anchor.diff:  [CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing) is enabled.
   
   
  -## keys, fresh metrics, and sponsored items
  +## keys, fresh metrics, and active items
   
   ImpactStory gathers metrics on any type of scholarly object with a url (or doi, or pubmed id, or github id, ...).  Because we cover such a large span of scholarly resources (and do not yet have the resources of Google), we only gather metrics on items once they have been specifically requested.
   
  
positive.code: add an item
  <a id="post_item"></a>
  Add an item to the ImpactStory system using the given namespace and id.  
  Returns `201` even if the item is already in the database, because this call also registers the item as sponsored under the supplied API Key (see top of this page for more information).
  
  After POSTing an item, the item data can be obtained through [GET /item](#get_item) calls.
  --
  
negative.code: 
  - the first time an item is added to ImpactStory (through the [web interface](http://impactstory.org), the javascript embed code, or the REST api)
  - while-you-wait when someone clicks the "update" button on the web interface
  - regularly, behind-the-scenes, for **active items**
  
  With an api key you can **activate** items to keep them up-to-date with fresh metrics.  
  These fresh metrics are made openly available to anyone who requests metrics for that item.
  Open dissemination for the win!
  
  We only guarantee an item requested through the API will have fresh metrics if that item has been activated.
  
  Items are activated by adding them to the ImpactStory database through a [POST /item](#post_item) API call.
  
  Up to 1000 items can be activated for free by each API key.  Activating more than 1000 items will have an annual fee to provide sustainability for our nonprofit service (waivers available in some cases).
  
  To request an ImpactStory API key, send an email to [team@impactstory.org](mailto:team@impactstory.org).
  
  ## rate limits
  
  We do not impose rate limits at the moment, but we recommend delaying for a few seconds between each request.  It often takes us 5-10 seconds to collect metrics on an item the first time, due to the latency of our external metrics providers.
  
  ## data licenses
  
  - All data in the ImpactStory API is released under as open a data licence as the primary data providers permit it to be.  We plan to inventory these licenses but haven't got an updated list at the moment, so please check with the primary data providers.
  - Some providers allow us to show their metrics in our webapp but restrict its dissemination through our api.  Scopus citation data is available through our web application but not through the API.  CiteULike data is available through the API only in certain circumstances.
  - Native ImpactStory data in the API (if there is any?) is released under a [CC0 waiver](http://creativecommons.org/publicdomain/zero/1.0/).  
  
  ## contact info
  
  