type="hidden" name="service_url" value="{{base64_encoded_service_url}}">
	Name: <input type="text" name="name" value="My Awesome Design"><br>
	Description: <input type="text" name="description" value="My Description"><br>
	<input type="submit" value="Upload to Thingiverse">
</form>

http://www.thingiverse.com/api

Thingiverse Simple Upload API Form

HTML