Back in 2006, Jeff Lindsayproposed a different way of consuming Web resources that would eliminate the need for constantly polling APIs for changes. This new pattern was called webhooks and has since been adopted by companies such as GitHub and Google.
The main advantage of the webhooks pattern is that your application doesn’t have to make periodic calls to APIs while it’s waiting for changes. Instead, APIs will call your application on a specific endpoint informing that something interesting has happened. What’s missing is a way to programmatically tell APIs that you’re interested in receiving calls and registering endpoints.
Pivotal Tracker just announced the availability of their API V5 in public beta, starting August 16, 2013. The launch is justified because the application itself has run against the new API version for a long time now.
photo by John Fischer
The new API introduces several improvements, like the ability to get access to all project data, including epics. They also say that everything in and out of the API is now JSON encoded but the activity Web Hooks still POST information using XML.
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.