And also I'd avoid 400 for invalid input in general, since it's meant to reject request entities with bad syntax, or incoming data that simply isn't HTTP. IMO

And also I'd avoid 400 for invalid input in general, since it's meant to reject request entities with bad syntax, or incoming data that simply isn't HTTP. IMO 422 is a better match, it indicates semantic errors. http://httpstatus.es/400 http://httpstatus.es/400 http://httpstatus.es/422 http://httpstatus.es/422