API versioning

It is an inevitable fact that all application APIs evolve. However, the evolution of public APIs with an unknown number of consumers, such as RESTful services, is a sensitive topic. As consumers may not be able to handle the modified data appropriately and there is no way of notifying all of them, we need to keep our APIs as backward-compatible as possible. One way to do so is to use different URIs for different versions of our application. Currently, our contacts API is available at /contacts.

When the time is right for a new version, for example, Version 2, we need to keep the previous version available at another URI for backward compatibility. I would use /v1/contacts/or contacts?version=1 and keep /contacts mapped to the latest version. Thus, requesting /contacts will cause a redirect to /v2/contacts or contacts?version=2 and will make use of the HTTP 3xx status codes to indicate the redirection to the latest version.

Another option for versioning would be to keep the URI...