Web APIs and Authentication

Web APIs can be classified into two categories:

• Open APIs that don’t need any authentication to be used
• APIs requiring the consumer to authenticate themself through various methods

Open APIs

These APIs are free to use by anyone, anyhow. To prevent abuse, they often use rate limiting instead: the number of calls from one specific source (identified by its IP address) is capped.

Many public institutions like the British Police or the French government publish data to citizens using open APIs.

There are also a few interesting APIs available. For example, the Punk API lets you search into a huge catalog of beers. Here’s how to renew your drinking habits by getting a random one from this API.