Suppose we want to capture information about a medical diagnosis for some patient. At left, a typical digital document in JSON. At right, the corresponding Finitio schema.

{ "patient" : { "id" : "27b3ceb0-7e10-0131-c9f1-3c07545ed162" , "name" : "Marcia Delgados" , "dob" : "1975-11-03" }, "symptoms" : [ "Nausea" , "Fever" ], "temperature" : 39.5 } Temp = < celsius > Real ( f | f >= 33 . 0 and f <= 45 . 0 ) { patient : { id : Uuid , name : String ( s | s . size > 0 ), dob : Date ( d | alive : d . year > 1890 ), }, symptoms : [ String ( s | s . size > 0 ) ] , temperature : Temp }

Suppose an invalid document comes in. With Finitio, you properly validate input data and get friendly error messages.