Evernote recently announced that they will enforce API rate limits starting today (August 14, 2013). They don’t specify what the limits are but they say that a “reasonable use of the API should not cause an integration to hit the limit”.
photo by Justin Ennis
Although this enforcement will only affect non-production applications for now, you should evaluate your code even if you have a production API integration, since rate limiting will also affect these applications starting November 1, 2013.