This month we’ll be looking at PSR-7, the HTTP Message Interface. Handling HTTP messages is crucial to web development. Request messages come into the server, are processed, and content is constructed and packaged into a response message and then sent back to the requesting entity. It sounds relatively simple on the surface, but it drives our internet experience. Requests and responses must be appropriately formed and follow the essential requirements and protocols. The intention of PHP-FIG’s HTTP Message Interface is exactly that, building structure around those requirements, so developers know what to expect and how to respond. by Frank Wallen