A bit more of a theme today, and that is diagnostic API/HTTP clients. I don’t want to call them REST clients because they are much more general than that. But sometimes that is what they call themselves, perhaps to capitalize on the jargon bonus.
Postman is probably the most well known of this group. It started out as a Chrome plugin, but I see that there is now a Mac app as well. It allows you build customized HTTP requests to arbitrary URLs using any of the standard HTTP verbs like GET, POST, PUT, DELETE, etc. You can add headers and whatever content you need, and it will also help visualize your responses with coloring, folding, and other inspection features. Postman also allows you to create tests for each of the URLs you are accessing, making assertions on the response. You can run these tests from the command line using a companion tool called Newman. Free for use, although they do offer a team-oriented cloud offering at a reasonable price.
Advanced REST Client
The Advanced REST Client (or ARC) is another Chrome extension which provides similar functionality to Postman with a slightly different UI (and color palette). However, instead of using Chrome’s XMLHttpRequest client to make requests, it works over raw sockets, allowing it to bypass restrictions that Chrome imposed. It also supports connecting to WebSocket servers as well. ARC is free.
Paw is Mac HTTP client that offers a full-featured suite of tools. It also can generate client code in various languages to call your APIs. It supports dynamic values in your requests which can come from previous responses; it can compute hashes; generate random values; all sorts of things which can help in your testing/debugging efforts. Probably the biggest problem with it is the price. Not free; $50.