The Stack Exchange API (https://api.stackexchange.com/docs) provides a programmatic access to all the Stack Exchange websites. Third-party applications that intend to use the API should be registered at http://stackapps.com in order to obtain a request key used to grant more requests per day. Registered apps can also perform authenticated API calls, that is, to interact with Stack Exchange on behalf of the authenticated user. The registration process is fairly straightforward, as shown in Figure 6.3-all the details required are an Application Name and Description:

Figure 6.3: An app registration on stackapps.com

The immediate effect of registering our application is the increased number of requests per day that are allowed by the API. It's important to note that rate limits are not only set on a daily basis, but also to prevent flooding (for example, if the same IP is sending more than 30 requests per second, the requests will be dropped). Details...