Can/should I use YAML as payload in RESTful webservice?

Question

As the header says.

In general I like YAML more than JSON these days. I implemented a RESTful WS PoC back in the day using JSON. I was wondering if I can instead use YAML or not.

E.g. are there enough tools/libraries/support for doing that? Or would I end up doing quite a bit of mundane/tedious coding which I would've avoided if I were using JSON instead?

Also as I understood from WWW: REST doesn't restrict one from using YAML as the payload, is that correct?

Thanks!

Answer 1

Yes, if it's a goal that the data be especially readable by humans. REST itself isn't focused on protocols/formats so much as patterns.

There's not a lot to gain here for webservices however, which typically represent app to app communication. Computers don't care, and JSON can be pretty-printed to improve legibility somewhat.

YAML is well supported by mainstream languages, though not always included in standard libraries as JSON typically is. So you'll probably be looking at an additional library dependency. Also, if the client is a browser, parsing will be slower, as you'll have to use a non-native external lib such as described here using: JavaScript YAML Parser . Make sure it gets compressed in transit or the extra indentation spaces will expand the size of the data.

Also, YAML has a lot of esoteric and downright potentially dangerous features. Whenever I'm using it I use the "safe" parser, and deactivate many if not most of its features besides data structures.

I could imagine some utility as a debug parameter however, perhaps url.yaml or …?fmt=yaml to assist during development. But, otherwise not much gain for all the trouble.