Flickr API: Programmatically Accessible Documentation

I'd like to be able to programmatically query the API. For example, I'd like to know what arguments are required/optional, and their types, for a given method. The info must be somewhere because it is used by the Explorer, but I didn't see a way to access it, and I struck out searching because the terms are so generic (e.g. 'metadata' brings up tons of hits on EXIF).

I'm asking because I'm writing a wrapper and want to provide interactive help without having to scrape the web documentation.

Solution

Cool! They have exactly what I wanted...

From https://www.flickr.com/services/api/flickr.reflection.getMethodInfo.html :

Example Response

<method name="flickr.fakeMethod" needslogin="1">
  <description>A fake method</description>
  <response>xml-response-example</response>
  <explanation>explanation of example response</explanation>
  <arguments>
    <argument name="api_key" optional="0">
          You API application key.</argument>
    <argument name="color" optional="1">
          Your favorite color.</argument>
  </arguments>
  <errors>
    <error code="1" message="Photo not found">
          Full explanation...</error>
    <error code="100" message="Invalid API Key">
          Full explanation...</error>
  </errors>
</method>